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The closer we look at time, the stranger it gets
71–80 of 119 posts
Re: The closer we look at time, the stranger it gets
#72The ads on this website are atrocious.
Re: The closer we look at time, the stranger it gets
#73The ads on this website are atrocious.
I recommend an ad blocker. I didn't see any ads.
Re: The closer we look at time, the stranger it gets
#74Earlier quoted context omitted.
The fact that at speed of light time stops is just so bonkers to me. A photon is, from its point of reference, at the point of creation and at the point of destination at the same "time". Its literally seeing both parts of the universe at the same time, and since its traveled some distance over that time it cannot perceive, its essentially connecting 2 points in spacetime. If I understand it correctly, every photon e…
Have a question related to this, if a photon has zero proper time between emission and absorption, how should I think about the influence of later-created photons or fields on it? In our frame, we can interact with a photon long after it's emitted send it through a filter, bounce it off a mirror, measure it, etc. But from the photon's own “no proper time” perspective, does it make sense to ask how something created a…
The photon doesn't have an inertial frame of reference precisely because it's moving at the speed of light, so it doesn't have a perspective. It's a (quantized) wave in the electromagnetic field. The closer you get to the speed of light, the closer the proper time of the journey goes to zero, but actually taking the limit does not make sense physically.
Re: The closer we look at time, the stranger it gets
#75This was perhaps my favorite part of Physics 390 ("modern physics") which was about quantum dynamics and relativity. The speed of light is defined in terms of a velocity (~300,000,000 m/s) but if you were traveling at the speed of light time stops (which keeps the rule that its constant in all frames of reference). That and time passes more quickly at higher altitudes and these days we can actually measure that. Wild…
The fact that at speed of light time stops is just so bonkers to me. A photon is, from its point of reference, at the point of creation and at the point of destination at the same "time". Its literally seeing both parts of the universe at the same time, and since its traveled some distance over that time it cannot perceive, its essentially connecting 2 points in spacetime. If I understand it correctly, every photon e…
Layman thoughts: The photon cannot experience the universe as it passes through it instantly. It seems to me the universal speed limit creates an observability barrier that is really fascinating. The question is what are we missing, because we're zipping through _something_ at the speed of light relative to it.
Lately, I've been wondering what evidence we have that the speed of the photon/light is really the universal speed limit, and not a very close fraction of it. I could find the argument that a photon must be massless, otherwise photons of different wavelengths would travel at different speeds. But that says nothing of the speed of a massless photon relative to maximum causality propagation speeds.
Re: The closer we look at time, the stranger it gets
#76Earlier quoted context omitted.
If we say that seconds "pass", at what rate do they pass? Could they pass at some rate other than one second per second? That would entail outer seconds (second seconds, if you like). Which also have their own rate at which they pass, so now we need a third-level "flow of time", and so on. So to say seconds "pass" is describing something else. They aren't moving.
I feel like you are overthinking it a bit, entangled in semantics. You can take any process that has a fixed frequency (like a clock), and measure the change in frequency in different situations, from the same point of reference. Moving that device at different speeds or into different places in a gravitational field. This is why satellite clocks move at a different rate than those on Earth. Practically speaking, tha…
I think our language is filled with misleading semantics about the flow of time, the passing of time, past, present, future, the arrow of time, all of that. It would be hopeless to try to use different language. But time isn't doing anything. There's no time for time to do anything in.
I'll acknowledge relativity and different frames of reference, but that isn't really the point.
Re: The closer we look at time, the stranger it gets
#77I strongly recommend reading Carlo Rovelli, starting with "The Order of Time"
Re: The closer we look at time, the stranger it gets
#78There's another inscrutable mystery in physics, the nature of consciousness. Time might as well be an artifact of that . I'm surprised this article doesn't mention this possibility. Here's an interesting lecture about it: https://www.youtube.com/watch?v=YusrOYGAhqM
I got downvoted on here not so long ago for mentioning time as an emergent property of quantum consciousness so maybe it's controversial.
I was downvoted for saying that our cosmological model might be wrong because "dark matter" sounds like a crutch.
Now JWST has collected enough evidence that it might, in fact, be wrong.
Re: The closer we look at time, the stranger it gets
#79Earlier quoted context omitted.
> we can't measure how quickly it "flows" or at least how quickly we travel through it. I don't understand this, because it seems like "with a clock" is too obvious an answer, so surely you can't have meant what it sounds like it meant?
If we say that seconds "pass", at what rate do they pass? Could they pass at some rate other than one second per second? That would entail outer seconds (second seconds, if you like). Which also have their own rate at which they pass, so now we need a third-level "flow of time", and so on. So to say seconds "pass" is describing something else. They aren't moving.
> If we say that seconds "pass", at what rate do they pass?
One second per second for yourself, but other observers generally disagree.
Or one could use it as an inverse of the things measured against time, so meters/second of speed can be turned into seconds flowing at a rate of length.
Does "miles per gallon" lead to similar questions about gallons passing?
> Could they pass at some rate other than one second per second?
Only, and always, from the point of view of people in different frames of reference.
Re: The closer we look at time, the stranger it gets
#80We understand "time" in the context that we must: to subsist in order to procreate. The extent it exists outside of our own perception as we imagine it does, is debatable. Ultimately, time is our sensory interpretation of the world around us to facilitate our survival and thus, we may never make sense of it outside the constraints it exists within.
We know empirically that time only flows in one direction, it can’t be described as just a perception. You’d have had at least the tiniest of evidence that time sometimes flows backwards.
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