I need a scientific "dressing down" if you will..

a reply to: odzeandennz

It is the sequence of things like the progression of photons and the way chemicals react moving from one state to another that gives an arrow to time. The mildly humorous observation that 'time is what stops everything happening at once' is actually very true.

As others have pointed out, we only see past events anyway because the light that strikes our retinas (and the neural signal we interpret) has taken time to arrive from the original situation we are observing.

As for quantum events, they are largely a "throw of the dice" compared with macro scale events which are deterministic. You have to be aware of the differences that scale introduces which are caused by measurement issues. Try and imagine that we are trying to determine the position and spin of a billiard ball on a flat surface by throwing bowling balls at it and seeing how the bowling balls scatter. The very tools we use for observation of quantum scale events are clumsily large.

Although Kurt Gödel and others have shown that "closed time-like curves" could possibly exist (at least under General Relativity) in spacetime (and could allow for retrograde traversal of time), they would most likely occur at very small scales due to the energies required.

Remember that Wheeler's delayed choice experiment and the Einstein, Podolsky and Rosen examples were very much "thought experiments" to explain particular aspects of quantum indeterminacy. They should not be interpreted as explanatory of other concepts (along the lines of the "What the Bleep..." nonsense).

originally posted by: VP740

originally posted by: chr0naut

originally posted by: onequestion
a reply to: chr0naut

What about looking in the other direction?

Can we only look out at the same perimeter, does it exist in a circle that we are somehow near the c enter of or does it move I to a specific direction more linear like outwards from a starting point?

The time dimension is shown to be linear and can be measured in meters by Einstein's equations. (1 second = 299 792 458 meters). However, mass can distort time (and space).

If time were the way some people conceive it, you could reverse time and in the case of the diffusion of a gas, it would go back into the container it came from. However, if you use a negative for a time value in most physics equations, the gas actually continues to diffuse. The genie won't go back into the bottle.

It is this divergence between the perceptual and physical concepts of time that causes the most confusion.

If we could see the future, then nothing in the universe could ever change. It would be a static monolithic block.

As it stands, things in the future are indeterminant and although we know the gas will diffuse, we cannot say precisely how each atom will end up. It is random and stochastic, to us.

I've always had a very strong instinct that nature is deterministic. In other words I think if you had the right equation and data, you could play things backwards on your computer simulation and watch the smoke go back into the container. The observations I make of the universe just don't look like they were generated at random. I suspect the increase in entropy observed over time has a resemblance to what happens as you calculate successive digits in say, the square root of two. In a sense the digits become more 'random' as you calculate each one. Probably best to take that up on another thread though.

We sometimes use the mental picture of a "light cone" to define the progression of a physical event through time. The event starts from a specific point but everything expands outward probabilisticly from the start point, which produces the cone.

If we were to reverse the traversal of the time axis, the cone would still expand, but back in the other direction. If we took a section of the cone after time reversal, it would look like a capital "W" on its side.

Overall nature IS deterministic but underneath there are events that are not. If this is because of measurement issues or because of "baked in" fuzziness is still under argument. I started a thread sometime ago: Physics is Broken which explored the disunity between the quantum and macro realms.

originally posted by: Cinrad
a reply to: Phage

The closest I have heard is like a raisin cake in the oven, all the raisins (points) are getting further away from each other, not from the center.

Having said that, I was wondering: if space time is expanding, then why do we get red shift, if the space time that the light is travelling in/through is expanding?

The universe is expanding but the metric of spacetime, (which is fixed by the speed of light being a constant) is not.

originally posted by: AceWombat04
As a layperson who can only begin to grasp such ideas conceptually, I always have the same questions and I've never received a truly satisfactory answer (possibly because there isn't one yet, and possibly because I'm simply, literally, too unintelligent to understand the answers.)

• Is the "time" component of spacetime ontologically real in and of itself, or is it just a way of mathematically representing and measuring different kinds of relative movement? E.g. is there really a thing called "time" that "passes" and dilates, or is it just another facet of space and movement therein? (I know time dilation has been proved, that's not what I'm asking. I'm asking whether said dilation really represents the classical mental conceptualization of "time," or just another kind of spatial movement.)
  
• Likewise, is the "membrane" described as being at the base of everything (in the sense that fundamental particles can apparently be described/thought of merely as coherent pertubations of said membrane) ontologically real, or is it just a mathematical construct describing something otherwise indescribable to us? E.g. is there really a substance or a thing that is "the membrane" that is being pertubed to constitute particles, or is it just mathematically correct? (Sort of how spacetime isn't really accurately described as a "rubber sheet" that bends because it's not two dimensional, but people still describe it that way because in its simplest form it can be mathematically represented as a warpable sort of graph right? Or is that wrong, too? Lol.)
  
• This is the one we can't really answer, I know, because any attempt to measure or perceive the "substance" of the membrane would be predicated upon particles and forces which are "part of" the same membrane, so we can't ever really "look at" it. But is there any burgeoning, early reasoning yet on what the membrane actually IS? What it could be comprised of? (It can't be particles as in our own universe right, since they're all just ripples in said membrane?)
  

As I said... just a layperson seeking answers to things that tease my simple monkey brain.

Peace.

These are good questions and despite all we know, are still pertinent.

Is our idea of what constitutes reality itself 'real'? Are we living in a completely misunderstood paradigm seeing things through distorting conceptual filters?

My belief is that we are, most likely, misunderstanding everything we see and think we know. We will only get to the truth by challenging our constructs and doubting their validity.

It may also be possible that the truth of things is simply beyond human capability to comprehend.

Regardless, working models with predictive power will be useful in engineering and anticipating natural events even if they are not entirely correct.