Comments on: Matter v Antimatter I: The Baryon Asymmetry

By: DPF 2009 - Detroit | Cosmic Variance | Discover Magazine

DPF 2009 - Detroit | Cosmic Variance | Discover Magazine — Tue, 28 Jul 2009 15:44:31 +0000

[...] and stable against quantum corrections – but also because cosmological observations such as the matter antimatter asymmetry of the universe and dark matter tell us that new particles and interactions must be out there, [...]

By: Hasanuddin

Hasanuddin — Mon, 01 Jun 2009 15:54:13 +0000

Hi Jimbo,

I wholeheartly agree, the potential opening of understanding caused through consideration of gravitational-repulsion between matter and antimatter (or “anti-gravity,” I hate that term) will be the next biggest thing, putting LHC on the back burner. I am very hopeful for the AEGIS experiment to prove the reality of gravitational-repulsion.

Why? Because I am in process of advancing a deduction-produced new cosmologic model that is completely seamless from end to end. Unlike current assumptions, all verified/concrete data is compatible, i.e., there are no paradoxes between theory and the physical record.

View, follow, and join the ongoing debate at: http://hypography.com/forums/alternative-theories/18910-the-dominium-model-by-hasanuddin.html

By: Jimbo

Jimbo — Tue, 19 May 2009 15:05:04 +0000

Our current DOE secretary has measured g to the ppb level about a decade ago, so the technology is definitely in place to measure g for trapped and cooled anti-atoms as CERN will soon do.
Baez is correct in advising caution, as nature often does present surprises. If the SN1987A neutrino & anti-neutrino fall times differed by only a few ppm, lets not get cocky. Anti-Hydrogen atoms weigh about one billion times what a neutrino weighs, and will pose pretty in the lab as their fall/rise times are measured.
I predict anti-gravity will surprise and excite the physics community like nothing from the LHC will.

By: Stochastic Scribbles » Blog Archive » Matter over antimatter

Stochastic Scribbles » Blog Archive » Matter over antimatter — Wed, 03 Sep 2008 18:41:46 +0000

[...] is writing and editing a series of excellent posts about baryogenesis. Starting off with an introduction to the problem, so far he has talked about the theories of electroweak baryogenesis and leptogenesis. They are [...]

By: Matter and Antimatter « disaphorism

Matter and Antimatter « disaphorism — Mon, 25 Aug 2008 14:57:17 +0000

[...] Posted in Science, energy by disaphorism on August 25th, 2008 Cosmic Variance has a great essay on matter and antimatter. Part one of a three part (at least that’s how high it is right now) series. Tagged [...]

By: Mark

Mark — Thu, 21 Aug 2008 16:18:22 +0000

Separated zones of matter and antimatter are not that easy to arrange it turns out. One can bound them by considering the observable effects of annihilations at their boundaries. A nice analysis here

http://arXiv.org/abs/astro-ph/9707087

shows that:

We ask whether the universe can be a patchwork consisting of distinct regions of matter and antimatter. We demonstrate that, after recombination, it is impossible to avoid annihilation near regional boundaries. We study the dynamics of this process to estimate two of its signatures: a contribution to the cosmic diffuse gamma-ray background and a distortion of the cosmic microwave background. The former signal exceeds observational limits unless the matter domain we inhabit is virtually the entire visible universe. On general grounds, we conclude that a matter-antimatter symmetric universe is empirically excluded.

By: ben wonders

ben wonders — Thu, 21 Aug 2008 16:07:20 +0000

Forgive my ignorance. As I was not able to understand the sentence

“In fact, this asymmetry between matter and antimatter can be made quantitative (for baryons such as protons and neutrons) through observations of the abundances of light elements in the universe (Big Bang Nucleosynthesis – BBN) and also from the pattern of anisotropies in the cosmic microwave background radiation (CMB)”

I can still imagine a universe where zones of matter and antimatter are so far apart that we don’t experience the annihilation of these opposites. The possible symmetry would feel so much better.

Or what if Dark matter is over proportionally Anti?

Where should I look to find references on how to conclude that there must be an asymmetry?

Thanks Ben

By: Matter v Antimatter III: Leptogenesis : Sophoblog

Matter v Antimatter III: Leptogenesis : Sophoblog — Wed, 20 Aug 2008 11:38:55 +0000

[...] been blogging the last few weeks about the question of the baryon asymmetry of the universe – the measured excess of matter over antimatter in the universe. Having already discussed [...]

By: Matter v Antimatter III: Leptogenesis | Cosmic Variance

Matter v Antimatter III: Leptogenesis | Cosmic Variance — Mon, 18 Aug 2008 15:00:31 +0000

[...] been blogging the last few weeks about the question of the baryon asymmetry of the universe – the measured excess of matter over antimatter in the universe. Having already discussed [...]

By: What Will the LHC Find? | Cosmic Variance

What Will the LHC Find? | Cosmic Variance — Mon, 04 Aug 2008 07:05:03 +0000

[...] Violation: 0.2%. As Mark is explaining, there are more baryons than anti-baryons in the universe, and most of us think that the asymmetry [...]