6 ms·

I'd like to see you try to define these terms.

deleted 9y ago
[deleted]
joslin01 9y ago
Coffee is sitting there as a bunch of molecules. Can you point at time as a bunch of molecules sitting there? If not, it's not by the same token.
- Certhas 9y ago
  I take your bunch of molecules ("physical manifestation") and squash them into a black hole. Now they have been turned into an aspect of the structure of space and time ("a measurement or perspective"). So no, space and time are not "measurements/perspectives" that are fundamentally distinct from "a bunch of molecules".
  - joslin01 9y ago
    Ok so you change the situation drastically by squashing them into a black hole, something nobody really understands, and tell me coffee and time are interchangeable. Right. Also I never said space was measurement/perspective, I said time was. You believe what you want to believe, but maybe stick to a single scenario in the future. I'll say it again, a cup of coffee just sitting there is distinct from time.
    - ben_w 9y ago
      While I agree that was a poor example for much the same reasons, I think I have a much better comparison: Duration is as much a measurement/perspective as displacement, this is an observation which led to Special Relatively. If time can be called an illusion, so can position.
      - SiempreViernes 9y ago
        If duration is a simple displacement between two points in another direction of space then you are right, the two are equivalent: you have then also accepted that time does not flow and lacks intrinsic direction for it is precisely these properties that separates "time" from "space". Time flows and is irreversible, this is what makes it special, and it is the denying that the flow and irreversibility are inherent properties of time that constitutes "dispelling the illusion". In other words, saying that "time is an illusion" is saying "time is just like space".
        ben_w 9y ago
        > Time flows In what sense? Normally people use that word in a sentence such as “time flows like water”, but water is made of discrete molecules and has momentum, which doesn’t generally ever sound like the subsequent sentence, whatever that happened to be at the — ah ha — time. > and is irreversible The funny thing is, thermodynamics is the only law of physics which say that and last I checked nobody knew (or agreed) why, as thermodynamics is inevitable from the other laws but the other laws don’t imply a direction for time. Of course, there’s also the difference of it acting like imaginary (sqrt(-1)) space…
        SiempreViernes 9y ago
        Look, I'm just listing the properties ascribed to time that sets it apart from distance, not taking a position as to their correctness or how accurate the similes are. If you are ready to accept the timeless unchanging universe that's fine by me, just acknowledge that is what you argue for.
        ben_w 9y ago
        Calling it “timeless and unchanging” is as incorrect as calling it “x-axis-less and dζ/dx is always exactly zero for all possible variables ζ“. I think you need to be precise with language for this sort of thing, and avoid similies everywhere, or you’ll run into the same sort of problems quantum physicists have with “observations collapse the wave function” being misunderstood as “conscious minds collapse the wave function”.
    - Certhas 9y ago
      Ok one thing at a time. I did not say they are interchangable, I said if one is an illusion, so is the other. I also claimed that your notion of "physical manifestation" is not a meaningful distinction. Or at least, it's not easy to make it into a meaningful distinction that is compatible with what we know about the laws of physics. It iis incorrect to claim that nobody really understands black holes. There are aspects of them that we don't understand, but we understand fairly well how a massive amount of coffee would turn into a black hole (a structure in space and time). Also space and time are really not on different epistemological or ontological footing anymore. We also should distinguish a particular instance of coffee and the concept of coffee itself, just as we should distinguish a particular time interval from the overall notion of time. A time interval then is a chunk of metric between two endpoints that would be marked, for example, by molecules doing something like ticking. It's a relative configuration of gravitational and matter fields. Your concrete cup of coffee is likewise a configuration of matter and gravitational fields. Ontologically they really aren't that different if you take general relativity seriously. Your perspective seems to be somewhat pre GR. Sort of Kantian: Time is not a category of reality but a category of our perception of reality. The work of Rovelli et.al. is two steps further. In GR time no longer has a distinguished foundational meaning in (and in that way it is like coffee). It's constructed from physical fields that describe its structure. The thermal time hypothesis goes one step further by making the "time field" (which is the metric, which is the gravitational field) be emergent. It's not the only theory to do so. Jacobsons GR from black hole entropy is conceptually similar.
  - SiempreViernes 9y ago
    Uh, so you have a reliable theory for the insides of a black hole? Or how do you know what happened inside the black hole? In any case, the cup distorted spacetime even when it wasn't big enough to form a event horizon, so that it still does it after being squashed proves nothing for the issue at hand.
    - Certhas 9y ago
      Yeah. I do. It's called general relativity. It doesn't tell me what happens at the singularity, but it's valid for the vast majority of the interior of a large black hole.
- deleted 9y ago
  [deleted]
- Senderman 9y ago
  "Pointing" is the part of the picture time is in. If you take out time, you can't point to the coffee: you'd be stuck not-pointing!

deleted 9y ago

[deleted]

Coffee is sitting there as a bunch of molecules. Can you point at time as a bunch of molecules sitting there? If not, it's not by the same token.

Certhas 9y ago
I take your bunch of molecules ("physical manifestation") and squash them into a black hole. Now they have been turned into an aspect of the structure of space and time ("a measurement or perspective"). So no, space and time are not "measurements/perspectives" that are fundamentally distinct from "a bunch of molecules".
- joslin01 9y ago
  Ok so you change the situation drastically by squashing them into a black hole, something nobody really understands, and tell me coffee and time are interchangeable. Right. Also I never said space was measurement/perspective, I said time was. You believe what you want to believe, but maybe stick to a single scenario in the future. I'll say it again, a cup of coffee just sitting there is distinct from time.
  - ben_w 9y ago
    While I agree that was a poor example for much the same reasons, I think I have a much better comparison: Duration is as much a measurement/perspective as displacement, this is an observation which led to Special Relatively. If time can be called an illusion, so can position.
    - SiempreViernes 9y ago
      If duration is a simple displacement between two points in another direction of space then you are right, the two are equivalent: you have then also accepted that time does not flow and lacks intrinsic direction for it is precisely these properties that separates "time" from "space". Time flows and is irreversible, this is what makes it special, and it is the denying that the flow and irreversibility are inherent properties of time that constitutes "dispelling the illusion". In other words, saying that "time is an illusion" is saying "time is just like space".
      - ben_w 9y ago
        > Time flows In what sense? Normally people use that word in a sentence such as “time flows like water”, but water is made of discrete molecules and has momentum, which doesn’t generally ever sound like the subsequent sentence, whatever that happened to be at the — ah ha — time. > and is irreversible The funny thing is, thermodynamics is the only law of physics which say that and last I checked nobody knew (or agreed) why, as thermodynamics is inevitable from the other laws but the other laws don’t imply a direction for time. Of course, there’s also the difference of it acting like imaginary (sqrt(-1)) space…
        SiempreViernes 9y ago
        Look, I'm just listing the properties ascribed to time that sets it apart from distance, not taking a position as to their correctness or how accurate the similes are. If you are ready to accept the timeless unchanging universe that's fine by me, just acknowledge that is what you argue for.
        ben_w 9y ago
        Calling it “timeless and unchanging” is as incorrect as calling it “x-axis-less and dζ/dx is always exactly zero for all possible variables ζ“. I think you need to be precise with language for this sort of thing, and avoid similies everywhere, or you’ll run into the same sort of problems quantum physicists have with “observations collapse the wave function” being misunderstood as “conscious minds collapse the wave function”.
  - Certhas 9y ago
    Ok one thing at a time. I did not say they are interchangable, I said if one is an illusion, so is the other. I also claimed that your notion of "physical manifestation" is not a meaningful distinction. Or at least, it's not easy to make it into a meaningful distinction that is compatible with what we know about the laws of physics. It iis incorrect to claim that nobody really understands black holes. There are aspects of them that we don't understand, but we understand fairly well how a massive amount of coffee would turn into a black hole (a structure in space and time). Also space and time are really not on different epistemological or ontological footing anymore. We also should distinguish a particular instance of coffee and the concept of coffee itself, just as we should distinguish a particular time interval from the overall notion of time. A time interval then is a chunk of metric between two endpoints that would be marked, for example, by molecules doing something like ticking. It's a relative configuration of gravitational and matter fields. Your concrete cup of coffee is likewise a configuration of matter and gravitational fields. Ontologically they really aren't that different if you take general relativity seriously. Your perspective seems to be somewhat pre GR. Sort of Kantian: Time is not a category of reality but a category of our perception of reality. The work of Rovelli et.al. is two steps further. In GR time no longer has a distinguished foundational meaning in (and in that way it is like coffee). It's constructed from physical fields that describe its structure. The thermal time hypothesis goes one step further by making the "time field" (which is the metric, which is the gravitational field) be emergent. It's not the only theory to do so. Jacobsons GR from black hole entropy is conceptually similar.
- SiempreViernes 9y ago
  Uh, so you have a reliable theory for the insides of a black hole? Or how do you know what happened inside the black hole? In any case, the cup distorted spacetime even when it wasn't big enough to form a event horizon, so that it still does it after being squashed proves nothing for the issue at hand.
  - Certhas 9y ago
    Yeah. I do. It's called general relativity. It doesn't tell me what happens at the singularity, but it's valid for the vast majority of the interior of a large black hole.
deleted 9y ago
[deleted]
Senderman 9y ago
"Pointing" is the part of the picture time is in. If you take out time, you can't point to the coffee: you'd be stuck not-pointing!