willawoga

Id say that space has no end, as our dimension is most likely full, and with the coordinate planes, i dont think that that makes much sense. I dont know how exactaly to explain it, but it just doesnt

One theory i heard of for supermassive black holes is that they used to be galaxies with a normal balck hole in the center, that ended up sucking up the whole galaxy. And about a galaxy without a black hole, it is theoretical, one possibility is that the gravitationaly pull of millions or billions of stars holds them together instead of the gravitational force of a black hole

Freezing via the circulatory system, wouldnt that freeze the patients blood? And antimatter, if you pumped pure O2 into the tanks, then there woul;d be too much O2 in the body after a while for you to survive

Well, if you dehydrate a person, even a little, when they wake up, wouldnt they not have enough water in them to be able to survive for very long?

the idea of it is good, but stimulating gravity would be nearly impossible, as you would have to have not only all parts of your body accelerating, but also you would need to figure out the exact rotation that it owuld take to properly stimulate earth's gravity. Thus meaning that it would be nearly impossible.

Cryogenics, the sceince of freezing people who are dead until they are brought back to life, is impossible. The problem with it is that the water inside people's cells would simply freeze and break the cell memberane, which would cause death on reviving. This means that it is impossible. If anyone can find a way around this please do so.