Anti- Matter
I don't know how many scientists believe this but I've heard a theory that at the beginning of the Big Bang there was anti-matter and matter and that when the two collided it would destroy each other, however there was more matter than anti-matter and hence leading to the next step.
My question regarding this why did the subject of anti-matter come up in the first place? To me it sounds like we can't prove it's real because of what I originally started in the theory. Is it just because everything normally has an opposite? or am I missing something?

(I'd just like to clarify that I've never really thought deep philosophical thoughts about the universe before so this is new to me and I think this is the only question I've come up with that can be considered "good".)

Nataliea Lowson


I thought that antimatter could be detected with radiation (with gamma rays...?). I'm under the impression that antiparticles are formed where there are particle collisions of extreme energy.

I was wondering if there is a way to know what happened before the Big Bang? Or if there is a definite start to time (as we know it at least)? Hawking seemed to think that there was a distinct start to time due to the second law of thermodynamics (with time, disorder increases). Suggesting that if without a beginning, there would be complete disorder by now.

Natalie Otten


Hi. Anti-matter can be detected and as far as I know, positron is the anti-particle of electron and it is used in PET (positron emission tomography) scan.

The second law of thermodynamics, as we know it, seemed correct to us and it fits most cases in our life such that over time, disorder increases. However, when I am trying to fit it to the Big Bang and birth of our universe, I am a bit doubtful. The formation of stars and planets from the particles produced from the Big Bang is contradicting with the law of entropy (at least in my view). Those particles are all over the universe at that time and I consider them as in the state of high disorder. But when they manage to come together to form celestial bodies, their entropy is decreasing. This is solely my opinion on entropy and disorder and I would like to know more on it (like when it is not applicable...).

Goh Tze How



Anti-matter definetly exsists. There are positron beamlines at the anu in the centre for anit-matter matter studies (Bad sense of humor) :

Also Goh has got it nailed A positron is like an anti-electron. And when they collide tons of energy is released. In the form of gamma rays probably where Natalie is coming from.

As for why anitmatter? Jees, beats me.

I'm pretty confused about why there is so much more matter than antimatter. Apparrently there were even quantities at the beginning. Why not now? Where has it all gone?

Nic Brown

All good stuff.

To answer what I think the original question was: The reason we label some particles "anti-matter" is really to do with symmetries in our current picture of particle physics. In other words, it makes the theory neat.

It's not just to do with annihilating particles: often anti-matter particles anihilate real matter particles, but sometimes they don't (e.g., photons are their own anti-particles, but when two photons meet they don't annihilate each other).