Grandfather paradox
Grandfather paradox
So fate is real?
This has blown my mind and I am not a maths person at all, it implies to me that events must happen how they happened and even if you time travel, nothing will change. So, fate then. But you can still try, so free will also. And contrary to all science fiction ever, it is actually quite hard to unravel the fabric of space time, thankfully.
Or I could be completely wrong or exaggerating. Please help!
This has blown my mind and I am not a maths person at all, it implies to me that events must happen how they happened and even if you time travel, nothing will change. So, fate then. But you can still try, so free will also. And contrary to all science fiction ever, it is actually quite hard to unravel the fabric of space time, thankfully.
Or I could be completely wrong or exaggerating. Please help!
Non fui. Fui. Non sum. Non curo.
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Re: Grandfather paradox
Just because some maths predicts something could exist doesn't mean that it actually exists.
The paper is at https://doi.org/10.1088/1361-6382/aba4bc and appears to be open access.
The paper is at https://doi.org/10.1088/1361-6382/aba4bc and appears to be open access.
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Grandfather paradox
Well, I shall see if I can understand it, and attempt to read. But thankyou for putting it in perspective. Too much madness going on this year, I haven't been able to think straight since mid Feb.shpalman wrote: ↑Fri Oct 02, 2020 3:58 pmJust because some maths predicts something could exist doesn't mean that it actually exists.
The paper is at https://doi.org/10.1088/1361-6382/aba4bc and appears to be open access.
Non fui. Fui. Non sum. Non curo.
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Re: Grandfather paradox
To be honest, I wouldn't really understand the maths in the paper either.
Someone who was at Warwick at the same time I was did his PhD on the idea that closed timelike curves from general relativity could explain quantum mechanical entanglement, or something.
It's not obvious that we live in a universe in which CTCs would be possible.
Someone who was at Warwick at the same time I was did his PhD on the idea that closed timelike curves from general relativity could explain quantum mechanical entanglement, or something.
It's not obvious that we live in a universe in which CTCs would be possible.
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Grandfather paradox
It's not all sci-fi. There's plenty that show you can't change the past, because you're reacting to things caused by you, 12 monkeys is the first example that popped into my head (as far as I remember it, it's been a while). But this does rule out stepping on a butterfly and ruining things for everyone.nezumi wrote: ↑Fri Oct 02, 2020 3:48 pmSo fate is real?
This has blown my mind and I am not a maths person at all, it implies to me that events must happen how they happened and even if you time travel, nothing will change. So, fate then. But you can still try, so free will also. And contrary to all science fiction ever, it is actually quite hard to unravel the fabric of space time, thankfully.
Or I could be completely wrong or exaggerating. Please help!
I'm not going to bother trying to get into the detail of the paper, but shalpman's right, just 'cos a theorist has a theory, it doesn't make it so. Still, it's fun to think about.
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Re: Grandfather paradox
Kurt Godel showed ages ago (don't know when, but presumably before his death in 1978) that closed timelike trajectories could exist in general relativity. This paper might not be as newsworthy as an average journalist or PR department think.
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Re: Grandfather paradox
According to wiki he showed that CTCs could exist in a particular metric; "Its definition is somewhat artificial in that the value of the cosmological constant must be carefully chosen to match the density of the dust grains"basementer wrote: ↑Fri Oct 02, 2020 4:39 pmKurt Godel showed ages ago (don't know when, but presumably before his death in 1978) that closed timelike trajectories could exist in general relativity. This paper might not be as newsworthy as an average journalist or PR department think.
https://en.wikipedia.org/wiki/G%C3%B6de ... rpretation
Just because it is allowed in general relativity doesn't mean it's allowed in our universe.Following Gödel, we can interpret the dust particles as galaxies, so that the Gödel solution becomes a cosmological model of a rotating universe. Besides rotating, this model exhibits no Hubble expansion, so it is not a realistic model of the universe in which we live, but can be taken as illustrating an alternative universe, which would in principle be allowed by general relativity (if one admits the legitimacy of a nonzero cosmological constant).
having that swing is a necessary but not sufficient condition for it meaning a thing
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Re: Grandfather paradox
I'm reminded of the Larry Niven short story in which the universe did indeed not allow* the construction of devices** that created closed time-like loops.
*Your sun went nova if you tried it
**large rapidly rotating cylinders the density of neutron stars
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Re: Grandfather paradox
tl;dr: Mathematicians write a paper and their uni has a creative PR department.
Something something hammer something something nail
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Re: Grandfather paradox
That came to my mind too, although I couldn't remember the author.JQH wrote: ↑Fri Oct 02, 2020 9:40 pmI'm reminded of the Larry Niven short story in which the universe did indeed not allow* the construction of devices** that created closed time-like loops.
*Your sun went nova if you tried it
**large rapidly rotating cylinders the density of neutron stars
Money is just a substitute for luck anyway. - Tom Siddell
Re: Grandfather paradox
Ahem. Just because a hypothesist has a hypothesis, it doesn't make it so. If it's a theory then it's a hypothesis which has been proven (or at least hasn't been disproven!)
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