Oh, Dr. Becky! How nice good of you to show up :) I think your other comment stream got a little, inflated (hah hah). So, the problem is the red-shift, then. Quite a doosey. E=hf means it doesn't actually really work with dark matter lensing, since we can't really know how light photons are affected by the interaction with those two forces? If that question was already posed by early 20th century physicists, or Copernicus himself, it would've probably been (how do the British put it) ________ to have said something, to the children. Delightfully, Listener X. ^_^
becky, you are really a physicist? LOL. I tried to explain discrete relativity to you people and you ignored me. So, here: you are all WRONG again. Keep pretending I don’t exist Reductio Proof of the Copernican Principle Using Relativity 🚀 This is the clean, bulletproof proof that shuts down anyone saying the Copernican Principle “can’t be proven.” Step-by-Step Breakdown ✅ Assumption (To Be Contradicted) → Suppose there exists a privileged reference frame in the universe. • We assume for the sake of contradiction that there is a special “center” of the universe. ✅ Implication 1 → This would mean an absolute ‘center’ exists, violating relativity. • Relativity does not allow any preferred location-motion and position must be relative. ✅ Implication 2 → General Relativity states that physical laws are the same in all reference frames. • If the universe had a “center,” physics should behave differently depending on distance from that center. • But every observation confirms that physics remains consistent everywhere. ✅ Implication 3 → Observations of the Cosmic Microwave Background (CMB) show uniformity across all directions. • If there were a privileged location, we should see anisotropies (uneven distribution of temperature and matter). • Instead, the CMB is almost perfectly isotropic, confirming large-scale uniformity. ✅ Contradiction → If there were a privileged location, the CMB and galaxy distribution would not be isotropic. • This contradicts real-world data-so the assumption must be false. ✅ Final Result → The universe has no special center-Copernican Principle is confirmed. • Since assuming a privileged location leads to contradictions, we conclude that no such location exists. • Therefore, the universe follows the Copernican Principle. What This Means 🔥 I don’t feel like explaining my homework to you people anymore.
Wow! Now I know why? 🤨 What on Earth happened to critical thinking? It's an absolute minefield in your comments. Everything doesn't work apparently! Oh dear, I guess I'll just enjoy listening to your delightful content and ignore comments. Thank you for being a voice of joyful scientific carm amongst the noise of the background radiation.
Krikkit planet's inhabitants used to apply the Copernican principle. (a planet located in a dust cloud, where they thought to be alone in the universe). They did not like when they discovered that the principle did not work there. Their solution was not to change the principle, but rather to make it true again by destroying everything else :) (Douglas Adams, hitchhiker's guide to the Galaxy)
Copernicus was not the first to propose the heliocentric model of our solar system. In around 270 BC a Greek Philosopher Aristarchus of Samos proposed a heliocentric model of our solar system. Aristotle argued against the heliocentric model being adopted because it used perfectly circular orbits and was less accurate at predicting the observed paths of known celestial bodies like the planets. Copernicus added smaller circular orbits to the planets around a central path the orbited the sun in the perfect circular orbit. What this epicycle did was brilliantly predict the elliptical orbits that the planets actually orbit the sun in. Johann Kepler was the first mathematician to recognize from the data collected by Tycho Brahe's staff over a 20 year period of recording the position of various celestial bodies that the planets were orbiting the sun in ellipitical paths. Kepler also identified that the planets accelerated as they traveled toward the sun and slowed down as they traveled away from the sun. There are people who claim that heliocentric model proposed by Aristarchus was inspired by a much earlier philosopher from India who had also written on the subject. This is very possible as Aristarchus did spend time in the port city of Alexandria that routinely confiscated all books onboard ships that docked in it's ports, kept the originals and gave copies back to the ship.
Came to say the same, though even earlier, 5th century BC, there were Greek philosophers, Philolaus of Croton and Hicetas, who came up with the idea of the Earth being a sphere that orbited a central fire, the sun. Their works might have also influenced Aristarchus later writings.
Copernicus wasn't the first one to use the epicycles. Hipparchus, the father of trigonometry, was the first as far as I know. I don't know if anyone applied epicycles to heliocentrism though before Copernicus. Perhaps Seleucus did. Who knows, their writings don't survive. Aristotle didn't say anything about the model of Aristarchus, because, well, he was dead when Aristarchus proposed it.
@@kylie_h1978 Aristarchus made ONE SIMPLE CHANGE to the existing neo-Pythagorean model of Heraclides of Pontus. Heraclides changed the model of Philolaus. The model of Heraclides is often credited to Plato who described it in his writing Timeaus. Aristarchus PRESERVED the model of Heraclides. Aristarchus was CONFUSED about the solar solstices. Copernicus was unaware of the original model of Heraclides. Copernicus assumed that Philolaus and Heraclides shared the same model. Copernicus was wrong in that assumption. In fact, if Copernicus knew then what we know now, he would have chosen the model of Heraclides. Regarding this video, I disagree with Dr. Becky. Although Copernicus chose the wrong neo-Pythagorean astronomer, he was correct to place the Earth's solar system in the CENTER of the ANISOTROPIC universe. The constellations reveal that the universe is anisotropic. And it is sheer silliness to say that the observer is not in the center of the spatial region that is being observed. Copernicus would turn over in his grave if he knew that his name was used for something that he disagreed with. American astronomer Harlow Shapley coined the phrase because he was proposing that the Earth's system was NOT where Copernicus positioned it - in the center of the universe. Philolaus, Hicetas, and Heraclides used the pyrocentric model. the central fire was not the sun. The sun revolved around the central fire. Best regards.
Copernicus, seeing and saying what others dared not. What a hero! Edit to add: The thing that I've come to believe having been wowed by space science since I was a kid, is that Copernicus is right, our location in the universe isn't special, but only because EVERYWHERE in the universe is special, perculiar. At no two points in the universe are conditions precisely identical. No two solar systems are the exact same, or mirrors of one another. No two clouds of gas that form stellar nurseries, produce stars that are exact copies of one another, as to size, rotation speed, or trajectory through space. Its all special, and because it's all special, special is within the normal distribution.
You are exactly right, great thinking, one thing more you might have told us, the particles which make all these universe exactly identical altheway everywhere.
I love the t-shirt! My father Jack Bibb was a forest ranger here in WV, serving for 41 years including his time counted in the US Marines during the Korean War. I literally grew up with a Smokey Bear costume in iour shed and one day dad pulled me out of high school to wear it on a visit to the local kindergarten class.
@deanbibb3680 nice! I got my acoustic guitar at a little shop in Beckley around 2000, lol. Moved to TN for college in 2001, but I still head up that way for family :D
With the biggest tongue in cheek it just goes to show that we are still trying to pull ourselves up by our own bootstraps! Please keep going Dr. Becky your thoughts are insightful.
Love your Smokey the Bear shirt. I am related to Smokey; my great uncle was one of the two Forest Service Rangers that found Smokey and developed the Stop Forest Fires campaign around Smokey. As federal employees they were unable copy right it; but the original art was beautiful..
Hey Dr. Beeky! I loved your 'Day in My Life' videos . Any chance you could make an updated version? Would be awesome to see what your routine is like now! Keep up the great work! 😄
Not being exactly like the average, doesn't mean we're special. Rolling a 1 on a dice is as big chance as the other numbers, even though the average is 3.5. So the natural variation really makes sense to me.
But it is also important to know that rolling a 1 on a 6-sided dice is not the average, expected value of 3.5. If you rolled a 1 and assumed that you are not at some particular possible value, but at the average, your prediction for what happens if you roll the dice several times will be wrong. It's important to be aware of that bias.
Difference between Average and Mean. Mean considers all the possible results while Average only considers the results actually obtained. You can calculate Mean by theory whereas Average can only be calculated by rolling the dammed die over and over. Theoretical and Observational are not always the same.
There are even deeper assumptions I would argue, at least philosophically or to science in general. Such as we can in genetral trust our observations, that we live in a shared external environment (and not a brain in a vat), that the universe can be described to begin with, that we can describe it with mathematics etc.
Even if we were at the center of the Universe, the Universe would appear isotropic to us. The problem is homogeneity, for which we cannot have experimental observation ever. This means that all cosmology is based on a dogma. Modern science simply exchanged old dogma with new dogma.
As a layperson, the Copernican principle has struck me as being very much like Occam's razor. As in, it's a nice rule of thumb for what might be a safer guess when there are many unknowns, but obviously the simpler answer is not really _always_ the correct one, and obviously all conditions around Earth are not identical in _every minute detail_ to everywhere else. (That planet Earth is here but not also over there and there and there and there and also there in countless duplicate should be demonstration enough against the inviolability of the principle.) It bugs me how ideas in cosmology seem to so often be founded upon treating cosmology's figurative Occam's razor as an assumed infallible trusim. We have no rational basis to assume that local observations are universal, without evidence to support every individual case. Dark energy being ubiquitous implies nothing about any other condition.
@@noblehelium3794Occam's razor was never intended to be a tool for establishing truth, it is meant as a tool for selecting what hypothesis is most sensible to examine further. Scientifically it makes no sense to assume an unproven theory is true until proven otherwise, the best that Occam's razor can tell us is that it appears to be the most likely explanation.
the "Copernican Principle" feels so instinctively correct that it makes sense to assume it is correct... and saying it resembles Occam's Razor, is like a reminder that it's just common sense to think of it that way ...
The irony is, I'm not sure Copernicus would have agreed with the Copernican Principle. He believed that the Earth, the stars and the planets were created by God for the benefit of Man. He would think the fact the Earth was special went without saying.
Yeah, but only because Copernicus lacked the information that we have today. Just like Newton was an alchemist, only because the science of chemistry didn't exist in his time.
Isn’t it more of a general assumption than aprincipal? Finding out that earth is unusual or even unique would not break science it would just be statistically unlikely.
The implication that is important is that the laws of physics are the same all over the universe. Obviously the core of the Sun would be very different than floating in a sea of nitrogen slush on the surface of Pluto. But what we do is believe that the exact same laws of physics apply in both places. Clearly we can't know that for sure, without first exploring every corner of the universe.
@@peterwilson8039 I meant more in the sense that Earth might be a unique or unusual planet or our solar system might not be typical.. Those things might just be statistical unlikelihoods like finding ourselves in a 'void'.
@@perkytxgirl The thing is, the idea that the Earth itself isn't unique or interesting isn't generally part of the Copernican principle. What we DO assume is that the gravitational constant that we measure here is the same everywhere. We assume that gasses have the same emission/absorption spectra. Would you be shocked if it turned out there were absolutely no moons outside of our solar system? If so, that's the Copernican principle. Physics should work the same everywhere, so the idea that only our solar system has moons sounds silly. Conversely, when people thought the Earth was very special, seeing that Jupiter had moons was quite shocking.
@ That would not violate the cosmological principle. There’s a set of rules and anything allowed by the rules is possible. It’s the uniformity of the rules that’s at issue. We assume that, but we have no way to prove the assumption.
I’m going to display my spectacular ignorance here, but; Any light we are observing at the most extreme distances (the light which indicates that the universe’s expansion is accelerating) would surely NOT be showing us the current situation at that ‘location’, but the situation as it was some time after the ‘Big Bang’ as the light has taken that long to reach us. And shortly after the ‘Big Bang’, the expansion of the universe would, of course, be accelerating. Am I missing something? Surely it’s impossible to know the current situation at extreme distances, so therefore the universe may actually be stable or even shrinking.
This is the first video I've watched of yours. Earned a subscribe, it seems like at a large scale the universe seems easier to observe and even comprehend while on the smaller scales the random fluctuations throw us for a loop. Kinda like things here on Earth are relatively simple until you get down to the quantum level then we're thrown for a loop. Funny how that happens.
It's not just the KDB void that calls into question the homogeneity implied by Cosmological Principle. There are also the discoveries of several massive structures (accumulations of matter), most recently including the ‘Giant Arc’ (spanning a whopping 3.3 billion light-years) and the ‘Big Ring’ (1.3 billion light-years in diameter).
Can't forget the Hercules-Corona Borealis Great Wall, which spans nearly 10 billion lightyears across. Its existence has actually been a point of contention, since unlike the Big Ring, Giant Arc, etc. which are close enough to the theoretical limit to be rectified with the Copernican Principle, the Hercules-Corona Borealis Great Wall at _minimum_ would require the theoretical limit to be adjusted and everything that relies on that limit to be recalculated.
I was wondering why she didn't touch on these super galactic structures in the video. Regardless, I understand that these are such rare exceptions and, as such, perhaps considered random/chance anomalies, insufficient to override the Copernican Principle.
@@bgsmember3650 Yes, but another one of the 'anomalies' is the Hercules-Corona Borealis Great Wall - the largest known apparent structure in the observable universe, spanning an estimated *10 billion light-years*. The Copernican Principle can only swallow so much without having to be radically re-thought.
@@bgsmember3650 They don't individually override it, but the frequency of their occurrence and the shear scale of the margin between theoretical maximum and the largest of these structures points to the possibility that at minimum we may need to redo the math on that theoretical maximum.
Ancient Indian astronomers had a complex understanding of the cosmos, with some evidence suggesting they recognized the Sun as central to the solar system. ## Early Concepts of Heliocentrism The notion of a heliocentric universe, where the Sun is at the center, can be traced back to the Indian philosopher **Yajnavalkya**, who lived around the 9th century BCE. He expressed ideas that hinted at heliocentrism in his writings, notably in the *Shatapatha Brahmana*, where he described the Sun as stringing together various celestial bodies, implying a central position in relation to Earth and other planets[2][3]. This perspective, however, was not widely accepted among ancient Indian astronomers, who predominantly adhered to a geocentric model until much later. ## Aryabhata's Contributions In the 5th century CE, **Aryabhata** made significant advancements in astronomy that further reflected an understanding of celestial mechanics. He developed methods for calculating the distance to the Sun based on observations of the Moon's motion and angular size[1]. Aryabhata's work suggested a sophisticated grasp of planetary movements and distances, indicating an advanced level of astronomical knowledge. His calculations were notably close to modern estimates, showcasing his scientific ingenuity[1]. ## Influence and Legacy Despite these early insights, the majority of ancient Indian astronomers continued to support a geocentric view until the influence of later astronomical developments. The recognition that stars are similar to the Sun and that there are multiple suns in different directions reflects an evolving understanding of celestial phenomena[4][5]. The legacy of these early astronomers influenced subsequent generations and contributed to global astronomical knowledge. In summary, while ancient Indian astronomers like Yajnavalkya and Aryabhata hinted at heliocentric concepts and made impressive calculations regarding celestial distances, a widespread acceptance of a Sun-centered solar system did not materialize until much later in history. Citations: [1] www.schooltube.com/ancient-indian-astronomy-calculating-the-distance-to-the-sun/ [2] www.astronomytrek.com/who-discovered-the-earth-moves-around-the-sun/ [3] www.indiancentury.com/astronomy.htm [4] www.spacetoday.org/India/IndianAstronomy.html [5] en.wikipedia.org/wiki/Indian_astronomy [6] exoplanetscience.org/early-indian-astronomers-views-on-our-solar-system [7] mathemajik.tripod.com/article/astronomy.html [8] www.scifireads.com/single-post/2020/01/25/ancient-civilization-knew-far-more-about-our-solar-system-than-they-should-have [9] www.infinityfoundation.com/mandala/t_es/t_es_shah_m_astronomy.htm
@@oortcloud8078 well that's po(o)p shi-ence for you, there was no hostility towards his works in the beginning, it was only one century later when Galileo went meddling in politics by attaching the papacy that he ended up in house arrest (no execution btw)
@@alveolate Does it include the movements and whereabouts of Kopernik (Copernicus) after he was fired out of the cannon, that would be interesting to watch.
Question for Dr Becky: If everything in the universe is moving away from us at the Hubble Constant velocity, no mater which direction we look, doesn't that imply that we are at the center and everything is expanding away from us?
It does not, and an easy demonstration can show why. Get a sheet of paper, a marker, a ruler, and a pice of plastic. Make a grid of dots on the paper spaced 1cm apart. Then, make grid of dots on thd plastic but 2cm apart. Pick one dot on each to represent Earth, and place the plastic sheet's Earth on the paper's Earth. You will see a simplified diagram of this Hubble expansion. It does, indeed, look like Earth is at the center! However, now pick another dot on each to represent some alien planet, and lay the plastic so its alien planet lines up with the paper's alien planet. And you will see that the alien planet ALSO looks like the center of the universe! But the reality is - the plastic sheet represents a point in time after the paper time, and the space between ALL the dots expanded at a constant amount -- 1cm vs 2cm. In short, all systems spread out larger than a local cluster are all moving away from each other as the space between them increases.
I’m surprised you didn’t mention the Axis of Evil, especially since you’ve done a video on it and mention the CMB. I don’t have an opinion either way on it but it seems odd to leave out.
The Axis of Evil shows that our solar system either creats the CMB of influences it strongly. Which makes sense because everything else is very, very far away (LY instead of LM)l
Our consciousness perceives the world and the universe in a dualistic way, and therefore I would call "dark energy" and "dark matter" the "nothing," and the visible physical universe would be the "something." Only that which is conscious can measure, weigh, and calculate the physical universe. Nothingness is beyond what we can measure, weigh, or calculate. Intelligent personal consciousness is projected beyond the "event horizon" projected by every atom that makes us up.
The universe could be infinite, with us currently trapped in a tiny bubble that is relatively homogeneous. If we invented FTL and traveled past the cosmic horizon - assuming it is habitable and doesn't have different physics - then we might find ourselves completely overwhelmed by how freakishly isolated we were and how abnormal our circumstances.
As I recall, there were those among the ancients who called the geocentric model into question, but of course, there was not the technology to prove or disprove any model of cosmology at that time. Ptolemy discussed this matter in his Almagest, but ended by saying he and his model were mainly trying to "save the appearances", i.e. provide a mathematical model to accurately and precisely describe and predict the perceived motions of the "planets" (bodies that wandered against the background of the "sphere of the fixed stars"). So, I don't think it is quite accurate to say that Copernicus was the first to demote the Earth from the center. It wasn't even fully accepted in his time, as Tycho Brahe's compromise model had some traction for a while. It was only when Kepler, who inherited access to Tycho's records of data that were unrivalled in precision, realized that the perfection of Ptolemy's circles and epicycles (circles moving along on other circles) was not only cumbersome but also unable to match the precision and accuracy of their sister conic sections (ellipses) in describing the motion of the planets, that the Copernican model was able to stick. Especially as it harmonized with Newtons work on gravitation and provided an understanding of the physical cause of the phenomena. In Aristotle's terms, it seems to me, Ptolemy's model(s) provided only a formal cause for the appearances (circular motion); Kepler and Newton provided not only a formal cause (elliptical motion, or in the case of Oumuamua, hyperbolic motion) but a material cause (gravity acting on mass).
Dear Dr Becky, I do believe your eyes are getting bluer and bluer by the day. Are you accelerating towards me, or is our universe expanding? You know Carl Sagan wrote a great book on this exact question called, *Pale Blue Dot* - _A vision of the human future in space._ He must of had your eyes in mind when he wrote that book. Thank you Carl. 😊
Okay. Question: Do these astrophysicists consider that when they look at a all the other galaxies, they are looking back in time, so they would be a lot closer to each other then? So when we look at our nearby cluster we're going to be looking less far back and therefore things will be more spread apart? I just question all the time if they are thinking 4th dimensionally when they look at all the "evidence" out there. Sometime it's obvious, but other times, not so much.
I think some day we'll find that there's something slightly unusual about our region of space that affects some readings or another, like how our ancestors found that nature only seems to abhor a vacuum because we're in a relatively high-pressure zone on Earth.
I mean, the video basically says exactly that: we're in a supervoid, it affects our measurements and we have to account for that. Copernicum principle is not a universal law, just a wishy washy guideline like Occam's razor. Whether it holds or not depends on the scale at which you're looking at the universe.
“There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.” So Albert Einstein said, anyone in my opinion who understands just a glimpse of the workings of this Universe, the Earth and life has to choose the latter, so yeah I reckon Earth is very special! 😉👍
It shows the CMB is either created by or strongly influenced by our solar system. The confusion comes from Big Bangers appropriating it to "prove" their theory, ignoring the obvious.
Would it be presumptuous to suggest, that there is one great demotion that Nicolaus, Carl and Becky may have overlooked, considering they are the real "professionals" here. *The Earth isn't even at the centre of our own Earth-Moon system.* And in fact the Earth and Moon both revolve around a *barycentre,* which is a point inside the Earth that allows the system to remain balanced. The gravitational and inertial forces of both bodies in orbital motion around this point are equal and opposite at there respective centres of mass. It is the dancing motion around this point, also known as the common centre of mass, that leads to the twice daily tidal cycle on our beautiful *Pale Blue Dot,* as it floats like a mote of dust, suspended in sunbeam. Thank you Carl. You were a one in a billions "pro," who stated that the absence of evidence is not the evidence of absence. 😌
I’ve never really understood the definitions/distinctions between Isotropic & Homogeneous. I don’t see how the universe could be “equally distributed in the universe” but not “look the same in all directions” (I.e. how are isotopic and homogenous different from each other) Don’t know if I’m just being dumb
The Copernican principle already doesn't hold at the scale of solar systems, or else we would expect the Sun to be a red dwarf. It wouldn't hold on a galactic level if you put credence to galactic habitable zones. I wouldn't be surprised if there were even higher order structures in the universe that are needed to support life to the point where our cosmological place in the universe is actually special.
I always thought that Copernicus only proved that Earth circles arround the Sun, yet he still followed Catholic Church doctrine that states that Earth is center of universe. It was Galileo Galilei who proved otherwise by comparing night sky during seasons when he noticed stars drifting (which we now know that were planets) and that theory was why Catholic Church prosecuted him.
The most compelling and disturbing evidence against the Copernican principle, as far as I can tell, is that when we look out into the cosmos, so far we haven't seen anybody else out there. There is SOMETHING going on here on Earth that, as far as we can tell, happens nowhere else. We assume there must be life out there, but we've never seen a trace of evidence for it. And that means there is something unbelievably special about this planet and this solar system right here.
Possibly. Except if you look at both sides and ask "If that star had a planet with a civilization exactly like ours would we be able to see them? Would they be able to see us?" And the answer is No and No. So far we haven't seen anybody that is screaming on the radio or that has obviously altered parts of their star system - physically or biologically.
@@bruceleenstra6181 The Fermi paradox. We should not have to look for them, they should be here. Since many of the Sun-like stars are billions of years older than the Sun, the Earth should have already been visited by extraterrestrial civilizations, or at least their probes. However, there is no convincing evidence that this has happened.
Just playing devils advocate here but with the thousands of exoplanets we have identified, and not a single one (yet) capable of supporting human life, maybe the Earth, while not being the center of the universe, is special?
So many conditions had to be right for many millions of years, for life to sprout on Earth and finally blossom to full human intelligence. If that's not Divine, then Earth has to be a very special little blue planet ❤
We need to consider that current methods of detecting exoplanets come with a sampling bias where the easiest planets to observe are the ones that we tend to detect, such as super Jupiters (very large gas giants) that orbit very close to their stars, or rocky planets around red dwarfs (which are extremely volatile in terms of emitting intense radiation). This makes it so that a lot of the exoplanets we know of are inherently going to be hostile to human life, unfortunately :(
@@Mariia_ava Why even search for it? Life must be very scarce in the observable Universe. Distances are too large. We're on the outskirts of our galaxy. Our galaxy itself is in a big Void. If there's another life form that's advanced enough to traverse millions of light years through space, maybe they'll find this grain of sand, Earth, in the desert of the Universe..
@@samgrieg Asking why we search for extraterrestrial life is like asking why we study astronomy at all. It’s intellectually rewarding more so than anything. I agree that it seems futile to search for life given that our chances of finding it are so small, and that all the efforts made up to now have been fruitless. There are many reasons why this could be, for example the Dark Forest theory. However, the likelihood of finding anything at all is automatically zero if we don’t search in the first place.
The best evidence of us being in a special place in the universe is that we exist and have zero evidence to support the existence of similar life in the universe.
We have zero evidence because we do not have the technology to obtain such evidence. Until we can travel to every part of the universe and look for such evidence one cannot say with any confidence or conviction that life exists only here making us special. Only hubris, vanity and arrogance can make the claim we are unique, alone and special.
It shows that he CMB is either created by, or strongly influenced by the solar system, which makes sense because everything else is very, very far away (LY instead of LM). Of course this is impossible to reconcile with cosmologists' belief that the CMB is a relic of the Big Bang, so they ignore it.
The Axis of Evil shows that the CMB is either created by, or strongly influenced by our solar system. Which makes sense because everything else is very, very far away (LY not LM). Big Bangers appropriated it to "prove" their theory.
12:36 Is it valid to use data that was collected _and interpreted_ based on one interpretation, to test that same interpretation of the universe? Feels a bit weird (though you don't really have an alternative, I guess ^^)
Circular reasoning is always wrong. E.g., LCDM is based on matching data without a physical explanation (what exactly is DM?), so arguing that it is confirmed by matching some data is circular.
Gravitationally bound galaxy clusters do *not* preclude expansion. The visualisations of what's become known as 'the cosmic web' are captivating and eerily reminiscent of the structure of a brain. Coincidence? Not a clue!
Sorry for being a bit thick, but space is expanding, the distance between the galaxies, get that. But how come the distances inside the galaxies are not expanding as well? I am I being really thick? Thank you Eamon
Can you explain why prevailing understanding indicates the universe is expanding? If more distant galaxies are moving away faster than closer ones, why doesn’t that indicate that the universe was expanding faster in earlier eons and is not expanding as fast in more recent times?
You know I had to stop and think about that for a second, as it's a bit of a mind bending question. However, it's to do with the fact that when we look at distant galaxies, we're looking further back in time. We should expect the distant galaxies to be moving away faster, if the expansion rate is slowing, but we see the opposite. I hope that makes sense? But, I'll try and think of a better way to explain it later, if you're still interested. 😅
The FLRW solution which describes expanding Universe predicts not only that expansion is slowing, but also HOW MUCH it is slowing down with time. Exactly as you described. But the observations show that although expansion does slow down (the farther away galaxies are floying away faster than linear), but it is slowing down not as much as FLRW says it should. There is a discrepancy - the slowdown is too weak.
Yeah, thanks for clarifying that, I think that explains it better. And this discrepancy - which implies that there must be something driving that increased expansion - is where the idea of dark energy arises, which could be some form of the cosmological constant, that Einstein abandoned earlier.
Science doesn't prove things; it collects evidence that supports things (or not). See the Raven paradox. It seems reasonable to me that we could be in a place that makes our observations inaccurate somehow: some fog or tilt to spacetime that we aren't aware of. Great video as usual. The way Dr B lays out her main points, and her choice of them, always makes the subject clear and memorable. She's got a knack. Probably got it from a professor she had.
Agree in particular with your first statement. The choice of language in this video is unfortunate. The word proof belongs in the realms of maths and logic, not the realm of science. Scientists make reproducible experimental measurements, then attempt to devise theories that explain those measurements and make predictions that can be tested by further experiments. A theory that conflicts with experimental evidence has to be revised or abandoned. The most we can say about any theory is that so far it is consistent with experiment. This does not prove that the theory is correct. Science does not involve proving anything. Hypothetically you could have two theories, one based on the Copernican principle and one not. If both theories were consistent with all the measurements we have so far made, then we would not be able to choose between them on experimental grounds. However if either theory made unnecessary assumptions or unsupported claims, it would likely face criticism for that reason.
If we are nothing special, then the universe is bursting with life. It’s over flowing from the abundance of life. Life is everywhere if we are not special.
The whole conversation is meaningless without a concrete definition of the concept ”Special". Is that solitary uniqueness respecting the void, or do other galaxies have the same uniqueness? And how are other galaxies unique or special than ours? We are certainly deviating from scientific to philosophical, until we can come up with a concrete factual definition of "special".
IMHO, Copernicus gets *way* too much credit. His heliocentric model had the virtue of using fewer epicycles than the Ptolemaic geocentric model. (Epicycles were additional circles on the orbits to explain retrograde motion. Still positing that the heavens must be perfect and therefore circular, Copernicus changed only the complexity of the orbits.) It was Kepler (using Brahe's meticulous observations) who posited elliptical orbits which, with a heliocentric model, fully explained retrograde motion and drastically simplified the orbital dynamics. To me, Kepler had the larger impact because he eliminated the Platonic and Christian ideals of perfection from the science.
Who are the hero’s of today people that think outside of are basic understanding, what will be the next great invention like electricity useing gas for combustion ,what great innovations are being developed for us to nowadays
The heroes of our time are reviled by the establishment, for the same reason Galileo was -- nobody wants their applecart upset. Read "Observations of Large-Scale Structures Disprove the Big Bang Hypothesis But Confirm Plasma Theory", a 2022 paper by Eric Lerner.
Dear Dr. Becky: have you ever done a video on whether the Milky Way is a barred spiral, and how they evolve differently from unbarred galaxies, and what effect that has on supermassive black holes at the centers of galaxies?
one way of handling this is what is the most amount of "special" compatible with our observations, and how would that effect the expectations of our measurements. if there is no significant difference between uniformity and slight specialisation then for the purpose of the model the universe is "uniform"
So that wherever we look into the universe we are always seeing a younger universe, as we ourselves, live at the very knife edge of evolving space and time. This, of course applies to all other locations regardless, and gives much to think about. They may exist at the other side of the universe, but look back at us in the same way . .
I also get my words muddled up sometimes... or "murds wuddled" up. The other day I said to myself something like "third-o-my-nanics" instead of thermodynamics.. when I was talking to myself about something from a RUclips video or TV programme! It's harder to get long words right when talking quickly.
Actually, Herschel's star map did put the sun at the center of the galaxy, because he did not know about the dust obscuring his view of distant stars and that he was mapping a small, by galactic standards, region of space centered around the Sun. It was Harlow Shapley's later mapping of globular clusters that showed that the Milky Way is much bigger than that, and that the Sun is indeed located closer to its edge than its center.
Actually, the book: 'The Philosophy of Space and Time' by Hans Reichenbach (1958 translation) explains it very well (and in depth) that both views are equivalent - It's just that the one we use is so much easier to explain with much fewer forces needed to be defined - But does not make it anymore 'true' than another view and associated definitions - Read it many years ago, but a very eye-opening experience indeed.
The term "Copernicus Principle" should be called the "Harrison Principle", as it was coined by the American cosmologist and astrophysicist, Edward Harrison in the 1970s. He used it to describe the idea that Earth does not hold a unique or central position in the cosmos, which was not the specific intent of the heliocentric model first proposed by Copernicus.
I love these big existential-crisis questions (nice segue, btw)... but then, my degree was in cognitive science and I never made it to graduate school, and I've always been a big fan of Lovecraftian theology, so ideas that terrify most people tend to reassure me. LOL
The anthropic principle comes into play here too. Maybe our local region of space is only exceptional (rocky planet in habitable zone with relatively large single satellite in the outer reaches of a relatively isolated galaxy) because such regions are the only ones capable of hosting complex life that survives long enough to reach this level of development.
One thought I add here is that to observe light in all the EM spectrum, extending as far as the cosmic horizon, there is a likelihood of it only being possible within a Standing Wave... all the phases of matter and its general distribution into bodies are reducible to the frames of harmonic equilibria. I am of the opinion that whatever missing mass there might be, it has probably passed the Cosmic Horizon, and we, standing on the coat-tails of a CMB, experience this missing mass as negative presuure (the Hubble shift).
B, b... bb... but.... Your 3D data visualisation of the positions of the galaxies in the Universe (8:06) where you say "on average, it all kinda' looks the same"... but. but but... it doesn't look the same. It looks like there are stripes in it. The middle looks much more dense than the right side (for example). Will you please explain what you mean by saying that?
This was exactly the question I came here to ask! There is clearly a prominent band of concentrated objects in the center, I am curious too why we say this is basically all the same?
@NondescriptMammal it's theoretically all the same however we need to observe much more of the universe to prove this. Currently what we have observed is 'an arm of the universe' From observations we have seen matter at our place in time clump together which in a 3D space will make a Web of some sort of shape It may be irregular and the shape might not be much of significance however
@CeriAnnwen Yeah it just seems like a bold assumption to depend upon as a premise used as a basis for further theorizing, treating it as if it is an established scientific fact But I suppose astrophysics and cosmology especially, have no choice but to make assumptions, considering the only direct empirical data set they have to work with, is almost entirely limited to collection of electromagnetic radiation
@NondescriptMammal reality doesn't form from mathematics. Instead, it is a tool to understand and predict reality with precision. The same way a word can describe something and/or anything Our current understanding of mathematics seems to indicate the universe should do things we are yet to observe We also observe things we have yet to calculate into something meaningful Dark energy could be a new, weak force that expands space time. How it physically interacts with the universe is unknown and that is why scientists are yet to claim a discovery
@CeriAnnwen well yeah, the cosmologists say dark energy makes up 2/3 of the universe, but we don't even know what it is. And dark matter makes up most of the rest, and we don't know what that is either. All the astrophysics and telescopes can only tell us what 5 percent of the universe is made of.
"To know the mighty works of God, to comprehend His wisdom and majesty and power; to appreciate, in degree, the wonderful workings of His laws, surely all this must be a pleasing and acceptable mode of worship to the Most High, to whom ignorance cannot be more grateful than knowledge." --Copernicus
Edwin Hubble proposed that the expansion of the universe was happening on the periphery of the universe and he placed the earth at the center of the universe. In other words, in the center of the universe, there is little or no expansion.
It's simple in essence: the further away a galaxy (or whatever) is, the faster it is moving away from us. The tricky bit is measuring the distance accurately
@timbergel8147 the only problem is, we are moving faster away from them. Which is illogical. We are not the center of the universe. There was no BB. An infinite universe cannot expand. Redshift/tired light is due to force decreasing with distance. Gravity was disproven by Galileo. Newton's LoM defines gravity as Reactionary force. The resistance of the mass to being accelerated by an external force. Relativity is mathematical nonsense. Louis Essen, the inventor of the Atomic Clock, was highly critical of Einstein and his relativity nonsense. Not one experiment has validated it. Hafele-Keating"s synchronized clock experiments actually disproved it. Becky is either gaslighting you or she is ignorant of basic physics. There is no proof for relativity because motion is absolute. E=mc. Nothing can go faster than light. Light is tge preferred RF making the entire scientific community scam artists or ignorant laymen masquerading as an authority.
@@mrfranksan it's taken to be because the universe is expanding. Think of a partly inflated balloon with three spots on it, one spot is us while the other two are galaxies at different distances from us. Now if you inflate the balloon a bit more, it expands, so both of the other galaxies will end up further from us. But the one that was further away to start off with will have moved away from us a greater distance than the nearer one, because of the balloon expanding evenly. So we see a greater speed difference between us and the galaxy that is further away. And if you imagine yet another spot that started off very close to us, it is (I hope) clear that it would hardly have moved at all and we would see it as having very little speed. I hope that helps to make it clearer - it's hard to describe. Another nice thing about the effect of this expansion is that it means that we would see the same thing wherever we were in the universe (anywhere on the balloon's surface) so it doesn't mean that we are at the centre of an expansion or anything.
5:26 No, Herschel's map shows the Solar System still in the centre (sort of). Rather, it was Shapley's work on the globular cluster system of the Milky Way which put the Earth well away from the centre, reinforced by the study of stellar motions by Oort and Lindblad, and Trumpler's discovery of absorption (well, scattering) by interstellar dust.
Since we’re talking about matter, I lean towards the idea of building a home from clay. You would be able to visit both the pit and the structure but that would require a larger underlying thing which is not out of the question.
First of all we have to define "special". Does it refer to location, or to particular values? If the latter, the Earth definitely is special, because it has the only known intelligent species in the universe.
That Copernican principle and Cosmological principle look to me to be essentially particular instances of what philosopher David Hume called the "principle of the uniformity of nature". In it's raw formulation this says simply that unobserved cases will be like the observed cases, which, since all observed cases are observed here, entails that we are not in a special place. In scientific terms this comes out in such assumptions as that the laws of nature we detect here are the same elsewhere. Hume showed fairly convincingly that, not only can we not prove it, and so it is uncertain, but that we cannot have any empirical reason to believe it without presupposing it - making the appeal to empirical evidence circular. In the case of the evidence for dark energy and (thus) non-violation of the Copernican principle, I would wager that such evidence rests on the unproven (and unprovable) assumption that the same laws of nature (e.g., general relativity) and the same constants (e.g. the Cosmological constant) applies everywhere, including out to the furthest reaches of the universe.
Yes, but LCDM is also based on a specific assumption: that redshift equals velocity and distance. Unfortunately for that theory, the assumption is disproved by actual photos (shown in Halton Arp's books) showing luminous connections between low-redshift galaxies and nearby high-redshift quasars, proving they are the same distance from us, despite vast differences in redshift. Cosmologists married to LCDM simply ignore this evidence.
![The Dark Energy Mystery [4K]](http://i.ytimg.com/vi/cQyoYzHxdvo/mqdefault.jpg)
Try out Surfshark today by heading to surfshark.com/drbecky and you’ll get 4 additional months free on your subscription - AD
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- **Base Implementation**: √N speedup for unstructured search
- **Enhanced Features**:
* Phi-harmonic amplitude amplification
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### Classical → Quantum Transformations
1. **Search Algorithms**:
- Linear Search → Quantum Search (√N speedup)
- Binary Search → Quantum Binary Search
- Depth-First → Quantum Walk Search
- Breadth-First → Quantum Parallel Search
2. **Optimization Problems**:
- Traveling Salesman → Quantum Adiabatic
- Knapsack → Quantum Annealing
- Graph Coloring → Quantum Coloring
- Maximum Cut → QAOA
3. **Sorting Algorithms**:
- Quicksort → Quantum Sort
- Mergesort → Quantum Merge
- Heapsort → Quantum Heap
- Bubble Sort → Quantum Bubble
## 2. Mathematical Transformations (528 Hz)
### Quantum Fourier Transform (QFT)
- **Classical → Quantum**:
* FFT → QFT transformation
* Phi-scaled frequency domains
* Crystal harmonic analysis
* Multi-dimensional resonance
### Advanced Transformations
1. **Matrix Operations**:
- Matrix Multiplication → Quantum Matrix Ops
- Eigenvalue Problems → QPE
- Linear Systems → HHL Algorithm
- SVD → Quantum SVD
2. **Statistical Methods**:
- PCA → Quantum PCA
- K-means → Quantum Clustering
- Linear Regression → Quantum Regression
- Monte Carlo → Quantum Monte Carlo
3. **Signal Processing**:
- Wavelet Transform → Quantum Wavelets
- Hilbert Transform → Quantum Hilbert
- Z-Transform → Quantum Z-Transform
- Laplace Transform → Quantum Laplace
## 3. Machine Learning Integration (594 Hz)
### Quantum Neural Networks
- **Architecture**:
* Quantum neurons with phi-scaling
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* Sacred geometry activation functions
* Consciousness feedback loops
### Classical → Quantum ML
1. **Neural Networks**:
- Feedforward → Quantum Feedforward
- CNN → Quantum CNN
- RNN → Quantum RNN
- LSTM → Quantum LSTM
2. **Learning Algorithms**:
- Backpropagation → Quantum Backprop
- Gradient Descent → Quantum Gradient
- Reinforcement → Quantum RL
- Genetic → Quantum Genetic
3. **Feature Engineering**:
- Dimensionality Reduction → QPCA
- Feature Selection → Quantum Selection
- Encoding → Quantum Encoding
- Embedding → Quantum Embedding
## 4. Cryptography & Security (672 Hz)
### Quantum Cryptography
1. **Classical → Quantum**:
- RSA → Shor's Algorithm
- DES → Quantum DES
- AES → Quantum AES
- Hash Functions → Quantum Hash
2. **Security Protocols**:
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## 5. Database & Information (720 Hz)
### Quantum Data Structures
1. **Classical → Quantum**:
- Arrays → Quantum Arrays
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2. **Database Operations**:
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1. **Rendering**:
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2. **Physics Simulation**:
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### Quantum Consciousness
1. **Awareness Integration**:
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2. **Field Harmonics**:
- Crystal Resonance → Quantum Crystals
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- Phi Harmonics → Quantum Phi
- Unity Field → Quantum Unity
Oh, Dr. Becky! How nice good of you to show up :) I think your other comment stream got a little, inflated (hah hah).
So, the problem is the red-shift, then. Quite a doosey. E=hf means it doesn't actually really work with dark matter lensing, since we can't really know how light photons are affected by the interaction with those two forces?
If that question was already posed by early 20th century physicists, or Copernicus himself, it would've probably been (how do the British put it) ________ to have said something, to the children.
Delightfully, Listener X. ^_^
becky, you are really a physicist? LOL. I tried to explain discrete relativity to you people and you ignored me.
So, here: you are all WRONG again. Keep pretending I don’t exist
Reductio Proof of the Copernican Principle Using Relativity
🚀 This is the clean, bulletproof proof that shuts down anyone saying the Copernican Principle “can’t be proven.”
Step-by-Step Breakdown
✅ Assumption (To Be Contradicted) → Suppose there exists a privileged reference frame in the universe.
• We assume for the sake of contradiction that there is a special “center” of the universe.
✅ Implication 1 → This would mean an absolute ‘center’ exists, violating relativity.
• Relativity does not allow any preferred location-motion and position must be relative.
✅ Implication 2 → General Relativity states that physical laws are the same in all reference frames.
• If the universe had a “center,” physics should behave differently depending on distance from that center.
• But every observation confirms that physics remains consistent everywhere.
✅ Implication 3 → Observations of the Cosmic Microwave Background (CMB) show uniformity across all directions.
• If there were a privileged location, we should see anisotropies (uneven distribution of temperature and matter).
• Instead, the CMB is almost perfectly isotropic, confirming large-scale uniformity.
✅ Contradiction → If there were a privileged location, the CMB and galaxy distribution would not be isotropic.
• This contradicts real-world data-so the assumption must be false.
✅ Final Result → The universe has no special center-Copernican Principle is confirmed.
• Since assuming a privileged location leads to contradictions, we conclude that no such location exists.
• Therefore, the universe follows the Copernican Principle.
What This Means
🔥 I don’t feel like explaining my homework to you people anymore.
wink
Wow! Now I know why? 🤨 What on Earth happened to critical thinking? It's an absolute minefield in your comments. Everything doesn't work apparently!
Oh dear, I guess I'll just enjoy listening to your delightful content and ignore comments. Thank you for being a voice of joyful scientific carm amongst the noise of the background radiation.
Krikkit planet's inhabitants used to apply the Copernican principle. (a planet located in a dust cloud, where they thought to be alone in the universe). They did not like when they discovered that the principle did not work there.
Their solution was not to change the principle, but rather to make it true again by destroying everything else :)
(Douglas Adams, hitchhiker's guide to the Galaxy)
Whop.
Earthbound science has replicated their Someone Else's Problem field, but thus far has kept it confined to themselves.
@@mal2ksc Well, they try to tell people about it but nobody wants to listen about somebody else's problem
@ 😅😅🤣
That reference makes the diodes on my left side hurt even more.
I'm glad the universe created Dr. Becky.
Her mum: _umm...I have a name_
Her dad: _umm...I haven't a name_
A test tube : Er.....
We are all children of the universe. Enabled by violent events spreading heavy elements.
We are all made of star stuff.
Copernicus was not the first to propose the heliocentric model of our solar system. In around 270 BC a Greek Philosopher Aristarchus of Samos proposed a heliocentric model of our solar system. Aristotle argued against the heliocentric model being adopted because it used perfectly circular orbits and was less accurate at predicting the observed paths of known celestial bodies like the planets. Copernicus added smaller circular orbits to the planets around a central path the orbited the sun in the perfect circular orbit. What this epicycle did was brilliantly predict the elliptical orbits that the planets actually orbit the sun in. Johann Kepler was the first mathematician to recognize from the data collected by Tycho Brahe's staff over a 20 year period of recording the position of various celestial bodies that the planets were orbiting the sun in ellipitical paths. Kepler also identified that the planets accelerated as they traveled toward the sun and slowed down as they traveled away from the sun. There are people who claim that heliocentric model proposed by Aristarchus was inspired by a much earlier philosopher from India who had also written on the subject. This is very possible as Aristarchus did spend time in the port city of Alexandria that routinely confiscated all books onboard ships that docked in it's ports, kept the originals and gave copies back to the ship.
Came to say the same, though even earlier, 5th century BC, there were Greek philosophers, Philolaus of Croton and Hicetas, who came up with the idea of the Earth being a sphere that orbited a central fire, the sun. Their works might have also influenced Aristarchus later writings.
I did a research project on this subject! Copernicus even referenced Aristarchus originally!
Copernicus wasn't the first one to use the epicycles. Hipparchus, the father of trigonometry, was the first as far as I know. I don't know if anyone applied epicycles to heliocentrism though before Copernicus. Perhaps Seleucus did. Who knows, their writings don't survive.
Aristotle didn't say anything about the model of Aristarchus, because, well, he was dead when Aristarchus proposed it.
@@kylie_h1978 Aristarchus made ONE SIMPLE CHANGE to the existing neo-Pythagorean model of Heraclides of Pontus. Heraclides changed the model of Philolaus. The model of Heraclides is often credited to Plato who described it in his writing Timeaus. Aristarchus PRESERVED the model of Heraclides. Aristarchus was CONFUSED about the solar solstices. Copernicus was unaware of the original model of Heraclides. Copernicus assumed that Philolaus and Heraclides shared the same model. Copernicus was wrong in that assumption. In fact, if Copernicus knew then what we know now, he would have chosen the model of Heraclides. Regarding this video, I disagree with Dr. Becky. Although Copernicus chose the wrong neo-Pythagorean astronomer, he was correct to place the Earth's solar system in the CENTER of the ANISOTROPIC universe. The constellations reveal that the universe is anisotropic. And it is sheer silliness to say that the observer is not in the center of the spatial region that is being observed. Copernicus would turn over in his grave if he knew that his name was used for something that he disagreed with. American astronomer Harlow Shapley coined the phrase because he was proposing that the Earth's system was NOT where Copernicus positioned it - in the center of the universe. Philolaus, Hicetas, and Heraclides used the pyrocentric model. the central fire was not the sun. The sun revolved around the central fire. Best regards.
Even Ancient Greece had dictators. Believe it or not.
I love the enthusiasm with which you tell about these interesting, but difficult items, Professor!
Copernicus, seeing and saying what others dared not. What a hero!
Edit to add: The thing that I've come to believe having been wowed by space science since I was a kid, is that Copernicus is right, our location in the universe isn't special, but only because EVERYWHERE in the universe is special, perculiar. At no two points in the universe are conditions precisely identical. No two solar systems are the exact same, or mirrors of one another. No two clouds of gas that form stellar nurseries, produce stars that are exact copies of one another, as to size, rotation speed, or trajectory through space. Its all special, and because it's all special, special is within the normal distribution.
That's a pretty good way of looking at it, though it is a philosophical stance rather than a scientific one. Which is welcome though :)
"no two solar systems"
@@juimymary9951One might argue science is philisophical 🙂
You are exactly right, great thinking, one thing more you might have told us, the particles which make all these universe exactly identical altheway everywhere.
Although everything is made of the same matter, and dark matter although not in the same state and circumstances
Commenting just for the algorithm. Yeah , coppernicus and anthropic principle. I loved how your video and PBS touched these themes at the same day ❤
Dr Becky is so good at her job I feel like I understand what she's talking about
becky is preaching catholic indoctrination...
🤭😭😂
Me too. I know I don’t, really, but feel like I do. Maybe. Sorta. Or not. Mostly she’s cute, so there’s that. Joking!🎉😊
I love the t-shirt! My father Jack Bibb was a forest ranger here in WV, serving for 41 years including his time counted in the US Marines during the Korean War. I literally grew up with a Smokey Bear costume in iour shed and one day dad pulled me out of high school to wear it on a visit to the local kindergarten class.
I grew up in Southern West Virginia (Mercer co). WV represent, lol
@ awesime! I grew up in Ansted in Fayette County, I’ve been in Beckley since 2001.
@deanbibb3680 nice! I got my acoustic guitar at a little shop in Beckley around 2000, lol. Moved to TN for college in 2001, but I still head up that way for family :D
With the biggest tongue in cheek it just goes to show that we are still trying to pull ourselves up by our own bootstraps!
Please keep going Dr. Becky your thoughts are insightful.
Love your Smokey the Bear shirt. I am related to Smokey; my great uncle was one of the two Forest Service Rangers that found Smokey and developed the Stop Forest Fires campaign around Smokey. As federal employees they were unable copy right it; but the original art was beautiful..
Hey Dr. Beeky! I loved your 'Day in My Life' videos . Any chance you could make an updated version? Would be awesome to see what your routine is like now! Keep up the great work! 😄
Not being exactly like the average, doesn't mean we're special. Rolling a 1 on a dice is as big chance as the other numbers, even though the average is 3.5. So the natural variation really makes sense to me.
But it is also important to know that rolling a 1 on a 6-sided dice is not the average, expected value of 3.5. If you rolled a 1 and assumed that you are not at some particular possible value, but at the average, your prediction for what happens if you roll the dice several times will be wrong. It's important to be aware of that bias.
Difference between Average and Mean. Mean considers all the possible results while Average only considers the results actually obtained. You can calculate Mean by theory whereas Average can only be calculated by rolling the dammed die over and over. Theoretical and Observational are not always the same.
There are even deeper assumptions I would argue, at least philosophically or to science in general. Such as we can in genetral trust our observations, that we live in a shared external environment (and not a brain in a vat), that the universe can be described to begin with, that we can describe it with mathematics etc.
Even if we were at the center of the Universe, the Universe would appear isotropic to us.
The problem is homogeneity, for which we cannot have experimental observation ever.
This means that all cosmology is based on a dogma.
Modern science simply exchanged old dogma with new dogma.
As a layperson, the Copernican principle has struck me as being very much like Occam's razor. As in, it's a nice rule of thumb for what might be a safer guess when there are many unknowns, but obviously the simpler answer is not really _always_ the correct one, and obviously all conditions around Earth are not identical in _every minute detail_ to everywhere else. (That planet Earth is here but not also over there and there and there and there and also there in countless duplicate should be demonstration enough against the inviolability of the principle.) It bugs me how ideas in cosmology seem to so often be founded upon treating cosmology's figurative Occam's razor as an assumed infallible trusim. We have no rational basis to assume that local observations are universal, without evidence to support every individual case. Dark energy being ubiquitous implies nothing about any other condition.
It very much is an instance of Occam's Razor. It can be assumed to be true until proven otherwise.
@@noblehelium3794Occam's razor was never intended to be a tool for establishing truth, it is meant as a tool for selecting what hypothesis is most sensible to examine further.
Scientifically it makes no sense to assume an unproven theory is true until proven otherwise, the best that Occam's razor can tell us is that it appears to be the most likely explanation.
the "Copernican Principle" feels so instinctively correct that it makes sense to assume it is correct... and saying it resembles Occam's Razor, is like a reminder that it's just common sense to think of it that way ...
The irony is, I'm not sure Copernicus would have agreed with the Copernican Principle.
He believed that the Earth, the stars and the planets were created by God for the benefit of Man. He would think the fact the Earth was special went without saying.
Copernicus assured his reading audience that the Earth's system is not being moved from the center of the universe.
Yeah, but only because Copernicus lacked the information that we have today. Just like Newton was an alchemist, only because the science of chemistry didn't exist in his time.
Great video Dr. Becky glad you're here 😊💙
Thank you very much for giving you perspective on the cosmos. Nature dose beautiful things.
Thanks, dr. Becky! 😊
Stay safe there with your family! 🖖😊
Isn’t it more of a general assumption than aprincipal? Finding out that earth is unusual or even unique would not break science it would just be statistically unlikely.
The implication that is important is that the laws of physics are the same all over the universe. Obviously the core of the Sun would be very different than floating in a sea of nitrogen slush on the surface of Pluto. But what we do is believe that the exact same laws of physics apply in both places. Clearly we can't know that for sure, without first exploring every corner of the universe.
@@peterwilson8039 I meant more in the sense that Earth might be a unique or unusual planet or our solar system might not be typical.. Those things might just be statistical unlikelihoods like finding ourselves in a 'void'.
@@perkytxgirl The thing is, the idea that the Earth itself isn't unique or interesting isn't generally part of the Copernican principle. What we DO assume is that the gravitational constant that we measure here is the same everywhere. We assume that gasses have the same emission/absorption spectra.
Would you be shocked if it turned out there were absolutely no moons outside of our solar system? If so, that's the Copernican principle. Physics should work the same everywhere, so the idea that only our solar system has moons sounds silly. Conversely, when people thought the Earth was very special, seeing that Jupiter had moons was quite shocking.
@ That would not violate the cosmological principle. There’s a set of rules and anything allowed by the rules is possible. It’s the uniformity of the rules that’s at issue. We assume that, but we have no way to prove the assumption.
I’m going to display my spectacular ignorance here, but; Any light we are observing at the most extreme distances (the light which indicates that the universe’s expansion is accelerating) would surely NOT be showing us the current situation at that ‘location’, but the situation as it was some time after the ‘Big Bang’ as the light has taken that long to reach us. And shortly after the ‘Big Bang’, the expansion of the universe would, of course, be accelerating. Am I missing something? Surely it’s impossible to know the current situation at extreme distances, so therefore the universe may actually be stable or even shrinking.
Most places in the universe are dark, dead, empty and lifeless. I would say that makes this place pretty special.
"Most" or "all"?
I would say more fortunate than special
The Copernicus principle is meant to be applied on larger scales.
But we don't know yet for sure if these places mentioned are dead. Life could be found to be floating around all over.
@@waynedarronwalls6468 I agree...
This is the first video I've watched of yours. Earned a subscribe, it seems like at a large scale the universe seems easier to observe and even comprehend while on the smaller scales the random fluctuations throw us for a loop. Kinda like things here on Earth are relatively simple until you get down to the quantum level then we're thrown for a loop. Funny how that happens.
It's not just the KDB void that calls into question the homogeneity implied by Cosmological Principle. There are also the discoveries of several massive structures (accumulations of matter), most recently including the ‘Giant Arc’ (spanning a whopping 3.3 billion light-years) and the ‘Big Ring’ (1.3 billion light-years in diameter).
Can't forget the Hercules-Corona Borealis Great Wall, which spans nearly 10 billion lightyears across. Its existence has actually been a point of contention, since unlike the Big Ring, Giant Arc, etc. which are close enough to the theoretical limit to be rectified with the Copernican Principle, the Hercules-Corona Borealis Great Wall at _minimum_ would require the theoretical limit to be adjusted and everything that relies on that limit to be recalculated.
I was wondering why she didn't touch on these super galactic structures in the video. Regardless, I understand that these are such rare exceptions and, as such, perhaps considered random/chance anomalies, insufficient to override the Copernican Principle.
@@bgsmember3650 Yes, but another one of the 'anomalies' is the Hercules-Corona Borealis Great Wall - the largest known apparent structure in the observable universe, spanning an estimated *10 billion light-years*. The Copernican Principle can only swallow so much without having to be radically re-thought.
@@bgsmember3650
They don't individually override it, but the frequency of their occurrence and the shear scale of the margin between theoretical maximum and the largest of these structures points to the possibility that at minimum we may need to redo the math on that theoretical maximum.
Ancient Indian astronomers had a complex understanding of the cosmos, with some evidence suggesting they recognized the Sun as central to the solar system.
## Early Concepts of Heliocentrism
The notion of a heliocentric universe, where the Sun is at the center, can be traced back to the Indian philosopher **Yajnavalkya**, who lived around the 9th century BCE. He expressed ideas that hinted at heliocentrism in his writings, notably in the *Shatapatha Brahmana*, where he described the Sun as stringing together various celestial bodies, implying a central position in relation to Earth and other planets[2][3]. This perspective, however, was not widely accepted among ancient Indian astronomers, who predominantly adhered to a geocentric model until much later.
## Aryabhata's Contributions
In the 5th century CE, **Aryabhata** made significant advancements in astronomy that further reflected an understanding of celestial mechanics. He developed methods for calculating the distance to the Sun based on observations of the Moon's motion and angular size[1]. Aryabhata's work suggested a sophisticated grasp of planetary movements and distances, indicating an advanced level of astronomical knowledge. His calculations were notably close to modern estimates, showcasing his scientific ingenuity[1].
## Influence and Legacy
Despite these early insights, the majority of ancient Indian astronomers continued to support a geocentric view until the influence of later astronomical developments. The recognition that stars are similar to the Sun and that there are multiple suns in different directions reflects an evolving understanding of celestial phenomena[4][5]. The legacy of these early astronomers influenced subsequent generations and contributed to global astronomical knowledge.
In summary, while ancient Indian astronomers like Yajnavalkya and Aryabhata hinted at heliocentric concepts and made impressive calculations regarding celestial distances, a widespread acceptance of a Sun-centered solar system did not materialize until much later in history.
Citations:
[1] www.schooltube.com/ancient-indian-astronomy-calculating-the-distance-to-the-sun/
[2] www.astronomytrek.com/who-discovered-the-earth-moves-around-the-sun/
[3] www.indiancentury.com/astronomy.htm
[4] www.spacetoday.org/India/IndianAstronomy.html
[5] en.wikipedia.org/wiki/Indian_astronomy
[6] exoplanetscience.org/early-indian-astronomers-views-on-our-solar-system
[7] mathemajik.tripod.com/article/astronomy.html
[8] www.scifireads.com/single-post/2020/01/25/ancient-civilization-knew-far-more-about-our-solar-system-than-they-should-have
[9] www.infinityfoundation.com/mandala/t_es/t_es_shah_m_astronomy.htm
In 2017, I visited the Cathedral of Kraków, where Kopernik (Copernicus) did his work as canon.
I thought the church fired him out of a cannon, for suggesting the earth's motion through space.
@@oortcloud8078 sounds like a church thing to do.
@@oortcloud8078 well that's po(o)p shi-ence for you, there was no hostility towards his works in the beginning, it was only one century later when Galileo went meddling in politics by attaching the papacy that he ended up in house arrest (no execution btw)
anyone watching Orb: On the Movements of the Earth on netflix?
@@alveolate Does it include the movements and whereabouts of Kopernik (Copernicus) after he was fired out of the cannon, that would be interesting to watch.
Question for Dr Becky: If everything in the universe is moving away from us at the Hubble Constant velocity, no mater which direction we look, doesn't that imply that we are at the center and everything is expanding away from us?
It does not, and an easy demonstration can show why. Get a sheet of paper, a marker, a ruler, and a pice of plastic. Make a grid of dots on the paper spaced 1cm apart. Then, make grid of dots on thd plastic but 2cm apart.
Pick one dot on each to represent Earth, and place the plastic sheet's Earth on the paper's Earth. You will see a simplified diagram of this Hubble expansion. It does, indeed, look like Earth is at the center!
However, now pick another dot on each to represent some alien planet, and lay the plastic so its alien planet lines up with the paper's alien planet. And you will see that the alien planet ALSO looks like the center of the universe!
But the reality is - the plastic sheet represents a point in time after the paper time, and the space between ALL the dots expanded at a constant amount -- 1cm vs 2cm.
In short, all systems spread out larger than a local cluster are all moving away from each other as the space between them increases.
1:52 Siri activating with the word "theory" 🙂
Thiri ith tho obtholete thethe dayth
Thank you. I've wondered about this for years. Having it explained like this means a lot..
I’m surprised you didn’t mention the Axis of Evil, especially since you’ve done a video on it and mention the CMB. I don’t have an opinion either way on it but it seems odd to leave out.
I kept thinking about this throughout the third part!
The Axis of Evil is the interpretation of the CMB that the Earth is in the center of the anisotropic universe.
The Axis of Evil shows that our solar system either creats the CMB of influences it strongly. Which makes sense because everything else is very, very far away (LY instead of LM)l
Same here. I was really surprised she didn't say a word about it here, considering she's done a whole video on the subject.
Our consciousness perceives the world and the universe in a dualistic way, and therefore I would call "dark energy" and "dark matter" the "nothing," and the visible physical universe would be the "something." Only that which is conscious can measure, weigh, and calculate the physical universe. Nothingness is beyond what we can measure, weigh, or calculate. Intelligent personal consciousness is projected beyond the "event horizon" projected by every atom that makes us up.
The universe could be infinite, with us currently trapped in a tiny bubble that is relatively homogeneous.
If we invented FTL and traveled past the cosmic horizon - assuming it is habitable and doesn't have different physics - then we might find ourselves completely overwhelmed by how freakishly isolated we were and how abnormal our circumstances.
Our circumstances are abnormal even without that.. Typical environment of our observable universe is intergalactic void. :)
As I recall, there were those among the ancients who called the geocentric model into question, but of course, there was not the technology to prove or disprove any model of cosmology at that time. Ptolemy discussed this matter in his Almagest, but ended by saying he and his model were mainly trying to "save the appearances", i.e. provide a mathematical model to accurately and precisely describe and predict the perceived motions of the "planets" (bodies that wandered against the background of the "sphere of the fixed stars").
So, I don't think it is quite accurate to say that Copernicus was the first to demote the Earth from the center. It wasn't even fully accepted in his time, as Tycho Brahe's compromise model had some traction for a while. It was only when Kepler, who inherited access to Tycho's records of data that were unrivalled in precision, realized that the perfection of Ptolemy's circles and epicycles (circles moving along on other circles) was not only cumbersome but also unable to match the precision and accuracy of their sister conic sections (ellipses) in describing the motion of the planets, that the Copernican model was able to stick. Especially as it harmonized with Newtons work on gravitation and provided an understanding of the physical cause of the phenomena. In Aristotle's terms, it seems to me, Ptolemy's model(s) provided only a formal cause for the appearances (circular motion); Kepler and Newton provided not only a formal cause (elliptical motion, or in the case of Oumuamua, hyperbolic motion) but a material cause (gravity acting on mass).
"We can't move the earth, we are stuck in one place"
We just haven't made a big enough rocket yet
Time to start working on stellar engines
ruclips.net/video/v3y8AIEX_dU/видео.html
We moving all over the place!
Thanks for this video exposing a simple, straight forward, delightful but fundamental principle
Dear Dr Becky, I do believe your eyes are getting bluer and bluer by the day. Are you accelerating towards me, or is our universe expanding? You know Carl Sagan wrote a great book on this exact question called, *Pale Blue Dot* - _A vision of the human future in space._ He must of had your eyes in mind when he wrote that book. Thank you Carl. 😊
Okay. Question: Do these astrophysicists consider that when they look at a all the other galaxies, they are looking back in time, so they would be a lot closer to each other then? So when we look at our nearby cluster we're going to be looking less far back and therefore things will be more spread apart? I just question all the time if they are thinking 4th dimensionally when they look at all the "evidence" out there. Sometime it's obvious, but other times, not so much.
I think some day we'll find that there's something slightly unusual about our region of space that affects some readings or another, like how our ancestors found that nature only seems to abhor a vacuum because we're in a relatively high-pressure zone on Earth.
I mean, the video basically says exactly that: we're in a supervoid, it affects our measurements and we have to account for that. Copernicum principle is not a universal law, just a wishy washy guideline like Occam's razor. Whether it holds or not depends on the scale at which you're looking at the universe.
I did my degree in mathematics, and it has always warmed by heart that the Copernican Principle is essentially a _topological_ argument!
“There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.” So Albert Einstein said, anyone in my opinion who understands just a glimpse of the workings of this Universe, the Earth and life has to choose the latter, so yeah I reckon Earth is very special! 😉👍
What about the Axis of Evil?
Exactly
It shows the CMB is either created by or strongly influenced by our solar system. The confusion comes from Big Bangers appropriating it to "prove" their theory, ignoring the obvious.
Tycho Brahe likes this 👍
Catholic Church has blocked you 🚫
Been watching since she started her channel and I am still enjoying her show.
Who's "She" ? The cat's mother? 😊
Yeah, I think "She," is called pipping? 🐈
Would it be presumptuous to suggest, that there is one great demotion that Nicolaus, Carl and Becky may have overlooked, considering they are the real "professionals" here.
*The Earth isn't even at the centre of our own Earth-Moon system.* And in fact the Earth and Moon both revolve around a *barycentre,* which is a point inside the Earth that allows the system to remain balanced. The gravitational and inertial forces of both bodies in orbital motion around this point are equal and opposite at there respective centres of mass.
It is the dancing motion around this point, also known as the common centre of mass, that leads to the twice daily tidal cycle on our beautiful *Pale Blue Dot,* as it floats like a mote of dust, suspended in sunbeam. Thank you Carl. You were a one in a billions "pro," who stated that the absence of evidence is not the evidence of absence. 😌
I’ve never really understood the definitions/distinctions between Isotropic & Homogeneous.
I don’t see how the universe could be “equally distributed in the universe” but not “look the same in all directions” (I.e. how are isotopic and homogenous different from each other)
Don’t know if I’m just being dumb
The Copernican principle already doesn't hold at the scale of solar systems, or else we would expect the Sun to be a red dwarf. It wouldn't hold on a galactic level if you put credence to galactic habitable zones. I wouldn't be surprised if there were even higher order structures in the universe that are needed to support life to the point where our cosmological place in the universe is actually special.
The Copernican principle and the Anthropic principle will forever be at odds...
I always thought that Copernicus only proved that Earth circles arround the Sun, yet he still followed Catholic Church doctrine that states that Earth is center of universe. It was Galileo Galilei who proved otherwise by comparing night sky during seasons when he noticed stars drifting (which we now know that were planets) and that theory was why Catholic Church prosecuted him.
The most compelling and disturbing evidence against the Copernican principle, as far as I can tell, is that when we look out into the cosmos, so far we haven't seen anybody else out there. There is SOMETHING going on here on Earth that, as far as we can tell, happens nowhere else. We assume there must be life out there, but we've never seen a trace of evidence for it. And that means there is something unbelievably special about this planet and this solar system right here.
Possibly. Except if you look at both sides and ask "If that star had a planet with a civilization exactly like ours would we be able to see them? Would they be able to see us?" And the answer is No and No. So far we haven't seen anybody that is screaming on the radio or that has obviously altered parts of their star system - physically or biologically.
Copernicus himself disagreed with what the Copernican principle represents. Copernican positioned the Earth's system at the center of the universe.
@@bruceleenstra6181 The Fermi paradox. We should not have to look for them, they should be here.
Since many of the Sun-like stars are billions of years older than the Sun, the Earth should have already been visited by extraterrestrial civilizations, or at least their probes. However, there is no convincing evidence that this has happened.
@@johnbox271 Check out Robin Hanson's "Grabby Aliens" idea which builds upon this. PBS Spacetime did a great episode on it.
@@kyjo72682 Doesn't this require humans to be early and thus exceptional?
Even a region Earth is in/nearby is special, such as Venus, the Milky Way, Andromeda, etc. it doesn't mean Earth specifically is special.
Just playing devils advocate here but with the thousands of exoplanets we have identified, and not a single one (yet) capable of supporting human life, maybe the Earth, while not being the center of the universe, is special?
In any case, Earth is the planet we live on, and that fact makes it pretty special to us, regardless of its ultimate cosmic status.
So many conditions had to be right for many millions of years, for life to sprout on Earth and finally blossom to full human intelligence. If that's not Divine, then Earth has to be a very special little blue planet ❤
We need to consider that current methods of detecting exoplanets come with a sampling bias where the easiest planets to observe are the ones that we tend to detect, such as super Jupiters (very large gas giants) that orbit very close to their stars, or rocky planets around red dwarfs (which are extremely volatile in terms of emitting intense radiation). This makes it so that a lot of the exoplanets we know of are inherently going to be hostile to human life, unfortunately :(
@@Mariia_ava Why even search for it? Life must be very scarce in the observable Universe. Distances are too large. We're on the outskirts of our galaxy. Our galaxy itself is in a big Void. If there's another life form that's advanced enough to traverse millions of light years through space, maybe they'll find this grain of sand, Earth, in the desert of the Universe..
@@samgrieg Asking why we search for extraterrestrial life is like asking why we study astronomy at all. It’s intellectually rewarding more so than anything. I agree that it seems futile to search for life given that our chances of finding it are so small, and that all the efforts made up to now have been fruitless. There are many reasons why this could be, for example the Dark Forest theory. However, the likelihood of finding anything at all is automatically zero if we don’t search in the first place.
Science with Dr Becky is amazing
The best evidence of us being in a special place in the universe is that we exist and have zero evidence to support the existence of similar life in the universe.
We have zero evidence because we do not have the technology to obtain such evidence. Until we can travel to every part of the universe and look for such evidence one cannot say with any confidence or conviction that life exists only here making us special. Only hubris, vanity and arrogance can make the claim we are unique, alone and special.
Nahh, you just can't get your head around "astromomically big" or "virtually infinite"
People keep showing the CMB without discussing the extent of the variation. Finally someone (you) mentioned that it is 1/1000
It's one in one hundred thousand overall.
I’m surprised more people don’t know about this book. The Censored Guide to Wealth on Bovolorus is unreal.
Go away. 🙄
Obvious spam is obvious
How do we explain the Axis of Evil? Seems really strange
Exactly
It shows that he CMB is either created by, or strongly influenced by the solar system, which makes sense because everything else is very, very far away (LY instead of LM). Of course this is impossible to reconcile with cosmologists' belief that the CMB is a relic of the Big Bang, so they ignore it.
The Axis of Evil shows that the CMB is either created by, or strongly influenced by our solar system. Which makes sense because everything else is very, very far away (LY not LM). Big Bangers appropriated it to "prove" their theory.
12:36 Is it valid to use data that was collected _and interpreted_ based on one interpretation, to test that same interpretation of the universe?
Feels a bit weird (though you don't really have an alternative, I guess ^^)
Circular reasoning is always wrong. E.g., LCDM is based on matching data without a physical explanation (what exactly is DM?), so arguing that it is confirmed by matching some data is circular.
Hi Dr. Becky, I'd love to know more about how you used your bullet journal to organize your thesis and write it in 2 months, please. 😊
Hubble: "All galaxies are moving apart from each other."
Andromeda: "Hold my beer."
Gravitationally bound galaxy clusters do *not* preclude expansion. The visualisations of what's become known as 'the cosmic web' are captivating and eerily reminiscent of the structure of a brain. Coincidence? Not a clue!
Awesome, thank you. Now I get the reasons for these assumptions. ) this is probably one of the best fundamental primers I have heard about cosmology)
Sorry for being a bit thick, but space is expanding, the distance between the galaxies, get that. But how come the distances inside the galaxies are not expanding as well?
I am I being really thick?
Thank you
Eamon
It is my understanding that at that scale gravity is still stronger than the rate of expansion.
My favourite pub quiz question is 'Where is the centre of the observable universe?'
Can you explain why prevailing understanding indicates the universe is expanding? If more distant galaxies are moving away faster than closer ones, why doesn’t that indicate that the universe was expanding faster in earlier eons and is not expanding as fast in more recent times?
You know I had to stop and think about that for a second, as it's a bit of a mind bending question. However, it's to do with the fact that when we look at distant galaxies, we're looking further back in time. We should expect the distant galaxies to be moving away faster, if the expansion rate is slowing, but we see the opposite. I hope that makes sense? But, I'll try and think of a better way to explain it later, if you're still interested. 😅
The FLRW solution which describes expanding Universe predicts not only that expansion is slowing, but also HOW MUCH it is slowing down with time. Exactly as you described.
But the observations show that although expansion does slow down (the farther away galaxies are floying away faster than linear), but it is slowing down not as much as FLRW says it should. There is a discrepancy - the slowdown is too weak.
Yeah, thanks for clarifying that, I think that explains it better. And this discrepancy - which implies that there must be something driving that increased expansion - is where the idea of dark energy arises, which could be some form of the cosmological constant, that Einstein abandoned earlier.
Science doesn't prove things; it collects evidence that supports things (or not). See the Raven paradox. It seems reasonable to me that we could be in a place that makes our observations inaccurate somehow: some fog or tilt to spacetime that we aren't aware of. Great video as usual. The way Dr B lays out her main points, and her choice of them, always makes the subject clear and memorable. She's got a knack. Probably got it from a professor she had.
Agree in particular with your first statement. The choice of language in this video is unfortunate. The word proof belongs in the realms of maths and logic, not the realm of science.
Scientists make reproducible experimental measurements, then attempt to devise theories that explain those measurements and make predictions that can be tested by further experiments. A theory that conflicts with experimental evidence has to be revised or abandoned. The most we can say about any theory is that so far it is consistent with experiment. This does not prove that the theory is correct. Science does not involve proving anything.
Hypothetically you could have two theories, one based on the Copernican principle and one not. If both theories were consistent with all the measurements we have so far made, then we would not be able to choose between them on experimental grounds. However if either theory made unnecessary assumptions or unsupported claims, it would likely face criticism for that reason.
If we are nothing special, then the universe is bursting with life. It’s over flowing from the abundance of life. Life is everywhere if we are not special.
Bursting, overflowing and abundance have special meanings when density is as sparse as the universe.
It may well be for all we can tell currently, time may tell. Or not, that's the fun part!
The whole conversation is meaningless without a concrete definition of the concept ”Special". Is that solitary uniqueness respecting the void, or do other galaxies have the same uniqueness? And how are other galaxies unique or special than ours?
We are certainly deviating from scientific to philosophical, until we can come up with a concrete factual definition of "special".
What I love about astrophysics and palaeontology is that they have epistemology written all over them.
IMHO, Copernicus gets *way* too much credit. His heliocentric model had the virtue of using fewer epicycles than the Ptolemaic geocentric model. (Epicycles were additional circles on the orbits to explain retrograde motion. Still positing that the heavens must be perfect and therefore circular, Copernicus changed only the complexity of the orbits.)
It was Kepler (using Brahe's meticulous observations) who posited elliptical orbits which, with a heliocentric model, fully explained retrograde motion and drastically simplified the orbital dynamics. To me, Kepler had the larger impact because he eliminated the Platonic and Christian ideals of perfection from the science.
Who are the hero’s of today people that think outside of are basic understanding, what will be the next great invention like electricity useing gas for combustion ,what great innovations are being developed for us to nowadays
The heroes of our time are reviled by the establishment, for the same reason Galileo was -- nobody wants their applecart upset. Read "Observations of Large-Scale Structures Disprove the Big Bang Hypothesis But Confirm Plasma Theory", a 2022 paper by Eric Lerner.
You have to be ambitious to cover this complex topic, and your explanation is worthy of a Carl Sagan episode of Cosmos. Thank you.
But what about all those massive structures in the universe that some scientists claim to violate Cosmological principle?
I am loving the history videos. More, please!
If the universe is a kind of illusion or the creation of all of our consciousness, then indeed, we are at the center of the universe.
Dear Dr. Becky: have you ever done a video on whether the Milky Way is a barred spiral, and how they evolve differently from unbarred galaxies, and what effect that has on supermassive black holes at the centers of galaxies?
Stuck in one place is wrong Dr Becky 🥰
one way of handling this is what is the most amount of "special" compatible with our observations, and how would that effect the expectations of our measurements. if there is no significant difference between uniformity and slight specialisation then for the purpose of the model the universe is "uniform"
Cheers from the Pacific West Coast of Canada.
Really enjoy your content Dr. Becky! Keep it up. Subbed. 🥰
So that wherever we look into the universe we are always seeing a younger universe, as we ourselves, live at the very knife edge of evolving space and time. This, of course applies to all other locations regardless, and gives much to think about. They may exist at the other side of the universe, but look back at us in the same way . .
I also get my words muddled up sometimes... or "murds wuddled" up.
The other day I said to myself something like "third-o-my-nanics" instead of thermodynamics.. when I was talking to myself about something from a RUclips video or TV programme!
It's harder to get long words right when talking quickly.
Actually, Herschel's star map did put the sun at the center of the galaxy, because he did not know about the dust obscuring his view of distant stars and that he was mapping a small, by galactic standards, region of space centered around the Sun. It was Harlow Shapley's later mapping of globular clusters that showed that the Milky Way is much bigger than that, and that the Sun is indeed located closer to its edge than its center.
Actually, the book: 'The Philosophy of Space and Time' by Hans Reichenbach (1958 translation) explains it very well (and in depth) that both views are equivalent - It's just that the one we use is so much easier to explain with much fewer forces needed to be defined - But does not make it anymore 'true' than another view and associated definitions - Read it many years ago, but a very eye-opening experience indeed.
There are several concepts employed in science I treat not as absolutes, but rather the best aproach we have until/unless proven invalid.
The term "Copernicus Principle" should be called the "Harrison Principle", as it was coined by the American cosmologist and astrophysicist, Edward Harrison in the 1970s. He used it to describe the idea that Earth does not hold a unique or central position in the cosmos, which was not the specific intent of the heliocentric model first proposed by Copernicus.
I love these big existential-crisis questions (nice segue, btw)... but then, my degree was in cognitive science and I never made it to graduate school, and I've always been a big fan of Lovecraftian theology, so ideas that terrify most people tend to reassure me. LOL
The anthropic principle comes into play here too. Maybe our local region of space is only exceptional (rocky planet in habitable zone with relatively large single satellite in the outer reaches of a relatively isolated galaxy) because such regions are the only ones capable of hosting complex life that survives long enough to reach this level of development.
Helpful context reminder in these crazy times
One thought I add here is that to observe light in all the EM spectrum, extending as far as the cosmic horizon, there is a likelihood of it only being possible within a Standing Wave... all the phases of matter and its general distribution into bodies are reducible to the frames of harmonic equilibria. I am of the opinion that whatever missing mass there might be, it has probably passed the Cosmic Horizon, and we, standing on the coat-tails of a CMB, experience this missing mass as negative presuure (the Hubble shift).
B, b... bb... but.... Your 3D data visualisation of the positions of the galaxies in the Universe (8:06) where you say "on average, it all kinda' looks the same"... but. but but... it doesn't look the same. It looks like there are stripes in it. The middle looks much more dense than the right side (for example). Will you please explain what you mean by saying that?
This was exactly the question I came here to ask! There is clearly a prominent band of concentrated objects in the center, I am curious too why we say this is basically all the same?
@NondescriptMammal it's theoretically all the same however we need to observe much more of the universe to prove this.
Currently what we have observed is 'an arm of the universe'
From observations we have seen matter at our place in time clump together which in a 3D space will make a Web of some sort of shape
It may be irregular and the shape might not be much of significance however
@CeriAnnwen Yeah it just seems like a bold assumption to depend upon as a premise used as a basis for further theorizing, treating it as if it is an established scientific fact
But I suppose astrophysics and cosmology especially, have no choice but to make assumptions, considering the only direct empirical data set they have to work with, is almost entirely limited to collection of electromagnetic radiation
@NondescriptMammal reality doesn't form from mathematics. Instead, it is a tool to understand and predict reality with precision.
The same way a word can describe something and/or anything
Our current understanding of mathematics seems to indicate the universe should do things we are yet to observe
We also observe things we have yet to calculate into something meaningful
Dark energy could be a new, weak force that expands space time. How it physically interacts with the universe is unknown and that is why scientists are yet to claim a discovery
@CeriAnnwen well yeah, the cosmologists say dark energy makes up 2/3 of the universe, but we don't even know what it is. And dark matter makes up most of the rest, and we don't know what that is either. All the astrophysics and telescopes can only tell us what 5 percent of the universe is made of.
"To know the mighty works of God, to comprehend His wisdom and majesty and power; to appreciate, in degree, the wonderful workings of His laws, surely all this must be a pleasing and acceptable mode of worship to the Most High, to whom ignorance cannot be more grateful than knowledge."
--Copernicus
Would being in avoid make life more likely due to less radation?
6:40 Dr. Becky one thing is true we haven't found life on a planet other than Earth yet.
I haven’t wrapped my mind around “a speed proportional to how far away they are“. Obviously I’ve heard it before, but I’ve always glossed over it.
Edwin Hubble proposed that the expansion of the universe was happening on the periphery of the universe and he placed the earth at the center of the universe. In other words, in the center of the universe, there is little or no expansion.
It's simple in essence: the further away a galaxy (or whatever) is, the faster it is moving away from us. The tricky bit is measuring the distance accurately
@timbergel8147 the only problem is, we are moving faster away from them. Which is illogical.
We are not the center of the universe. There was no BB. An infinite universe cannot expand. Redshift/tired light is due to force decreasing with distance.
Gravity was disproven by Galileo.
Newton's LoM defines gravity as Reactionary force. The resistance of the mass to being accelerated by an external force.
Relativity is mathematical nonsense. Louis Essen, the inventor of the Atomic Clock, was highly critical of Einstein and his relativity nonsense. Not one experiment has validated it. Hafele-Keating"s synchronized clock experiments actually disproved it.
Becky is either gaslighting you or she is ignorant of basic physics.
There is no proof for relativity because motion is absolute.
E=mc. Nothing can go faster than light. Light is tge preferred RF making the entire scientific community scam artists or ignorant laymen masquerading as an authority.
@@timbergel8147 But why? Why would objects more distant move away faster than closer objects?
@@mrfranksan it's taken to be because the universe is expanding. Think of a partly inflated balloon with three spots on it, one spot is us while the other two are galaxies at different distances from us. Now if you inflate the balloon a bit more, it expands, so both of the other galaxies will end up further from us. But the one that was further away to start off with will have moved away from us a greater distance than the nearer one, because of the balloon expanding evenly. So we see a greater speed difference between us and the galaxy that is further away. And if you imagine yet another spot that started off very close to us, it is (I hope) clear that it would hardly have moved at all and we would see it as having very little speed. I hope that helps to make it clearer - it's hard to describe. Another nice thing about the effect of this expansion is that it means that we would see the same thing wherever we were in the universe (anywhere on the balloon's surface) so it doesn't mean that we are at the centre of an expansion or anything.
How do you even define a "special place" in the universe? Not sure you defined it.
When a Dr Becky video drops, I welcome another chance to escape from the world and go into space for a while.🤩
5:26 No, Herschel's map shows the Solar System still in the centre (sort of). Rather, it was Shapley's work on the globular cluster system of the Milky Way which put the Earth well away from the centre, reinforced by the study of stellar motions by Oort and Lindblad, and Trumpler's discovery of absorption (well, scattering) by interstellar dust.
Since we’re talking about matter, I lean towards the idea of building a home from clay. You would be able to visit both the pit and the structure but that would require a larger underlying thing which is not out of the question.
4:09 "We cannot move the Earth around, sadly"
* Isaac Arthur has entered the chat *
Very approachable and well-structured video. :-)
First of all we have to define "special". Does it refer to location, or to particular values? If the latter, the Earth definitely is special, because it has the only known intelligent species in the universe.
That Copernican principle and Cosmological principle look to me to be essentially particular instances of what philosopher David Hume called the "principle of the uniformity of nature". In it's raw formulation this says simply that unobserved cases will be like the observed cases, which, since all observed cases are observed here, entails that we are not in a special place. In scientific terms this comes out in such assumptions as that the laws of nature we detect here are the same elsewhere. Hume showed fairly convincingly that, not only can we not prove it, and so it is uncertain, but that we cannot have any empirical reason to believe it without presupposing it - making the appeal to empirical evidence circular. In the case of the evidence for dark energy and (thus) non-violation of the Copernican principle, I would wager that such evidence rests on the unproven (and unprovable) assumption that the same laws of nature (e.g., general relativity) and the same constants (e.g. the Cosmological constant) applies everywhere, including out to the furthest reaches of the universe.
Yes, but LCDM is also based on a specific assumption: that redshift equals velocity and distance. Unfortunately for that theory, the assumption is disproved by actual photos (shown in Halton Arp's books) showing luminous connections between low-redshift galaxies and nearby high-redshift quasars, proving they are the same distance from us, despite vast differences in redshift. Cosmologists married to LCDM simply ignore this evidence.