Considering that before I started watching you I thought stars in the night sky were just all planets and literally didn't know what a "star" was, to now having a general understanding of our universe and what it's made of, hats off to you Dave. You're an amazing teacher. There's always more to learn!
Thanks for clarifying. I had thought previously that it was called dark because it wasn’t yet understood. I think it’s interesting that it’s dark in the literal sense that it doesn’t emit light.
Discovered your channel after your debate with ,as you quote " A greasy Pig". Love your videos on Science courses . your channel is actual Gem . Thank you
I know this video is two years old, but the fact that we have such an in-depth understanding of the universe and what lies within it is so amazing to me. I'm amazed I haven't watched your videos sooner, and frankly, I can't wait to see where science goes next. Forces and energy in particular are so interesting to me, because I've always thought of them as some arbitrary system, but they are really linked with the physical. Thanks, Professor Dave.
I see the flat earth community is starting to infect all your videos now. I guess views are views. You are a good teacher. Concise, organized presentations.
"Visible matter makes up only 5% of our universe, which is dominated by dark, unexplained forces. Congrats on being one of the sparkly bits" --Dr. Katie Mack
Also thank you for clarifying the circle graph saying mass energy equivalence, I have always had problems understanding how energy can be on the same graph as matter
I’ve just posted this comment in another science related video and looking the comments below here it fits perfectly. why is it that the comments section of every video of scientific education always attracts a lot of the show offs, the “I know better” , the Dunning Kruger effected, the conspiracy theorists? I’m aware that by commenting I could include myself in this category , but I’m not implying that all comments are like that just that there are too many of those that go like, oh Einstein got it all wrong because.....reasons, or this is where all scientists are wrong .. reasons and watch this video, or I think therefore I know better than all of THEM. Just eat some humble pie and understand that probably you are NOT a genius, real geniuses don’t get Nobel prizes by commenting on RUclips, instead if you think you got the gift, take university courses, put your head down on books and try to stand on the shoulders of the giants that came before you to see further. If you can’t, just ask your questions and listen to the answers by those that know more than you do, and if you believe in conspiracies... well I’m sorry there’s is nothing much we can do except wishing you to enjoy a bit of your sad life also thanks to the technology brought to you by “THEM”.
Yes, there is an epidemic of pseudo-intellectuals that claim to understand physics better than Einstein when they couldn't pass a high school physics quiz. Unfortunately, there are many channels that cater to these delusional asshats and churn out content with the anti-establishment narrative they enjoy, and it makes things worse. I've been debunking several of them and they invite mountains of toxicity from precisely these bozos.
Its a great question. I think there are several reasons: loss of trust in educational institutions and authority, internet anonymity, growing arrogance in our culture that somehow so many of us are 'smart' perhaps based on how we raise children over the last 50 years or so, and the shift from questioning things to questioning everything
If the vacuum energy is present at every point in space and space is expanding, wouldn't that mean more vacuum energy is showing up as space expands to help accelerate the expansion on even faster?
Hello proffesor Dave, I have a question. In nuclear fusion, 4 protons come together to form a helium nucleus, a neutrino and a positron and gamma rays. So how does the sun produce visible light? Are there electrons somewhere I am not aware of?
helium has two protons, but in general the sun is a blackbody, it produces electromagnetic radiation of all wavelengths, the peak is in the visible spectrum
@@ProfessorDaveExplains I understand that helium is 2 neutrons 2 protons. But my question was how does it produce emr without electrons? Or does it have electrons?
Well there are electrons in there, it was neutral gas that collected to form the star, which only ionized once it got hot enough, but also the fusion events themselves produce photons.
how this is have only 440 likes?! Prof. Dave, you have VERY interesting channel, your vid about star formation was very informative, and I like when you summarized a section before a lot! Cheers! (my english is bad :P)
At 1.57 you say "if something is not capable of producing photons in this manner, or relate nuclear processes, it can't produce visible light". As far as I know, all electromagnetic radiations (visible or not visible to our eyes) consist of photons emitted by the same process you have described for visible light, that is: electrons moving from excited states to lower states.
Huh, I've never thought of the word tutorial as just learning info from a tutor. I've always thought of it only being something where you learn a process.
To differentiate dark matter and dark energy for some people who think dark matter is responsible for cosmic expansion: Dark Matter is not normally observable like matter, but we can observe it by gravity. There have been numerous hypothesis about dark matter. Heres a long quote from Yale about Dark Matter. “Dark matter - which has never been directly observed - is thought to constitute the majority of matter in the universe and act as the unseen scaffolding upon which galaxies form and develop. Physicists have spent years testing a variety of dark matter candidates, including hypothetical particles such as sterile neutrinos, Weakly Interacting Massive Particles (WIMPS), and axions. Black holes, on the other hand, have been observed. A black hole is a point in space where matter is so tightly compacted it creates intense gravity. Not even light can resist its pull. Black holes are found at the centers of most galaxies. The new study, accepted for publication in The Astrophysical Journal, harkens back to a theory first proposed in the 1970s by physicists Stephen Hawking and Bernard Carr. At the time, Hawking and Carr argued that in the first fraction of a second after the Big Bang, tiny fluctuations in the density of the universe may have created an undulating landscape with “lumpy” regions that had extra mass. These lumpy areas would collapse into black holes. Although the theory did not gain traction within the wider scientific community - the new study suggests that, if modified slightly, it could have explanatory power after all. If most of the primordial black holes were “born” at a size roughly 1.4 times the mass of Earth’s sun, they could potentially account for all dark matter, said Yale professor of astronomy and physics Priyamvada Natarajan, the paper’s theorist. Natarajan and her colleagues say their new model shows that the first stars and galaxies would have formed around black holes in the early universe. Also, she said, primordial black holes would have had the ability to grow into supermassive black holes by feasting on gas and stars in their vicinity, or by merging with other black holes. “Primordial black holes, if they do exist, could well be the seeds from which all supermassive black holes form, including the one at the center of the Milky Way,” Natarajan said. “What I find personally super exciting about this idea is how it elegantly unifies the two really challenging problems that I work on - that of probing the nature of dark matter and the formation and growth of black holes - and resolves them in one fell swoop,” she added. The James Webb telescope’s mission will be to find the first galaxies that formed in the early universe and see stars forming planetary systems. The new study’s first author is Nico Cappelluti, a former Yale Center for Astronomy & Astrophysics Prize postdoctoral fellow who is now an assistant professor of physics at the University of Miami. Günther Hasinger, ESA’s director of science, is the study’s second author. “Our study shows that without introducing new particles or new physics, we can solve mysteries of modern cosmology from the nature of dark matter itself to the origin of super-massive black holes,” Cappelluti said. Primordial black holes also may resolve another cosmological puzzle: the excess of infra-red radiation, synced with X-ray radiation, that has been detected from distant, dim sources scattered around the universe. Natarajan and her colleagues said growing, primordial black holes would present “exactly” the same radiation signature. Best of all, the existence of primordial black holes can be proven - or disproven - in the near future, courtesy of the James Webb Space Telescope and ESA’s Laser Interferometer Space Antenna (LISA) mission announced for the 2030s. If dark matter is comprised of primordial black holes, more stars and galaxies would have formed around them in the early universe - precisely the epoch that the James Webb telescope will be able to see. LISA, meanwhile, will be able to pick up gravitational wave signals from early mergers of primordial black holes. “If the first stars and galaxies already formed in the so-called ‘dark ages,’ Webb should be able to see evidence of them,” Hasinger said. Natarajan added, “It was irresistible to explore this idea deeply, knowing it had the potential to be validated fairly soon.”” While _Dark Energy_ is the *component* that causes cosmic expansion, or expansion of the universe. Quoting Wikipedia: “The expansion of the universe is the increase in distance between any two given gravitationally unbound parts of the observable universe with time. It is an intrinsic expansion whereby the scale of space itself changes. The universe does not expand "into" anything and does not require space to exist "outside" it.”
I am very troubled by this: people seem to refer to dark energy as vacuum energy, the energy contained in vacuum due to quantum fluctuations. But I heard that if you calculate the quantum energy and compare it with the observed magnitude of dark energy, the numbers are wrong by like 20 orders of magnitude.
Hmm, it sounds like you may be confusing dark energy with the zero-point energy, as the latter is what we associate with quantum fluctuations. At least that is my understanding!
@@ProfessorDaveExplains I just looked online and I think there is dispute regarding whether zero-point energy is a candidate of dark energy; the papers I saw were way beyond the power of my little brain though. Thank you for the reply Professor.
Models trying to describe dark matter do not support dwarf galaxies on a near flat plane "organized" surrounding larger galaxies. Dwarf galaxies should be erratically positioned. Models also determined the dark matter should be concentrated in the center of galaxies and that is clearly wrong too.
What was that? Duration 0:11 to 0:14 . In that Milkyway Timelapse. 15% from left top. a star "Appeared Still" for 3 seconds. Please can you explain that ? a Quick Supernova? ;)
I have seen this a few times. It is most likely a geostationary or geosynchronous satellite. You can see the same thing in this linked time-lapse. Because they rotate at the same speed as the earth, they appear not to move. This video has more than one that pop in and out of view like the one in Daves video. Easy to miss so look carefully. ruclips.net/video/vxHpaLqFYNc/видео.html
How does dark energy correlate wity the conservation of energy? Does the creation of new space by inflation create more dark energy or does the total amount of dark energy remain constant with a decreasing energy density? Do we simply don't know?
In our solar system, the planets closest to the sun move faster in their orbit than those farther from the sun. Why is this different in the galaxy you used in your example?
so the orbital velocities have to do with how much matter lies interior to the orbital radius of any particular star, but as to exactly how that data is gathered i'm not too sure!
Then you would be spitting in the face of everything he is trying to do! The people we should question the most are those who teach us! Dave is very well researched but still human!
Could dark matter be electromagnetic radiation that is still on the move? Because obviously light is not visible as long as it does not reach the observer. Hence the following question: How much does light actually weigh in our galaxy, i.e. all radiation that does not hit a surface for a long time, is directed outwards into infinity or is even stuck under the event horizon of black holes? A fraction is sufficient as an answer, namely the relation to the total mass.
i dont think dark matter is actually real, i think its just an error in relativity that we haven't come up with a new theory to explain this hole in relativity, like how quantum mechanics and relativity are different and there is no universal theory to explain it yet
Have you heard of carbonaceous chrondites? Some of the most ancient matter still remaining of the solar system that hasn't been incorporated into either the Sun or the planets, this material is as dark as coal and mostly about the size of grains of sand so obviously light reflection from such objects is pretty much impossible so they ARE "dark matter"...
Hey dave, is dark matter a hypothetical variable to explain things or is there graphs and such that are getting closer to truly unravel it for what scientists think its is: matter which cannot be seen. Btw love the vids
Astrophysicists are very confident it exists, we just don't know what it is. As to when we will know what it is, I have no idea. It is not a hypothetical variable.
Can anyone tell me If my theory on dark matter and possibly dark energy can be disproven. As energy and mass are interchangeable, could all the energy no longer in a usable state not account for the extra mass known as dark energy?
@@ProfessorDaveExplainsThanks fir your prompt response. Apologies, I meant to ask if the mass could be dark matter, not energy. Also can that energy not be transformed into matter with mass by some process, like for example when we try to accelerate particals closer to the speed of light, the more energy added simply adds mass not speed?
@@paulwardrope I think I see what you're trying to say. And since you're making an honest effort to try and understand the world, unlike the flat earth tards and basic science deniers and conspiracists, I cant sit here and say oh thats ridiculous because again, you're making an honest effort to try and understand things. What I will say however, is that its like asking about a difficult (but perhaps easy to state) problem from, say, advanced math class like Calc 3 or something, but you don't yet have a basic foundation in even algebra or trigonomtery. My advice would be, if you are really interested, is you have to build a foundation from the beginning, which means learning basic physics & astronomy, and from there moving into astrophysics before attempting to try and understand or theorize about dark matter or dark energy.
Is it possible to explain these things with the addition of the holographic universe theory? (it also explains the galaxies rotational anomaly, accelerating expanding of the universe and even the black holes singularity anomaly)
I thought since the galactic Center mass is higher, objects near or close the center have higher orbital velocity. I mean which planet has the higher orbital velocity , earth or mercury.
But professor Dave, Dark Matter constitutes 28% of the universe while regular matter constitutes 5% of the universe. So, dark matter is 5.6 times more than regular matter, and not 10 times.
He didn’t say that it’s ten times more in general, but that the mass of dark matter around the galaxy is ten times more than the mass of visible matter in a galaxy. So it is likely just denser around galaxies, which then produces than relation in the specific case of galaxies.
From what I saw, dark matter doesn't interact with light but because it should have a mass it should bend space so it curve the path of light therefor "obstructing" the path of the light.
"they are no longer gods." This is blasphemy. You know that if a multiverse exists, then Thor exists. Therefore, you blaspheme against the multiverse and Thor
It could be that the fundamental unit of energy which is 'Prana' of the physical observable universe, be the source of dark energy filling in all atoms, and the spaces in between.
Critique on your general method of operation: Interesting how you give full weight and credit to an "assumption" (~4:35) inherent in Dark Matter theory which has consistently failed empirical testing for required particles after decades and billions in research over multiple teams and contributors. This is directly opposite the personal attack laden, derisive approach to Electric/Plasma Cosmology. It's appears that you approached the latter topic with disdain before even attempting research into the subject. In fact, you present the least favorable light to the argument, utilize perhaps the least defensible purveyors, and include only portions of the theoretical body of work. At the same time you state with near absolute confidence that we know, for fact/done deal, no other research or countervailing theories exist on any of these related topics (gravity, plasma, electromagnetism at both quantum and cosmological scales). How can you state we know what black holes are made of (~00:45) without anyone ever coming any where near such an object? That is absolutely wrong given the breadth and depth of research, both practical engineering and theoretical physics, ongoing now around the world on each of these subjects. Science is an iterative approach to understanding with every new inquiry leading to discovery, knowledge, and revision. You do include a lot of rhetorical bandwagon techniques influencing your viewers to simply accept what you're conveying; phrasing such as "we believe" (~10:44) demonstrates an implicit need to dissuade questioning, dissent, and detraction (not the tools of the discipline and practice of science). Yet the vast majority of this presentation is loaded with subtle hints that the viewer should just agree on foundational assertions. The lead statement sets the tone for irrational obedience; (~00:14) "You have to admit that our current understanding of the universe is nothing short of astounding". You give scant caveats that would lead a lay person to question or seek out further resources and depth. My rhetorical retort to your rhetorical flourish: I'm interpreting your presentation, in total, as either a near zero understanding of physics or specific theories yet pretend to, or you are simply unable to understand your limitations on what that you understand. Feigning knowledge is an unforgivable sin to science. Ignorance by contrast is fine, so long as it drives an approach towards subject at large with a level of skepticism and open mindedness. A philosophy of questioning and seeking is required for academic and scientific integrity. Unabashed shilling in promotion of popularism for fact, for profit, is just ridiculous. All of your viewers should dig in to alternatives, contrary views, and challenge every presentation. Obedience is not science. Challenge: Review gravitational-based non-dark matter/energy cosmological models such as MOG (modified gravitational theory), SVTG (scalar-tensor- vector theory). Let's see if you can digest and honorably convey a theory. Or if there is, as I suspect, an irrational clinging to a popular position. Perhaps then you may be able to tackle the subject of cosmological lensing without baryonic material
_"Review gravitational-based non-dark matter/energy cosmological models such as MOG (modified gravitational theory), SVTG (scalar-tensor- vector theory). "_ They fail at large scales. Such as in galaxy cluster collision lensing observations. Simple as that. We then find the apologists of such hypotheses having to introduce some dark matter to keep their hypotheses alive. Which is kind of pointless, given that they were dreamed up to get rid of the need for dark matter! As it stands, there is only one model which explains observations.
certainly my friend......ill just go along with the points in your video 1 Dark matter is a "THEORY".....period.... 2 Dark matter DOES NOT interact with light because it IS NOT there! 3 Orbital velocity of nothing is theory....and ignorant 4 There MUST be 10x the unseen matter in the universe....hahahahaha 5 Einsteins "THEORY" of general relativity has been disproven...period 6 "Dark matter must accumulate first" again theory and ignorant 7 Early galaxy evolution is a theory....period 8 there COULD EXIST sub atomic particles....hahahahah BIG theory and one that is on the verge of being discredited as we speak 9 Dark energy is a "CONCEPT" hahahaha thats another word for dream...lol 10 "We thought because of GRAVITATIONAL matter things were being pulled together" Gravity is a theory....period 11 Big Crunch and Big Bang...both wild conceptual theories... 12 you say in the end of the video quote "Some other thing? we don't know yet";...hahahahaha 13 5 billion years ago....lmao is a stupid theory...disproven in the 70s and lets not forget Einsteins big mistakes....hahahaha Basically the entire video is one big stoner kids idea of space hahahaha...not one single thing in it was a fact....you can argue that all you would like but it is my field of expertise and you are not only wrong but misleading.....the problem is that you get all of your information from the internet......@@ProfessorDaveExplains
Every single physicist in the world disagrees with everything you just said. Where exactly are you getting this? General relativity has been disproven? How and by whom? Tell me the details. The big bang was disproven in the 70s? How and by whom? Tell me the details. You are constantly laughing at your own statements because... even you realize how ridiculous they sound?
again showing your ignorance . This would explain why none of the professors or students or anyone you will ever meet will be in the "KNOW" of things....think about it....where do i get this information? we will just call it "the source" i will tell you that as I set here in my home by the beach listening to young people on the internet that I am saddened for the world you dillusionally live in, but it must be that way for a while longer. You are not prepared, nor can you grasp the nature of true reality. But I promise you that in your lifetime your information and view of the world around you will change and almost all of the things you believe to be true will become false theories that at one time fueled movies and books and music. We live in an amazing time.....you don't seem like a bad kid...I wish the best for you. Try to remember that ALL ideas of space and extraterrestrials are just fun ideas.......and I never laugh at the situation, actually it makes me sad. But there is nothing I can do about it.@@ProfessorDaveExplains
@@ProfessorDaveExplains and as a side note....try to remember that all of the books that you are ALLOWED to have access to are outdated by many, many decades.
Considering that before I started watching you I thought stars in the night sky were just all planets and literally didn't know what a "star" was, to now having a general understanding of our universe and what it's made of, hats off to you Dave. You're an amazing teacher.
There's always more to learn!
You can create an institute where youre the physics, chemistry, maths, biology, Italian, English, astrophysics, astronomy and quantam physics teacher.
geologist to sum all teachers required
Italian and English too? XD
he is not a teacher, he is THE teacher
Maybe it's not necessary.
A complete video here is the cost-effective lecture material.
I love how you threw in Douglas Adams early on. Easily one of my all time favorite book series.
Thanks for clarifying. I had thought previously that it was called dark because it wasn’t yet understood. I think it’s interesting that it’s dark in the literal sense that it doesn’t emit light.
Me too. I was in the dark as to why it was call that...😁
It's not just that is don't emit light, it dont' even interact with light, much more like an invisible thing and not a dark thing
Discovered your channel after your debate with ,as you quote " A greasy Pig". Love your videos on Science courses . your channel is actual Gem . Thank you
I know this video is two years old, but the fact that we have such an in-depth understanding of the universe and what lies within it is so amazing to me. I'm amazed I haven't watched your videos sooner, and frankly, I can't wait to see where science goes next. Forces and energy in particular are so interesting to me, because I've always thought of them as some arbitrary system, but they are really linked with the physical.
Thanks, Professor Dave.
More than half of our theories are non proven. Its just a speculative guess.
I see the flat earth community is starting to infect all your videos now.
I guess views are views.
You are a good teacher. Concise, organized presentations.
Again, thanks for the great explanations that tie these different subjects in each video.
Great video, do you think you may be able to make a video on some of the concepts in m-theory
maybe one day!
Excellent video Prof. Dave! Keep up the great work!
I immediately subscribed because of the brilliant intro.
His content is brilliant too
Incredible content. Underrated channel
He literally deserves 10 million subs!!
"Visible matter makes up only 5% of our universe, which is dominated by dark, unexplained forces.
Congrats on being one of the sparkly bits"
--Dr. Katie Mack
science has come so far but it seems like every time we make a discovery, we also find out just how much we don't know
Very true 😊
Also thank you for clarifying the circle graph saying mass energy equivalence, I have always had problems understanding how energy can be on the same graph as matter
I’ve just posted this comment in another science related video and looking the comments below here it fits perfectly.
why is it that the comments section of every video of scientific education always attracts a lot of the show offs, the “I know better” , the Dunning Kruger effected, the conspiracy theorists? I’m aware that by commenting I could include myself in this category , but I’m not implying that all comments are like that just that there are too many of those that go like, oh Einstein got it all wrong because.....reasons, or this is where all scientists are wrong .. reasons and watch this video, or I think therefore I know better than all of THEM. Just eat some humble pie and understand that probably you are NOT a genius, real geniuses don’t get Nobel prizes by commenting on RUclips, instead if you think you got the gift, take university courses, put your head down on books and try to stand on the shoulders of the giants that came before you to see further. If you can’t, just ask your questions and listen to the answers by those that know more than you do, and if you believe in conspiracies... well I’m sorry there’s is nothing much we can do except wishing you to enjoy a bit of your sad life also thanks to the technology brought to you by “THEM”.
Yes, there is an epidemic of pseudo-intellectuals that claim to understand physics better than Einstein when they couldn't pass a high school physics quiz. Unfortunately, there are many channels that cater to these delusional asshats and churn out content with the anti-establishment narrative they enjoy, and it makes things worse. I've been debunking several of them and they invite mountains of toxicity from precisely these bozos.
@@ProfessorDaveExplains Please continue to do so! 🙏🏻
Its a great question. I think there are several reasons: loss of trust in educational institutions and authority, internet anonymity, growing arrogance in our culture that somehow so many of us are 'smart' perhaps based on how we raise children over the last 50 years or so, and the shift from questioning things to questioning everything
If the vacuum energy is present at every point in space and space is expanding, wouldn't that mean more vacuum energy is showing up as space expands to help accelerate the expansion on even faster?
Hello proffesor Dave, I have a question.
In nuclear fusion, 4 protons come together to form a helium nucleus, a neutrino and a positron and gamma rays. So how does the sun produce visible light? Are there electrons somewhere I am not aware of?
helium has two protons, but in general the sun is a blackbody, it produces electromagnetic radiation of all wavelengths, the peak is in the visible spectrum
@@ProfessorDaveExplains I understand that helium is 2 neutrons 2 protons. But my question was how does it produce emr without electrons? Or does it have electrons?
Well there are electrons in there, it was neutral gas that collected to form the star, which only ionized once it got hot enough, but also the fusion events themselves produce photons.
Thank you very much for explaining.
how this is have only 440 likes?! Prof. Dave, you have VERY interesting channel, your vid about star formation was very informative, and I like when you summarized a section before a lot! Cheers! (my english is bad :P)
VERY UNDERRATED CHANNEL!
absolutely fascinating, thank you
Super interesting video! thank you for sharing
At 1.57 you say "if something is not capable of producing photons in this manner, or relate nuclear processes, it can't produce visible light". As far as I know, all electromagnetic radiations (visible or not visible to our eyes) consist of photons emitted by the same process you have described for visible light, that is: electrons moving from excited states to lower states.
For the most part! But there are a few other processes that produce photons as well, which occur in the nucleus.
Huh, I've never thought of the word tutorial as just learning info from a tutor. I've always thought of it only being something where you learn a process.
I wanted to know about dark matter...thanks bro
Maths: it should do this
Dark matter: n o p e
hi Dave, your hair is back.. good to see you professor.
To differentiate dark matter and dark energy for some people who think dark matter is responsible for cosmic expansion:
Dark Matter is not normally observable like matter, but we can observe it by gravity. There have been numerous hypothesis about dark matter. Heres a long quote from Yale about Dark Matter.
“Dark matter - which has never been directly observed - is thought to constitute the majority of matter in the universe and act as the unseen scaffolding upon which galaxies form and develop. Physicists have spent years testing a variety of dark matter candidates, including hypothetical particles such as sterile neutrinos, Weakly Interacting Massive Particles (WIMPS), and axions.
Black holes, on the other hand, have been observed. A black hole is a point in space where matter is so tightly compacted it creates intense gravity. Not even light can resist its pull. Black holes are found at the centers of most galaxies.
The new study, accepted for publication in The Astrophysical Journal, harkens back to a theory first proposed in the 1970s by physicists Stephen Hawking and Bernard Carr. At the time, Hawking and Carr argued that in the first fraction of a second after the Big Bang, tiny fluctuations in the density of the universe may have created an undulating landscape with “lumpy” regions that had extra mass. These lumpy areas would collapse into black holes.
Although the theory did not gain traction within the wider scientific community - the new study suggests that, if modified slightly, it could have explanatory power after all.
If most of the primordial black holes were “born” at a size roughly 1.4 times the mass of Earth’s sun, they could potentially account for all dark matter, said Yale professor of astronomy and physics Priyamvada Natarajan, the paper’s theorist.
Natarajan and her colleagues say their new model shows that the first stars and galaxies would have formed around black holes in the early universe. Also, she said, primordial black holes would have had the ability to grow into supermassive black holes by feasting on gas and stars in their vicinity, or by merging with other black holes.
“Primordial black holes, if they do exist, could well be the seeds from which all supermassive black holes form, including the one at the center of the Milky Way,” Natarajan said.
“What I find personally super exciting about this idea is how it elegantly unifies the two really challenging problems that I work on - that of probing the nature of dark matter and the formation and growth of black holes - and resolves them in one fell swoop,” she added.
The James Webb telescope’s mission will be to find the first galaxies that formed in the early universe and see stars forming planetary systems.
The new study’s first author is Nico Cappelluti, a former Yale Center for Astronomy & Astrophysics Prize postdoctoral fellow who is now an assistant professor of physics at the University of Miami. Günther Hasinger, ESA’s director of science, is the study’s second author.
“Our study shows that without introducing new particles or new physics, we can solve mysteries of modern cosmology from the nature of dark matter itself to the origin of super-massive black holes,” Cappelluti said.
Primordial black holes also may resolve another cosmological puzzle: the excess of infra-red radiation, synced with X-ray radiation, that has been detected from distant, dim sources scattered around the universe. Natarajan and her colleagues said growing, primordial black holes would present “exactly” the same radiation signature.
Best of all, the existence of primordial black holes can be proven - or disproven - in the near future, courtesy of the James Webb Space Telescope and ESA’s Laser Interferometer Space Antenna (LISA) mission announced for the 2030s.
If dark matter is comprised of primordial black holes, more stars and galaxies would have formed around them in the early universe - precisely the epoch that the James Webb telescope will be able to see. LISA, meanwhile, will be able to pick up gravitational wave signals from early mergers of primordial black holes.
“If the first stars and galaxies already formed in the so-called ‘dark ages,’ Webb should be able to see evidence of them,” Hasinger said.
Natarajan added, “It was irresistible to explore this idea deeply, knowing it had the potential to be validated fairly soon.””
While _Dark Energy_ is the *component* that causes cosmic expansion, or expansion of the universe. Quoting Wikipedia: “The expansion of the universe is the increase in distance between any two given gravitationally unbound parts of the observable universe with time. It is an intrinsic expansion whereby the scale of space itself changes. The universe does not expand "into" anything and does not require space to exist "outside" it.”
Damn, 68% of the universe is dark energy? Can we find a way to make dark matter so that we can bump that number up to 69%?
I am very troubled by this: people seem to refer to dark energy as vacuum energy, the energy contained in vacuum due to quantum fluctuations. But I heard that if you calculate the quantum energy and compare it with the observed magnitude of dark energy, the numbers are wrong by like 20 orders of magnitude.
Hmm, it sounds like you may be confusing dark energy with the zero-point energy, as the latter is what we associate with quantum fluctuations. At least that is my understanding!
@@ProfessorDaveExplains I just looked online and I think there is dispute regarding whether zero-point energy is a candidate of dark energy; the papers I saw were way beyond the power of my little brain though. Thank you for the reply Professor.
Finally! Dark matter!
Can you do a video on antimatter!
In this playlist, the next 5 videos (27-31) show as [private video] and do not play. Is there a reason for this?
i release them one per week, don't worry you'll get them all!
Brilliant! How about you propose this to the Flatearthers for a response? Careful not to finally blow their disc apart 😈🤯
Professor Dave explains 🎶🎶
Shouldn’t we be able to use gravitational lensing of the farthest objects from us to see beyond the edge of the observable universe?
Models trying to describe dark matter do not support dwarf galaxies on a near flat plane "organized" surrounding larger galaxies. Dwarf galaxies should be erratically positioned. Models also determined the dark matter should be concentrated in the center of galaxies and that is clearly wrong too.
I love this!!!!
You are brilliant
What was that? Duration 0:11 to 0:14 . In that Milkyway Timelapse. 15% from left top. a star "Appeared Still" for 3 seconds. Please can you explain that ? a Quick Supernova? ;)
I have seen this a few times. It is most likely a geostationary or geosynchronous satellite. You can see the same thing in this linked time-lapse. Because they rotate at the same speed as the earth, they appear not to move. This video has more than one that pop in and out of view like the one in Daves video. Easy to miss so look carefully. ruclips.net/video/vxHpaLqFYNc/видео.html
How does dark energy correlate wity the conservation of energy? Does the creation of new space by inflation create more dark energy or does the total amount of dark energy remain constant with a decreasing energy density? Do we simply don't know?
In our solar system, the planets closest to the sun move faster in their orbit than those farther from the sun. Why is this different in the galaxy you used in your example?
so the orbital velocities have to do with how much matter lies interior to the orbital radius of any particular star, but as to exactly how that data is gathered i'm not too sure!
I feel like dave could tell me anything and I would take it as a fact.
Then you would be spitting in the face of everything he is trying to do! The people we should question the most are those who teach us! Dave is very well researched but still human!
Could dark matter be electromagnetic radiation that is still on the move? Because obviously light is not visible as long as it does not reach the observer. Hence the following question: How much does light actually weigh in our galaxy, i.e. all radiation that does not hit a surface for a long time, is directed outwards into infinity or is even stuck under the event horizon of black holes? A fraction is sufficient as an answer, namely the relation to the total mass.
EM radiation does not have mass, so that doesn't work.
i dont think dark matter is actually real, i think its just an error in relativity that we haven't come up with a new theory to explain this hole in relativity, like how quantum mechanics and relativity are different and there is no universal theory to explain it yet
You should probably watch this video then, bud.
Have you heard of carbonaceous chrondites? Some of the most ancient matter still remaining of the solar system that hasn't been incorporated into either the Sun or the planets, this material is as dark as coal and mostly about the size of grains of sand so obviously light reflection from such objects is pretty much impossible so they ARE "dark matter"...
what is the unit of mass of the light?
its phoTONe
(its a dad joke)
🤣🤣🤣
Out of curiosity, what is your field of expertise?
Yes.
Hey dave, is dark matter a hypothetical variable to explain things or is there graphs and such that are getting closer to truly unravel it for what scientists think its is: matter which cannot be seen.
Btw love the vids
Astrophysicists are very confident it exists, we just don't know what it is. As to when we will know what it is, I have no idea. It is not a hypothetical variable.
@@ProfessorDaveExplains thank you dave
Perhaps dark matter is a combination of those things
Can anyone tell me If my theory on dark matter and possibly dark energy can be disproven.
As energy and mass are interchangeable, could all the energy no longer in a usable state not account for the extra mass known as dark energy?
Energy is not a substance that possesses mass and dark energy is not matter.
@@ProfessorDaveExplainsThanks fir your prompt response. Apologies, I meant to ask if the mass could be dark matter, not energy. Also can that energy not be transformed into matter with mass by some process, like for example when we try to accelerate particals closer to the speed of light, the more energy added simply adds mass not speed?
@@paulwardrope I think I see what you're trying to say. And since you're making an honest effort to try and understand the world, unlike the flat earth tards and basic science deniers and conspiracists, I cant sit here and say oh thats ridiculous because again, you're making an honest effort to try and understand things. What I will say however, is that its like asking about a difficult (but perhaps easy to state) problem from, say, advanced math class like Calc 3 or something, but you don't yet have a basic foundation in even algebra or trigonomtery. My advice would be, if you are really interested, is you have to build a foundation from the beginning, which means learning basic physics & astronomy, and from there moving into astrophysics before attempting to try and understand or theorize about dark matter or dark energy.
Is it possible to explain these things with the addition of the holographic universe theory? (it also explains the galaxies rotational anomaly, accelerating expanding of the universe and even the black holes singularity anomaly)
I thought since the galactic Center mass is higher, objects near or close the center have higher orbital velocity. I mean which planet has the higher orbital velocity , earth or mercury.
But professor Dave, Dark Matter constitutes 28% of the universe while regular matter constitutes 5% of the universe. So, dark matter is 5.6 times more than regular matter, and not 10 times.
He didn’t say that it’s ten times more in general, but that the mass of dark matter around the galaxy is ten times more than the mass of visible matter in a galaxy. So it is likely just denser around galaxies, which then produces than relation in the specific case of galaxies.
First.
2nd💪🏻🥈💪🏻
Question, will a rocket ship crash if it directly goes into dark matter?
No
@@Ryder-wt9tk why
@@marsar1775 Dark matter likely has no significant particle interactions with normal matter (like neutrinos)
@@Ryder-wt9tk oh
hi professer dave, wil u be my boyfren?
Dark matter can't be seen but can dark matter obstruct the path of visible matter?
hmm, well i guess we don't know how dark matter and visible matter would interact, but sure, i suppose it could.
@@ProfessorDaveExplains So, as of now we don't have any evidence of interaction?
not that i'm aware of, though i'm not a physicist
@@ProfessorDaveExplains Thanks for replying
From what I saw, dark matter doesn't interact with light but because it should have a mass it should bend space so it curve the path of light therefor "obstructing" the path of the light.
Damn i do understand dark matter better now
You understand the idea but not what it is. Nobody know yet
@@the10thdoctor84 yeah yeah that's what I meant
"they are no longer gods."
This is blasphemy. You know that if a multiverse exists, then Thor exists. Therefore, you blaspheme against the multiverse and Thor
It’s a sad state of our society when I can’t tell if this is sarcasm, or serious. 🧐
what the fuck is energy
Check out my classical physics playlist.
@@ProfessorDaveExplains Thank you Dave, you are very good mate!
Youi literally are s genius man like your iq has to be atleast 145
why would we expect gravity to get stronger as things get further from each other? That seems counter intuitive
It doesn't, the opposite is true.
It could be that the fundamental unit of energy which is 'Prana' of the physical observable universe, be the source of dark energy filling in all atoms, and the spaces in between.
Geek
By "we" he means, of course, "they".
We = the human race.
God is made of dark matter
no
I assume the assumptions parade LoL 😂Gotta love uniform industrial strength ideas
If you're not interested in learning science, why are you watching science tutorials?
Well what next biology?
nerd
Is that supposed to be a question?
Don't you mean the downfall of astronomy...
No.
Critique on your general method of operation: Interesting how you give full weight and credit to an "assumption" (~4:35) inherent in Dark Matter theory which has consistently failed empirical testing for required particles after decades and billions in research over multiple teams and contributors. This is directly opposite the personal attack laden, derisive approach to Electric/Plasma Cosmology. It's appears that you approached the latter topic with disdain before even attempting research into the subject. In fact, you present the least favorable light to the argument, utilize perhaps the least defensible purveyors, and include only portions of the theoretical body of work.
At the same time you state with near absolute confidence that we know, for fact/done deal, no other research or countervailing theories exist on any of these related topics (gravity, plasma, electromagnetism at both quantum and cosmological scales). How can you state we know what black holes are made of (~00:45) without anyone ever coming any where near such an object? That is absolutely wrong given the breadth and depth of research, both practical engineering and theoretical physics, ongoing now around the world on each of these subjects. Science is an iterative approach to understanding with every new inquiry leading to discovery, knowledge, and revision.
You do include a lot of rhetorical bandwagon techniques influencing your viewers to simply accept what you're conveying; phrasing such as "we believe" (~10:44) demonstrates an implicit need to dissuade questioning, dissent, and detraction (not the tools of the discipline and practice of science). Yet the vast majority of this presentation is loaded with subtle hints that the viewer should just agree on foundational assertions. The lead statement sets the tone for irrational obedience; (~00:14) "You have to admit that our current understanding of the universe is nothing short of astounding". You give scant caveats that would lead a lay person to question or seek out further resources and depth.
My rhetorical retort to your rhetorical flourish: I'm interpreting your presentation, in total, as either a near zero understanding of physics or specific theories yet pretend to, or you are simply unable to understand your limitations on what that you understand. Feigning knowledge is an unforgivable sin to science. Ignorance by contrast is fine, so long as it drives an approach towards subject at large with a level of skepticism and open mindedness. A philosophy of questioning and seeking is required for academic and scientific integrity. Unabashed shilling in promotion of popularism for fact, for profit, is just ridiculous. All of your viewers should dig in to alternatives, contrary views, and challenge every presentation. Obedience is not science.
Challenge: Review gravitational-based non-dark matter/energy cosmological models such as MOG (modified gravitational theory), SVTG (scalar-tensor- vector theory). Let's see if you can digest and honorably convey a theory. Or if there is, as I suspect, an irrational clinging to a popular position. Perhaps then you may be able to tackle the subject of cosmological lensing without baryonic material
Plasma cosmology is 40 years obsolete, bud. Get over it. Stop swallowing fringe science from RUclips.
_"Review gravitational-based non-dark matter/energy cosmological models such as MOG (modified gravitational theory), SVTG (scalar-tensor- vector theory). "_
They fail at large scales. Such as in galaxy cluster collision lensing observations. Simple as that. We then find the apologists of such hypotheses having to introduce some dark matter to keep their hypotheses alive. Which is kind of pointless, given that they were dreamed up to get rid of the need for dark matter! As it stands, there is only one model which explains observations.
Lies....period
care to back that up, or are we just throwing around wild accusations today?
certainly my friend......ill just go along with the points in your video
1 Dark matter is a "THEORY".....period....
2 Dark matter DOES NOT interact with light because it IS NOT there!
3 Orbital velocity of nothing is theory....and ignorant
4 There MUST be 10x the unseen matter in the universe....hahahahaha
5 Einsteins "THEORY" of general relativity has been disproven...period
6 "Dark matter must accumulate first" again theory and ignorant
7 Early galaxy evolution is a theory....period
8 there COULD EXIST sub atomic particles....hahahahah BIG theory and one that is on the verge of being discredited as we speak
9 Dark energy is a "CONCEPT" hahahaha thats another word for dream...lol
10 "We thought because of GRAVITATIONAL matter things were being pulled together" Gravity is a theory....period
11 Big Crunch and Big Bang...both wild conceptual theories...
12 you say in the end of the video quote "Some other thing? we don't know yet";...hahahahaha
13 5 billion years ago....lmao is a stupid theory...disproven in the 70s
and lets not forget Einsteins big mistakes....hahahaha
Basically the entire video is one big stoner kids idea of space hahahaha...not one single thing in it was a fact....you can argue that all you would like but it is my field of expertise and you are not only wrong but misleading.....the problem is that you get all of your information from the internet......@@ProfessorDaveExplains
Every single physicist in the world disagrees with everything you just said. Where exactly are you getting this? General relativity has been disproven? How and by whom? Tell me the details. The big bang was disproven in the 70s? How and by whom? Tell me the details. You are constantly laughing at your own statements because... even you realize how ridiculous they sound?
again showing your ignorance . This would explain why none of the professors or students or anyone you will ever meet will be in the "KNOW" of things....think about it....where do i get this information? we will just call it "the source" i will tell you that as I set here in my home by the beach listening to young people on the internet that I am saddened for the world you dillusionally live in, but it must be that way for a while longer. You are not prepared, nor can you grasp the nature of true reality. But I promise you that in your lifetime your information and view of the world around you will change and almost all of the things you believe to be true will become false theories that at one time fueled movies and books and music. We live in an amazing time.....you don't seem like a bad kid...I wish the best for you. Try to remember that ALL ideas of space and extraterrestrials are just fun ideas.......and I never laugh at the situation, actually it makes me sad. But there is nothing I can do about it.@@ProfessorDaveExplains
@@ProfessorDaveExplains and as a side note....try to remember that all of the books that you are ALLOWED to have access to are outdated by many, many decades.