What "is" time...?

[mark kennedy]

What did he say about time?

He said it was perceived a priori (without prior) empirical testing on the other hand is a posteria. His interest was in how read on works not given to the semantics of time. Stephen Hawkins on the other hand wrote A Brief History of Time. Apparently time is stubbornly confounded physic, preventing the discipline from developing a unified theory. That why string theory has all that time travel stuff, trying to resolve conflicts

 

[drjean]

.... Apparently time is stubbornly confounded physic, preventing the discipline from developing a unified theory. That why string theory has all that time travel stuff, trying to resolve conflicts

Ah but until you experience that shift, that 'time-space warp' you might not realize God's view of things.

 

[Halbhh]

Good question.

 

[mark kennedy]

Ah but until you experience that shift, that 'time-space warp' you might not realize God's view of things.

Time speeds up and slows down based on acceleration. I'm standing on a tarmac and you het on a plane and fly around the world. When you leave both our clocks will have the same time, when you get back invariably we will have two different times. The problem is no one knows why.

 

[AV1611VET]

What "is" time...?

Time is the quotient of distance divided by velocity.

 

[drjean]

Didn't Einstein have an idea when he viewed the wheels on a locomotive

Time speeds up and slows down based on acceleration. I'm standing on a tarmac and you het on a plane and fly around the world. When you leave both our clocks will have the same time, when you get back invariably we will have two different times. The problem is no one knows why.

?

 

[FrumiousBandersnatch]

Time speeds up and slows down based on acceleration. I'm standing on a tarmac and you het on a plane and fly around the world. When you leave both our clocks will have the same time, when you get back invariably we will have two different times. The problem is no one knows why.

But we do know why - Einstein explained it with Special Relativity (and General Relativity).

 

[mark kennedy]

But we do know why - Einstein explained it with Special Relativity (and General Relativity).

I realize that but physics has fallen short of a unified theory and the problem always comes down to time

 

[FrumiousBandersnatch]

Time, as we experience it, is really best described - as has been mentioned - as what clocks measure.

The arrow or flow of time that we experience is an emergent phenomenon; in fundamental physics, at the smallest scales, there is no direction of time and no useful concept of causality; interactions are time-reversible.

The arrow/flow of time we experience at macro scales arises as a statistical result of increasing entropy, which roughly corresponds to the amount of disorder in a system; and entropy tends to increase because there are many more ways for a system to be disordered than ordered. When particles in an ordered system randomly interact, entropy will tend to increase even though each interaction is time-reversible (as described by statistical mechanics, aka thermodynamics).

The big bang was a state of very low entropy, the progressive increase of which has generated the arrow of time we experience.

 

[FrumiousBandersnatch]

I realize that but physics has fallen short of a unified theory and the problem always comes down to time

As I understand it, the problem in unifying classical physics and quantum mechanics is gravity.

I'm interested to know how time is the key problem - can you explain?

 

[mark kennedy]

As I understand it, the problem in unifying classical physics and quantum mechanics is gravity.

I'm interested to know how time is the key problem - can you explain?

I'm just shooting the breeze here not wanting to plumb the depths of metaphyisic. But invariably string theory involves time riddles and a multiverse.

 

[FrumiousBandersnatch]

I'm just shooting the breeze here not wanting to plumb the depths of metaphyisic. But invariably string theory involves time riddles and a multiverse.

I'm not asking you to plumb the depths of metaphysics, just to explain why you asserted that "the problem always comes down to time". What makes you think so?

String theory may suggest the possibility of a multiverse, but it doesn't involve a multiverse.

Anyhow, how does it involve time riddles?

 

[mark kennedy]

I'm not asking you to plumb the depths of metaphysics, just to explain why you asserted that "the problem always comes down to time". What makes you think so?

String theory may suggest the possibility of a multiverse, but it doesn't involve a multiverse.

Anyhow, how does it involve time riddles?

Perhaps I misspoke, probably should have said my biggest problem with string theory is time. I wasn't intending to defend a thesis here, just tossing out some ideas about how time is related to unified theory in physics.

 

[drjean]

Perhaps time doesn't really exist in the heavens? That might be the cog thrown into those wheels.

 

[FrumiousBandersnatch]

Perhaps I misspoke, probably should have said my biggest problem with string theory is time. I wasn't intending to defend a thesis here, just tossing out some ideas about how time is related to unified theory in physics.

All you've said so far is that you think it's a problem - I'm curious to know why you think so.

If you can't find the words to explain it, perhaps you could provide a reference or citation that does?

 

[Everybodyknows]

The arrow/flow of time we experience at macro scales arises as a statistical result of increasing entropy, which roughly corresponds to the amount of disorder in a system; and entropy tends to increase because there are many more ways for a system to be disordered than ordered. When particles in an ordered system randomly interact, entropy will tend to increase even though each interaction is time-reversible (as described by statistical mechanics, aka thermodynamics).

Spot on!

 

[Everybodyknows]

I realize that but physics has fallen short of a unified theory and the problem always comes down to time

No. The problem with a unified theory is that we don't yet have a theory of quantum gravity.

 

[mark kennedy]

All you've said so far is that you think it's a problem - I'm curious to know why you think so.

If you can't find the words to explain it, perhaps you could provide a reference or citation that does?

I'm not sure what I've gotten myself into but this is pretty typical of what I've stumbled across over the years:

However, in a remarkable paper written in 1905, when he was a clerk in the Swiss patent office, Einstein showed that the time and position at which one thought an event occurred, depended on how one was moving. This meant that time and space, were inextricably bound up with each other. The times that different observers would assign to events would agree if the observers were not moving relative to each other. But they would disagree more, the faster their relative speed. So one can ask, how fast does one need to go, in order that the time for one observer, should go backwards relative to the time of another observer. The answer is given in the following Limerick.

There was a young lady of Wight,
Who traveled much faster than light,
She departed one day,
In a relative way,
And arrived on the previous night. (Stephen Hawking. Space and Time Warps)​

My interest wasn't really in string theory, but what I have always seemed to encounter is this problem with time. I am in no way shape or form a student of String Theory, this is just something I have repeatedly encountered with regards to String Theory and the problems of relativity and time.

I wasn't interested in a debate, I thought this was a recurring problem. Perhaps I simply misunderstood or misspoke in some way.

 

[Neogaia777]

A measurement of what exactly?

In reality, motion...
Nothing is really still or completely at rest, or completely stopped ever, cause everything is in motion, but at less than the speed of light, and because of being less than the speed of light, time is a measure of decay for a fallen reality... And is there so when can measure when a thing ends or dies...

Now being in eternity on the other hand there might not be time as we know it...

Only something moving at the speed of light is in "real time"... If you were in a ship, capable of traveling at the speed of light from here, where would go...? Nearest one, 4 light years away, take you four years to get there, and you will arrive at the "time", I guess, that we saw in our telescopes from here, that is four years old (supposedly)... If it takes you four years to get there, and then four years back to earth, what time will it be now...? (scratches head)...

Anyhow, you gotta wonder what time really is...?

God Bless!

 

[mark kennedy]

No. The problem with a unified theory is that we don't yet have a theory of quantum gravity.

The way I always got it is things act differently at a sub atomic level as compared to a cosmological level. Gravity is of course a major issue to the principles of motion, I expect the Y-squared encounters some interesting problems with regards to how time relates.