The Missing Baryon Problem in Physics

[@arindammukhopadhyay4359]

Thank You. Straight forward introduction with brief, to the point discussion.

[@qubex]

It’s kind of hilarious that in the first minute or so we’re introduced to the surprising notion that for the purposes of this problem, ‘baryons’ includes leptons, which by definition are not baryons.

[@OVAstronomy]

Yeah cosmologists are quite annoying for that 😂

[@seanspartan2023]

I really enjoyed this topic. It makes me wonder... You know, eventually the universe may expand so much that our galaxy would be like an island in a great ocean of dark. Civilizations evolving during that time would have no way of determining the universe's true scale. The knowledge of other galaxies would be lost. Even the universal background radiation will fade eventually. But what if such an event has already occurred? Maybe we are missing a large piece of the puzzle because of inflation or some other event in the early universe that separated us from the light of that knowledge. We could be floating in our own bubble, cut-off and oblivious to a larger-scale structure.

[@OVAstronomy]

That's an interesting thought. However, the fact we can still detect the CMB means that we can detect everything available to us via EM. The CMB acts as a curtain which hides the early Universe from our view, it formed when neutral atoms formed and the Universe stopped being opaque - so we cannot see structure further back in time than the CMB regardless as it is all opaque to photons. Therefore, we can be fairly sure that at this point in cosmic history we are not missing anything (as would be the case in the far future when galaxies become island universes as you mentioned), other than what's beyond the CMB which we could never see before anyway using EM. Whether we develop new techniques in the future to probe before it, I cannot say. Thanks for this question though, it's a really interesting topic!

[@seanspartan2023]

@@OVAstronomy Thank you so much! Your explanations always make a lot of sense.

[@cleanerben9636]

the answer is obvious; the missing Baryons are in the same place as missing socks.

[@brianl7321]

Good video! I wonder if there's also an impact from non-accreting black holes. Those would be tricky to detect especially in interglacactic space.

[@OVAstronomy]

Thank you - and it's entirely likely that non accreting BHs have an impact! Although some feedback mechanisms are more dominant and efficient at redistributing baryons than others, but I'd be surprised if BHs had no impact

[@dhnguyen68]

Are baryons and fermions synonymous ?

[@OVAstronomy]

Baryons are particles made of 3 quarks. Fermions are particles with anti-symmetric wavefunctions (half integer spin). All baryons are fermions, but there are other non-baryonic fermions such as electrons, neutrinos, muons etc.

[@David-ce7mh]

You have a gift brother. Please keep making these videos. I just discovered your channel last night, watching every video. Nice surprise you just came out with another!

[@OVAstronomy]

Thanks man - I have no desire to stop any time soon!

[@krisjupp]

Tried slowing down 😢either ur on charlie or drunk. This one is a much better speed ! Thanks !! Brilliant stuff

[@OVAstronomy]

Haha, cheers.

[@xyzxyzxyzxyz636]

Exquisite!

[@shawns0762]

Black holes are based on a mathematical misconception. Most people don't know that Einstein said that singularities are not possible. In the 1939 journal "Annals of Mathematics" he wrote "The essential result of this investigation is a clear understanding as to why the Schwarzchild singularities (Schwarzchild was the first to raise the issue of General relativity predicting singularities) not exist in physical reality. Although the theory given here treats only clusters (star clusters) whose particles move along circular paths it does seem to be subject to reasonable doubt that more general cases will have analogous results. The Schwarzchild singularities do not appear for the reason that matter cannot be concentrated arbitrarily. And this is due to the fact that otherwise the constituting particles would reach the velocity of light." He was referring to the phenomenon of dilation (sometimes called gamma or y) mass that is dilated is smeared through spacetime relative to an outside observer. Time dilation is just one aspect of dilation. Even mass that exists at 75% light speed is partially dilated. General relativity does not predict singularities when you factor in dilation. Einstein is known to have repeatedly spoken about this. Nobody believed in black holes when he was alive for this reason. Dilation will occur wherever there is an astronomical quantity of mass because high mass means high momentum. There is no place in the universe where mass is more concentrated than at the center of a galaxy. It can be shown mathematically that the mass at the center of our own galaxy must be dilated. This means that there is no valid XYZ coordinate we can attribute to it, you can't point your finger at something that is smeared through spacetime. Or more precisely, everywhere you point is equally valid. This is the explanation for the abnormally high rotation rates of stars in spiral galaxies (the reason for the theory of dark matter) the missing mass is dilated mass. According to Einstein's math, there would be no dilation in galaxies with very, very low mass because they do not have enough mass in their centers to achieve relativistic velocities. It has recently been confirmed in 5 very, very low mass galaxies to show no signs of dark matter

[@richardthelong]

duh they are in black holes

[@OVAstronomy]

Black holes are a part of the

[@richardthelong]

@@OVAstronomy we don’t even know what’s in our ocean and you are trying to tell me you know what’s inside black holes. Ok bud.

[@OVAstronomy]

@@richardthelong Since black holes form from the collapse of massive stars (which are made of baryons), it is highly likely that black hole mass is baryonic. Hence, although we cannot see into them, we know their mass must contribute to the baryon energy density.

[@fartsniffa8043]

4:20 why should the baryonic density not change over time if the universe is expanding? Great video btw.

[@OVAstronomy]

Apologies, I was not clear. What I meant is that the baryon density won't decrease because of decays or interactions - only due to the expansion. Essentially that the energy contained within baryons is conserved, but you are correct that their density will decrease by the expansion factor cubed.