A delightful quirk of relativity theory • Hacker News Board

Re: A delightful quirk of relativity theory

#61

Post by awb » Tue, Jan 18, 2022, 1:58 PM UTC

irthomasthomas wrote: post #21

This would be more fun in a blog post. Twitter is a fucking horrible format for a complex analysis of special relativity. That aside, my favourite quirk from relativity is this: "The more you move in space, the less you move in time." Like relativity in general, it sounds simple enough, but it's consequences are profoundly shocking. (That is, if you take the time to understand it, and don't leap to the conclusion tha…

> Take the case of two people on Earth, one stationary and one travelling past in a car. They each have a different reference frame, and a different set events which make up their present. Now imagine that there is an alien government in Andromeda debating a possible invasion of Earth. In the reference frame of the person on Earth who is moving, the debate is still going on. But, in the reference frame of the stationary person, it is a day or so later in Andromeda, and the invasion fleet is already on it's way!

I’m pretty sure this is wrong (or misleading) on multiple levels:

1) An event in Andromeda occurs at single moment, it’s our observation of the event that is warped. So there aren’t two realities, one where they’re still debating and one where they aren’t. In both realities the debate has concluded, it’s just our observation of the event takes place at different reference times.

2) The car would need to be moving at a non-insignificant fraction of the speed of light to have an observation dilution of a day or more. It’s physically impossible for humans to move that fast with our current technology.

https://www.quora.com/Does-time-slow-down-in-a-moving-vehicl...!

You’d have to be traveling at 0.86c for an entire day to be observing 1 day slower than a stationary person.

Re: A delightful quirk of relativity theory

#62

Post by antattack » Tue, Jan 18, 2022, 2:00 PM UTC

danbruc wrote: post #42

irthomasthomas wrote: post #21

This would be more fun in a blog post. Twitter is a fucking horrible format for a complex analysis of special relativity. That aside, my favourite quirk from relativity is this: "The more you move in space, the less you move in time." Like relativity in general, it sounds simple enough, but it's consequences are profoundly shocking. (That is, if you take the time to understand it, and don't leap to the conclusion tha…

Rescuing free-will from the jaws of spacetime would be cool! Free will does not exist. It is logically inconsistent. Either your choice is some function of your current state and the environment you are in, then the choice is not free, or it is independent of your current state and the environment you are in, then it is not your choice in any meaningful way, it is just the result of a coin flip. You can do some menta…

If your definition of free will existed, how would you prove it?

Re: A delightful quirk of relativity theory

#63

Post by topaz0 » Tue, Jan 18, 2022, 2:06 PM UTC

Markus Deserno is a fantastic scientist in my field, and always gives the best talk at the conference.

Re: A delightful quirk of relativity theory

#64

Post by deelly » Tue, Jan 18, 2022, 2:06 PM UTC

300bps wrote: post #22

enriquto wrote: post #18

Earlier quoted context omitted.

Oh, I don't bother by the stupidly repeated usernames and dates. I just want to read the damn thing. But it is literally unreadable to me. I couldn't finish reading the thread and had to find an alternative way out of twitter. Fist trial, using my android phone with fennec fox. There is a modal that hides the content asking me to "log in"; if I close the modal I go back to the twitter homepage. Thus unreadable becaus…

For what it’s worth, I clicked on the HN link on my iPhone and it opened in the Twitter app (that I never use) and it was extremely readable. Literally no problems reading it at all.

I can't say that buying IPhone with preinstalled Twitter app is very convenient way of reading twitter post.

Re: A delightful quirk of relativity theory

#65

Post by pmontra » Tue, Jan 18, 2022, 2:15 PM UTC

Unrolled for sanity of readers https://threadreaderapp.com/thread/1482811504424542211.html

I don't know if I admire more the mastery of science of the author or the willpower necessary to write those posts on such a wrong medium for them. Worse than one twit per paragraph, only MMSes.

Re: A delightful quirk of relativity theory

#66

Post by kybernetikos » Tue, Jan 18, 2022, 2:15 PM UTC

vidarh wrote: post #53

V-2 wrote: post #44

Earlier quoted context omitted.

The typical source of confusion is conflating "free" with "unpredictable". But they're not the same thing at all.

"Unpredictable" is imprecise to the point of being meaningless. If a black box is fully deterministic to the point that you can construct a model that is entirely accurate, then there's nothing "free" about it. What you're modelling has no agency. For the notion of "free will" to have any meaning at all, it doesn't need to be "unpredictable" in the sense that it keeps confounding someone trying to predict it all the…

> What you're modelling has no agency

I see no reason to think that just because something is predictable it is not free. That seems like such a strange constraint to me that I can only assume that we have different understandings of what it means to be free.

If I know someone well, I might predict that when offered a free choice between an ice cream and a brussels sprout they will choose the ice cream. The fact that I was able to predict that with an incredibly high degree of certainty didn't stop them from being free.

Re: A delightful quirk of relativity theory

#67

Post by wruza » Tue, Jan 18, 2022, 2:18 PM UTC

danbruc wrote: post #42

irthomasthomas wrote: post #21

This would be more fun in a blog post. Twitter is a fucking horrible format for a complex analysis of special relativity. That aside, my favourite quirk from relativity is this: "The more you move in space, the less you move in time." Like relativity in general, it sounds simple enough, but it's consequences are profoundly shocking. (That is, if you take the time to understand it, and don't leap to the conclusion tha…

Rescuing free-will from the jaws of spacetime would be cool! Free will does not exist. It is logically inconsistent. Either your choice is some function of your current state and the environment you are in, then the choice is not free, or it is independent of your current state and the environment you are in, then it is not your choice in any meaningful way, it is just the result of a coin flip. You can do some menta…

I prefer to think that it's a soulspace dynamically mapped onto a physical space at stochastic points designated by a wave function density distribution. So that at any point in time we have zero, one or more random souls influencing our behavior. So it wasn't particularly me, your honor.

Re: A delightful quirk of relativity theory

#68

Post by ngcc_hk » Tue, Jan 18, 2022, 2:22 PM UTC

Quite a good description of “𝙇𝙤𝙧𝙚𝙣𝙩𝙯 𝙩𝙧𝙖𝙣𝙨𝙛𝙤𝙧𝙢𝙖𝙩𝙞𝙤𝙣𝙨”. Still hard to understand intuitive, but sort of understand “logically”.

Btw the blog site is so much better.

Re: A delightful quirk of relativity theory

#69

Post by cjameskeller » Tue, Jan 18, 2022, 2:23 PM UTC

danbruc wrote: post #42

irthomasthomas wrote: post #21

This would be more fun in a blog post. Twitter is a fucking horrible format for a complex analysis of special relativity. That aside, my favourite quirk from relativity is this: "The more you move in space, the less you move in time." Like relativity in general, it sounds simple enough, but it's consequences are profoundly shocking. (That is, if you take the time to understand it, and don't leap to the conclusion tha…

Rescuing free-will from the jaws of spacetime would be cool! Free will does not exist. It is logically inconsistent. Either your choice is some function of your current state and the environment you are in, then the choice is not free, or it is independent of your current state and the environment you are in, then it is not your choice in any meaningful way, it is just the result of a coin flip. You can do some menta…

This is conflating causation and determination. It is true that one's choice must have a cause, and this can either be internal or external to oneself. But it is not true that the choice must be _determined_ by the cause. The Agent Causation [0] view denies the notion that only states or events can serve as causal priors, and instead asserts that substances themselves may be the terminal "cause"

[0] https://plato.stanford.edu/entries/incompatibilism-theories/...

Re: A delightful quirk of relativity theory

#70

Post by ngcc_hk » Tue, Jan 18, 2022, 2:25 PM UTC

kybernetikos wrote: post #45

danbruc wrote: post #42

Earlier quoted context omitted.

Rescuing free-will from the jaws of spacetime would be cool! Free will does not exist. It is logically inconsistent. Either your choice is some function of your current state and the environment you are in, then the choice is not free, or it is independent of your current state and the environment you are in, then it is not your choice in any meaningful way, it is just the result of a coin flip. You can do some menta…

You've put the dilemma nicely - it can't be both 'free' and 'your will' by your definitions (well, without admitting supernatural beings that can affect and be affected by the natural world, but are not part of it). Personally I'm happy with other definitions, not because I feel I'm doing mental gymnastics, but because the version you give is clearly not what normal people mean by it when they refer to it. It might w…

Our “soul” is that being which “ can affect and be affected by the natural world, but are not part of it”. You can feel it as you are one of these “supernatural being”. Case closed.