where did it all go?

[nicks90]

I was at a talk by Dr Julian Onions a few months ago with WADAS and something he said is playing on my mind a little and just thought I'd ask the collective conciousness of SGL if they had any ideas?

 

When the universe formed after the big bang, it did various things like expansion etc, but then it formed matter. It produced in virtually equal numbers matter and anti matter. Obviously with the universe being quite compact the matter and anti matter obliterated each other. For whatever reason there was a tiny bit more matter than anti matter (i think he said like one part in a billion) and all the matter in our entire universe is the left over 1 part in a billion that wasnt obliterated. 

Thats pretty awesome all by itself, as theres quite a bit of 'stuff' in our universe and to think thats like only a billionth of what was originally formed is pretty impressive!

 

But my question is - when matter and antimatter obliterate each other, it produces A LOT of energy. Where is all that energy now? Do we know what type of energy it released and could "dark energy" and "dark matter" be a product of that? Sort of like 'anti energy'..... its there and exhibits all the properties of normal energy, but ... well anti... and therefore we cant see it.

[andrew s]

In GR energy is not conserved. Energy conservation comes from time reversal symetry. This requires a static space time which was not the case then, big time, and not now but is approximately true when the space-time is essentially flat.

 

Regards Andrew

[symesie04]

Now i suspect im totally out of my depth here but ill throw my hat in anyway. Isnt the energy from the big bang itself conserved as the background radiation which due to the expanding universe has been stretched out into the microwave length. Therefore one would assume that energy in the form of light from matter - antimatter collisions would also undergo the same process. I would also assume that as big as the particles bangs may have been their microwave signature would be lost against the microwave background filling the universe from the big bang itself.

[andrew s]

18 minutes ago, symesie04 said:

Now i suspect im totally out of my depth here but ill throw my hat in anyway. Isnt the energy from the big bang itself conserved as the background radiation which due to the expanding universe has been stretched out into the microwave length. Therefore one would assume that energy in the form of light from matter - antimatter collisions would also undergo the same process. I would also assume that as big as the particles bangs may have been their microwave signature would be lost against the microwave background filling the universe from the big bang itself.

The CMB was emitted as UV during "recombination" when it had cooled enough for bare H, He and Li nuclei to captured electrons. Exactly how, the matter anti matter imbalance was created is not fully understood so it is difficult to say what happened. I don't know the details of the current view on the very early universe and inflation so will have to leave it there.

Regards Andrew

[Physicist13]

the matter/anti-matter inbalance is v v interesting.....work is going on to produce long lived anti-hydrogen with aim to study and compare to normal H....spectroscopy may show differences....nobel on way to those who find something...  

 

[acey]

The matter and anti-matter anihilated to produce photons, contributing to the overall temperature of the early universe (which was a hot plasma). As the universe expanded it also cooled, until the plasma became transparent, so that photons could travel for effectively unlimited distances. Some of those photons are still travelling today, and can be caught by detectors on Earth: this is the cosmic microwave background radiation. The high-energy photons have been red-shifted by cosmological expansion, which is why we now see them as microwaves.

[nicks90]

so if all our matter in the universe constitutes just 1 billionth of the matter when it all annihilated shortly after the BB - then 999,999,999 times our current universe (and the exact same amount of antimatter) annihilated itself in to photons instantaneously.

thats 1,999,999,998 times all the matter in the universe went pop at once and turned in to pure energy.

 

just think about that a moment.........

One billion, nine hundred and ninety nine million, nine hundred and ninety thousand, nine hundred and ninety eight times our total universe in matter went through Einsteins E=MC² process.

 

 that rocks

[andrew s]

27 minutes ago, nicks90 said:

so if all our matter in the universe constitutes just 1 billionth of the matter when it all annihilated shortly after the BB - then 999,999,999 times our current universe (and the exact same amount of antimatter) annihilated itself in to photons instantaneously.

thats 1,999,999,998 times all the matter in the universe went pop at once and turned in to pure energy.

 

just think about that a moment.........

One billion, nine hundred and ninety nine million, nine hundred and ninety thousand, nine hundred and ninety eight times our total universe in matter went through Einsteins E=MC² process.

 

 that rocks

Unfortunately, that is way too much energy for the energy balance of our current cosmological models. Something is amiss here.

Regards Andrew

[nicks90]

hmmm - just double checked my figure from CERN - http://press.cern/backgrounders/matterantimatter-asymmetry

Quote

If matter and antimatter are created and destroyed together, it seems the universe should contain nothing but leftover energy. Nevertheless, a tiny portion of matter – about one particle per billion – managed to survive. This is what we see today

 

[symesie04]

Ah but does that mean that for every 1.1 billion matter particles there was 1 billion anti matter particles or does it mean that for every .5 billion matter particles there was .49 billion antimatter particles?

[nicks90]

maybe, but that is grammatically very picky! Even if that is the case, its still a blooooomin HUGE number even if it is halved!

[saac]

7 hours ago, nicks90 said:

so if all our matter in the universe constitutes just 1 billionth of the matter when it all annihilated shortly after the BB - then 999,999,999 times our current universe (and the exact same amount of antimatter) annihilated itself in to photons instantaneously.

thats 1,999,999,998 times all the matter in the universe went pop at once and turned in to pure energy.

 

just think about that a moment.........

One billion, nine hundred and ninety nine million, nine hundred and ninety thousand, nine hundred and ninety eight times our total universe in matter went through Einsteins E=MC² process.

 

 that rocks

The way my energy  supplier raids my bank balance each month I sometimes think they are billing me for the matter anti matter annihilation.

 

Jim

[andrew s]

This is a good discussion on this topic https://www.physicsforums.com/insights/poor-mans-cmb-primer-part-1-birth-cosmic-background-radiation/

It looks like my post above on the cause of the CMB  was wrong.

Regards Andrew

[George Jones]

It is thought by many (but certainly not all!) physicists that the early universe experienced a fantastically brief rapid expansion called inflation driven by something called the inflation field. At the end of inflation, the energy of the inflation field was dumped into normal radiation and matter in a process called reheating. One of my books (an advanced cosmology text by Weinberg) says

Quote

In contemporary models of inflation this is the source of all the matter and radiation in the present universe.

Another book says

Quote

Reheating is complete when practically all of the energy is in radiation at thermal equilibrium.

 

[Sai Samarth]

What I think is that, all the energy might have been used or still used for the expansion of the universe. We still just scratched the surface of all these matters, and is quite new for us.