3 ms·

All these are true: - A happened before B - B happened before A - A & B happened at the exact same time - Neither / there is no "before"/"after" Considerin

All these are true: - A happened before B - B happened before A - A & B happened at the exact same time - Neither / there is no "before"/"after" Considering this is the case with anything measured, what explanatory "truth" would be left when you consider a perfect description of reality? One that accounts for the global reference frames of every possible metric (not just order of events)? There's no absolute "truth" to any of the mainstays: Where things are When they happened In what order they happened Even whether or not they happened (there is a perspective where all the values of a measured thing can be zero - like mirroring the velocity of a speeding object to reduce its speed to zero, or rotating a plane to make its height zero - and the different physical implications therein). We correlate observed "locations in space" and the "passage of time" to heuristical approximations that work (as scientific theories) for our intents and purposes on a hyper local level (a tiny fraction of just our galaxy), but they break down on macro levels because they aren't really accurate descriptions of reality. Our physics doesn't work at scale - not smaller than atoms, nor larger than ~solar systems, without theories falling apart. Space The XYZ coordinate system we understand as "3D space" works great for locating and measuring the size of objects locally, we could perfectly track a tiny marble bouncing down a huge mountain with a granular enough XYZ coordinate system and telemetry. But that wouldn't work on larger scales like comparing the movement of subatomic particles with the movement of stars in the same graph. The graph couldn't accurately chart that without normalizing data or adjusting the reference frame toward one bias or the other (see scale invariance, vacuum catastrophe). We can only neatly slap a fixed reference frame over a scoped area, invent units and call it a "field", if we expect any predictive utility. Time There's not really an absolute "arrow of time" with a past and future, where A happened, then B happened, etc. in an absolute sense. As shown in the star example, it completely depends on the orientation and velocity of the observer, and other factors. No one perspective is more true than the other. We all happen to hang out in the same frames, so it seems like some of these are rigid laws - they effectively are, for us - but they aren't really, ultimately. When you eliminate the heuristics that give value to science there's nothing left - which as mentioned above is a possible and potential state.

Viliam1234 2y ago
Relativity is not the same as relativism. Theory of relativity gives us a precise description of the relation between A and B... it's just not the kind of relation we would naively expect. But we can still calculate the answer from the perspective of any reference frame. (Also, it is possible to have other events C and D such that C happened before D in every reference frame.) Instead of living in a 3D universe with an absolute time, we are living in a 4D universe where time is a relative direction in the space-time. That doesn't mean we can't model things in principle, it just means we need to model them as things existing in 4D space-time.
- bschmidt1 2y ago
  > Relativity is not the same as relativism True, really just meant "not absolute". > such that C happened before D in every reference frame If that's possible, considering the seemingly infinite number of instances where it'd have to both happen and in that way/order, I would consider those kinds of events to be the fundamental/baseline "forces" or asymmetries.
  - Viliam1234 2y ago
    The keywords related to this are "spacelike" and "timelike". https://en.wikipedia.org/wiki/Causal_structure https://en.wikipedia.org/wiki/Causal_structure For example, the distance between Earth and Moon is about 1.3 light-seconds. That means that is A happens on Earth now, and B happens on Moon 1 second later (from our perspective), it is possible that from someone else's perspective B happened before A. (Note that "someone else" in this example does not refer to the Moon, because its perspective is very similar to the perspective of the Earth. It refers to a hypothetical alien spaceship flying at an extremely high speed in a line parallel to the line between the Earth and the Moon.) However, if C happens on Earth now, and D happens on Moon 2 seconds later (from our perspective), then C happened before D from everyone's perspective. Individual aliens would disagree on the exact time interval between C and D, where 0.7 would be the smallest possible value, but it could be any larger value. (You get the smallest possible value when you are not moving relatively to the Earth and the Moon.) This is because a hypothetical light particle emitted at A couldn't reach B in time, but a hypothetical light particle emitted at C could reach D in time. The speed of light is the speed of causality, kind of. Events A and B couldn't possibly have caused each other (they could have a common cause X, but that's different), but C hypothetically could have caused D, which is why C happened before D from everyone's perspective.

Viliam1234 2y ago

Relativity is not the same as relativism. Theory of relativity gives us a precise description of the relation between A and B... it's just not the kind of relation we would naively expect. But we can still calculate the answer from the perspective of any reference frame. (Also, it is possible to have other events C and D such that C happened before D in every reference frame.) Instead of living in a 3D universe with an absolute time, we are living in a 4D universe where time is a relative direction in the space-time. That doesn't mean we can't model things in principle, it just means we need to model them as things existing in 4D space-time.

bschmidt1 2y ago
> Relativity is not the same as relativism True, really just meant "not absolute". > such that C happened before D in every reference frame If that's possible, considering the seemingly infinite number of instances where it'd have to both happen and in that way/order, I would consider those kinds of events to be the fundamental/baseline "forces" or asymmetries.
- Viliam1234 2y ago
  The keywords related to this are "spacelike" and "timelike". https://en.wikipedia.org/wiki/Causal_structure https://en.wikipedia.org/wiki/Causal_structure For example, the distance between Earth and Moon is about 1.3 light-seconds. That means that is A happens on Earth now, and B happens on Moon 1 second later (from our perspective), it is possible that from someone else's perspective B happened before A. (Note that "someone else" in this example does not refer to the Moon, because its perspective is very similar to the perspective of the Earth. It refers to a hypothetical alien spaceship flying at an extremely high speed in a line parallel to the line between the Earth and the Moon.) However, if C happens on Earth now, and D happens on Moon 2 seconds later (from our perspective), then C happened before D from everyone's perspective. Individual aliens would disagree on the exact time interval between C and D, where 0.7 would be the smallest possible value, but it could be any larger value. (You get the smallest possible value when you are not moving relatively to the Earth and the Moon.) This is because a hypothetical light particle emitted at A couldn't reach B in time, but a hypothetical light particle emitted at C could reach D in time. The speed of light is the speed of causality, kind of. Events A and B couldn't possibly have caused each other (they could have a common cause X, but that's different), but C hypothetically could have caused D, which is why C happened before D from everyone's perspective.