Cosmic Inflation: The Solution to the Big Bang Theory and the Universe
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- Опубликовано: 1 июн 2024
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Follow up video on Eternal Inflation:
• Eternal Inflation: The...
References:
Gary Felder's Wondrium lectures on Big Bang: t.ly/emdPY
Alan Guth paper summary and lecture: t.ly/WqKQ
Alan Guth paper: t.ly/wF3x
Paul Steinhardt list of articles on Inflationary cosmology: t.ly/ZqmH
Excellent article on Inflation: t.ly/rrZU
Chapters:
0:00 - Popular models of Big Bang are incorrect
2:27 - Observations not explained by original Big Bang model
4:37 - Common misunderstandings of Big Bang
7:12 - How Inflation "fixes" the Big Bang
11:56 - What caused cosmic Inflation?
15:23 - Next video: Eternal Inflation!
Summary:
The Big Bang theory: In the beginning, the universe was packed tightly together into a point of infinite density. It then exploded into the universe we see today. This is actually INCORRECT.
There was no explosion. There was no substance like stars, galaxies, or even atoms that went flying. The universe did not have zero size or infinite density. It is just a moment in time when the universe was very hot and very dense.
And contrary to popular belief, the big bang model is not a theory of how the universe began. We don't know how it began.
The early model of the BB failed to explain some later observations about the universe - its homogeneity, its flatness, and no magnetic monopoles. The theory of cosmic inflation proposed by Alan Guth and others, solved these puzzles.
What is this theory of Inflation? How does it fix the big bang? What caused Inflation to happen?
Cosmic Inflation is a sudden expansion, faster than the speed of light, whcih happend from about 10^-36 seconds after the beginning to 10^-32 seconds. It expanded a factor of at least 10^78x
How could inflation occur faster than speed of light? Einstein’s theory of special relativity shows that speed limit applies only to things moving within space, not the expansion of space itself.
Some descriptions of inflation say the universe started out smaller than an atom, then expanded to the size of a grapefruit. This is misleading because it implies that the universe has an edge. It doesn’t.
Other common misunderstandings about the Big Bang: The universe did not come from a point of infinite density and heat. This is purely due to mathematical extrapolation. A singularity is probably not a physical thing.
Universe is expanding, but galaxies aren’t actually moving at that expansion rate, only the space between galaxies is becoming larger, and only on very large scales. But on smaller scales gravity still holds stars together within a galaxy, and certain galaxies are still attracted to each other.
There is no center of the universe or location. Every point moved away from every other point.
The universe is extremely homogenous and isotropic which means that it appears roughly the same anywhere. This can be seen in the cosmic microwave background, or CMB, where the tiny differences you see on its image represent temperature fluctuations of only 0.0001 Kelvin.
How did the universe smooth out? Imagine it like the surface of deflated balloon. There may be tiny imperfections like wrinkles randomly distributed on it. If the balloon is suddenly inflated to a very large size, the wrinkles get smoothed out.
How does inflation explain the flatness issue? If you were the size of an ant on a small balloon, and the balloon expanded to the size of the Earth, it would appear flat to you, even though it is still a sphere, that it's flat. Note "curvature" means an overall curvature of the universe in FOUR dimensions. This is usually shown as 2D surface on a 3D object like a balloon.
How does inflation solve the fact that we observe no magnetic monopoles?
Monopoles can only theoretically form at very high temperatures, that were only present during the big bang. But once they formed they would be stable enough to survive. Since Inflation would have quickly cooled the universe, no new monopoles would be created after inflation. These would have been distributed so broadly that there would be hardly any left in any given part of space.
The universe is not completely smooth. CMB shows that there were small temperature differences. This anisotropy explains the large scale structures of the universe.
How did inflation start? What was responsible for inflation?
This is not well understood. It is thought that there may have been a scalar inflation field during the time of the big bang, called the inflation field.
#cosmicinflation
#bigbang
This field would have been in a false vacuum at very high temperatures, but moved to its true vacuum at lower temperatures, with the help of quantum tunneling. When the field reached the lowest minimum energy density in the potential, Inflation came to a stop. This is a very short process. 
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I've said it many times but. Your explanations are absolutely remarkable, in that you can explain so many complicated ideas so straight forward and accessible. I have no idea how you can do it.
Bravo, on another fascinating video.
You seem to have understood everything in the video, kindly explain what infinite density is, and what would be making it infinite, is it the mass or volume? If its the mass, what would contain an infinite mass, and if its the volume, how can that be when the big bang is theorized to have originated from a point smaller than an atom?? Science is great, but I am getting the feeling more and more that people just aren't questioning things and are just swallowing whatever science presents, some of which is in my opinion ridiculous. How can density be infinite if you logically think about it? Even though I am not a physicist, I am willing to bet my life that there's no way something like mass can be infinite, it wouldn't make any logical sense.
Why do I found your videos addicting? Like, I can’t stop watching them… Ur my favorite educator so far.
i love your videos so so much, thank you for putting so much work in to them💗
This channel always has the best physics explanations on RUclips!
Guth is the opposite of arrogant. He never brags or even gets heated in discussions. I really like his attitude and yours too sir
Good timing. I literally just finished reading chapter 4 in the book "Origins" by Tyson that goes over this very subject. Seeing it after reading it makes it easier to understand. Always love your videos!
thank you for addressing those many misconceptions. the story is now much more clearer for me.
Thanks, Arvin, for another great video! My mind was still struggling with the X10^78 growth during Inflation when you said "unimaginably bigger"... I wonder what would be "unimaginable" to a person like you or Dr Guth :)
I've heard this explained by many others, but this is one of the better presentations.
Thanks, that is super interesting. This has to be one of my favourite channels, please keep up the outstanding videos.
Impatiently waiting for the next part!
Excellent lecture! Thank you, Mr. Ash.
Great verbal & visual explanations 👍🏻
Simply amazing videos that makes us all more and more interested in physics
Absolutely fantastic video as always sir. Can't wait for your video on eternal inflation - this topic absolutely fascinates me!
Even though I know this stuff backwards and forwards I have never heard it explained so well! You've earned my subscritption!
Thank you for this video!! The conceptualization of the Big Bang finally clicked for me.
Such a great explanation!
Arvin you make the best videos!
Wow! Great video. Thank you.
absolutely brilliant. Keep it going.
I watched videos from other sources (and read articles). Arvin's contribution clarifies a few concepts. I find inflation theory makes sense now. The timeline presented gives me a feel (sort of) for such tiny durations, like 10^-32 second. At the level of the Planck units, this is a huge duration. A lot can and did happen. That the universe expands from every single spot in the universe, and in all directions, can only be possible with a fourth dimension feeding space with energy (dark energy?). It's not the time dimension.
As always a great presentation. In combination with your other videos, I think of the incredible odds it took to make our universe just right and for us to be inhabitants of this universe. Your next video will answer (or at least explain) my question about fine tuning, so I will ask this. What is the purpose of the Universe? Thanks again and welcome back. It feels like aeons since you last posted.
I made a video about cosmic purpose: ruclips.net/video/SJ6943_Qtyg/видео.html - Do I think there is one? Let me sum it up in one phrase - "Shining piece of dust" -- the video above explains what that means.
@@ArvinAsh Thanks Arvin! I should've known! I'll check it now!🧠
It seems like incredible odds but if it's a deterministic universe the chance of us chatting about it was 100%.
@@charliemeyer6475 May be a non-zero chance of happening which means it will happen over time. At least once. However; there is an equal chance of it happening only once.
Was Copernicus wrong? Are we special?
A@@charliemeyer6475 And so for you to be born among millions of spermatozoos.
Given that recent observations have largely falsified the cosmological principal assumption of the existence of any scale where the universe is isotropic and homogeneous up to 4.9 sigma (meaning there is only a 1 in 2 million statistical odds of the observations being a statistical fluke arising by chance within a universe where the cosmological principal largely applies) I have personally become extremely skeptical of the so called inflationary model.
What has been conveniently forgotten with the standard narrative for modern cosmology is that we have *never* had proof that the dipole observed in the CMB is "kinematic" that was merely assumed for convenience in the absence of any data. However there was an experimental test proposed in the 1980's which could test this assumption either verifying or falsifying the kinematic dipole assumption. The catch is that the test requires millions of cosmologically distant sources all across the whole sky which can be used to construct a dipole to compare to the CMB dipole in magnitude and direction data which hasn't existed. As such the field of cosmology largely went on assuming their assumption since then as an initial premise despite warnings of other cosmologists and mathematicians
Last year this test was finally performed by Nathan J. Secrest et al. using 1.36 million quasars measured over the various initial and extended missions of WISE that are cataloged into the meta catalogue catWISE.
The Dipole differs in 8 degrees of direction with over twice the magnitude of the CMB dipole which is at 4.9 sigma disagreement with the kinematic dipole assumption which requires that both dipoles be the same in both magnitude and direction. Citation: Nathan J. Secrest et al 2021 ApJL 908 L51
This is significant enough to rule out the pure kinematic dipole assumption, i.e. the cosmological components of the CMB dipole arising from inhomogeneities and anisotropies encoded in the CMB epoch must be nonzero.
Remember the observed dipole in the CMB is in general a combination of the kinematic component of the dipole but also two cosmological components that respectively represent both the initial inhomogeneities and anisotropies at the time of recombination when the CMB was emitted and all the distortions from intervening inhomogeneities in density.
The standard cosmological model is built on the *assumption* that all of these components are zero except the kinematic term. This has now been experimentally *falsified* showing that at least one of these other components must be significantly nonzero.
*The existence of a nonzero cosmological component to the CMB dipole automatically is sufficient to falsify the existence of the cosmological principal within the observable universe.*
This in turn is sufficient to falsify one of the main lines of "evidence for inflation namely the supposed "smoothness" of the early universe, hence inflation is now on far more shaky ground as the reason it appears smooth turns out to be that you have applied a correction to eliminate the large temperature and density fluctuations that were actually encoded in the CMB because they looked to large for cosmologists to except.
TDLR *the CMB fluctuations appear small not because they actually are small but because cosmologists have removed the large fluctuations from the data set before they analyzed it because they seemed too large to be fluctuations in their assumed model.*
If you want the paper to check for yourself I have cited it above and if needed I can provide a link to the paper so you can read it for yourself.
Holy you dont punctuate anything
Very techy, but...wouldn't a simple "inflationary model is garbage" suffice?
Very impressive techhead
Brilliant eye opening video
Excellent!! Good show!!
Absolutely brilliant.
Very good episode! But I have a one question.
How is related symmetry breaking to cosmic inflation? It's a bit hard to understand how symmetry breaking is related to the quantum field responsabile for inflation.
I believe you are referring to electroweak symmetry breaking causing the Higgs Field mechanism? The decay of the inflation field is separate from that and occurred earlier at higher temperatures.
@@ArvinAsh Well I was reading Lawrence Krauss book "A Universe from Nothing" and at some point he disscus the idea about inflation but in a different way.
He made a good analogy by saying that the universe went through a phase transition to a low-energy state similar to supercooled water and symmetry is breaking when ice crystals are instantly formed on it. So lower energy state I suppose it's mean symmetry breaking and inflation it's generated when this happens. I was currious how it is your explanation of scalar field it's related to this.
Hey @@ArvinAsh did you look into Pangburn before you agreed to be a speaker at the Vancouver event? Are you aware of Pangburn's history of not paying speakers or performers, and of not reimbursing ticket holders for cancelled events? Do you approve of the misogynistic posters they've used to advertise the event? Or Pangburn's long history of promoting right-wing anti-science / fox news / breitbart "philosophy"? Are you aware that you'll be sharing the stage with a man who has been penalized for sexual misconduct, and who chose to associate with child sex trafficker Jeffrey Epstein?
Now this is a quality content!
Here, in Argentina, economic inflation grows almost in the same way as cosmological inflation every year.
It just occurred to me watching the video, couldn't we be a black hole that exploded in another universe by Hawking radiation?
Your explanation of inflation starting at about 13:20 is very interesting. I have never seen anything like it on a popular science channel 👍
That's because it's not an accepted or proven part of the hypothesis, but just one of many ideas.
@@periurban BB is *theory, and the inflaton state is the best explanation. Do you have a superior alternative?
@@gravitonthongs1363 I take your point. I think there is a great deal of circumstantial evidence that surrounds our cosmological observations, leading to the idea called the big bang.
I don't think inflation is an explanation. Someone said elsewhere in these comments that observing that two cars have collided is a good description of a car crash, but fails to explain the events.
I think inflation is the same, as far as it is required for the BB theory to make sense.
Even so, there are a few other ways that the modern universe doesn't quite look like the theory predicts.
The good news is that the JWST will be looking back in time to perhaps 100m years after the BB. That will give us some great new observations that should help focus our minds.
No, I don't have a better theory, and I know the anomalies don't necessitate a radically different idea, but there is something missing, and I cannot wait to see what it might be.
@@periurban well said
@@gravitonthongs1363 There is CCC theory (i forgot the full name, something Conformal Cyclical...) that still technically says the Big Bang happened but for a different reason.
Hey Arvin, can I ask a personal question? You don't have to answer of course. But do you make all these videos by yourself or do you work with a team. The reason I ask is I've been watching a lot of your videos and you cover so many different topics with such great knowledge of it all in simple explanations which is a serious gift and ability which demonstrates great wisdom imo. It's hard for me to image how you could do so much by yourself!! And thank you so much for making me smarter!!
I create the concepts, write the scripts and direct the videos. But I have a team that creates the various and animations, and does the visual and sound editing. Thanks for watching my friend. I'm glad these videos are enjoyable.
@Arvin Ash Wow man, that is very impressive. You're such a great personality, and your voice is strangely unique and recognizable as such. But above all I love how passionate you are, I can tell you are just loving it and having a great time... I geuss I can't know that for certain but so it appears. Really have taught me so much about the universe and myself and I appreciate it because that kind of stuff is very important to me, self-realization and things of that nature. Thanks Arvin!!!
mindblown. I realized that the universe could be in different forms!
great work
Thank you for tackling this subject, inflation is always just passed over in the popular sources, this was a real help, thanks again!
trolkjhgffv
big thanks,
Amazing video ❤️🔥🤜👍
Awesome video Arvin! Looking forward to eternal inflation!
Thanks Marvin
That's a great video sir with very great explanation. But i want to ask a question which is, to where universe expands? Like when you use the analogy of the inflating balloon, the volume of balloon is increasing in spacetime itself, so to where the spacetime itself expands?
The balloon analogy only works for the 2D surface. It does not expand into anything. Universe does not have an outside. It expands into more universe.
Ok sir, so universe is not expanding into anything its just the apparent distance between two objects in space is increasing with time which appears us to be expansion of universe. But couldn't it be due to decreases in strength of interaction of matter and energy with spacetime.Like I do not know in early stage of universe but it can be true for now because we do not know why matter interacts with spacetime afterall and latter is true by a simple analogy of a plane sheet of cloth. When the cloth is stretched and we put a heavier ball at the center of it and mark any point on it and measure the distance between them and repeat the same with a lighter ball, the distance between them is appeared to be reduced and can be termed as expansion.
Another great video
Hi I've got a question, I'm wrapping my head around the relationship between gravity and time-space, so our experience of time is influenced by gravity, and if we were to manage to travel at a very fast speed somewhere very far away from any large gravity source we would experience time differently, so my question is whats influencing our experience of time when we travel very fast, is it the lack of the gravity or the velocity that we're travelling, which somehow causes some kind of effect on timespace and our experience of time, sorry for the long question and thank you.
We do not experience time any differently whether we are traveling fast or whether we are in a large gravitational well. We experience time exactly the same regardless of these factors. The only effect you would notice is when you compare the ticking of your clock to the clock of on a different reference frame. And paradoxically, it would appear to you that you are standing still, and everyone else is moving fast. So your clock on your fast spaceship would run faster compared to say a clock on earth. See this video for deeper explanation: ruclips.net/video/mTf4eqdQXpA/видео.html
I never thought of the big bang in terms of the beginning of time, or even being a moment in time. More like thats when the universe began its expansion, an expansion made possible by its sudden interaction with a dimension it previously had no interaction with, time. Had the universe not been in the dimension of time, then the entirety of our universe cannot change. Essentially everything existing simultaneously with no means to interact at all.
Excelente mi admirado y apreciado Arvin! Excelente.
Gracias mi amigo
amazing video
THANK YOU DR.ARVIN ASH...!!!
Love from INDIA🇮🇳
Sir! Really great👏👍😊
Why is the flatness problem not just assumed to mean the universe is so HUGE that we cannot even measure the curvature due to a lack of experimental sensitivity to the curve?
You are on the right track. Pity arvin and co don't realize it but repeating.
@@capjus I think it’s obviously a tell… If we measure no curvature, and our best theories say it should be curved either inwards or outwards, then obviously the entire universe is quite huge indeed, so huge that we might be silly to even try measuring that with current instruments. We are even sillier to not realize that the universe is something huge and we are infinitesimally small against the size of it. We must be a lot like bacteria living in a toilet bowl, thinking the porcelain molecules are galaxies and seem to go on forever with porcelain molecules as far as we can see… We think the entire universe and the physics of it all is the same everywhere as it is inside the toilet bowl. We haven’t yet realized there is a kitchen and refrigerator, oven, microwave, etc.. there’s an entire house outside our toilet bowl of an observable universe. There’s an entire city outside the house! An entire universe outside our toilet bowl. We think we can derive a theory for EVERYTHING! Wow now wouldn’t that be an accomplishment - To derive a “theory for everything”, all from down inside this little toilet bowl, wow!
You need prove that it's curved in the first place
@@yalexander9432 Well what if I say, you need to prove that it's small enough to measure a curvature with current technologies "in the first place" ... No i think the simplest explanation is that the universe is big enough, that our instruments are laughable in trying to measure such a curvature.
@effectingcause5484 no, because 1. curvature is more complex than flatness, meaning flatness is actually the simplest solution.
2. There is no evidence of curvature. Curvature would also imply that there is a higher dimension beyond normal space and time that we observe...
I was enjoying this video a lot but suddenly at time 14:02 my mother called me for dinner and after dinner i continued the Video but I didn't able To understand, I think Dinner Has Done Something with my Mind. Now i will See this Video Again In morning...
There's a very good reason there are no magnetic monopoles and it has nothing to do with cosmic inflation. It's a quirk in the way we choose to represent the magnetic field. Early on, we decided to define the magnetic field as a vector, or more correctly as an axial vector (through the cross product). But the cross product is a poor way of defining the magnetic field. Taking two vectors and multiplying them with the cross product results in a strange vector pointed in an arbitrary direction. It doesn't even transform properly when reflected. The magnetic field is better represented by a wedge product; ie. a directed area. Seen in this light, if we apply Gauss' Law to a magnetic charge and look at the surface surrounding the charge, we see that integrating over the surface by looking at infinitesimal areas of magnetic field, the edges of all those surfaces cancel out. Each of those areas can be viewed as tiny circulating currents and the currents at the edges cancel to give an total integral of zero. Of course you can poke a hole in the surface and the areas wont cancel. This is essentially what Dirac did. But it's kind of a cheat.
Hey, I had question. If the 4D is indeed curved, the time axis must be curved as well, right? If so, we should get a gravitational effect due to the geometry of the universe itself, even if the universe contained no massive objects?
Good👍but the effect of time dillation will too tiny/around second maybe microsecond since the gravity isn't from massive objects
Do the particles created after the reheating of the universe by the decay of the inflaton have the same temperature as the pre-inflation particles that achieved thermal equilibrium in that small space which was streched? And where do those pre-inflation particles come from?
Exactly. This entire "theory" is a band aid. Trying to cover the wound created by a Catholic priest to avoid the inevitable.
Could space and particles be generated for each galaxy separately? As the galaxy expands, the space encompassing it also expands and kind of overlaps with neighbouring galaxies allowing light to pass through from farther galaxies?
Like bubbles coalescing?
@@Rampart.X yeah something like that
What does the uniformity, or lack thereof, in the universe say about determinism and real randomness?
What is temperature at quantum level? Ex. If rise of heat in water increases its temperature, then at quantum level temperature is just exchange of photons.
So how can temperature exist before formation of particals? If it did, in what form?
Well this explains a lot. As I always wondered how all of the matter in the Universe could be compacted so small. And essentially what this is saying, is that at the dawn of the Big Bang. That it was just space itself that started expanding. And then shortly after is when matter started appearing. i.e. where a matter and an anti-matter start popping into existence, and for some reason not all of the matter got destroyed by the anti-matter, which is what makes up all of the galaxies, stars, planets, etc. that we see today.
Yes, matter did not exist at the very beginning, it was created during the big bang through a bunch of interactions.
Brilliant
So why did the universe need to be causally connected to be homogeneous? Could the homogeneity be due to a property of the universe? When I heat steel, it expands exactly the same way as the same composition of steel anywhere else in the universe no matter how far apart they are, they don't need to be causally connected. Inflation dosent explain why we can't separate magnetic poles either.
Not well understood? I understand it to be total science fiction.
Brilliant.
Dear Arvin, thank you for another great episode! However, I am still having a great deal of difficulty wrapping my head around or rather reconciling a potentially infinite universe with the singularity of Big Bang. If the universe (by "universe" I meam our cluster of universe that appeared as a result of "slowing down" of part of the eternally inflationary universe) is currently infinite in size, then it must have been infinite at the Big Bang as well. If so is it true that space-time wise only the point in the center of this universe ("central volume"/"singularity point") had all the building blocks that eventually turned into matter and energy and everywhere else in this infinite universe had nothing at all even at quantum levels (or maybe just the "quantum foam")? I am having even hard time to elaborat what I am trying to say :) but simply put I cannot reconcile the infinity of universe with the Big Bang theory and it is really nagging me
Stay tuned for the next video where I talk about eternal Inflation - this will show you how the universe could be infinite even though our universe had a beginning.
@@ArvinAsh just admit nobody knows the answer. We wil never know.
Please answer Arvin:
Q: what is the approximate minimum size that the observable universe had to be at 10^-43 seconds in order to be 93 billion light years diameter now?
I don't know for sure. I would go with the minimum size, a universe having a radius of one Planck length - 1.6x10^-35m.
@@ArvinAsh thank you my friend 🙂🌌🙌
Thank you so much for this video Arvin
So, is it fair to say, The "Big bang" is the "moment" when General Relativity and Quantum Mechanic Theories started not to disagree with each other?
Well General Relativity is incomplete, so it would not hold up at quantum scales. But it would be fair to say that all forces, including gravity, were united by some laws we have not discovered yet.
In other words Entropy. Yup, pretty much.
Great video, I have also listened to Sir Roger Penrose alternative theory of Conformal Cyclic Cosmology, could you comment on his theory as it does have some interesting ideas.
With expansion (and it never ceasing), wouldn't space effectively be negatively curved since parallel lines would expand apart from each other over time?
Would the cosmological constant be the lowest energy state of inflation field (point C)?
Please make a video on Conformal Cyclic Cosmology.
So with the idea being that dimension's unspecified, (probably fractul dimensions..) Are all of the unobservable universe. But existent and stable in some cases.
Would it be plausible to make an energy device that has a zone of space time energy within, that functions as unobservable universe matterial and space/time. With which you could arc or otherwise incrementally store and distribute power from by having a gear ratio system between prime dimensions and thier force carrying expression particle. Some 4d structure in a 4d environment being strained out into a 2d matter area. And is it also plausible using some clever mechanical tricks/inventions, that it could transfer enough power and pressure through static means, (pressure tank under water, drain outer tank to change pressure, as a fine tune static method example.....) Or solar etc... To run it sustainably as some form of reactor for eating waste materials and pumping out energy...
As a suggestion. This could work both ways. Depending if you want More immediate power or power over time. Gearing....
Also a good material to start with would be Graphene i expect. Feeding in an iron core and making it spin in containment with magnetic fields that should cancel out other influences. Im hoping that graphene and iron in the right pressure scenario with the right stabilising tweaks like pressure adjustment mid process. May be able to create a dynamo with incredibly limited friction....
Monopoles would be expected much more in 2D scenarios. And i expect maybe in some format in higher dimensions that fall on even whole numbers. Example 4d,6d,
Maybe it acts more like a single proton or electron on a larger scale in such bigger dimensions. Not found seperately often but performing as a monopole item.
The interior of a 2d item and the exterior are the only 2 interaction zones. Allowing the entire outer area to become the thin bubble of area seperated from exterior fields. Making a 2d bubble feeds toward my other comment/idea's on (notablackhole) dimensional gearing energy syphon thingy
Sir i have a question why light had enough time to travel uniformly if space was accelerated by inflation rather than decelerated by gravitational effect ?
And why in supercooled state energy of particles becomes high?
There was no light that traversed the universe during the time of inflation. The first light that you can see, CMB, came about 380,000 years after the big bang.
@@ArvinAsh then sir why CMB is uniform throughout the universe and why it was necessary that the universe should be supercooled to inflate , why symmtery should not be broken between forces?
you should make a video daily, i find them very therapeutic.
Anton Petrov for that. These high quality productions take far to much resources.
Watching this video makes it really clear that you do not believe in a multiverse.
Not saying we ARE in a multiverse, but the way you described the universe means it is impossible to believe in a multiverse theory.
I don't think we humans are advanced enough to really know, I mean, strictly speaking, there are still other theories that can explain our universe without a "big bang"
Also, I still believe you can have a center of a universe, even if you use the balloon example, a balloon has a center.
Our universe is so huge and if you truly believe our universe has no boundaries, which I still find so difficult to believe, then we might have no center.
It is very hard to explain why it is so hard to believe we have no boundaries, I mean, even watching this video, I find it is clear that we actually do have a boundary, this does not mean a physical one.
Many countries have a boundary you can cross from one country to an other without crossing a wall for example.
But, I really love science and most of all, the universe. And I really love your videos, because what makes it interesting is that we STILL are on a journey to discover the mysteries.
I don’t think you interpreted the video quite correctly.
1. Arvin did not suggest the multiverse was not feasible, stay tuned for the next episode to see that it is still possible.
2. While the ballon analogy can insinuate a finite universe, that was not the intention. The balloon analogy can still be used for an infinite universe.
@@gravitonthongs1363 if the universe has no boundaries, how can there be a multiverse?
Let us say, just as a theory, we can move from one universe to an other, that means we HAVE to cross the boundary of the universe to cross into the next one, right?
But he stated very clearly in the beginning that the universe has no bounderies.
@@spyofborg where did he state the universe has no boundaries? I can’t find it. That is possibly where your misinterpretation stems from.
Well, you might change your mind after you see the next video. Stay tuned my friend!
@@gravitonthongs1363 I used the wrong word, at around 4:30, he says, no edge, but for me boundary and edge are almost the same.
If there is no edge, how can we have a multiverse? I mean, let us PRETEND we are Gods and can actually zoom out, if you see a multiverse, then each universe must have an edge, then a universe should have a center, etc ... But I just LOVE thinking about this, and that is why I like videos like this, it makes you think, but it also makes you question things, and that is what science is all about. To challenge theories and find answers. :)
Could this inflation field have a negative value and consume space instead of creating it? Could mass interfere with this field so gravity is space being consumed?
I guess I missed the explanation of why inflation fixes the conundrum of missing magnetic monopoles. What time s it discussed?
Perfecto.
@Arvin Ash if all the matter/energy was concentrated into a Planck length (how is this in itself even possible under the Pauli exclusion principle), why did space expand rather than collapse into a black hole/singularity (which we would expect today)?
Ok great question! You have to change your paradigm to visualize this. The universe was not like a point with an edge. There was no edge. The entire universe was dense. And it was homogenous. Now, if something is the same everywhere, there is no point which has more concentration of energy than another. It could not conglomerate. Nothing will be attracted towards one spot more than another spot. In addition, as outlined in the video, the Inflation field decayed very shortly afterward, causing rapid expansion of this initial state. Only quantum fluctuations existed which caused some of the large scale matter concentrations we observe today.
@@ArvinAsh Thanks Arvin, good answer. But I was referring to that very first Planck second after the Big Bang, when the universe was only a Planck length long (in 3/4 dimensions). Then all matter/energy in existence today must have been concentrated into a single point (I.e. that of a Planck length), and there would’ve been no “in between” since that would be smaller than the Planck length (so no quantum fluctuations yet etc). At that point, collapse back to the singularity (that existed before that very first Planck second) should’ve happened reasonably (all of universe’s matter curving the FUBAR out of such small spacetime).
And if the universe had no edge per se, even at the size of a Planck length, do you mean that the universe was still “infinite” at that point?
@@NiToNi2002 Could the answer be the rapid expansion or velocity of space so that gravity could not hold things together or cause it to collapse into a black hole. Maybe the expansion was so fast and powerful it managed to escape the gravitational pull.
@@NiToNi2002 finite, but without boundaries.
@@NiToNi2002 No edge should probably be replaced by a "conceptal" edge which is 0 for the purpose of inception of creation by beginning mathematics (number system) and physics (big bang), the two pillars of describing reality.
I believe some say if we accept the universe to be flat, it could be infinite.
My question is how can the universe be infinite if it had a finite size in the past??
There is no evidence that it ever had a finite size. It is safely presumed to be infinite. As this video states: BBT is explanation of the universe from dense non zero spacetime, not mythical and unexplainable singularity.
@@gravitonthongs1363 if it had a beginning and started small, then no matter how fast it grew, it cannot be infinite.
@@samcena3942 dense to less dense, rather than small to big. Think infinite dough to infinite bread.
BB is not theory from beginning, it starts from nonzero time.
I have a question. How long would it take for our universe to get to the point that it ends up expanding as quickly as it did during the inflationary epoch? And is that point anywhere near the amount of time it's been estimated it would take to spawn a universe such as our own just based on random quantum fluctuations?
Great job!
My brain just went through cosmic inflation.
When saying “the universe was small” does that primarily refer to the observable universe?
If the entire universe is infinite it should become more dense but not really smaller as you rewind the clock?
No it refers to the observable as well as the part we can't observe because light has not reached us yet.
Dear Mr Ash: you say in the video that universe expanded by a factor of 10^78 during cosmic inflation. I am not following that comment. If universe was of the order of plank scale 10^-35m pre inflation, then that much expansion will put the diameter of the universe at 10^43m post inflation which seems to be much much much much (quadrillion times) larger than the current observable universe. Did you mean to say the rate of expansion of universe during inflationary phase was 10^78 orders of magnitude per second but lasted only for 10^-32 seconds ?
No, the former is correct. The universe is much larger than the observable universe. We don't know. Some physicists think it could be infinite. This minimum expansion comes from what's needed to get the observed curvature or flatness of the universe correct. Inflation could actually have been much larger. We don't know as of now, especially since we again don't know the real size of the universe.
How can u say there is no outside if there was an expansion and a size? What space did the universe expand into?
Could u Explain further
We just know the the universe was smaller than it is today. But the universe has always been the size of the universe. There is no reference frame outside of it
@@ArvinAsh thank you for the reply 😊
So are u saying the universe has always been, the Big Bang is just a thing inside that space that expanded into the uni we see today? I’m genuinely curious about the before even though ik that question is nonsensical
Also, do know about Penrose’s theory on previous eons?
Space is moving in all directions at light speed. Time is a measure of relative motion of objects moving in space. As speed of object increases, its relative motion decreases and its time slows. When object reaches light speed relative motion reaches zero and time stops.
Would the monopoles attract each other, N and S, and make the dipoles we see? Would they have been created in equal amounts like matter and antimatter?
Yes, but if inflation is true, the theory goes that they could have survived and pulled apart far enough away to continue existing.
Is it important that the universe had a pre-inflation period, albeit short? How would the universe be different if inflation started at t=0?
The time is chosen because that's when the strong force is thought to have separated from the electroweak force. This is when a scalar field would have dumped its energy into radiation, quarks, and other particles.
Could inflation energy be pulling or stretching the universe out, rather than pushing from within?
Is it possible for gravity to be the result of mass resisting expansion? Like the ants forming dimples in the balloon as the balloon expands into them?
Yes, it is possible. 😉 From, Alpha and Omega
Sounds like a good explanation however, as the expansion rate changes value you would expect gravitational value to change correspondingly, but that isn’t the case.
@@gravitonthongs1363 So the thing I was visualizing was the trampoline and balls demonstration but without friction inside a rocket (the thought experiment where you can't tell if its gravity or lift from your reference frame) where the expansion of the universe is that thrust. Basically, the acceleration of the universe's expansion corresponds to gravity's apparent acceleration.
@@ThrashmIO an interesting thought.
I think the main deterrent for your idea is the additional reference frame of travel through spacetime. We don’t experience significant changes to gravitational values depending on earths motion through spacetime. If gravity is dependent on the expanding motion of spacetime we would expect for the values to change correspondingly to our direction of orbit around the sun / spacetime reference.
Feel free to correct me if I am off track.
I have started thinking of the 'big bang' as more of a decay in an inflationary field. These areas of decay are universes being born. It saves of from a uniqueness problem and allows for eternal inflation.
Inflaton field hypothesis. I am also a fan.
This is a promising idea and interesting thought. Decay implys time is ticking though so his "start of time" mark may have to be rethought.
I hope Arvin touches on that in the next episode.
@@charliemeyer6475 It preserves the Second Law, which I agree with Susskind , cannot be violated, like it would be in Penrose's bouncy Universe model. It actually makes it intrinsic to universe formation.
The best description of the inflation I've seen so far!
I've also been disturbed by the grapefruit, or golf ball, or small galaxy representing the size of the universe after the inflation, which we can read about in popular science books concerning the expansion of the universe and the Big-Bang theory, but for it's size rather than it's lack of flatness. Today the expansion rate (r) is something like 0.074 per billion years. meaning that any distance in expanding space will be about 7 % bigger when a billion years have past, than it was before. Also, because the expansion is supposed to have been accelerating over the last billions of years, the expansion rate must have been lower before. And 13.8 billion years of expansion would mean that the "diameter" of the universe has grown less than 2.8 times (e^(r*t), with t=13.8) since then. Going backwards 13.8 billion years, to the time directly after the inflation phase, would mean a diameter at more than 30 billion light years (only for the visible part of the universe, said to be about 90 billion light years today). That is not exactly the medium size of a grapefruit! Our grapefruit would at best be the size of a watermelon today. Houston, we have a problem! There's some expansion missing in our universe. Also I have a hard time realizing that "distant parts" of the grapefruit should be beyond communication by the speed of light from each other. So, how would we account for the invisible part of the universe, surrounding us out there, if it wasn't the inflation that ripped the regions apart? Was the phase of slowing down from the inflation-rate long enough to fix this leap? Why not include that time, then, into the inflation phase? Or was the grapefruit just a joke, passed on by the next storyteller?
Arvin I have a big question. Let's imagine we drilled a hole from Artic through the earth to Antarctica. If a person jump from the hole in Artic will he come out from the hole in Antarctica. I'm asking this question because of the force of gravity in both sides
No, he would not come out of the hole in Antartica. He would go through the center due to momentum, but be pulled back to the center of the earth.
@@ArvinAsh Thank you so much for answering my question and it was a big question to me
@@ArvinAsh I'm waiting for the video about Ion Thrusters
It will stabilize in the center, where the gravity forces are in equilibrium.
If you take air friction, uneven ground level and rotational effects out of the picture it would just be like an endless orbit around the earth except in a highly elliptical orbit going through the center of the earth. Jumping in feet first at the Arctic end, the person's toes would pop out in the Antarctica only to immediately disappear and then their head would pop out in the Arctic only to immediately disappear and this would repeat without end for a very long time.
Some papers came out recently that showed that inflation doesn't work when you account for quantum mechanics. However a slow contraction then expansion model works better.
Citations please.
@@ArvinAsh He probably means Paul Steinhardt... ruclips.net/video/5JM9RJFMHgc/видео.html
@@ArvinAsh Some work by Paul Steinhardt e.g. ruclips.net/video/S7-HNi2ne44/видео.html
@@theosib I actually watched that video you linked. It was the most unscientific hocus pocus I have heard for ages. It contradicts everything astrophysicists agree on.
Two main points you should recognise is that:
1. his objections are based on the Big Bang being a singularity which we all agree it isn’t. 1:05
2. He doesn’t understand nucleosynthesis or when it occurred.
Gather information from more reputable sources.
I just got an idea! The universe only seemingly expanded faster than light. It did not expand faster than light. All that happened during the inflation epic was that there was NO MASS during that time! During the time when there was pure energy, the universe expanded without any time passing by, so this would "seem" to be happening in an instant from the perspective of the pure energy (photons and gluons) and there was no spacetime relativistic inertial frames, if you will. There was an ever-growing sea of photons and gluons, which do not experience time or space. Only when massive particles were introduced, electrons protons and neutrons, did time and space begin bcus that's when inertial frames of reference began.
I don't know how one can simply say that the universe doesn't have an edge and think "well that's solved". Philosophically speaking, to me, that's absurd.
Why is it absurd? Why shouldn't the universe be what it really is, regardless of our incredulity?
It would be cool if you did a collaboration with Isaac Arthur! That and this channel cover such interesting topics but make it easy to understand.
Were those inflatons massless? When did matter start to form? It must be shortly after space formed. And how? Perhaps, you could make a video about this. I have read about this. I know you can make this topic crystal clear.
I like to think that each thought is just another instantaneous Boltzman Brain disconnected from space and time....wonder how cosmic-inflation jives with Boltzman Brains.
Keep up the great educational/philosophical videos!!!
Once again the same clarification Mr Ash. By saying that the universe expanded by a factor of 10^78 from the time interval 10^-36 to 10^-32 seconds after the Big Bang, did you mean that the volume expanded by that factor or diameter expanded by that factor ? Does my question make sense ?
volume - There is no outside to the universe, so speaking in terms of diameter could be misleading.
According to some theories, colliding universes could lead to cosmic inflation, causing a rapid expansion of the universe.