Experiments have already been done on how antimatter is affected by gravity, and so far, they’ve all found that, if there is any difference in how antimatter and matter are effected, it’s too small to detect. Certainly, it’s not the case that antimatter falls up.
Since photons are their own antiparticle (at least in some sense) and we know that light is gravitationally attracted by ordinary matter, it seems very unlikely (and very asymmetrical which physicists hate) that antimatter would be repelled by ordinary matter.
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature09610.html
Anti-hydrogen (and by extension, all matter) is predicted by the standard model to have the same emission/absorption spectrum. Assuming that this would prove anti-matter chemistry to be equivalent to matter chemistry, anti-matter should bond the same way as matter and light should reflect and scatter in the same fashion. So it should look the same, in theory.
This is by no means proven though, so the big deal with CERN is that they now have enough anti-hydrogen collected in big enough quantities to go forward and measure its emission/absorption spectrum to test your question.
If they can repeatedly and reliably make antihydrogen, I suspect that it will be the most expensive substance by mass.
Unless positronium is stable?
That depends on your definition of “stable”. By particle physics standards, it can be regarded as stable, but then, that’s in comparison to things that decay via the strong interaction. By any standard other than that, though, it’s highly unstable.
One more question if I may.
Would any matter and antimatter annihilate itself, or does it have to be say lead/anti-lead or any other substance/anti-substance to cause a reaction?
Any antimatter with any matter will annihilate.
Normal lead will react with anti-carbon, say.
Hence the problems with storage.
Not quite “any”. An anti-electron (positron) won’t annihilate with a proton, for example. But protons and neutrons are made of Up and Down quarks, and those will annihilate with the anti-Up and anti-Down of antimatter, even if it’s some different anti-element. (And of course the electrons and positrons can annihilate each other.)
To go a little further, a neutron and an anti-neutron can annihilate each other, even though they are both electrically neutral. A single proton and a single anti-neutron can partially annihilate, but you’d have an Up and an anti-Down left over, which could from a Pion.
I’m thinking about antineutrinos… would radioactive decay in anti-matter produce a different signature of neutrino/antineutrino emissions?
If so, this would be a way to detect anti-matter in the universe. I realize how difficult it is to detect neutrinos and antineutrinos by the way.
All these anti-substances would be made of the same constituents: anti-electrons, anti-protons, and anti-neutrons. The annihilations take place on that level (and deeper, at the quark level), so all these substances are equivalently reactive despite being made of different numbers of each component, atom by atom.
If antimatter does fall up (I know, sounds like it probably doesn’t), it would fall up off the scale so you would just be measuring the matter anyway.
That may be why nobody’s found a decent amount of antimatter yet. They haven’t checked on the ceiling. :smack:
Wouldn’t help much. We know that antimatter occurs in nature; it just doesn’t last very long in a universe full of matter. Many common particle reactions produce neutrinos and/or antineutrinos from transient antimatter. The fusion reactions in the Sun, for instance, produce neutrinos, but the most common form of beta decay produces antineutrinos.
Just an interesting aside: antimatter fountains in the center of the galaxy.
And wondering if they have something to do with these recently described huge bubbles of hot charged gas also at the galactic core.
Let’s say a chunk of anti-lead came into contact with a chunk of “regular” lead. What would that reaction look like? Would both masses just disappear? And would the reaction be limited to the masses that are actually touching or would it set off some sort of chain reaction and swallow up everything in the vicinity?
Well, it has been put this way:
So what gets emitted by the annihilation? Is it just EM radiation, or are there particles produced as well?
Complete conversion into energy although there may be some particles transiently created along the way in the process before the conversion finishes off.
So what would a universe look like that had equal parts of matter and antimatter in it just oriented in the curled up extra spatial dimensions differentially such that they could interact (and be observable by each other) only when their movements in those curled up spatial dimensions intersected, which was of limited extent? How does that compare to what we see? What would that predict that we have not observed at this point and how could those predictions be tested?
Take into account that gravity is felt to travel throughout n-dimensional space. And that the amount of energy a matter antimatter collision produces is calculable.
So, what if an atom of anti-carbon annihilates an atom of fluorine? Does that mean that the 6 protons and electrons and neutrons all annihilate their respective antiparticles leaving an atom of lithium? Or does the whole thing kind of explode, leaving weird things left over?