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PhysOrg.com has an article Early Universe Rapid Expansion Weird. They report on a paper by University at Buffalo physicists Ghazal Geshnizjani, Will Kinney and Azadeh Moradinezhad Dizgah. In their paper they report that several alternate theories to explain the current state of the universe require some really weird physics that does not agree with current theories.

Sounds like the Inflationary Theory is still alive and kicking.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
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Interesting link, Bill. I like the idea of "weird physics that does not agree with current theories" even if I don't understand it. smile

“According to cosmic inflation, materializing pairs of matter and antimatter particles flew apart so quickly in the rapidly expanding early universe that they did not have time to recombine.”

This does seem to leave unanswered the question as to why there seems to be an excess of matter over antimatter.


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Would I be right in thinking that a particle, or antiparticle, would not necessarily have to make contact with its original partner in order to annihilate, but that contact between any one of each would do the trick?


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Antiparticles do not necessarily have a partner Bill they aren't required to be entangled or paired.

An antiparticle just means that the spins and charge are backward so an electron has a +ve charge and protons have -ve charge.

If any antipartcle meets any particle they instantly annihilate and produce photons.

According to standard model both antiparticle and particles should be produced at the same rate there is no known mechanism why that wouldn't be so.

What the above results are showing is that isn't the case there is far more particles produced than antiparticles so we have a symmetry breaking and we don't understand why.

That is we have new physics outside the standard model.


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Indeed, and since we don't understand why there's a difference, neither do we know why the difference is such as it is. Why 0.8%? Why isn't it, say, 10%? I'd really like to know the answer to that.


"Time is what prevents everything from happening at once" - John Wheeler
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Quote:
Antiparticles do not necessarily have a partner Bill they aren't required to be entangled or paired.


Agreed. I was referring only to the “materializing pairs of matter and antimatter particles” mentioned in the article.

Quote:
If any antiparticle meets any particle they instantly annihilate and produce photons.


Thanks, that answers the question.


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Quote:
Indeed, and since we don't understand why there's a difference, neither do we know why the difference is such as it is. Why 0.8%? Why isn't it, say, 10%?


If the original pairs separated so quickly that they were not able to mutually annihilate, could there be some part of the Universe composed of the 0.8% antimatter?


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We sort of see that in that we have found large clouds or belts of antimatter in our own solar system and galaxy as well as other galaxies

http://news.sciencemag.org/sciencenow/2011/08/antimatter-belt-found-circling-e.html

http://www.nasa.gov/centers/goddard/news/topstory/2007/antimatter_binary.html


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Since we are discussing anti-matter perhaps we should add this link in for you

http://www.physorg.com/news/2012-03-anti-atomic-fingerprint-physicists-anti-hydrogen-atoms.html

Thats the first direct manipulation of antimatter.


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Thanks for the links, Orac. All very interesting, especially the last, which reads like sci-fi and concludes:

"The mystery of why there is so much ordinary matter in the universe and so little antimatter has long exercised theorists and experimentalists alike. It's at least conceivable that part of the answer lies in the spectrum of antihydrogen. If so, the ALPHA collaboration is on the path to finding it."


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Apart from admiring it, what might you do with a captured antihydrogen atom at 0.5K?


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I am not sure about others but for myself the question for me is does it form bose-einsten condesate like normal hyrdrogen ... I guess technically its anti-bec.

http://physics.aps.org/story/v2/st22

See what we are probing here is symmetry and the question is do the laws of quantum mechanics also translate directly to antimatter which in some ways is a much more interesting question than just whether physical properties translate.


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Quote:
do the laws of quantum mechanics also translate directly to antimatter


Is there any reason to think they might not?


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There is a disparity between matter and antimatter production something has to cause it and we no suspects at the moment.

So the question nags is QM behaviour different for antimatter the mysterious behaviour of things that pop in and out of existance could different rates of poping in and out for antimatter versus matter explain the difference?

Its worth doing a refresher on standard model in its simplified form.

http://www.benbest.com/science/standard.html


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Physics was my favorite subject when i was in 12th class. I just loved that subject. Keep it up.

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Hi, Jonathan 2340; welcome.

It's good to have a physics enthusiast join the ranks!
Hopefully you will help us "keep it up".


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If only left-handed fermions are affected by the weak force, would this not mean that electrons and neutrinos are affected, but their anti-particles are not. This would be one difference between matter and antimatter at QM level.


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Correct and it's a very important question

So lets add a couple of more recent experiments into the mix

Dmitry Budker's group

http://www.physorg.com/news/2010-10-physicists-discuss-largest-parity-violation.html
http://www.physorg.com/news196672191.html

Qusetion=> do photons act like bosons all the time, or could they sometimes act like fermions?

Answer=>Based on the results of their experiment to test this possibility, published June 25 in the journal Physical Review Letters, the answer is a solid “no.”


Another small experiment with big implications

http://www.physorg.com/news143374744.html

=>At first, it looked as though all was as it should be. Thomas and his colleagues took images of the atoms just after applying the rf field, and found that immediately following the change, the fermions behaved as expected. “But, after tenths of a second,” Thomas continues, “we saw that things were different. The spin-downs were moving to the edges of the bowl, and the spin-ups were moving to the center, remaining in this pattern for several seconds.”

Note carefully what this last experiment is saying.


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