71–80 of 215 posts
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I don’t have the details but I’m pretty sure passage of time is due to a tendency for entropy to increase, and that if I go back in time a second by, say, walking backwards, it is no more a violation of the cons of energy as if I walk forward.
I think the point about conservation of mass still applies. There are literally 2x yourself at a certain point in time, mass is not conserved.
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Iirc there is no requirement for mass/energy to be conserved, and some models of expansion require conservation to be violated.
Depends if the system is open or closed and if mass is converting to energy or visa versa. Also conditions near big bang are not representative.
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Think what they're getting at is that it won't happen that way. Gun will jam, you die of a brain aneurysm. We don't exist in a universe where impossible things happen, so we can't bring them about. But yes, the article doesn't really sink its teeth into it.
"The past is obdurate." This concept is narritively explored in Stephen King's "11/22/63" if anyone finds this interesting. The novel is an entertaining read and the audiobook available on the Libby app (requires a local library card here in the US) is high quality.
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Think what they're getting at is that it won't happen that way. Gun will jam, you die of a brain aneurysm. We don't exist in a universe where impossible things happen, so we can't bring them about. But yes, the article doesn't really sink its teeth into it.
I could see how a universe with such rules could exist. But is it our universe? In the universe you describe, wouldn't we already have seen time travellers from the future? The only explanation I can think of for why we haven't seen any, if we live in such a universe, is that we need to build an "arrivals hall" first, and that as soon we manage to do that, people from all over start popping in for a visit.
Sounds like they're describing the Novikov self-consistency principle [1] in a roundabout way. [1] https://en.wikipedia.org/wiki/Novikov_self-consistency_princ...
This, on the other hand, suggests you can change the fine detail of history (e.g. the identity of patient zero) but not its broad strokes (the occurrence of a global pandemic).
At least, that's what I gather from the article: I haven't read the paper, and suspect it would be a waste of time as my maths and physics are both rudimentary.
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Think what they're getting at is that it won't happen that way. Gun will jam, you die of a brain aneurysm. We don't exist in a universe where impossible things happen, so we can't bring them about. But yes, the article doesn't really sink its teeth into it.
The thing about this "self-correction" is that nobody, but nobody has a mechanism to explain this force. Not how it works or worse yet, how it will know how to self-correct. What particular force decides that the friction on some surface will briefly rise and cause the gun to jam? How does it know to do that? In all of the paradox-forbidding time travel scenarios, nobody has ever mentioned anything deeper than "Well,…
Why time travelers in sci-fi also move to the position and rotation of the Earth at the given moment? They should end floating in space.
Oh actually, I've found the way to convenience myself about that: The "reality" is, when somebody travels through time, most of them (god knows how many) got killed in the process, but the story will just pick another "instance" who has survived the journey from the pool of "Multiverse" and continues.
Only 5 minutes and it's kind of along this line of thought. I won't spoil the details.
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I could see how a universe with such rules could exist. But is it our universe? In the universe you describe, wouldn't we already have seen time travellers from the future? The only explanation I can think of for why we haven't seen any, if we live in such a universe, is that we need to build an "arrivals hall" first, and that as soon we manage to do that, people from all over start popping in for a visit.
I can’t see how a universe like that could exist. Perhaps if some time-traveler was unlucky, their gun might jam, but I can’t figure out how you could successfully thwart a “well-prepared time traveler” who knows all the details of the situation they’re jumping into and has double-checked their gun after making the jump.
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Exactly. The article mentions the grandfather paradox, but doesn't really address it at all. Can't "self correct" shooting your past self in the head.
Think what they're getting at is that it won't happen that way. Gun will jam, you die of a brain aneurysm. We don't exist in a universe where impossible things happen, so we can't bring them about. But yes, the article doesn't really sink its teeth into it.
Pasting the abstract from the paper: The theory of general relativity predicts the existence of closed time-like curves (CTCs), which theoretically would allow an observer to travel back in time and interact with their past self. This raises the question of whether this could create a grandfather paradox, in which the observer interacts in such a way to prevent their own time travel. Previous research has proposed a…
"Further studies will be necessary to find genuine physical scenarios realising the acausal processes we have discovered." To bad no one went back in time to tell the authors whether they actually discovered anything or not.