Puzzling Mysteries of the Universe
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- เผยแพร่เมื่อ 20 พ.ค. 2024
- The cosmic microwave background (CMB) has been a treasure trove of information about the universe, as well as a source of questions that have not yet been resolved. In this video, Fermilab’s Dr. Don Lincoln describes two unsolved mysteries of the CMB. The first makes you ask if the solar system has a special place in the universe and the second is a giant cold spot that could be the signature of a giant void or, much more unlikely, of colliding universes.
Recent research: Scientists move a step closer to understanding the cold spot in the CMB:
news.fnal.gov/2022/01/scienti...
Fermilab physics 101:
www.fnal.gov/pub/science/part...
Fermilab home page:
fnal.gov
Further reference:
astronomy.com/issues/2007/dec...
www.newscientist.com/article/... - วิทยาศาสตร์และเทคโนโลยี
This is one of the best science channels on TH-cam for sure and Don is such a good host!
Sabine Hossenfelder also awesome !!!
He is THE host, others are boring :)
@@sokolum - She is OK, pretty good for the most part. She does have some more fringe ideas about a few topics if I remember right, but still with watching.
Consider the following:
a. Numbers: Modern science does not even know how numbers and certain mathematical constants exist for math to do what math does. (And nobody as of yet has been able to show me how numbers and certain mathematical constants can come from the Standard Model Of Particle Physics).
b. Space: Modern science does not even know what 'space' actually is nor how it could actually expand.
c. Time: Modern science does not even know what 'time' actually is nor how it could actually vary.
d. Gravity: Modern science does not even know what 'gravity' actually is nor how gravity actually does what it appears to do.
e. Speed of Light: 'Speed', distance divided by time, distance being two points in space with space between those two points. But yet, here again, modern science does not even know what space and time actually are that makes up 'speed' and they also claim that space can expand and time can vary, so how could they truly know even what the speed of light actually is that they utilize in many of the formulas? Speed of light should also vary depending upon what space and time it was in. And if the speed of light can vary in space and time, how then do far away astronomical observations actually work that are based upon light and the speed of light that could vary in actual reality?
No, this is science for children. Real science channels don't shy away from the math.
Thanks Don. I wanted to personally congratulate and thank you for the effort you've put into explaining physics to the public for a very long time. I wish you health and the joy of knowledge of physics never ends.
rugby ball would've made more sense though. 😅
I’m not a physicist but I understand everything that you say easily.. Not fully, but easily.. Kudos for simplifying it for us, mere mortals..
If a lay person can understand something, it is probably "un-scientific".
@@hidgik Such nonsense.
@@metcas Apparently you have absolutely no idea of what used to be called sarcasm or irony. Good luck.
@@hidgik Use /s then. This is the internet lol
This video popped up on my TH-cam feed and I realized I was behind one my Fermilab videos. I am going back right now to see what I missed. Keep it up Fermilab!
I have been waiting for this for so long! I finally "see" it. Thank you so much for the graphical explanation!!
I love this sort of content hearing about the unknown framed in this way stirs the imagination. It is the best form of science education I have come across. Please keep making this content.
This cmb series you have is just fascinating to me, keep them coming!! I appreciate you putting things into terms that "regular" folks can understand. I'm already familiar with Fourier transforms and such, so your explanation there was simple to follow.
Great video! I had read some articles about the topics covered here, but didn't really understand them until i saw this video. Hope to see more, and wishing you a quick recovery from whatever is ailing you, take care!
Amazing video. Thank you to all Fermilab team working for this excellent channel and Dr. Lincoln for explaining things so complex in this accessible way. I appreciate how the big questions are addressed, and the misconceptions are exposed and the right answers explained. I always learn something really amazing in any single video. I am sincerely thankful.
fascinating as ever.thanks Doctor Lincoln and keep up the good work.
I love your channel, you have helped me understand so much! Please keep doing it as long as you can!
I love that our minds seek rules and order and sensible answers to every cosmic bump in the road, never settling for "it might just be made like that" . Love your teaching method, keeping me riveted 30 years after I last saw the inside of a lecture hall.
This channel immediately shows me how much I don't know. Thanks!
Is everything OK Dr. Don? Are you well? I hope so!!
Thank you sir for taking the time to explain these interesting subjects for nonmathemeticians. I could understand the concepts you were illustrating and enjoy the wonderment! Well done.
Keep these coming! Thanks for the fun approach to complex topics!
I read somewhere that this cold part of the universe may be the result of a severe energy exploition of entire galaxies or even galaxy clusters by a type 3 civilization. Any comments on that? I personally find it a very likely explanation.
It might also explain the hot ring around it. As the civilization expands like a bubble turning its frontiers hotter than normal and leaving at his path a drained from energy part of the universe.
@@petrosgitsidis295 I am not expert in physics at all (engineer here), but I don't think so. By one side the concept of a 3rd level civilization is highly speculative already and do not extends (as far as I remember) to more than one galaxy, and in any case it would generate a signal signature identifiable in some way (as energy is only transformed). By other hand, the CMB radiation was originated about 380 000 years after big bang, in an epoch in which galaxies still didn't exist.
I am really interested in the cold spot and what we know and don't know about it. I would love it if you made another video about it in the future. Thank you for expanding my personal universe!
10:15. At 2.7°K, calling the CMB "a pretty cool thing" is quite an understatement!
Real science videos about mysteries of the universe are awesome, can't wait for more!
Always a great day when Don appears on my feed! Thank you Don!
Hi Don!! Thanks for filling the super-void in my head! I have had no episodes of brain freeze anymore since shortly after I started watching this channel! (
My head already has a super void in it.
I do love these mind bending journeys with Dr Don
thank you very much for making these videos ❤️🌻
Best of the Best current physical science channel. Thank you.
Excellent Program
thank you Dr Don
Dr. Lincoln is nailing it, as usually! ;)
Mind-blowingly awesome, Dr. Don! Perhaps the super void has something to do with your going mustacheless? Great explanation about Fourier analysis.
Yoooo Don is back!!! Great video as always!
Congrats on the 600K subs!!!
THANK YOU PROFESSOR LINCOLN...!!!
Good seeing you back Dr. Don! I am going with the "it just happened that way" theory! 😂😂👍👍
Beautiful, inspiring work.
Thanks for sharing your knowledge of the cosmos
Love your explanation. Thanks
An entertaining and easy-to-understand book about the cosmic microwave background radiation alignment debate is Axis of Beginning.
Thank you!
Thank you, professor!
Dr. Don, looking good. Wish you good health and a nice day, thank you for the video.
Don Lincoln is a such a total hero. I fully expect him to be the one who explains the meaning of life soon.
Excellent explanations .
Great Video !!!
Thanks Don.
What an awesome explanation of Fourrier analysis for the layman! Hope I may use it too!
Great! Thank you!
Love this series,
Dr. Don's sprinkles of down-to-earth non-physicist humor is what makes his physics topics so fascinating to watch. Thanks Dr. Don!!
Dude. Dr. Don. That goofball analogy was wonderful. I've never heard it before.
I love that there's so much more that we don't know. So much adventure ahead! We are going to learn some amazing things!
I'd like to hear some discussion about Roger Penrose's claim that the CMB contains concentric patterns that support his theory of a cyclic universe.
Penrose 🤦♂️🤦♀️🤦
Nice presentation.
Just want more...always entertaining.
thank you 😊
I love this so much! Thank you for sharing! Humanity has gone so far!!!
very interesting! thank you
Very interesting, informative and worthwhile video.
I love watching your informative videos. Your voice and lungs seem much weaker- hopefully not Covid!
Be well!!! : )
Could the alignment of of the spherical waveforms be a function of observation bias? We can only see them from effectively a singularity so the CMB will appear perpendicular to is in all directions.
Actually the alignment is exactly what would be predicted if the measured dipole in the CMB is *cosmological*(i.e. caused by an inherit asymmetry in the distribution of matter/energy at the time of the reionization epoch) rather than kinematic (due to the motion of our solar system) as has been typically assumed for simplicity (without any supporting evidence) and to allow the analytically solvable Friedmann solutions to be able to be assumed to be approximately applicable for our universe (and thus avoiding the nonlinear domain of the Einstein field equations)
Thankfully Ellis & Baldwin (1984) devised an experimental test which would be able to check the validity of the assumption of a kinematic dipole by measuring a large sample size of over a million cosmologically distant i.e. high redshift sources one could construct a dipole measurement which if the assumption of a kinematic dipole was true should be identical in both direction and magnitude of the CMB dipole. If it is not identical then the purely kinematic dipole assumption is falsified, i.e. there is a large real cosmological dipole component in the CMB which can not be removed by a relativistic reference frame correction to allow one to shift to a supposed CMB inertial frame.
In what is probably the most important breakthrough in cosmology in recent years which sadly has been largely ignored this was finally tested with over a million sources by Nathan J. Secrest et. al (Nathan J. Secrest et al 2021 APJL 908 L51). Using a final sample size of 1.36 million quasars after the removal of possible sources of contamination from the local universe they were able to show that the measured dipole while similar enough in direction (only off by 8 degrees so not statistically significant enough) the magnitude was more than twice that of the CMB dipole which is a 4.9 Sigma significance discrepancy from a kinematic dipole.
This *is* significant enough to falsify the kinematic dipole assumption while also solving a number of cosmological mysteries, the apparent dipole quadrupole octupole etc. alignment, the measured acceleration of the rate of expansion(without requiring the existence of dark energy), the discrepancy in observed rate of expansion over time(again without requiring the existence of dark energy).
Basically about half a dozen mysteries/discrepancies in cosmology just go away just by removing the cosmological principal which hinged on the purely kinematic CMB dipole assumption to avoid falsification by the CMB measurements since all these discrepancies under Lambda CDM are natural predictions of the general Einstein field equations in a universe with a significant initial anisotropy and inhomogeneity.
Occam's razor strikes lambda CDM dead in favor of an anisotropic and inhomogeneous general solution of the Einstein field equations without the assumption of dark energy. It is just about as big of a simplification as the Heliocentric model of the solar system(with Kepler's laws) were over the Ptolemaic model except that the math is of course much harder since there are no nice neat analytical solutions anymore.
Thanks for another great video, one thing that struck me, if it turns out that there is really no cold spot wouldn't that impune all the rest of the data we have on the CMB?
I had the exact same thought
As always, I will generously like this Fermilab vid which was extremely interesting, but went way over my head.
Great video !
Thanks Don your the best!
Great video as usual ☘️☘️☘️
Is the fact that we can see back in to time at all, due to the expansion of the universe and the speed of light a unique thing we should appreciate how unique that is? I mean it is pretty special that what we see is any galaxy as it was in the past, not current. That's pretty interesting.
Actually when we look at our own feet we see them as how they looked in the past, when light got reflected by them and started it's journey up to our eyes.
Dude, you got a haircut! Thanks for the awesome videos BTW!
I propose that this man be given a Nobel Prize for ‘talking’. He is that good in talking down complexity into digestible quantised bits for his viewers.
The first time I've seen some things, thanks.
Im and electrical engineer but I have worked as a mechanical engineer for the past several years. In my mechanical work I have used FFTs quite a bit. Just as much as I do with my electrical work. Machine vibrations, pressure signals, flow signals and even sound, help diagnose system issues when broken into their individual frequencies. And in a recent case I worked on, we proved a digital system was inducing mechanical vibrarions by probing several signals and correlating bode plots.
The CMB map is always presented in its modified form. It would be interesting to see the processing it goes through, with details, so we could understand how much delicate it is. To me it seems that some amount of "cleaning up" is left undone, if there are solar system related artifacts left.
Also, why the sphere map of CMB is almost never shown, only the not-so-clear elliptic map?
Bingo this is a critical point that has often been missed in the discussion. In particular the data clean up is largely dependent on our *assumptions* In particular a really big assumption is that the dipole in the CMB is purely kinematic allowing us to perform a relativistic frame shift to an *assumed* frame where the CMB is isotropic and uniform.
If part of the CMB dipole is not kinematic i.e. not due to the net motion of our frame of reference then the assumed frame where the CMB is isotropic and uniform does not exist and all conclusions dependent on that assumption (in particular the supposed existence of dark energy as a major component of the Universe and the validity of the cosmological principal) fall apart like a house of cards in the wind under the weight of huge systematic biases that swamp out any signals in the data.
Luckily this assumption can be tested as proposed by Elis & Baldwin in 1984 (G. F. R. Ellis, J. E. Baldwin, MNRAS, Volume 206, Issue 2, January 1984, Pages 377-381, doi.org/10.1093/mnras/206.2.377) The tricky bit is that you need a very large sample size to show this with any degree of statistical significance i.e. you need more than a million sources.
Last year however Nathan Secrest and collaborators (Nathan J. Secrest et al 2021 APJL 908 L51) finally performed this test on a final sample size of 1.36 million quasars measured by WISE over its initial and extended mission phases. The results show that distant sources have a significantly larger dipole which while "only" 8 degrees off from the CMB dipole is more than twice as large in magnitude and thus is at 4.9 sigma discrepancy with a purely kinematic dipole (i.e. only a 1 in 2 million chance of being a statistical fluke)
Things are consequently looking pretty bad for a lot of cosmological results it looks like Cosmology is going to have to come to terms with the general nonlinear domain of the Einstein field equations.
@@Dragrath1 thank you very much for the information
What's the answer? I don't know. That in itself gives Don such credibility that he is clear on the boundaries between knowledge and conjecture. Keep it up Don. Oh, and his audiobook for The Evidence for Modern Physics was outstanding. A lot of material overlap with some of his videos, but I thoroughly enjoyed the whole thing as it was organized in a more front-to-back explanation rather than topical like this channel.
We need more Dr. Don please.....
I always look forward to these videos. Does the analysis of the CMB allow us to determine the distance to the CMB? I presume the the origin of the CMB to be at or near the boundary of the univirse in all directions ?
As far as I know the CMB is the boundary of the "observable" universe, 46 billion (1E9) light years away, which arrived to us from all directions after travelling almost 13.8 billion (1E9) years. This is possible because the universe expanded, allowing the light to seems as having travelled more than possible in an stationary universe. The universe could be even much bigger than this 92 billions light years diameter bubble, but that is the further we can see.
The origin of the CMB was the Big Bang. The CMB was about 380,000 years after the BB. So technically it's 13.7 Billions - 380,000 Light-years away and ago. I'd guess you could say it's at near the boundary of the visible universe and yes all directions. Although it's about something like 45 billion light-years away today because the universe has been expanding ever since. The whole universe may be at least 500 times bigger than the visible universe. Something like that.
@@tTtt-ho3tq Thanks, that's what I presumed. I was just wondering if we developed any tricks to measure the distance the way we can to some stars. In other words does the CMB reveal or confirm anything about the uniform shape of the universe?
@@alanr3705
Oh, those are the details. I don't do details or windows. The details are hard. You really have to know to study the details. Sorry I've no idea. Even Einstein's special relativity don't make no sense to me already. I'm sure they have methods to measure all those things. I'd think someone would come up with some good ideas if there's something better. I just follow blindly. Physics is universal worldwide. Einstein's, quantum mechanics, etc are all the same to every scientists around the world. And remember physics is everything. That's why I watch this or others.
Is there any difference in polorization or wavelength in the microwaves comming from the cold spot and around it, compared to microvaves from other parts of the CMB? If, can that information then be used to substantiate any of the theories?
I KNEW YOU WOULD GET A NEW HAIRCUT! LOOKING HANDSOME Dr. D! Best channel.
Spacetime channel is getting weird and stepping away from fundamentals (watered down with a lot of conjecture) and sometimes goes on tangents perpendicular to logic. Your videos are the best.
The data from Dark Energy Survey recently matched with CMB supervoid theory. I hope you shed some light on the current understanding Dr. Lincoln ..?
10:58
"That was pretty cool"
Indeed, but if you go far enough back in time, CMB was really hot.
Hi Don. Can you consider doing a video on how the universe possibly came into existence?
I love the colliding universes idea, I hope that will end up being the answer
Great vid, gracias señor
I really enjoy several speakers, but this fellow is my favorite. What I’d like to see is Neil Matt Sabine Becky all sit with Don and chat for an hour or two about, we’ll, about anything they want. I’d likely find most topics interesting. Lol. I’m easy. Just to have them all together chatting over coffee/tea. Just an idea!!
A good science channel is the one in which they are not affraid to say we don’t know
Approximately how many points went into creating the famous CMB? One would presume that is something that is known. Also, the most evocative title cards!
Very good video! Thank you!
How would the supervoid explain the hot ring around the cold spot?
The most interesting videos with content "I don't know" on TH-cam. 👍
This channel: "Bearing a gift beyond price, almost free..." to quote my favorite band, who I think would approve.
Rush!
I miss the mustache Don! But I love your videos, keep them coming please!
Love it
Also, where do the 16 spot, 32 spot and other point at?
11 minutes well spent!
Dear Dr. Lincoln,
Hello, fellow Rose-Hulman alum who decided to pursue a research career with a focus on teaching! I have a couple questions that I'd love to get your input on:
1. Suppose we have a black hole out on the edge of a galaxy. As it moves about, it will of course accrete dust and light, but it'll also accrete dark matter (assuming dark matter is made of particles). What fraction of its growth would be attributed to regular matter, what fraction to radiation, and what fraction to dark matter? Would an excess of growth over the expected growth from radiation & regular matter be evidence for dark matter? What would be the best way to measure its mass? Period of an orbiting pulsar, maybe?
2. When looking for new fundamental particles, what are the benefits of colliding protons in the LHC, instead of, say, protons & antiprotons, or lead ions, or electrons?
3. Who, in your opinion, are the great science communicators of biology and chemistry?
4. What aspects of science communication do we as a community need to focus more on? Early education? Technical explanations? Visualization?
The CMB void seems to have similarities to the voids discovered in the nuclear materials found after the Chernobyl accident. During the investigation they looked at how materials fail due to radiation damage and found void-pockets of vacuum in those materials effected. They have the football shape to them due to crystallinity and they are all aligned on the same axis.
Havent seen him for a while and is it me or does he seem out of breath alot. Hope he is doing ok, great channel
Good explanation. It's interesting how you can describe the CMB using these 'spherical harmonics' (which involve functions called 'Legendre polymials') like you can break down a wiggly graph into a set of sine & cosine waves using 'Fourier analysis'
It isn't surprising given that it has been proven that any differentiable function can be broken down into an infinite series decomposition. The issue is of course with how these terms are interpreted for example it has been traditional to assume the dipole term is kinematic but this is just an assumption a cosmological dipole due to significant matter asymmetries back during the CMB epoch would for example naturally predict an alignment between the dipole quadrupole octupole etc..
@@Dragrath1 - What do you mean any function can be broke down infinitely? It's been a long time since I have take Calc, so you'll have to forgive my ignorance. Take x^2 for example. The derivative is 2x. The second derivative is 2. Where do you go from there?
@@ElectronFieldPulse any function can be reproduced from a weighted sum of infinitely many sine waves of different wavelengths. He tried to explain this at 1:40.
@@ElectronFieldPulse Ah sorry for the confusion yes that has a finite Taylor series decomposition there are no other terms in that particular case.
The value of series decompositions has more to do with much more complex functions, such as those which are solutions to a system of partial differential equations, as it means that there is a series decomposition that can be fitted to it which becomes exact with infinite terms. Though generally you don't usually need more than a few terms to approximately fit many such function solutions. It usually is a bad sign that you likely made an error if it doesn't dampen out with subsequent terms. It is an example of such a non terminating expansion that leads physicists to consider GR and Quantum Field Theory incompatible as the terms blow up to infinity.
The first thing that comes to mind here is that somehow the CMB axis orientation influenced the axis of the formation of the solar system like some sort of universal coriolis effect (but this would imply that most star systems in the universe are aligned and I think we'd have noticed that)
The second thing that comes to mind is that the flat distribution of gravity in the solar system is somehow distorting our perception of the CMB
(not even sure how either of these would or wouldn't make sense, though)
Hi Professor. Great episode 👍 but there's something bothers me: why the void is causing wavelength to change while regular (non-void) space does not?
Great question, if you wanna understand easily in simple terms.
Let's take a example when you speak in vaccum your voice will be slow and diminished after a certain distance. But you can listen upto very small distance. If there is membrane at that some voice can be heard.
Just like sound need medium to travel. In the same way the wave also need energy and other particles to travel.
At the exit of the void the wave particles gain similar energy what they lost at the entrance of the void.
In rhe actual space wavelength also changes, that thing known as redshift happenings because of expansion of universe
Thanks for asking the question 😊
I think it's about the fact that when entering the void, there's more mass behind than in front of a given photon. The photon can't slow down, so it loses energy by becoming lower frequency. As it travels towards the opposite edge, there's more mass in front than behind, causing the opposite effect.
Monis's explanation is a great analogy but that's about waves in a medium. A photon is a quantum wavelet that (in theory) doesn't need a medium. It's also a particle that goes at the speed of light. Those are important differences.
@@gyozakeynsianism thanks a lot for the applause, wait lemme explain more simply
Temperature of the void is responsible for the change, as dr said temp is lower in the void. When the quantum particles travel in the colder area the speed of particles slower down and vice versa.
To understand this in real world scenario.
Imagine you are boiling water in covered beaker in which a pipe is connected and the end of pipe is also in beaker but a pipe is cooled by ice
The water gained energy during boiling ( but condensed into water from water vapours when this condensed water again become water vapours because it gain energy.
And you also tried nicely. But there is a catch here, space isn't true vaccum.
Even so called void has some particle density
@@monisrajput8056 Dr. Don said temperature is measured to be lower in the supervoid. This is assuming that what we're actually measuring is true, original CMB. But one alternative theory is that a large, empty opening in space that is younger than the Big Bang could be in the way of the CMB, which could result in lower temperatures (meaning the supervoid would not actually be a measure of the CMB). CMB radiation passes through this smaller, closer void and makes it cooler.
It's hard to believe this is about interaction between photons and matter, because even outside this theorized void, space between galaxies is both immense and very empty. The theorized void would be even emptier. And if there were interaction with matter, we'd expect scattering of the light; the light that makes it though is almost certainly not scattered and therefore didn't interact with matter.
@@gyozakeynsianism well man the void may be created with the perfect supernova of star.
Every matter interacts with other matter except dark matter.
Scattering also happens but it very minute it remains unnoticed.
For me this is the best scientific classrom for ignorant viewers like myself. I enjoy the channel enourmosly. Thank you very much.
I would love to see Don's T-shirts as the glimpses I have seen have told me how clever they are. However, the blazer/sports jacket means I almost never see them. Is there any chance of an insert showing his t-shirt in future videos, please?
The t-shirts are usually exposed in the video thumbnails (which you can easily extract online)
Aha! Thank you very much for your help. I am grateful!!@@narfwhals7843
That t-shirt is awesome!
Maybe the universe started out as some kind of (particle) with gargantuan mass, in some infinite vacuum, that became unstable and decayed in a release of all the energy and mass that resulted in the Big Bang. The genesis particle would be a cool name. But seriously is it plausible?
Check out "quantum creation." I think it points to a very likely scenario for how the big bang occurred.
@@moonchase A Genesis Particle, if it even exists, could be a particle of pure energy rather than one of actual mass. Or one with properties unknown to us. But I'm just speculating here. The other thing is could the unification of gravity with other forces of the universe be combined in such a primordial particle? Bear in mind I'm just trying to think outside the box with this because conventional physics doesn't seem to be getting us anywhere. IDK.
Rockin Don delivers! All hail the CMB, pretty cool to think I'm ridin a frisbee through it. Just wondering if some dawg catches it.