@@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?
it's not ONLY for children. what an ignorant comment. you apparently have an ego problem. in a developed nation about 70% of people never make it to university. of the remaining 30% maybe half go into sciences and half into humanities, so only 15% get past high school math. half of those get a C+ or less so don't really know what they're doing. 7.5% therefore know something, and probably only a tenth of those use high level math on a regular basis. so you are now at 0.75% of the adult population... that's being generous. and in developing countries it's probably 1/100th of that. so, no, 99%+ of the adult population are not children. nor do they have the intellect of children.
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!
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.
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.
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.
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.
The greatest mystery : Where have all the missing Odd Socks gone ? You always started off life with Even socks... but eventually, as you do laundry, you will discover you now have an odd amount of socks... and ... where have the vanished gone ?!?
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.
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.
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.
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! (
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!
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!
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.
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.
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.
So..the CMB proved the Earth is the center of the Universe. Big deal, that's not important. Pay no attention to the man behind the curtain and just move on... Now, let's talk about the cold spot. You gotta love 'science'.
The ecliptic plane is nearly perpendicular to the galactic plane. As a result, the heliosphere is highly non-symmetric with respect to the "top" half facing "forward" and "bottom" half facing "backwards". Perhaps the "axis of evil" is an artifact of the structure of the heliosphere?
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!!
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?
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?
@@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.
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 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.
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.
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.
I wonder how we can be sure the CMB apparent alignment with the solar system is not more than a ficticious artifact created during the measurements. I wonder how it is possible to remove all the interference created by the Milky Way in order to get a clean CMB signal.
Actually the CMB alignment is more tricky than given here because it is only an assumption that the total dipole in the CMB is kinematic in origin i.e. purely a Doppler shift which can be removed by a relativistic transformation to reach an assumed isotropic CMB reference frame. If the dipole is at east partly not kinematic but rather is cosmological in origin i.e. caused by a large scale asymmetry in the energy/matter distribution of the early universe back during the CMB epoch then the alignment of that CMB dipole with the Quadrupole and Octupole etc. terms is exactly what would be predicted. This kinematic assumption has been typically assumed for simplicity (without any supporting evidence) and to allow the cosmological principal to avoid being falsified by the CMB which by saving the cosmological principal allows cosmologists to make assumptions to let them use the analytically solvable Friedmann solutions to the general Einstein field equations which are only exact solutions in the case of prefect isotropy and homogeneity at all scales. This then allows cosmologists to avoid having to deal with the nonlinear domain of the Einstein field equations which are fundamentally chaotic. 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. When this finally gets through to cosmology it will just mean that like every other field of science they will have to deal with the fundamentally chaotic and thus unpredictable nature of complex systems governed by nonlinear systems of partial differential equations. Honestly this becomes obvious in the face of Gödel's incompleteness theorems which are a fundamental corner stone of the mathematical rules of logic and form the basis of modern computational mathematics and theory.
For sure, and now they have subtracted the entire milkyway to produce an image of the black hole in the middle. I find that impossible to do with any statistical significance. Looking past a billion highly compact region of stars? I don't think so. Computer programs can do anything you want, called confirmation bias. Once it produced what they wanted, it was all good.
I wonder: if a super void can distort the CMB signal, how can we be sure other factors like gravity lensing by dark matter distribution are not distorting it too?
Because they use computer programs to remove the heat detected from galaxies, stars, etc, etc, which means they can make their program produce anything they want! Sure they might try hard, but how can you know how much heat to subtract? These videos NEVER explain HOW they come up with this stuff we take as fact.
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?
The idea that intervening space can cause variations in the signal we receive from the CMB makes me concerned that it may be the cause of other variation seen in the CMB.
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)
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.
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.
If you went a few dozen light years to the left and took a picture of the CMB, would it be the same? Also, if we waited a million years and took the picture again, would it look the same? I suppose it wouldnt, and therefore since its an evolving picture, coincidences like the cold spot will happen sometimes.
It would the same way a few light years to the left, but not exactly the same. It would not look the same a few million years in the future. Because the universe is expanding the cmb cools down with time. In a few million years it will be somewhat colder.
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.
You might be interested in learning that the assumption that the dipole term is purely kinematic has recently been tested as first proposed by Ellis & Baldwin (1984). One consequence of a kinematic dipole is that it should be the same for all distant sources so you can 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. This has been tested a number of times but the sample sizes have always been far too small to make any actual conclusions Just last year however the first test of this with over a million cosmologically distant sources was published back in February 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 (1 in 2 million odds of occurring purely by chance) from a kinematic dipole. If the dipole itself is cosmological in origin it changes everything as it means our universe falls within the highly nonlinear regime of the Einstein field equations and thus structure scale becomes chaotic in terms of how big of voids or galaxy superclusters etc. can form with the local rate of expansion varying in time and space in all directions. In particular one automatic prediction for the general solutions to the Einstein field equations in a geometrically flat universe is that any arbitrary anisotropy must drive accelerated expansion with a natural arrow of time since the No big Crunch theorem proves through contradiction that in the anisotropic and inhomogeneous domain of the Einstein field equations there can not be any time slice of the universe with a maximum (or minimum) total spatial volume.(Matthew Kleban and Leonardo Senatore JCAP10(2016)022) Additionally as there is a countably finite number of possible configurations for a spatial manifold for a given total spatial volume it can be shown there is a direct equivalence from this constraint to avoid a self contradiction within the Einstein field equations and the second law of thermodynamics and associated arrow of time. Basically for any anisotropic and inhomogeneous initial conditions all possible solutions to the Einstein field equations will always either expand forever at an accelerated rate globally maximizing entropy over all time slices or contract forever minimizing entropy over time slices(which is effectively the expanding solution time reversed). Fundamentally it means you get an arrow of time within any universe that starts with a large scale asymmetry in its initial conditions which can only get amplified with time. So every minor fluctuation from equilibrium will eventually produce an associated large scale structure in time forward time slices of spacetime.
I like the idea of the alignment being real but due to one of a few non-anthropocentric explanations: 1) Maybe the solar system's own dust refracts or polarizes the CMB data we collect? 2) Maybe there's a relativistic effect distorting the CMB data we collect due to the solar system's relative motion? 3) Inflation somehow gave the early universe a slight twist and we're coincidentally slightly aligned with it?
Even your video editors are trying to hurry you up, they're playing music louder and louder at the end like it's the Academy Awards and they're trying to play you off the stage. 😂
![ละลาย (LALALYE) - DAOU PITTAYA ต้าห์อู๋ พิทยา [OFFICIAL MV]](http://i.ytimg.com/vi/wo6r9TgausI/mqdefault.jpg)
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?
it's not ONLY for children. what an ignorant comment. you apparently have an ego problem. in a developed nation about 70% of people never make it to university. of the remaining 30% maybe half go into sciences and half into humanities, so only 15% get past high school math. half of those get a C+ or less so don't really know what they're doing. 7.5% therefore know something, and probably only a tenth of those use high level math on a regular basis. so you are now at 0.75% of the adult population... that's being generous. and in developing countries it's probably 1/100th of that.
so, no, 99%+ of the adult population are not children. nor do they have the intellect of children.
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!
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. 😅
An entertaining and easy-to-understand book about the cosmic microwave background radiation alignment debate is Axis of Beginning.
10:15. At 2.7°K, calling the CMB "a pretty cool thing" is quite an understatement!
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.
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 channel immediately shows me how much I don't know. Thanks!
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.
Is everything OK Dr. Don? Are you well? I hope so!!
Don Lincoln is a such a total hero. I fully expect him to be the one who explains the meaning of life soon.
I do love these mind bending journeys with Dr Don
Best of the Best current physical science channel. Thank you.
Dr. Don's sprinkles of down-to-earth non-physicist humor is what makes his physics topics so fascinating to watch. Thanks Dr. Don!!
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.
The greatest mystery : Where have all the missing Odd Socks gone ? You always started off life with Even socks... but eventually, as you do laundry, you will discover you now have an odd amount of socks... and ... where have the vanished gone ?!?
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.
THANK YOU PROFESSOR LINCOLN...!!!
Dude. Dr. Don. That goofball analogy was wonderful. I've never heard it before.
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.
Real science videos about mysteries of the universe are awesome, can't wait for more!
fascinating as ever.thanks Doctor Lincoln and keep up the good work.
Always a great day when Don appears on my feed! Thank you Don!
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.
I have been waiting for this for so long! I finally "see" it. Thank you so much for the graphical explanation!!
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.
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!
Dr. Lincoln is nailing it, as usually! ;)
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!
Just want more...always entertaining.
Good seeing you back Dr. Don! I am going with the "it just happened that way" theory! 😂😂👍👍
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 🤦♂️🤦♀️🤦
in case anyone is interested, his t-shirt reads: √-4=2 it's all fun and games until someone loses an i
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.
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.
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.
So..the CMB proved the Earth is the center of the Universe. Big deal, that's not important.
Pay no attention to the man behind the curtain and just move on...
Now, let's talk about the cold spot.
You gotta love 'science'.
The ecliptic plane is nearly perpendicular to the galactic plane. As a result, the heliosphere is highly non-symmetric with respect to the "top" half facing "forward" and "bottom" half facing "backwards". Perhaps the "axis of evil" is an artifact of the structure of the heliosphere?
A good science channel is the one in which they are not affraid to say we don’t know
thank you Dr Don
For me this is the best scientific classrom for ignorant viewers like myself. I enjoy the channel enourmosly. Thank you very much.
This channel: "Bearing a gift beyond price, almost free..." to quote my favorite band, who I think would approve.
Rush!
Thank you!
The most interesting videos with content "I don't know" on TH-cam. 👍
Dr. Don, looking good. Wish you good health and a nice day, thank you for the video.
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!!
Thanks for sharing your knowledge of the cosmos
Yoooo Don is back!!! Great video as always!
Great! Thank you!
I love watching your informative videos. Your voice and lungs seem much weaker- hopefully not Covid!
Be well!!! : )
Excellent Program
Very interesting, informative and worthwhile video.
As always, I will generously like this Fermilab vid which was extremely interesting, but went way over my head.
Beautiful, inspiring work.
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!
What an awesome explanation of Fourrier analysis for the layman! Hope I may use it too!
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?
I love your channel, you have helped me understand so much! Please keep doing it as long as you can!
Congrats on the 600K subs!!!
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.
We need more Dr. Don please.....
10:58
"That was pretty cool"
Indeed, but if you go far enough back in time, CMB was really hot.
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 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
Great Video !!!
Excellent explanations .
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
The data from Dark Energy Survey recently matched with CMB supervoid theory. I hope you shed some light on the current understanding Dr. Lincoln ..?
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.
thank you very much for making these videos ❤️🌻
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.
I love those "I dunno"-moments. that's when some less honest pop-scientists try to peddle speculation.
Great video as usual ☘️☘️☘️
I wonder how we can be sure the CMB apparent alignment with the solar system is not more than a ficticious artifact created during the measurements. I wonder how it is possible to remove all the interference created by the Milky Way in order to get a clean CMB signal.
My thoughts too.
Actually the CMB alignment is more tricky than given here because it is only an assumption that the total dipole in the CMB is kinematic in origin i.e. purely a Doppler shift which can be removed by a relativistic transformation to reach an assumed isotropic CMB reference frame.
If the dipole is at east partly not kinematic but rather is cosmological in origin i.e. caused by a large scale asymmetry in the energy/matter distribution of the early universe back during the CMB epoch then the alignment of that CMB dipole with the Quadrupole and Octupole etc. terms is exactly what would be predicted. This kinematic assumption has been typically assumed for simplicity (without any supporting evidence) and to allow the cosmological principal to avoid being falsified by the CMB which by saving the cosmological principal allows cosmologists to make assumptions to let them use the analytically solvable Friedmann solutions to the general Einstein field equations which are only exact solutions in the case of prefect isotropy and homogeneity at all scales.
This then allows cosmologists to avoid having to deal with the nonlinear domain of the Einstein field equations which are fundamentally chaotic.
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.
When this finally gets through to cosmology it will just mean that like every other field of science they will have to deal with the fundamentally chaotic and thus unpredictable nature of complex systems governed by nonlinear systems of partial differential equations. Honestly this becomes obvious in the face of Gödel's incompleteness theorems which are a fundamental corner stone of the mathematical rules of logic and form the basis of modern computational mathematics and theory.
For sure, and now they have subtracted the entire milkyway to produce an image of the black hole in the middle. I find that impossible to do with any statistical significance. Looking past a billion highly compact region of stars? I don't think so. Computer programs can do anything you want, called confirmation bias. Once it produced what they wanted, it was all good.
I love this so much! Thank you for sharing! Humanity has gone so far!!!
The first time I've seen some things, thanks.
I wonder: if a super void can distort the CMB signal, how can we be sure other factors like gravity lensing by dark matter distribution are not distorting it too?
Maybe a super void and a black whole in between or inside it?
No doubt such factors *are* distorting it. It just appears that their effects are minimal.
@@jursamaj maybe we can't see it (the effect)or imagine what it could be changed into?
Because they use computer programs to remove the heat detected from galaxies, stars, etc, etc, which means they can make their program produce anything they want! Sure they might try hard, but how can you know how much heat to subtract? These videos NEVER explain HOW they come up with this stuff we take as fact.
Mind-blowingly awesome, Dr. Don! Perhaps the super void has something to do with your going mustacheless? Great explanation about Fourier analysis.
Nice presentation.
Love your explanation. Thanks
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
Thanks Don.
Popping here is always worth it.
The idea that intervening space can cause variations in the signal we receive from the CMB makes me concerned that it may be the cause of other variation seen in the CMB.
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)
Thanks Don your the best!
Is it possible the answers to the questions in this video can be derived from tacos? Because all I’ve got is tacos.
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.
It wasn't clear for me the difference of a 'photon on a void' and not making the 'void photon' less energetic...
I love the colliding universes idea, I hope that will end up being the answer
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.
If you went a few dozen light years to the left and took a picture of the CMB, would it be the same? Also, if we waited a million years and took the picture again, would it look the same?
I suppose it wouldnt, and therefore since its an evolving picture, coincidences like the cold spot will happen sometimes.
It would the same way a few light years to the left, but not exactly the same.
It would not look the same a few million years in the future. Because the universe is expanding the cmb cools down with time. In a few million years it will be somewhat colder.
nice questions
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.
Dude, you got a haircut! Thanks for the awesome videos BTW!
Love this series,
mind blown
I miss the mustache Don! But I love your videos, keep them coming please!
If a supervoid can explain the cosmic cold spot, can't other voids explain all the fluctuations of the CMB?
Voids are localized structures and are not enough to explain the CMB variations.
You might be interested in learning that the assumption that the dipole term is purely kinematic has recently been tested as first proposed by Ellis & Baldwin (1984). One consequence of a kinematic dipole is that it should be the same for all distant sources so you can 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. This has been tested a number of times but the sample sizes have always been far too small to make any actual conclusions
Just last year however the first test of this with over a million cosmologically distant sources was published back in February 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 (1 in 2 million odds of occurring purely by chance) from a kinematic dipole.
If the dipole itself is cosmological in origin it changes everything as it means our universe falls within the highly nonlinear regime of the Einstein field equations and thus structure scale becomes chaotic in terms of how big of voids or galaxy superclusters etc. can form with the local rate of expansion varying in time and space in all directions. In particular one automatic prediction for the general solutions to the Einstein field equations in a geometrically flat universe is that any arbitrary anisotropy must drive accelerated expansion with a natural arrow of time since the No big Crunch theorem proves through contradiction that in the anisotropic and inhomogeneous domain of the Einstein field equations there can not be any time slice of the universe with a maximum (or minimum) total spatial volume.(Matthew Kleban and Leonardo Senatore JCAP10(2016)022)
Additionally as there is a countably finite number of possible configurations for a spatial manifold for a given total spatial volume it can be shown there is a direct equivalence from this constraint to avoid a self contradiction within the Einstein field equations and the second law of thermodynamics and associated arrow of time.
Basically for any anisotropic and inhomogeneous initial conditions all possible solutions to the Einstein field equations will always either expand forever at an accelerated rate globally maximizing entropy over all time slices or contract forever minimizing entropy over time slices(which is effectively the expanding solution time reversed).
Fundamentally it means you get an arrow of time within any universe that starts with a large scale asymmetry in its initial conditions which can only get amplified with time.
So every minor fluctuation from equilibrium will eventually produce an associated large scale structure in time forward time slices of spacetime.
I like the idea of the alignment being real but due to one of a few non-anthropocentric explanations:
1) Maybe the solar system's own dust refracts or polarizes the CMB data we collect?
2) Maybe there's a relativistic effect distorting the CMB data we collect due to the solar system's relative motion?
3) Inflation somehow gave the early universe a slight twist and we're coincidentally slightly aligned with it?
Astronomer Brian May might have some input for discussion point #1.
Even your video editors are trying to hurry you up, they're playing music louder and louder at the end like it's the Academy Awards and they're trying to play you off the stage. 😂