Does time have a speed?

[qwe)k]

My question is, does time have a speed? could events be going along faster in different places in the universe? can it be speed up or slowed down?

[insane_alien]

depends on how fast you are going and your depth in the local gravitaional well.

 

'speed' is the wrong word though, language wasn't developed with the complexities of modern physics in mind.

[Country Boy]

As insane alien said, "speed" is not the right word. By any reasonable definition of "speed", the "speed" of time is "one second per second" and cant change!

[timo]

What's unreasonable with [math] \frac{\partial \tau }{\partial t} [/math] i.e. change of eigentime with coordinate time ?

[thedarkshade]

By any reasonable definition of "speed", the "speed" of time is "one second per second" and cant change!

I don't think this really makes sense. Since by this you're using time to measure time.

[iNow]

I think that was exactly HallsofIvy's point. The concept of speed requires change over time, hence cannot be used to describe, discuss, or apply attributes to the concept of time itself.

[stingray78]

Time changes with realtivity because velocity=dx/dt so we know distance changes with realtivity therefore time needs to change also. So if u r at an inertial system; objects passing at highers speed will experience a "slower" time tha yours, but for them it just goes by like for you.

[Graviphoton]

Time is a universal invariant, in that it cannot ever be removed from space, so a change in space plays the exact same roles as it does with time.

 

Time doesn't have a real speed at all... this would assume it has a flow, and time doesn't flow at all.

 

However, and i don't want to complicate things, is if you are sitting still, you are moving off the spacetime map in such a way that the imaginary dimension of space [time] is in fact moving past you at the speed of light.

 

But this doesn't mean time flows or moves. It can move in respect to an observer, but when an observer isn't present, time would need to move in respect to itself, and this isn't accepted in physics.

[FastTrack]

TIME IS JUST A FIXED DIMENSION, JUST AS IS SPACE.

 

Everything is constantly on the move with an equal magnitude of motion.

 

The only thing that can be changed, is the direction at which one travels within the open four dimensional environment known as Space-Time.

 

A simple logical analysis of motion leads one to this conclusion. It also leads to the creation of equations such as the Lorentz Fitzgerald Contraction Equation, the Time Dilation Equation, the Lorentz Transformation Equations, and the Velocity Addition Equation. It thus explains the foundation which creates relativistic circumstances. Nothing can occur without a reason or a cause. Thus Special Relativity has a cause, or a foundation, and this constant motion is it.

Edited June 6, 2008 by Phi for All
removed link advertising personal site

[pioneer]

One can run an experiment to show that time can be scooped out of the stream of time and preserved. Here is how it can be done. We start with two twins, exactly the same in every genetic way. One of the twins stays on earth and the other gets into a SR rocket ship. We tweak the numbers so one year in the moving reference equals tens years in the slower earth reference. There are two time streams in this experiment.

 

Next, we slow the moving reference and reintroduce the two twins. They are still genetically identical, but not at the cellular level, since one has had their time preserved in a bottle for an extra nine years. All else being equal I will predict the one who had their time preserved will always look nine years younger than the other.

 

I chose twins, but one can also do this by cutting a piece of radioactive material exactly down the middle. The half that was make part of the slower time stream will have its decay amount preserved for an additional nine years of time. So we can save time in a bottle.

 

Arkham's Razor: The simplest explanation is the best. If time is a thing end of story. If it is not, be ready to read the book.

[iNow]

Arkham's Razor: The simplest explanation is the best.

 

I ignored most of your post since it's all speculative mind dancing where your logic is based on faulty premises.

 

 

Either way, I couldn't help but correct the above.

 

It's "Ockham's razor," and that's NOT what it says.

 

 

http://en.wikipedia.org/wiki/Occams_razor

The principle states that the explanation of any phenomenon should make as few assumptions as possible, eliminating those that make no difference in the observable predictions of the explanatory hypothesis or theory. The principle is often expressed in Latin as the lex parsimoniae ("law of parsimony" or "law of succinctness"): "entia non sunt multiplicanda praeter necessitatem", roughly translated as "entities must not be multiplied beyond necessity".

[alanrocks]

simply put

 

time is a constant. it does not have a "speed". time is a word created by man as a way to wrap their puny minds around the passage of their lives.

 

as a word and concept created by man it is totally subject to each organisms own perceptions

[iNow]

Well, then it's not constant.

[lancelot]

People getting introduced to SR often have a bit of a problem grasping how Anna's time can appear 'frozen' as seen by Betty, but equally Betty's time can appear frozen as seen by Anna. Yet time for Anna and Betty actually carries on at the same rate as far as they are concerned. Eye glaze takes over.....

 

I have found that a useful analogy to help grasp the concept is the familiar one of visual perspective. Anna walks into the distance and Betty sees her as smaller. Anna sees Betty as smaller. But they stay the same size. How is this possible???

 

Once people ponder on that familiar phenomenon they begin to accept time dilation quite easily!

[Pete]

My question is, does time have a speed? could events be going along faster in different places in the universe? can it be speed up or slowed down?

The term speed refers to a spatial displacement which occurs during a unit of time. Since there is no spatial displacements associated with what you're asking then the question makes no sense. However the rate a which time flows can certainly change with the observers choice of reference frame.

 

Pete

[booker]

What's unreasonable with [math] \frac{\partial \tau }{\partial t} [/math] i.e. change of eigentime with coordinate time ?

 

Never heard of it. You're referring to proper time. Is there some mathematical justification in calling it eigentime?

[Pete]

Never heard of it. You're referring to proper time. Is there some mathematical justification in calling it eigentime?

The term "eigen" means "proper". See

http://germanenglishwords.com/rlge.htm

 

Therefore the terms proper-time and eigen-time mean the same thing. I myself only use the former. In fact I've never heard of the later being used.

 

By the way its the ratio of total differentials not the ratio of partial derivatives that is normally found in relativity. What purpose does the ratio of partials serve??

 

Pete

Edited August 2, 2008 by Pete

[booker]

The term "eigen" means "proper". See

http://germanenglishwords.com/rlge.htm

 

Therefore the terms proper-time and eigen-time mean the same thing. I myself only use the former. In fact I've never heard of the later being used.

 

Pete

 

Don't tell anyone, but I've thought of using it myself--just never heard 'eigen' used in this context.

 

Shamlessly pasting out of a German-English dictionary,

 

"eigen

own {adj}

fussy {adj}

proper {adj}

peculiar {adj}

separate {adj}

distinct {adj}

peculiarly {adv}

possessive {adj}

inherent (in) {adj}

appropriate (to) {adj}

singular {adj} [eccentric]

several {adj} [archaic: distinct, separate]"

 

Rather a long and confusing list to correlate.

 

By the way its the ratio of total differentials not the ratio of partial derivatives that is normally found in relativity. What purpose does the ratio of partials serve??

 

Beats me, Pete. In finding extermal time, [math]\tau[/math] is independent, and the integral is over [math]dx^u / d\tau[/math].

 

My question is, does time have a speed? could events be going along faster in different places in the universe? can it be speed up or slowed down?

 

Hello, qwe)k.

 

I'm not sure anyone has really explained this properly to you. In physics you want to explain things, ultimately, based on how you measure or observe them--what values they take. After all, this makes it physics rather than, philosophy, or BS even. So you might ask, "how do I measure the speed of time?" If you draw a blank, maybe it's not really a question about the physical universe--not really a valid qhysics question.

 

As far as events proceeding faster in some places than others, this is kinda what relativity is all about. Observers (that's us) in different states of velocity may notice their clocks progressing at different rates, as well as lengths having different measured values. As someone else already talked about, gravity also effects how different observers measure the time interval between events.

Edited August 2, 2008 by booker
multiple post merged

[timo]

Therefore the terms proper-time and eigen-time mean the same thing. I myself only use the former. In fact I've never heard of the later being used.

If the term is not used in english then it probably simply was a mistranslation of mine, not the usage of a less-frequently-used term. "Eigenzeit" is the german term for it (@booker: The -non-mathmetical- justification there is that it is the time that an object experiences; its "own time"); I simply assumed that the "eigen" prefix also translates to english (like for eigenvectors).

 

By the way its the ratio of total differentials not the ratio of partial derivatives that is normally found in relativity. What purpose does the ratio of partials serve??

That would depend on the non-given context, I think. It does not matter for the sake of the argument that you can compare the ratios or behaviours of two different time parameters.

[booker]

Thanks, Athiest!

[FayeKane]

FastTrack was correct.

 

It is meaningless to talk about "speed of time" for the same reason that it's meaningless to talk about "the length of up".

 

We don't notice the "direction" of time as being like the other three because the lengths of all lines in that direction are negative numbers (see the interval metric).

 

Also, our perception of what's going on is distorted because we are not stationary. We are moving through time. All mass is. It's that momentum in the time direction that gives mass it's mass-energy.

 

Light, on the other hand, moves only through space but does not experience the passage of time. Light has momentum in space, not time.

 

You may have meant to ask "at what speed do we move through time?" The answer is "at c".

 

-- faye kane, homeless brain

http://blog.myspace.com/fayekane

[ajb]

I agree with Atheist's first post.

 

What you can do for massive particles is use the proper time to parametrise the paths of the particles. Thus you get the speed of proper time with respect to proper time is one!

 

Same thing for velocity really, "speed" depends on how you parametrise things. Only for massive particles can you do an affine transformation and bring this parameter to the proper time.

 

So, this also answers the question about photons experiencing time.

[booker]

The speed of time can be purchased on Ebay.

[doctorp]

I would think that question is easy to answer. Yes and no. A simplified explanation is speed is distance traveled over time. Since it is not traveling its distance is 0 and without definite answer to the end of time we can say time is [math]\infty[/math] . So the answer would be 0/[math]\infty[/math] . Of course a logical person might wonder why I even wasted time typing stuff like that and say something like "If time is a property of speed how can you even try to use speed to calculate it? you might as well try asking the speed of an inch" I agree with the logical person and say NO. Time does not have a speed.

[ajb]

I would think that question is easy to answer. Yes and no. A simplified explanation is speed is distance traveled over time. Since it is not traveling its distance is 0 and without definite answer to the end of time we can say time is [math]\infty[/math] . So the answer would be 0/[math]\infty[/math] . Of course a logical person might wonder why I even wasted time typing stuff like that and say something like "If time is a property of speed how can you even try to use speed to calculate it? you might as well try asking the speed of an inch" I agree with the logical person and say NO. Time does not have a speed.

 

If you get answers like [math]\frac{0}{\infty}[/math] then this suggests that the question has not been formulated well. Have a look at what Atheist and myself posted on the subject.

 

In the context of relativity one should be careful about time as a dimension and time as the "time" measured by a moving clock. This I think has coursed confusion and to statements that "photons experience no time" etc.