The Closer We Look at Time, the Stranger It Gets
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The mysteries of time are sparking a lively debate, with commenters diving into the complexities of time's arrow and the interplay between quantum mechanics and General Relativity. Some, like hnfong, argue that time's flow is a subjective experience shaped by our environment, while others, like alex77456, propose intriguing thought experiments, such as a brain flowing backwards in time, to challenge our understanding. As the discussion unfolds, humor and wit shine through, with quips like klipt's "Time is an illusion, lunchtime doubly so" and charlieflowers' "Ohh, time flows _that_ way for you." Amidst the banter, insightful links and explanations, like russdill's pointer to the "Past Hypothesis" on Wikipedia, add depth to the conversation, making this thread a fascinating exploration of time's strange and multifaceted nature.
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Time still flows and ebbs, we just lack the ability to sense it just like a cork in a river doesn't feel the water flowing past.
but in other environments (talking about same universe here!) the future is more predictable than here on earth, for example motions of planetary bodies can be predicted way in advance within error bars as in the past, and when you have that kind of relatively symmetrical system, any subjective experiences within those systems would be much less inclined to feel that time flows on way or the other. (of course, the only kind of subjective experiencers we know are made of biological stuff which structurally remembers the past and leaves the future open as form of evolved ability, so this timelessness experience may be harder to imagine for us)
If you subject a brain-like neural network to watch planets and stars orbiting around each other and rewarding it for getting things right, it will likely do quite well.
Consider a black box. A person opens it, sees a dice with a number, closes it. In our version of the time flow, the person finds out there's a dice and remembers it. In the 'reverse time' persons brain, they would know they would open the black box and know which number they will see. Then they will close it and completely forget what was inside forever.
Supplication for unknown outcomes surely already determined in the objective past wrt the present time still makes sense. The Divine Successive Relaxation with physical laws as the substrate, and the choices of human free will, human petition and desire, and Divine Will And Intention as boundary conditions, will solidify objective reality into a coherent whole in Open Theism.
https://en.wikipedia.org/wiki/Past_hypothesis
You can happily run physics backwards and forwards, and there's no difference. But assuming that entropy was very low in the distant past is very useful and lets us talk about fascinating things, like what happened last tuesday (or 12 billion years ago)
If you just know the current state of the a system, there isn't really any difference between running time backwards and forwards. Of course, if you know exactly the state of every particle, field, etc, and the past hypothesis is true, running time one way will lead to lowering entropy, and the other way will lead to raising entropy. But if you're a mere mortal and just know the macrostate, either way you run time, the entropy of the system will increase.
We don't know empirically what came before the beginning.
_Everything_ flows in one direction, all particles goes in a straight line from their self reference, fields "modifying direction" is just an observer point of view. The separation of time and space is purely a perception matter.
A gross comparison would be to compare with objects perception, it only exists because our mind can leverage it for a strong evolutional advantage (I'm not only speaking of humans here).
But in time, it can only go forwards, at very slow rates like far from gravity wells, or fast like in relativistic situations. Never backwards. Never stop.
If one twin stays on earth and the other makes an intergalactic trip (with the speed of light), upon return, the one on earth will have aged much more than the one on the trip.
(p.s. the spacefaring twin doesn't have to move at the speed of light, and indeed cannot, it's enough to move at a "relativistic" speed, i.e. fast enough that this is actually measurable. With today's clock that doesn't have to be very fast actually)
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 exists, from its point of view, for only infinitely small amount of time (similar to how virtual particles do exist from our point of reference), but for us its so easy to "play" with the photon along its path, giving us plenty of time to even decide what we want to do with it after it has already been created.
Its just so bonkers that time can be perceived such differently depending on frame of reference.
> every photon exists, from its point of view, for only infinitely small amount of time
Why is that amount “infinitely small” and not 0 since photons travel exactly at the speed of light?
In the mathematics of infinity, something can have exactly zero probability yet still happen, and exactly one probability yet nonetheless fail to happen (hence the standard term “almost surely”).
If something can have literally zero probability of existing yet still exist, why can’t it exist for literally zero time yet still exist?
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 after its emission could affect its path?
Like, from our point of view, we assume that from photons point of view it has no perspective.
But maybe we are limited by our spacetime, where photon goes trough our universe in an instant, and continues to pierce infinite universes over its non-zero frame of reference.
The problem here is likely the concept of "after". It's relativity; what's "after" in our frame of reference isn't after in all frames of reference.
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.
My question is if this part of the model has been validated experimentally somehow.
BTW, it seems odd calling a photon a zero-energy object.
Are we saying then that it is theoretically possible that (a) photons have a zero or near-zero lifetime, but that also (in our frame of reference) (b) they exist for a finite duration of time and are visible during that time simply because time stops for them ? Or did someone manage to slow down light to some fraction of light speed ?
> One might think this means that imaginary numbers are just a mathematical game having nothing to do with the real world. From the viewpoint of positivist philosophy, however, one cannot determine what is real. All one can do is find which mathematical models describe the universe we live in. [1]
[1] https://en.wikipedia.org/wiki/Imaginary_time
Upon death the etheric body opens up and turns itself inside out and as you identify less with your physical body and more with your etheric body your perception of time is now in reverse. Your entire life tableau is opened in front of you, and as your spiritual organs of perception once "facing inwards" to your interior are now "outward-facing" and working backwards you start to see the effects of all your choices and actions from the perspective of its consequences. This is the source of those "life flashes before your eyes" moments people with near death experiences go through.
Only for very unconscious people is it a hell-like experience. Even if you lived a rather thoughtless and abusive life it is said that it can still be a time of reflection and learning. Eventually after viewing your entire life "inside out" your perception opens up to your pre-birth condition, the etheric body sloughs off (being made of elemental beings itself) and is picked up and put together with all the karma of your previous lives for your next go-around on Earth. You liberate the elementals in your etheric body (which are just below humans in the spiritual hierarchy) by growing spiritually either during life or in the etheric condition and eventually, hopefully, move up the spiritual hierarchy to a being that liberates humans, an Angel.
Thought maybe HN might be interested in some other conceptions of time. :^)
Don't ask Newton about the pseudo babble stuff. Nor the string "theorists". In fact, don't ask any of the "theoretical" physicists (an oxymoron by definition, which seems to be lost on almost all of them) about "magical thinking and pseudo babble".
Scientific hypotheses and religious/metaphysical articles of faith are orthogonal ideas.
Thanks for your insights of the non scientific part of the universe. Harder to navigate but definitely not less important. May we one day discover.
You do get some minimal upgrades with enough karma, like the ability to downvote. But it's not like you get any priority or special treatment, and the numbers are not exposed unless you open individual profiles.
I suppose it could be useful to give legitimacy to bot accounts to be able to inflate upvotes of some posts, but from what I've seen vote-ring detection is really good on HN.
[0] https://plato.stanford.edu/entries/time/
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?
So to say seconds "pass" is describing something else. They aren't moving.
Practically speaking, that's really what we care about when we talk about the speed of time. If some process takes a certain amount of time to complete, sending it to space and back, without changing anything else about it, might make it complete earlier from our point of reference.
I'll acknowledge relativity and different frames of reference, but that isn't really the point.
If a clock is in a frame of faster time, it will tick faster, its ticks will happen before, than an identical clock in a frame of slower time.
That’s how I see time, it is the ordering of physical events, which we can trivially observe.
You keep trying to explain time as if it was a thing of its own, like a water flow, but it is no more than an abstraction to indicate how some things happen before others, and they definitely do, at least in the same frame.
My teacher explained it in a similar way. Time passes when we can observe change. If there is no change then we can not measure time. Like with the heat death of the universe. At that time (lol) no more time would "happening".
Let's assume that time is discrete dimension (which it might be). Then there would be a measure of distance of how many ticks of potential events there are between two actual events, even if nothing happened in between. Or maybe that's not the case and it's more of a directed graph defining the partial ordering of actual events.
Not sure if we could measure that in any case, we always need some kind of actually ticking clock, and it's not like we can isolate a period of time where nothing happens globally, unless its in a simulation.
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.
Sure, it wasn't clear which way you were going with that question, but I recognised that it could have been either.
I only find that boggling in the context we both agree you're not using: relativity (block universe in particular).
In so far as we ignore all of relativity because it's so counter-intuitive and strange, "all moments of time being equally real" seems as trivial and straightforward as "all places in cartesian 3-dimensional space being equally real".
But yes, boggling is never compulsory.
Our experience of time passing is heavily influenced by the temporal granuality of our subjective experience-at the upper end, “now” lasts 2-3 seconds; at the lower end, our temporal discrimination goes down to tens of milliseconds for visual and tactile stimuli, and reaches down to microseconds for certain types of auditory stimuli. But, one supposes other species with different neurology would have these durations be shorter or longer, which would make time pass more slowly or faster for them, in subjective terms.
Here's an interesting lecture about it: https://www.youtube.com/watch?v=YusrOYGAhqM
Now JWST has collected enough evidence that it might, in fact, be wrong.
It's "dark" in the sense that the (fabled) Dark Ages were dark. They didn't have more cloud cover then. And dark matter is 'dark' as in 'inobservable, except by gravitational attraction'. So we admit it might not even be "matter" by any definition we have; it's just what we're calling this invisible, untouchable, silent elephant in the room. That is very heavy. And might not be an elephant.
Honestly, "invisible matter" might have been a better term, but that too would have been misinterpreted.
Psychedelics can remove the sensation of time passing. But they are also modifying the experience of "consciousness" itself.
Electro-magnetic radiation, on the other hands, is highly describable in precise, testable, repeatable terms.
When you can state Maxwell's Laws of Consciousness, we'll talk. And rename them "Grishka's".
Isn't there some sort of "quantum foam" ? So it's going to be difficult to define a metric ?
I likely need to reread it, though, as some of its ideas are a bit above my weight class when it comes to understanding physics. But, you may enjoy it!
Here's a much longer take from Tim Maudlin, "Tim Maudlin: A Masterclass on the Philosophy of Time" (https://youtu.be/3riyyEmWwoY?si=9aI-bETWcNpdjMW9), Tim Maudlin is Professor of Philosophy at NYU and Founder and Director of the John Bell Institute for the Foundations of Physics. The podcast is Robinson Erhardt's.
Their math give an answer with artefacts they can’t match to reality so they keep probing the outliers of these absolutely bonkers ideas, and rabbit holes keep getting deeper & weirder.
Time doesn’t exist. Do the people writing this garbage live in a vacuum? Is it AI slop?
Maybe don't dismiss an idea as garbage before trying to understand it.
One of the ideas here is that time is an emergent phenomenon, like how temperature and gas pressure seem real at a macroscopic level, but disappear once you look closer. They simply describe the average kinetic energy of all the molecules in the area.
The _hypothesis_ is that time could be similar.
I will reread it like three times maybe the third time is the charm
Consider (note -- I'm basically doxxing myself, but this is an example from a book I'm set to publish next year):
"One bright day you and your friend Tacitus are playing a duet. You've got a guitar, he's got a harp; you're sitting on one side of the garden, he's sitting on the other. You simultaneously hit a note. Your note is 1 and Tacitus' note is 2. Shortly thereafter, you hit note 3 and Tacitus hits note 4. Unbeknownst to you, a couple of interstellar spacefaring yachts, Dragon and Crab, have passed each other directly overhead. On those yachts, with velocity at .9c shifting their own reference frames, things flow differently. On Dragon, notes 2 and 3 appear to sound simultaneously. On Crab, which is heading in the opposite direction, it's 4 and 1 that sound at the same time. So, to Crab, prior event 1 is simultaneous with present event 4 – or, alternatively framed, future event 4 takes place simultaneously with present event 1.
"Now imagine that the garden you're sitting in is very large, and you're separated from Tacitus by about a kilometer. You'd notice a bit of time lag affecting your performance, but Crab would notice something much stranger: That note 4 takes place before note 1. In other words, that an event in your future has already taken place."
And just as Crab saw 4 played before 1, things that shall happen in our future are in principle already available to other observers.
One doesn't need to travel at a large fraction of the speed of light for this to be true. Even a sufficiently fast aircraft, moving directly overhead the duet, would have its perception of time altered somewhat, so that 2 takes place slightly before 1 – a very small effect, on the order of attoseconds – even though to the guitar player the two events are perfectly simultaneous, e.g. happen in the same Planck moment.
Science doesn't like the obvious implications of this, because determinism is considered something that poisons science by making free experimentation impossible. But there are no credible alternatives. The only ones I've seen proposed boil down to solipsism or relativism -- and those are even worse, especially when they're obfuscated to such an extent that they seem almost credible, e.g. in "cone presentism."
To be clear, solipsism in this context is: "One frame of reference is true, and every other observer is wrong about the reality of its perceptions to whatever extent they disagree with the privileged frame."
Relativism is essentially: "A future I cannot perceive and do not experience is not my future; I disavow it." (More sophisticated forms attempt to play games with semantics and redefine concepts like "present time.")