Time Slower In Orbit?

[Blaggard]

Time is indeed still one of sciences deepest mysteries, it exists as time/space a relationship but as to what it is, what direction it moves in and any fundamental knowledge it is still very much a concept.

[HexHammer]

Time is indeed still one of sciences deepest mysteries, it exists as time/space a relationship but as to what it is, what direction it moves in and any fundamental knowledge it is still very much a concept.

If it would have a "direction" it would suggest it's an object of sort, but it's merely just how me messure things and if there's an observer it just becomes relative, don't make it more mysterious than it is.

We have most of the basics coverd as of now, specially with the new pole sattelites which take more accurate messurements there than the US gps sattelites, which are very inaccurate at the poles.

[Blaggard]

Actually that is a big issue in science or at least as it stands the philosophy of science, whether we can know the direction of times flow it would alter nothing if we were going backwards in time, it could be that the Universe started out at some point either from heat death or from a singularity nothing really changes.

[HexHammer]

Right now we can only make unconfirmed theories, we need vastly different machines to messure things, like explore far beyond the current observations of the farthest galaxies to see what's really "out there" if we live in a "smoke pule universe" admist a superverse and many other "smoke plume universes".

[uwot]

Time is only mysterious if you take how it can be manipulated mathematically as representative of, as HexHammer says, some 'object of sort'. For all I know reality is tumbling backwards through some temporal soup, but I don't know of any physical evidence that should make me seriously doubt that the second law of thermodynamics describes what is actually happening. The hypothesis that the universe began as a very hot, dense thing and is becoming a very cold, rarefied thing fits all the data that I am aware of.

[Blaggard]

Well you would see it like that if you were the only species of the universe who travelled backwards through time, it wouldn't be until you met other aliens you would realise you were an oddity assuming they could convey to you your reversed perspective. Like I say all available evidence does not tell us which direction time goes in, it only gives us a relative idea of what is happening or likely to happen in our future, which could be the rest of the species in the Universes past for all we know.

[HexHammer]

Well you would see it like that if you were the only species of the universe who travelled backwards through time, it wouldn't be until you met other aliens you would realise you were an oddity assuming they could convey to you your reversed perspective. Like I say all available evidence does not tell us which direction time goes in, it only gives us a relative idea of what is happening or likely to happen in our future, which could be the rest of the species in the Universes past for all we know.

Let me just say that I put more faith in string than what you just said.

[Blaggard]

Well you would see it like that if you were the only species of the universe who travelled backwards through time, it wouldn't be until you met other aliens you would realise you were an oddity assuming they could convey to you your reversed perspective. Like I say all available evidence does not tell us which direction time goes in, it only gives us a relative idea of what is happening or likely to happen in our future, which could be the rest of the species in the Universes past for all we know.

Let me just say that I put more faith in string than what you just said.

Well it is an entirely philosophical question so...

String theory is also only a philosophical idea at least atm, so it's a matter of taste.

How do you establish a direction in time, let's say every species in the universe was going backwards in time, how would they know?

[HexHammer]

Well it is an entirely philosophical question so...

String theory is also only a philosophical idea at least atm, so it's a matter of taste.

How do you establish a direction in time, let's say every species in the universe was going backwards in time, how would they know?

The same way one can make iron burn, you have to actively help the process, not something that just magically happens, thus it's not something philosophically.

[HexHammer]

I think James makes a very good point; we don't have any direct evidence of time that we can measure independently of things happening: the world spinning, clocks ticking or atoms vibrating, for example. So despite it's usefulness as an abstract quantity in maths, there is no reason to believe time exists as such.
Photons don't really collide, they behave much more like waves and generally pass through each other unaffected. Fermions, matter particles, on the other hand do collide and regardless of how fast we think they are moving relative to each other, the energy released by Hadrons in the LHC is equivalent to two times a smidge under c. You can draw your own conclusions.

That's why we have accurate GPS? Without understanding of time, GPS wouldn't work! ..get real!

[Blaggard]

I don't think scientists are going to abandon the notion that time runs in a certain direction any time soon, nor do I think the philosophical questions around it are going to be solved soon. And clearly if you think that GPS would not work if time ran backwards or you changed the arrow of time you really don't understand how GPS works or the philosophical issue of times direction. it wouldn't make any difference GPS would work in either direction or in fact any direction.

Suffice to say speed = distance/time

in 4 dimensons with x,y,z,i where i=time, the imaginary axis for time is just a mirror image of forward time, with equal but opposite distances, since in either direction the absolute values are the same it makes no difference to GPS.

Putting negative numbers in place of time would not change the equations at all really in any appreciable way we might notice from our perspective. In fact we would probably think negative time or backwards time was forwards time anyway and assign it a positive value.

Although such notions appear flippant they drove Boltzman to try and formulate an entropic theory of time which affected his mental health and lead to a break down. It's now considered a problem only to the philosophy of science since it is an academic question at best, although it does have profound fundamental importance to us.

About time: Why does time's arrow fly only one way?

10 October 2011 by Amanda Gefter
Magazine issue 2833. Subscribe and save

Read full article
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Read more: "About time: Adventures in the fourth dimension"

TAKE a few steps forward, turn around and walk back. No problem. Now let a few seconds pass, then turn around and head back a few seconds in time. No luck? Of course not. As we know only too well, time, unlike space, has only one direction - it flows from past to future, and never the other way round.

That all sounds like the natural order of things, but if you look closely enough at nature, you will find that it isn't. A thorough search of the laws of physics turns up no such arrow of time. For example, you can use Newton's laws of motion to work out where a ball was thrown from in the past just as well as where it will land in the future. And when it comes to particles, the laws and forces that govern their behaviour do not change if you swap the future for the past.

"The truly odd thing is that the laws of physics, which surely ought to be responsible for what we see in the world, can work just as well both forwards and backwards in time," says Dean Rickles, a philosopher of science at the University of Sydney in New South Wales, Australia. "There shouldn't be an arrow."

If time's arrow is not in the laws of physics, where does it come from? An important clue emerges from the complex interactions of large numbers of particles. Every object you see around you, including you, is made up of a vast collection of particles. These particles are not just sitting around - they are constantly shuffling about and rearranging.

To any macroscopic system - say, a puddle of water or a crystal of ice - physicists assign an entropy. Entropy reflects the number of ways you can rearrange a system's constituent particles without changing its overall appearance. A puddle of water can be made by arranging H2O molecules in a huge number of ways, making it a high entropy system. An ice crystal, on the other hand, has to be arranged in a very precise way, and because there are fewer ways to do that it has a low entropy.

In terms of pure statistics, high entropy systems are always more likely than low ones since there are so many more ways to produce them. That's why, given temperatures warm enough to allow molecules to move around into new arrangements, you'll always see ice turn to water, and never see a puddle spontaneously crystallise into ice. Indeed, if you were watching a film and saw a scene where a puddle suddenly froze on a warm day, you would assume the film was playing in reverse - that time was moving backwards.

Even though entropy increase is a statistical, and not fundamental, phenomenon, it is enough to give rise to a powerful pillar of physics: the second law of thermodynamics. According to the second law, the entropy of the universe can never decrease. And there, you might think, lies the key to time's arrow - the steady march from low entropy to high is what we perceive as the passage from the past to the future.

If only it were so easy. Unfortunately the second law does not really explain the arrow of time. It merely says that high entropy states are more likely than low entropy ones. Time does not enter the picture, meaning that the world 5 minutes from now is likely to have higher entropy and so should the world 5 minutes ago.

The only way to explain the arrow of time, then, is to assume that the universe just happened to start out in an extremely unlikely low entropy state. If it had not, time would have become stuck and nothing interesting, like us, would ever have happened. "Time's arrow depends on the fact that the universe started up in a very peculiar state," says physicist Carlo Rovelli of the Centre for Theoretical Physics in Marseilles, France. "Had it started up in a random state, there would be nothing to distinguish the future from the past."

In fact, observation proves that the universe did start out in a low entropy state. Radiation left over from the big bang provides a snapshot of the infant universe. It shows that near the beginning of time, matter and radiation were spread extremely smoothly throughout space. On first glance, that looks like a high entropy state - until you take gravity into account.

Gravity always wants to clump things together, so in a system governed by gravity, a black hole is a far more likely state, and so is of higher entropy than a smooth distribution. This low entropy smoothness is extraordinarily unlikely - so how did we get so lucky? "If we can explain the low entropy past, then we will have pretty much cracked the problem of time's arrow," says Rickles...[]

An excerpt from this article explains it better than I could. Although I can't print it all as it is copyrighted.

[HexHammer]

And clearly if you think that GPS would not work if time ran backwards or you changed the arrow of time you really don't understand how GPS works or the philosophical issue of times direction.

Now you are just jumping to conclusions and putting words into other people's mouths.

[uwot]

I don't think scientists are going to abandon the notion that time runs in a certain direction any time soon, nor do I think the philosophical questions around it are going to be solved soon.

Not if religion is any type of analogy. In both cases the claim is that there is some all pervading entity that acts in mysterious ways, is completely invisible and that the universe wouldn't behave any differently without. We can only judge time by counting physical events and as I said with regards to the atomic clocks in Hafele-Keating, there is an obvious, mechanical reason why events take longer the faster you go. It seems to me that Occam's Razor has gone walkies and whenever you multiply entities beyond necessity, you end up with metaphysics. The irony of physics is that some of it's key notions are metaphysical, if they are taken to be real and independent of whatever 'matter' is; it's an ontological issue. You cannot measure time any way that doesn't involve counting events; you cannot measure space except as the distance between objects, again by comparing objects or events, and you cannot measure energy if there is no mass (or momentum if you want to get picky).
The thing that puzzles me about the article is this:
"Even though entropy increase is a statistical, and not fundamental, phenomenon, it is enough to give rise to a powerful pillar of physics: the second law of thermodynamics."
What difference would it make to anything that happens if entropy/the arrow of time were fundamental?
You close your excerpt at this point, Blggard:
"If we can explain the low entropy past, then we will have pretty much cracked the problem of time's arrow," says Rickles..
People have speculated about eternal recurrence, Big Crunches and bouncing universes, any of which might be true and for which some bright spark might find some evidence. Until they do, isn't it most parsimonious to assume the universe began with all it's 'matter' tightly organised in a hot Big Bang and is slobbing out, becoming much bigger and less energetic (or at least usefully so?)

[Blaggard]

Oh i know uwot, I was just introducing a little philosophy to the equation, don't mind me. Usually I am pretty level headed. Oh no wait, well fairly level headed, well headed anyway, well I have a head.

[Blaggard]

And clearly if you think that GPS would not work if time ran backwards or you changed the arrow of time you really don't understand how GPS works or the philosophical issue of times direction.

Now you are just jumping to conclusions and putting words into other people's mouths.

I think you are right their Hex and I offer an apology, sorry I am in and out so fast these days I sometimes get the wrong end of the stick, sorry about that. I
misread your answer as a reply to me, as opposed to how I should of read it as a reply to the post above me. My bad.

There's a lesson in there somewhere, I am sure.