What IS space?

[Boerseun]

As matter and energy is the same thing, so space and time is the same thing.

Seeing as time is the impression we get from things moving through space, I suppose space/time is indeed two perspectives of one and the same thing.

Now, "What if" time:

What if, from a 'higher' level, everything is just the same thing looked at from different 'angles'? (for want of a better word...)

So that we can actually have a matter/energy/space/time reality, where it's actually all just the same thing? Where every single one of those four is just different manifestations of different perspectives of the other three?

Diarrhoea of the keyboard again...

[Qfwfq]

Space and time are the same thing except...

They are different types of direction in space-time. Timelike directions and spacelike ones have opposite signs of the interval squared. Null directions are those for which the interval squared is zero, light and other massles particles go in null directions, while one with mass goes in a timelike direction. No Lorentz coordinate transformation changes one type of direction into another.

[damocles]

Originally Posted by Qfwfq

Space and time are the same thing except...

They are different types of direction in space-time. Timelike directions and spacelike ones have opposite signs of the interval squared. Null directions are those for which the interval squared is zero, light and other massles particles go in null directions, while one with mass goes in a timelike direction. No Lorentz coordinate transformation changes one type of direction into another.

That brings up a question I have.

I always understood that the interval a photon had from emission to reception was an observed interval exterior to the photon's local frame of reference; that within the photon's frame of reference, that there was no time.

Did I mis-understand this completely?

Best wishes;

[coldcreation]

The question of what happened before the ‘beginning’ has very often been shrugged off as irrelevant, as there was no time or space to even think about. In the language of geometry, the void is a spacetime that contains no points: i.e., there is no spacetime, no language of geometry.

It would characterize absolutely “nothing.” The ‘nothingness’ prior to the creation of the universe is considered (by several specialists) as the most complete void imaginable—no space, no time, no matter, no radiation, no light, no darkness, no temperature, no dimensions, no size, no vacuum, no energy, no pressure, no force, no particles, no fluctuation, no density, no mass, no general relativity, no quantum mechanics, no thermodynamics, no laws of nature, no order, no disorder, no universe, no God, and no Astrophysical Journals—the empty set—as referred to by mathematicians.

Because all scientific theories are formulated on a spacetime manifold, all explosion theories break down before the colossal creation (destruction) event, ab irato. Hence, because of the impossibility to predict any events before time t = 0, they are simply cut out of the theories; swept under the carpet.

coldcreation

[HydrogenBond]

I agree with you that the beginning is important and may be necessary to nail down the one true theory among all the contenders. Without an origin how does one know if the theory lines up with the present. Most theory don't want to address the problem, not because it is irrelavent ,but becasue it has already been attempted based on their assumption, and it can not be done. What does that tell us about these theories? Thet can not line up with an origin they can not find.

[sergey500]

spacetime, we know it the same thing, what was your main point Boersuem?

People please, damn. I am confused by reading some of your stuff. You can you all just use dumbass language, you know the one....with like four letters per word. The one idiots, like me, can understand with out picturing an array of mental experiments.

[Qfwfq]

Originally Posted by damocles

I always understood that the interval a photon had from emission to reception was an observed interval exterior to the photon's local frame of reference; that within the photon's frame of reference, that there was no time.

Sorry, I've been terribly busy on my job.

The interval squared being zero means that proper time is zero for the massless particle, such as a photon. For the bystander, time is greater than zero but ds^2 = t^2 - x^2 = 0 (in natural units). The quantity ds^2 is an invariant for any interval in space-time. In particular, its invariance when it's zero is what explains the observed invariance of the velocity of light.

[damocles]

Originally Posted by Qfwfq

Sorry, I've been terribly busy on my job.

The interval squared being zero means that proper time is zero for the massless particle, such as a photon. For the bystander, time is greater than zero but ds^2 = t^2 - x^2 = 0 (in natural units). The quantity ds^2 is an invariant for any interval in space-time. In particular, its invariance when it's zero is what explains the observed invariance of the velocity of light.

That clarified it. The photon exists in time, but the interval for it is zero, So I did completely misunderstand this, originally. Thank you for the explanation.

Best wishes,

[CraigD]

Originally Posted by That Rascal Puff

… Thank you for reading - and inspiring - this missive.

- That Rascal Poof (er, I mean Puff.).

Good to see you back at scienceforums, Puff/poof. You’re arguably the most colorful personality to grace these forums - no mean feat – and while you seem far from a paragon of formal Science, I find your posts insight-provoking. Keep on rocking in the free world.

[goku]

what is space?
a lack of something (almost nothing)