This is not the same for all crypto currency, but a bitcoin represents a "proof of work". When people "mine" bitcoins, they are consuming computational resources, and when they find a bitcoin, it is a certification of the work that was done to find it that becomes the value of the coin. And then, as others as mentioned, people just agree that that work has a certain amount of monetary value. But the proof of work is what limits the supply and allows that value to exist. 3Blue1Brown has a really good video that goes into the technical details if you're interested.
I think this would fall in to the latter scenario. 46 billion light years is the edge of the observable universe in the sense that light emitted by those regions has reached us by now. But these regions are beyond the cosmic event horizon, which is the distance at which light emitted now will ever reach us. That distance is about 17 billion light years.
Is there any point at which the distance becomes too large to the extreme where you basically get “deleted” from existence?
This is basically what the definition of "observable universe" is. It is the part of the universe that is close enough in space and time for light to reach us. So if you say they get transported to the observable part of the universe, then yes, their signals will eventually reach earth. But the closer they are to the edge of the observable universe, the longer the signals will take to reach, and the more red shifted they will be due to the expansion of the intermediate space as the signals travel to Earth.
Note that there are some semantics at play; "observable universe" might refer to the parts of the universe that have emitted light in the past that is reaching earth now. But the the light emitted by those places now might never reach Earth because they are now too far away. So if these astronauts got sent to one of those places then no, their signals would not reach earth.
How is the definition of theft determined? Typically the definition is determined by the government. Why would the government define its own funding source as theft?
HIPAA allows medical care providers to share your information with each other for the purposes of providing care (whether that sharing happens through MyChart or some other means). It does not require your consent (and this could be a good thing if, for example, you were taken to a hospital while unconscious). You simply may not have a lot of options for preventing this. As NOT_RICK mentioned, you could opt out of Care Everywhere at the psychiatric hospital to prevent them from sharing your information that way. You could also try to amend their record or request that they restrict access to your records, as per https://www.hhs.gov/hipaa/for-professionals/privacy/laws-regulations/index.html#general. All of those options would require interacting with the original psychiatric hospital, so if you're unwilling to do that, I'm not aware that there are other options available.
Small correction, but this bit isn't quite correct:
If you go just below light speed, you’ll see the world outside go past like it’s being fast forwarded, and when you return, 8 years will have been compressed into something that seems much shorter to you.
During the time that you are just below light speed at a constant velocity, clocks that are "stationary" will appear to be moving slow to you. And clocks moving with you will appear to be running slow for a "stationary" observer. As I mentioned in a comment in another reply, the trip would feel short to you because the distance to your destination would contract to nearly zero. "Fast forwarding" (ie, having both you and a stationary observer agree that more time has passed on the stationary observer's clock) would happen during the periods of acceleration/deceleration at the beginning and end of the trip.
Just want to add that what the person on the ship observes is length contraction. When their ship is at near light speed, the distance to their destination contracts to nearly zero (because it is moving at near light speed relative to them); this is why the trip seems short to them.
One of my favorites is the "ladder paradox" in special relativity, although I originally learned is as a pole vaulter rather than a ladder:
A pole vaulter is running carrying a pole that is 12m long at rest, holding it parallel to the ground. He is running at relativistic speed, such that lengths dilate by 50% (this would be (√3/2)c). And he runs through a barn that is 10m long that has open doors in the front and back.
Imagine standing inside barn. The pole vaulter is running so fast that the length of the pole, in your frame of reference, has contracted to 6m. So while the pole is entirely inside the barn you press a button the briefly closes the doors, so that for just a moment the pole is entirely closed inside the barn.
The question is, what does the pole vaulter see? For him, the pole has not contracted; instead the barn has. He's running with a 12m pole through what, in his frame of reference, is a 5m barn. What happens when the doors shut? How can both the doors shut?
I will admit that I have never used this thought experiment for any practical end.
This is the "big crunch" question, and I think the current theory is that no, there's enough energy, and space is curved in such a way that it won't crunch back down. At least not all at once? We do have black holes that are sort of similar in that they pack so much stuff into small spaces that the current laws of physics are unable to completely describe them.
Is this why the second coming hasn't actually come yet? He's on his dieback?