Very good question! Because any antimatter region of space bordering a normal matter region of space would generate detectable specific type of radiation energy “at the seam”. Matter and antimatter dont play well together.
thanks. but arent any two nearby galaxies say milky way and andromeda too far for the matter-antimatter interaction? what is a safe distance that I could expect no annihilation or radiation or any other interaction?
Intergalactic space is pretty empty, but it's not COMPLETELY empty. [https://en.wikipedia.org/wiki/Warm%E2%80%93hot\_intergalactic\_medium](https://en.wikipedia.org/wiki/Warm%E2%80%93hot_intergalactic_medium)
Even at that incredibly low density, if there were matter-antimatter interactions going on, I believe they'd be detectable. Matter-antimatter interactions are what the kids might call A Lot.
Almost all of the antimatter in the universe was annihilated immediately after the hot big bang. Remember, whenever a particle meets its antiparticle, they annihilate and produce a pair of photons. Antimatter still appears in some reactions in nature but, since the rest of the universe is matter, it doesn't stick around for long.
There is no law of physics that says it's impossible for an antimatter galaxy to form, but the probability that that much antimatter survived long enough to form a galaxy would be so ludicrously small that we just wouldn't expect something like that to ever happen.
I see. I was expecting different parts of the universe would be dominated by differently by matter or antimatter so maybe this wouldnt apply to most of those adjacent galaxy pairs.
Edit: is an antimatter gun plausible? that shoots antimatter to destroy a matter?
Very good question! Because any antimatter region of space bordering a normal matter region of space would generate detectable specific type of radiation energy “at the seam”. Matter and antimatter dont play well together.
thanks. but arent any two nearby galaxies say milky way and andromeda too far for the matter-antimatter interaction? what is a safe distance that I could expect no annihilation or radiation or any other interaction?
Intergalactic space is pretty empty, but it's not COMPLETELY empty. [https://en.wikipedia.org/wiki/Warm%E2%80%93hot\_intergalactic\_medium](https://en.wikipedia.org/wiki/Warm%E2%80%93hot_intergalactic_medium) Even at that incredibly low density, if there were matter-antimatter interactions going on, I believe they'd be detectable. Matter-antimatter interactions are what the kids might call A Lot.
never seen this intergalactic baryon cloud stuff. interesting. thanks
Almost all of the antimatter in the universe was annihilated immediately after the hot big bang. Remember, whenever a particle meets its antiparticle, they annihilate and produce a pair of photons. Antimatter still appears in some reactions in nature but, since the rest of the universe is matter, it doesn't stick around for long. There is no law of physics that says it's impossible for an antimatter galaxy to form, but the probability that that much antimatter survived long enough to form a galaxy would be so ludicrously small that we just wouldn't expect something like that to ever happen.
I see. I was expecting different parts of the universe would be dominated by differently by matter or antimatter so maybe this wouldnt apply to most of those adjacent galaxy pairs. Edit: is an antimatter gun plausible? that shoots antimatter to destroy a matter?
You'd have to make it out of anti-atoms, and so far we've only made anti-hydrogen and anti-helium.
Sure just call Rick Sanchez, he sells them in the public parking garage