16

The paradox only occurs if you assume a single timeline. In which case it is pretty much identical to the 'grandfather paradox'. In the left fig. below, if there is a single timeline then there is a single 'time-path' for you (red line) - that doesn't in itself produce a paradox, but the time-machine also only has a single path (blue line) which by ...


7

There is a thought experiment out there that says that time travel is impossible; not because of the physics, but because of what we do with it. Basically it goes like this. If time travel is possible, we'll use it to change the past. Eventually, we'll change the past to one in which it is impossible to create or use time travel. Hence, time travel is ...


3

The Bootstrap Paradox is a theoretical paradox of time travel that occurs when an object or piece of information sent back in time becomes trapped within an infinite cause-effect loop in which the item no longer has a discernible point of origin, and is said to be “uncaused” or “self-created”. It is also known as an Ontological Paradox, in reference to ...


3

My gut says Latin, and I'm not really inclined to disagree. Unfortunately, there are a lot of types of Latin, so if you have to pick one, choose Vulgar Latin. Latin's pretty useful, considering that half of Europe is derived from it, and every Western scholar, up until even half a century ago, was required to have a passing knowledge of it. Chinese seems to ...


3

This question just has to be about USA currency. It wouldn't make sense in any other country in the world. Head a little north and look at Canadian money. For instance the $10 bill: 1935: 1937: few 1954: 1969: 1989: 2005: 2013: 2017: 2019: The differences are far from subtle. There's no way any of them could pass for real before they were ...


3

"I use this machine to travel to the future, where I realize I am the person who placed the machine in my room. I then travel to the past to drop off the time machine and let my past self use it." I am going to assume you mean that FutureYou created the time machine, then went back in time to give it to CurrentYou (PastYou from FutureYou's perspective). ...


2

How close you pass to the black hole is almost completely irrelevant. The galaxy is only 100,000 ly across, and the Earth is only about 25,000 ly from the center. If the aliens are coming from a direction diametrically opposite the Earth across the galactic core, only 75,000 ly of their 66 million ly journey will even by within our galaxy, let alone near the ...


2

The time machine doesn't break down - its condition oscillates. If there are multiple timelines, then you have no "obligation" to return the time machine. If you do it regardless (perhaps out of belief that you have to do it), then Penguino's answer covers what happens. If there is only one timeline, then when you return the time machine to the past and ...


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