The Problem of Time

I forget who said it, but the quote goes something like this:
"Even Einstein, the master of time, ran out of it"
I know thats cruel of me. But I have a good point. The fact is that Einstein was never a master of time.
We all know by now that Einstein discovered a deep and permament insight into the nature of space and time. He called this framework General Relativity. No longer was space and time some empty stage that things move about; it is dynamical and can fluctuate, bend, form singularities, evaporate etc. Just like Maxwell equations govern how electric and magnetic fields behave in the presence of charged entities, the Einstein field equations tell us (in a very complicated set of equations) how space and time will behave in the presence of matter and energy. Well enough of the is pedagogy. My point is that the Einstein equations can be rewritten in a form where time does not exist. How could this be? General Relativity is based on a fundamental principle which simply states that the laws of physics do not change if you make a shift in the reference frame of the system under study. Objects will fall on Mars as well as on Earth (albeit at different rates). Mathematically speaking this means that the theory has a specific symmetry, called
diffeomorphism invariance. This means that I can relabel a function with different coordinate systems but the function will always look the same (stated naively). It turns out that the Einstein equation has a diffeomorphism symmetry related to shifting time forwards or backwards and the laws of physics according to General relativity does not care. Therefore, time is gone!

What does this mean? Why does there seem to be physical time? More on that later.

Comments

[Paul Valletta]

Stephon, you state this:My point is that the Einstein equations can be rewritten in a form where time does not exist. How could this be? General Relativity is based on a fundamental principle which simply states that the laws of physics do not change if you make a shift in the reference frame of the system under study. Objects will fall on Mars as well as on Earth (albeit at different rates). Mathematically speaking this means that the theory has a specific symmetry, called diffeomorphism invariance.

But surely, if one is local to events in Spacetime, then all experiments are locally "relative". I can observe events at a far-away distance, but I cannot interact with events occuring at that far-away "locality", in the same sense that I cannot interact with events locally below a certain limit, the limit of "observation" is not the same as a limit of "interaction"?

Detection does not mean interaction has occured in dual directions? Hubble Space Telescope for instance, can see events occuring at a far-away location, this is a 'one-way', "observation-event" . Hubble ST in this sense, is purely just an "observer", not an "interacter".

The Laws of physics DO change for "Observers", they do NOT change for "Interacters", which is locally frame dependant. Observation is not a form of measure in spacetime by default? I can observe a speck of dust without influencing the speck of dust in any way, but if I try to "measure" the dust in its local environment, then I would atomatically have to set-up 'two-way-detection' measure sytems, and this would be interacting in the measured quantity, and therby be changing the detection paramiters.

Observation in Spactime, does not equal measure in Spactime.
local Quantum Observation does not occur in Spactime, because you cannot observe, unless you measure?

The Law of Observation is therfore surely scale dependant? Space=time gets fused by "OBSERVATIONAL observers, space-time gets seperated by "MEASURING" measurers?

[m.visaya]

bb:dh:: C^1 X C^3 X C^5 -> C^2
proof: p(RPRF)=10/(49*50*51*52)

(CRS-214)

[Terry L Hewett Sr]

Space-time is observational.
Had we developed on mars our concept of time would be different. had any intelligent bieng developed on mars we would forever be debating which bieng is correct on their concept of time. however the result would more than likely be a universal method of time keeping.

We may in the future localize time to a galactic scale rather than universal. siting that other galaxies may have a different algorithm.

[sweet trini]

nothing to do with your post, just aiming for the most recent one in the hope that you'll read and respond: i'm a trini who was home the other day and a friend mentioned something about a trini positing a new gravitational theory that was getting some minor consideration, so i wanted to know more- i googled "new gravity theory trinidad" and your blog was the first hit. you seem to be in the field, and you apparently could real lime (i'm very amused @ your spelling of it) so i figured it was worth asking if you've heard anything about this new theory...
please remail me if you have any idea what i'm talking about, or where i should look, or just to say 'aye'.
walk good.

[sweet trini]

i had to rush back here cuz i just read somthing you wrote (yay pbs) about developing a quantum theory of gravity, so now i think you may be the dude i want to talk to.
i'm off to read more, but please remail me...
walk good.

[m.visaya]

start small, like a taxi and this blog is already an observational challenge. eventually, you will arrive at the moment of a collaborative speech development. this example is by bordner... (PAR-472)