Antimatter

[Aeschylus]

if it started before us and is faster than us, how hasn't it passed seconds after the big bang. actually, it should have passed before matter was even created.

 

Rubbish, buy a decent book on cosmology and you'll understand why that is not the case.

[ydoaPs]

why don't you explain it to me?

[Aeschylus]

Okay:

 

During the recombination era the unievrse was very homogenous and isotropic, so the CMBR was emitted by all areas of the unievrse during pretty much the same tim period.

 

Now you know that, due to the fact that light has a finite speed, the further we look, the furtehr back in time we look. If we look in any direction far enough we we 'see' the unievsre 300,000 yrs after the BB (infact this is the furtherest back we can see as before this time the unievrse was opaque to EM radiation) and so we will see the CMBR as it was emitted 300,000yrs after the BB.

[Guest TwonAPimp]

I know I'm only a kid here, but I just got through reading Angels & Demons by Dan Brown. The subject on Anti-Matter sparked my attention on something. I started reading a lot of articles and facts about anti-matter and got to thinking. I have a few questions if someone would respond to them. The Big Bang theory states that our universe was created by matter colliding fomring matter and anti-matter, but that the anti matter was out numbered by matter. Ex. Anti-matt was a billion and Matter was a billion plus one. How could this Be? From most the articles I've found and forums it states that there is both an equal amount of both anti-matter and matter. A couple other articles stated that there's been some research that some of the anti-matter was not actually well....anti-matter. I can't remeber exactly what it said it basically said that the anti-matter what it was supposed to be...Can someone please reply and tell me what they ment by that and tell me how can the Big Bang Theory still be true? ANd can some one tell me more about anti-matter. I've go the basic parts of it down but I'm going as far into this subject as the internet and ya'll are willing to let me.

[Gilded]

I don't think there's a proper answer for the anti-matter and matter not being balanced. At least not yet. The theory is still going on though.

 

"ANd can some one tell me more about anti-matter"

 

Well, basically it's anti-particles of particles (duh). For example, a positron is the antiparticle of an electron (it has an opposite charge). The CERN has made anti-hydrogen atoms, that compose of an antiproton and a positron. And whenever anti-matter and matter collide, an annihilation happens that transforms both particles to energy (the E=mc2 thingie is useful here ). If there was a large natural source of anti-matter, it would be a tremendous source of energy, but since there isn't, making anti-matter for energy creating purposes is not worth it (as you can probably imagine). It could be used in a weapon though... YES! A BIG WEAPON THAT WILL SMITE ALL PINE TABLES! ...Ahem. That's about it.

[MulderMan]

so anti-matters actually real, not theoretical? i thought it was all star trek...

[swansont]

Yes, antimatter is real. (It's about the only thing from Star Trek that is)

 

Some forms of antimatter does not actually behave the same as its matter counterpart, and undergoes asymmetric decays. This has been observed in K and B mesons.

 

Severian touches upon this and explains a bit in this thread.

[[Tycho?]]

Okay:

 

During the recombination era the unievrse was very homogenous and isotropic' date=' so the CMBR was emitted by [b']all[/b] areas of the unievrse during pretty much the same tim period.

 

Now you know that, due to the fact that light has a finite speed, the further we look, the furtehr back in time we look. If we look in any direction far enough we we 'see' the unievsre 300,000 yrs after the BB (infact this is the furtherest back we can see as before this time the unievrse was opaque to EM radiation) and so we will see the CMBR as it was emitted 300,000yrs after the BB.

 

I too have trouble wrapping my mind around this. Namely its that direction thing, that I think of the big bang as something like, say, the sun, only way brighter. But I can't really think of how that would mean that I would be able to see the light no matter where I look. I know that the universe is expanding, and expanded at an extremely high speed during the early universe, but I still have trouble with it.

[ydoaPs]

'']I too have trouble wrapping my mind around this. Namely its that direction thing, that I think of the big bang as something like, say, the sun, only way brighter. But I can't really think of how that would mean that I would be able to see the light no matter where I look. I know that the universe is expanding, and expanded at an extremely high speed during the early universe, but I still have trouble with it.

 

i too am still perplexed by this. how can we see light that, logically, should have passed us billions of years ago?

 

if you are a fan of brane theory then you know that the big bang may not have happened in the one place. it could have happened when two branes collided. there would have been a "big bang" in every point the two branes touched

[Cap'n Refsmmat]

Ignore this until I figure out the dumb code tags and such. Isn't there a way to keep it from removing spaces?

 

i too am still perplexed by this. how can we see light that, logically, should have passed us billions of years ago?

Simple. Let's say the early universe looks like this (2d version):

   ______
  /		   \
     /		    \
    |	   us |
        \		   /
           \_____ /

Where Earth is/will be at is at the "us." Now, radiation is being emitted at all points. But the universe is still very large at this point. It is expanding rapidly. So radiation emitted at the middle will go like this:

      ______
    /             \
  /                \
  |          -  us  |
  \                /
             \______/

The "-" is radiation. Considering the expansion of the universe, and the distances involved, that radiation is just getting to us now.

ARGH! What's with the stupid code tags? Can't I just get it to do it right?

[Sorcerer]

Background radiation is too uniform to be a result of matter/antimatter collisions. It is also too cold (a mere 2.7K) and at the wrong wavelength (microwaves) to be explained via this process.

 

The source of the background radiation is the afterglow of the big bang. We can say this with a fair degree of confidence because its temperature/distribution/wavelength match well with other estimations of the age/size of the universe.

 

Ummmm actually, the after glow of the big bang is from the production of matter and antimatter, which then annihilated and produced the background radiation. The reason its so cool and at the wrong wavelength is because its been redshifted by the expansion of space and has traveled for 14 billion years.

[Woxor]

Regarding CMBR: I was under the impression that it did pass "us" (or what would eventually form the solar system and its inhabitants) at the beginning, and is being pulled back inward by universal gravitation.

[Sorcerer]

then how the bloody hell did we get in front of it???????????????

 

radiation was created before matter. radiation travels faster than matter. we should not be able to see radiation from the big bang.

 

We are infront of it in space-time, its light from the past.

[Aeschylus]

The CMBR is not the after glow of the big bang per se but it is from 300,00 years after the big bang when the unievrse's density became low enoguh that any photon emitted wasn't instantly reabsorbed, during a short period of time all areas of the univere (because at this time the universe was very, very, very homogenous) emitted alot of light within a very short period of time. Nothing to do with antimatter.

 

The CMBR does pass us and it doesn't come back due to the effects of gravity, BUT there is always more CMBR coming to us.

 

From our postion, the CMBR that we see at any insatnt is like viewing a giant spherical shell with a radius of about ~13 billion light years taht we are at the centre of, but this is only due to the effects of the unievrse we are exapniodn as by looking at the CMBR we are really looking at an area of space, much, much smaller than a spherical shell of radius 13 billion light years. If you've ever performed an inversion on a circle you might understand what I mean.

[[Tycho?]]

Ummmm actually, the after glow of the big bang is from the production of matter and antimatter, which then annihilated and produced the background radiation. The reason its so cool and at the wrong wavelength is because its been redshifted by the expansion of space and has traveled for 14 billion years.

 

I'm almost postive that this energy was emmited because of the heat of the universe, not matter anti-matter reactions.

[ydoaPs]

time for another crappy diagram. how can we, who travel at a velocity less than c, beat light, which travels at c, from point a to b?

[Aeschylus]

time for another crappy diagram. how can we, who travel at a velocity less than c, beat light, which travels at c, from point a to b?

 

The simple answer is we can't.

[Edisonian]

We are only beginning to learn about the wonders of anti-matter, so I agree that we really don't know at this point.