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But haven't we visually detected exoplanets? I remember seeing a gif showing 5 giant exoplanets orbiting a single star and the view was from above- the kind of thing I wish we could do with our own solar system!
There have been a few. It is easiest for large planets that are far from their stars. The problem is the glare of the sunlight, which swamps out the much fainter glow of the planets -- like trying observe the glow of a firefly next to a searchlight. So you must use an occulting disk to block out the star but not the planets. Observing in infrared also helps reduce the brightness of the star relative to the planets.
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But I really like paradoxes and I hope we become advanced enough as a species one day to create a few ourselves
About black holes, I remember reading about this particular paradox and it was resolved using the cloning theorem, that the particle both falls into the black hole and doesn't- there is a duplicate created
Paradoxes cannot exist in nature -- basically by definition. The appearance of a paradox means you've tried describing something with knowledge that does not correctly describe it, or is incomplete. We encounter paradoxes quite often in physics and they are a signal that we are missing something important, and can act as clues to figuring out how to reconcile different apparently contradictory concepts.
A good example is the twin paradox in relativity. A naive application of principles of special relativity would suggest that you see time pass more slowly in frame which is moving relative to you, and so two observers moving relative to each other will see each other age more slowly. Therefore if your twin goes on a high speed trip through the universe and comes back, both of you say that the other twin is younger. That's a paradox -- how are both of you younger than the other?
The appearance of this paradox tells you that a crucial bit of physics wasn't accounted for. In order to meet back up, your twin must accelerate and switch reference frames, and that introduces a new time dilation effect. What really happens is that your twin is unambiguously younger when you meet back up, and you are the older twin. There is no paradox at all.
For the black hole example, having the particle both fall into and not fall into the black hole doesn't work. You cannot clone a particle
. And if it did work, it would violate conservation laws -- the black hole would gain the mass without removing it from the external universe.
What really happens is if the particle approaches the black hole, it unambiguously either falls in, or it doesn't. If the particle does fall in, the distant observer still sees it smushed onto the event horizon due to the infinite time dilation there, but he would not be able to meet up with it. If he tries to swoop down in close to catch the particle, he will find it is not at the horizon, but always some distance in front of him -- all the way down to the singularity.