The problem is not with event horizons. Any body with an escape velocity of at least c will necessarily form an event horizon, there is no doubt about this, as it's inevitable. The question is whether there is an actual physical singularity "behind" the horizon or not.
Make 1 and 3 have really thick atmospheres like Venus, so that they're very bright and very visible from 2, but doing astronomy from them is either too hard or impossible. You'd have to make 2 invisible to them too, so that you can only see 1 and 3 <from each other> if and only if they're very...
They are basically trying to find limits on how much DM interacts with regular matter. So now we have even weaker limits on how weakly it might interact. As of it nature, who knows so far.
Oh I know they don't function and can be fatal. I'm just wondering about the size of teeth and jawbones in teratomas. Are they the same size of regular teeth and jawbones, or do they tend to be smaller/larger, or may they grow to any random size? I'm asking independently of the tumor in/from...
Do pieces such as teeth grow to normal size in teratomas, or are they usually of abnormal dimensions? I have read of rare cases where (at least partially formed) jawbones were found in the tumor, but how much do they resemble the actual, functional body parts of the patient?
There is a center of the observable universe and that's wherever you are. Everything would get closer and closer to you if you rewound. You'd see the same thing if you were anywhere else. Then that the universe (not the observable universe) is finite or infinite is a different question.
Now to...
Proper time (your own) always ticks at the same rate, but depending on movement relative to other clocks you will observe them tick differently from yours, and so will they. You can't travel a c, your thought experiment is invalid from the very premise.
But space would be distance between particles, that is a variable of particles and not a stand-alone entity. If the number of particles remains constant then I don't see why you'd ever need more power to compute it. If particles decay, which they do, then make sure you have power to compute for...