Primordial Hum

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Psnarf
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Primordial Hum

Post by Psnarf » Sun Oct 08, 2023 6:46 pm

"In the first few hundred thousand years after our Universe was born, a primordial hum ripped through a plasma of superheated particles. Scientists are listening in with the hope of gaining new insights about the mysterious force known as dark energy."

https://www.bbc.com/future/article/2023 ... e-universe

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Psnarf
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Re: Primordial Hum

Post by Psnarf » Sun Oct 08, 2023 6:56 pm

If there were equal parts of matter particles and anti-matter particles way back when, why didn't everything just annihilate leaving no particles at all? The fact that we now find a lot more matter than anti-matter, suggests something separated the remaining particles at some point in time. Perhaps it was baryon acoustic oscillations that kept a relative handful of anti-matter separated?

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Chris Peterson
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Re: Primordial Hum

Post by Chris Peterson » Sun Oct 08, 2023 7:04 pm

Psnarf wrote: Sun Oct 08, 2023 6:56 pm If there were equal parts of matter particles and anti-matter particles way back when, why didn't everything just annihilate leaving no particles at all? The fact that we now find a lot more matter than anti-matter, suggests something separated the remaining particles at some point in time. Perhaps it was baryon acoustic oscillations that kept a relative handful of anti-matter separated?
I think the general view is that there were not an equal number of each at the beginning. That matter outmassed antimatter by a tiny, tiny, tiny percentage.
Chris

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Markus Schwarz
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Re: Primordial Hum

Post by Markus Schwarz » Wed Oct 11, 2023 3:22 pm

Psnarf wrote: Sun Oct 08, 2023 6:56 pm If there were equal parts of matter particles and anti-matter particles way back when, why didn't everything just annihilate leaving no particles at all? The fact that we now find a lot more matter than anti-matter, suggests something separated the remaining particles at some point in time.
This is indeed an unsolved question. The known mechanisms that distinguish between matter and anti-matter are insufficient to explain the observed matter anti-matter asymmetry.

wrestlingbright
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Re: Primordial Hum

Post by wrestlingbright » Wed Jan 31, 2024 4:34 am

Psnarf wrote: Sun Oct 08, 2023 6:56 pm If there were equal parts of matter particles and anti-matter particles way back when, why didn't everything just annihilate leaving no particles at all? The fact that we now find a lot more matter than anti-matter, suggests something separated the remaining particles at some point in time. Perhaps it was baryon acoustic oscillations that kept a relative handful of anti-matter separated?
Very excellent question, and one that, despite a century of research, has no satisfactory solution.

This is referred to as the riddle of CP violation.

It turns out that, for every billion or so matter-antimatter collisions, just one does not annihilate, leaving matter behind!

It is unclear why this happens, however it can be described within the Standard Model and has been seen in accelerator tests.

However, CP violation seems to be the reason why the Universe is made up of matter rather than antimatter or pure radiation energy. It is the reason why the CMB contains about one billion photons for every atom in the Universe.

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Re: Primordial Hum

Post by plutoson » Mon Feb 26, 2024 6:52 pm

wrestlingbright wrote: Wed Jan 31, 2024 4:34 am
Psnarf wrote: Sun Oct 08, 2023 6:56 pm If there were equal parts of matter particles and anti-matter particles way back when, why didn't everything just annihilate leaving no particles at all? The fact that we now find a lot more matter than anti-matter, suggests something separated the remaining particles at some point in time. Perhaps it was baryon acoustic oscillations that kept a relative handful of anti-matter separated?
Very excellent question, and one that, despite a century of research, has no satisfactory solution.

This is referred to as the riddle of CP violation.

It turns out that, for every billion or so matter-antimatter collisions, just one does not annihilate, leaving matter behind!

It is unclear why this happens, however it can be described within the Standard Model and has been seen in accelerator tests.

However, CP violation seems to be the reason why the Universe is made up of matter rather than antimatter or pure radiation energy. It is the reason why the CMB contains about one billion photons for every atom in the Universe.
Thank you for the explanation. The riddle of CP violation truly remains a fascinating puzzle despite decades of exploration.