Is there any evidence of a fundemental quantized unit of time existing? Can I fundementally treat time as continuous or discrete? Plank time isn't good enough because it's possible that we see a phenomenon that happens over a shorter time period and that we need better instruments.
This question very important to me because I don't see a possibility that we can situate identity as existing metaphysically without quantized time. It also seems to imply to me that determinism is wrong.
But please correct me on this you big-brains I don't study quantum physics or general relativity
So far many of the comments seem to have misread the article, which doesn't seek to address the mystery of what time is directly, but rather it describes a supposed mismatch between quantum and classical (via general relativity) interpretations of it's essence.
Think of a donut. Think of a vertical plane through the donut. The plane has two disconnected circles on it. Imagine trying to move the two circles apart. They resist your effort because they are attached together through their three-dimensional structure.
In one view of time (“eternalism”, roughly speaking) saying “there is no change” or “no interaction” between any particles in the universe would mean that in the fixed structure of the universe of which time is a dimension, everything is constant in the direction of that dimension.
As another HN member mentioned, this is a pretty awful article.
What is the alleged conflict supposed to be?
It's my understanding that quantum mechanics necessarily describes systems in a single inertial reference frame, so for that system, time is absolute w.r.t to both general relativity and QM.
Isn't time just a history of movement? For example, if you stopped the movement of everything in the universe (all the way down to subatomic particles) for a "moment" and then turned movement back on again, how long would that moment have lasted for? 1 second or 100 years? There's no way to define how long that moment lasted, since nothing was moving during that moment. So it seems to me that time cannot exist without movement which makes me think that time is a byproduct of motion (a history of motion).
Maybe, it’s an open question whether or not what you are calling time is a useful way to look at the problem the article is talking about. The article wants to know if time is a universal constant (as in quantum mechanics) or if it’s malleable and relative (as in general relativity). It’s not clear to me if viewing time as a history is useful here.
According to general relativity, the time order of events is relative depending on your position and velocity. This also seems to break causality in textbook quantum mechanics since local changes can lead to global adjustments (collapse, for one) of the wavefunction.
That’s an intuitive understanding, but it doesn’t account for quantum effects like superposition, and it doesn’t account for relativistic effects either.
Basically the answer has to be something like: in the multiverse of possible arrangements of particles, some of them are in your past, some of them are in your future, and some are in neither, but which depends on the observer, who is inside the universe they are trying to describe, and that creates the illusion of the flow of time.
This is a pretty awful Wikipedia article. Unless it’s a plea for an actual expert in the field to go in and fix it, I’m not seeing how this is a good submission :(
It is an interesting discussion topic, people are confined to their houses for many days now and naturally experience existential issues. And, because noone sees the world the same way, HN relies on a sophisticated algorithm that tries to minimize bias on what is a good and what is a bad submission. A more constructive approach would be to point out why you think it is an awful article and share some knowledge on the topic.
I have nothing against the topic, I think the Wikipedia article is incredibly poor. It does little to explain the topic and presents a one-sided viewpoint authoritatively when it seems anything but. It’s clearly lacking an encyclopedic tone. There’s a couple of warnings for its poor quality both in the article itself and on the talk page.
Just to add to what saagarjha said; there's large parts of the article that just don't seem to make sense on their own. I only have a Master's degree in Physics, and haven't specialized in general relativity - nevertheless I usually have enough background to at least follow along with Wikipedia.
In particular, the "Overturning of absolute time in general relativity" section is very hard to follow, and I suspect would only make passing sense to a reader already very familiar with the subject matter. It has a very stream-of-consciousness feel to it, it doesn't introduce concepts as it moves along, and it makes unexplained logical leaps from one idea to another.
I'm glad someone took the time to start the article and it sounds like an interesting subject; but it could certainly see improvement from someone with the right knowledge.
I think that the article which supports its definition of the problem with the article written by an author who "obtained a bachelor's degree in physics" and then "left graduate school during the first year in order to pursue a career in science journalism, and "has never looked back"" (1) should just not exist.
In my perception, even that article is such a "popularization" of the topics on which physicists work that it stopped "being even true." The Wikipedia article just continues in that direction.
The "problem" that exists should not even be present as a Wikipedia entry under that specific name. As far as I see it, even the name is wrong.
TBH, >95% of the commentators here don't reach the education level of the editor of the article by far in terms of the specific domain, but still this doesn't stop them from criticizing it.
Not meant to be snarky, and in general imho it is good the be critical always - but this should include oneself. The latter part is often lacking, and the amount of lacking very often appears to be proportional to the lack of knowledge of the commentator.
> The latter part is often lacking, and the amount of lacking very often appears to be proportional to the lack of knowledge of the commentator.
Very good: how does your comment fare using that frame?
And since you commented under my comment, what parts of my comment do you agree with and what do you thing you can correct, and based on which sources? I've given mine.
Maybe i misunderstood your comment, if so I like to apologize.
In any case, would you please explain to me how you consider the title "The problem of time" being wrong. It appears to me as one of the most fundamental questions in physics. The wikipedia article does - from my PoV - a reasonably good try to explain the problem at hand in laymans terms. It touches the relevant aspects of the problem (no absolute time, time/space interdependency) and expands to a more speculative theory (thermal time hypothesis).
I will not at all claim to have even a basic understanding of the covered topics, despite being an avid reader of related bloggers and papers.
I just am astonished how people disregard work of others even without (basic) knowledge of the domain. Maybe I'm wrong, but noone in this thread even tried to show her/his accomplishments in the mentioned domain.
And thanks for replying without simply downvoting.
And please don't think i automatically included you in the perceived group not having "even a basic understanding o the topic". Maybe you have, but since this is even less recognizable than the merits of the wikipedia author it is - from an outside PoV - even less credible.
> how you consider the title "The problem of time" being wrong.
Because as far as I understand it is not commonly accepted name among the physicists for the issues that prevents them developing the "Theory of Everything"
It's just how only a few authors name their articles and books. The title would be OK if it would be a title of the article about the specific book, but not as a title for the "problem" of physics. Because, as far as I know, it's not commonly called as such among the physicists, and that's why even the very support for the whole wikipedia article is a reference to the Quanta article and not some physics textbook, and that is what then confuses readers who don't have "even a basic understanding of the covered topics."
Reducing all the issues about "TOE" to the "problem of time" is not correct, from the perspective of physics. It is probably "fun" for "philosophers" though.
Precise clocks don't care about your sentience or lack thereof. They still measure the gravity and speed-induced time dilation that is entirely missing in quantum mechanics. Relativity is a physical phenomenon that does not require sentience to operate, and time is part of that physical phenomenon.
There is nothing sophistic about this argument. It's pretty obvious.
This is why some people argue that we might be living in a simulation. Because we don't have direct (not mediated by our senses) access to the underlying reality.
My conjecture that consciousness is made of events is an attempt to explain why we see ‘the problem of time’. There are more widely accepted concepts around the subject, like the idea that all moments in time exists equally, not just now. Now is a slice through the cosmos that really exists. I have had thoughts about how relativistic effects work with that, but I honestly think I went far enough. I leave that to others to think about or scoff at.
The direction is purely philosophical. Things are changing from one state to the other. Even if it was backwards, you'd still convince yourself that it is the forward way. Things simply change.
Are there distinct events in the real world or we simply draw the lines arbitrarily simply for the sake of practicality? The whole existence could be the light of a match, experienced in an immensely detailed spacetime scale.
This question very important to me because I don't see a possibility that we can situate identity as existing metaphysically without quantized time. It also seems to imply to me that determinism is wrong.
But please correct me on this you big-brains I don't study quantum physics or general relativity
Also, Your brain is a time machine - Dean Buonomano
The quantum concept of time was invented by physicist Bryce DeWitt in the 1960s:[5]
"Different times are special cases of different universes."
In one view of time (“eternalism”, roughly speaking) saying “there is no change” or “no interaction” between any particles in the universe would mean that in the fixed structure of the universe of which time is a dimension, everything is constant in the direction of that dimension.
So the two statements become roughly equivalent.
What would a physical law that required a single direction look like?
That physical limitation on how fast a mass can move is what keeps causality in check and things like the grandfather paradox from being possible.
Edit: now that I think more on it, this is probably a better law that ensures causality: https://en.wikipedia.org/wiki/Entropy#Second_law_of_thermody...
It's my understanding that quantum mechanics necessarily describes systems in a single inertial reference frame, so for that system, time is absolute w.r.t to both general relativity and QM.
The complexity of things - the things within things - just seems to be endless. I mean nothing is easy, nothing is simple. ~Alice Munro
0 seconds.
Time is the sequence of states every time the rules are applied, or am I missing something?
Basically the answer has to be something like: in the multiverse of possible arrangements of particles, some of them are in your past, some of them are in your future, and some are in neither, but which depends on the observer, who is inside the universe they are trying to describe, and that creates the illusion of the flow of time.
I don’t totally get it either.
In particular, the "Overturning of absolute time in general relativity" section is very hard to follow, and I suspect would only make passing sense to a reader already very familiar with the subject matter. It has a very stream-of-consciousness feel to it, it doesn't introduce concepts as it moves along, and it makes unexplained logical leaps from one idea to another.
I'm glad someone took the time to start the article and it sounds like an interesting subject; but it could certainly see improvement from someone with the right knowledge.
In my perception, even that article is such a "popularization" of the topics on which physicists work that it stopped "being even true." The Wikipedia article just continues in that direction.
The "problem" that exists should not even be present as a Wikipedia entry under that specific name. As far as I see it, even the name is wrong.
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1) https://en.wikipedia.org/wiki/Natalie_Wolchover
Not meant to be snarky, and in general imho it is good the be critical always - but this should include oneself. The latter part is often lacking, and the amount of lacking very often appears to be proportional to the lack of knowledge of the commentator.
Very good: how does your comment fare using that frame?
And since you commented under my comment, what parts of my comment do you agree with and what do you thing you can correct, and based on which sources? I've given mine.
In any case, would you please explain to me how you consider the title "The problem of time" being wrong. It appears to me as one of the most fundamental questions in physics. The wikipedia article does - from my PoV - a reasonably good try to explain the problem at hand in laymans terms. It touches the relevant aspects of the problem (no absolute time, time/space interdependency) and expands to a more speculative theory (thermal time hypothesis).
I will not at all claim to have even a basic understanding of the covered topics, despite being an avid reader of related bloggers and papers.
I just am astonished how people disregard work of others even without (basic) knowledge of the domain. Maybe I'm wrong, but noone in this thread even tried to show her/his accomplishments in the mentioned domain.
And thanks for replying without simply downvoting.
And please don't think i automatically included you in the perceived group not having "even a basic understanding o the topic". Maybe you have, but since this is even less recognizable than the merits of the wikipedia author it is - from an outside PoV - even less credible.
Because as far as I understand it is not commonly accepted name among the physicists for the issues that prevents them developing the "Theory of Everything"
https://en.wikipedia.org/wiki/Theory_of_everything
It's just how only a few authors name their articles and books. The title would be OK if it would be a title of the article about the specific book, but not as a title for the "problem" of physics. Because, as far as I know, it's not commonly called as such among the physicists, and that's why even the very support for the whole wikipedia article is a reference to the Quanta article and not some physics textbook, and that is what then confuses readers who don't have "even a basic understanding of the covered topics."
Reducing all the issues about "TOE" to the "problem of time" is not correct, from the perspective of physics. It is probably "fun" for "philosophers" though.
We do not and cannot know that because all observations me make involve sentience. In fact, we can't even know if anything exists without sentience.
That last bit - "...we can't even know.." is sophistry.
This is why some people argue that we might be living in a simulation. Because we don't have direct (not mediated by our senses) access to the underlying reality.
The fact is, the universe operates consistent with Relativity.