Is there the possibility of absolute time

[matheinste]

Hello hartlw.

We can, and do, use certain clocks as a references for time, but the choice is purely arbitrary. The same can be done for movement. Any inertial frame can be chosen as a reference non-moving frame to suit our particular purpose. Again it is purely arbitrary and we could have used any other inertial frame if it was more convenient to do so.

Matheinste.

 

[Dale]

say that absolute time is the size of the light wave with respect to its center.

That would just be relative to the observer at the center.

 

[ckollerer]

Can we agree that "absolute time" began with the big bang? The big bang's origin then would be the point of inertia, prior to all movement. "Absolute distance" is referenced to that one point in the universe. "Absolute speed" is referenced to that point of zero speed prior to the beginning of time. SR still holds.

Of course, identifying that point of zero-time origin is the trick. Since we are not likely to identify the origin of the universe, then, sadly,"absolute time" is not identifiable or quantifiable, only a hypothetical marvel. Nonetheless, the possibility of "absolute time" exists. And this answers the OP's question, albeit sans scientific usefulness.

 

[The Dagda]

Can we agree that "absolute time" began with the big bang? The big bang's origin then would be the point of inertia, prior to all movement. "Absolute distance" is referenced to that one point in the universe. "Absolute speed" is referenced to that point of zero speed prior to the beginning of time. SR still holds.

Of course, identifying that point of zero-time origin is the trick. Since we are not likely to identify the origin of the universe, then, sadly,"absolute time" is not identifiable or quantifiable, only a hypothetical marvel. Nonetheless, the possibility of "absolute time" exists. And this answers the OP's question, albeit sans scientific usefulness.

Because of the nature of the singularity we could not be sure exactly when it began even if we knew, at least to pin it down exactly. So no. The possibility of absolute time does not exist and it never has. Even at t=10^-87 it was subject to relativistic concerns anyway.

 

[ckollerer]

Because of the nature of the singularity we could not be sure exactly when it began even if we knew, at least to pin it down exactly. So no. The possibility of absolute time does not exist and it never has. Even at t=10^-87 it was subject to relativistic concerns anyway.

I think we agree, except for the definition of "possible." To me, just because something is impossible to identify or measure does not preclude the possibility of its existence.

 

[The Dagda]

I think we agree, except for the definition of "possible." To me, just because something is impossible to identify or measure does not preclude the possibility of its existence.

Philosophical possibilities are best left to the appropriate area of the forum. In this case SR would have to be violated and the quantum mechanics of the singularity for it to be possible. I can't say absolutely it doesn't exist in another universe, or that it has never existed. But I can say it's pointless arm waving. Logically speaking anything can exist, and science cannot prove something doesn't exist. But then that's the remit of philosophers: to argue the unarguable.

 

[ckollerer]

Philosophical possibilities are best left to the appropriate area of the forum. In this case SR would have to be violated and the quantum mechanics of the singularity for it to be possible. I can't say absolutely it doesn't exist in another universe, or that it has never existed. But I can say it's pointless arm waving. Logically speaking anything can exist, and science cannot prove something doesn't exist. But then that's the remit of philosophers: to argue the unarguable.

We agree again: Let's not debate the merits of a theoretical zero-point of time here.

 

[Dale]

Can we agree that "absolute time" began with the big bang?

No, I don't agree. The current estimate is that the big bang occurred 13.7 billion years ago. So, which law of physics would be different in a coordinate system where the current time t=13.7 billion years vs t=0? If you cannot identify such a law then that is not absolute time.

The point of the principle of relativity is that you can do physics in whatever coordinate system you like. You don't need to determine irrelevant details like the age of the universe in order to calculate the acceleration of a box sliding down a frictionless inclined plane.

 

[hartlw]

The point of the principle of relativity is that you can do physics in whatever coordinate system you like. You don't need to determine irrelevant details like the age of the universe in order to calculate the acceleration of a box sliding down a frictionless inclined plane.

I believe the question was is there the possibility of "absolute time."

Taking into account relativity, no matter how small the effect, how do you calculate the acceleration of a box sliding down a frictionless plane.

 

[The Dagda]

I believe the question was is there the possibility of "absolute time."

Taking into account relativity, no matter how small the effect, how do you calculate the acceleration of a box sliding down a frictionless plane.

When the effect is below a certain threshold most people don't bother with relativity because the frame of reference and your measuring devices are no where near refined enough to notice any effect. In this case I'd stick with Newtons laws, it's accurate enough.

The answer to the question is no and no, but in philosophical circles where their are multiple realities/dimensions/Universes, then maybe.

 

[ckollerer]

No, I don't agree. The current estimate is that the big bang occurred 13.7 billion years ago. So, which law of physics would be different in a coordinate system where the current time t=13.7 billion years vs t=0? If you cannot identify such a law then that is not absolute time.

The point of the principle of relativity is that you can do physics in whatever coordinate system you like. You don't need to determine irrelevant details like the age of the universe in order to calculate the acceleration of a box sliding down a frictionless inclined plane.

I understand. Assigning zero SR coordinates to that point of origin does nothing to develop its absolute measurability from another set of SR coordinates. Other active threads are scratching around this too. I concede, you just can't get there from here... absolutely.

 

[hartlw]

Time is not an abstract philosophical concept.

Without a specific definition of time physical theories are meaningless. How can you discuss motion without a specific definition of time? The objective is to come up with a reasonable definition of time in an arbitrary coordinate system.

 

[The Dagda]

Time is not an abstract philosophical concept.

Without a specific definition of time physical theories are meaningless. How can you discuss motion without a specific definition of time? The objective is to come up with a reasonable definition of time in an arbitrary coordinate system.

Who said it was?

I tell you what I could do, I could take c as a constant and that light always propagates at c and the idea that their are no discreet frames of reference and then model a theory around it? Oh now wait...

We have one it works, absolute time is a philosophical concern that might as well not exist.

Let me know when someone figures out how to disprove special relativity...

 

[hartlw]

Without a specific definition of time physical theories are meaningless. How can you discuss motion without a specific definition of time? The objective is to come up with a reasonable definition of time in an arbitrary coordinate system.

Create a frame in a vacuum with a fluorescent marker at an equal distance on each of the three axes. Let a flash of light occur at the origin. If the observer at the origin sees all the flashes return simultaneously, a repeatable time interval, clock, is established in this frame. Define this particular frame and the distance and time interval as absolute. Proceed from there. Good luck. Let me know how you make out.

 

[The Dagda]

Create a frame in a vacuum with a fluorescent marker at an equal distance on each of the three axes. Let a flash of light occur at the origin. If the observer at the origin sees all the flashes return simultaneously, a repeatable time interval, clock, is established in this frame. Define this particular frame and the distance and time interval as absolute. Proceed from there. Good luck. Let me know how you make out.

We've already established that that is meaningless though, it's all very well saying that point of time is absolute, but it isn't because it is not discreet. What you have there is a pointlessly arbitrary measurement that means nothing. As someone already said about CMBT, why bother? What you might as well say is from the perspective of God, who is outside the Universe and thus not subject to its laws, absolute time = t after big bang. It's just as valid and equally as pointless in terms of science.

Let me tell you a story, a friend of mine tried to establish absolute time as a concern working in terms of a triplet paradox, he presented his paper to his University, who promptly returned it saying it's meaningless. Now he was a grad student, and they were professors. Let's try and understand why they threw his paper back in his face?

 

[Dale]

Taking into account relativity, no matter how small the effect, how do you calculate the acceleration of a box sliding down a frictionless plane.

Easy, use Newton's 2nd law, f=dp/dt. You can use 3-vectors for the Newtonian version or 4-vectors if you want to be anal about it and include the SR corrections, but the law is the same in either case.

The point is that time is not absolute because you can analyze the box's motion in a coordinate system where it is released at t=0 or one where it is released at t=13.7 billion years. In either case you can use the same laws to calculate the same result.

 

[Dale]

Create a frame in a vacuum with a fluorescent marker at an equal distance on each of the three axes. Let a flash of light occur at the origin. If the observer at the origin sees all the flashes return simultaneously, a repeatable time interval, clock, is established in this frame. Define this particular frame and the distance and time interval as absolute. Proceed from there.

This is absurd.

Create an identical frame moving inertially wrt the first. Perform the same procedure. Now you have two different sets of "absolute time" that disagree with each other.

 

[hartlw]

Refer the second to the first. Or make the second absolute. Then refer the first to the second.

 

[matheinste]

Perhaps an agreed definition of absolute time may be useful here.

Matheinste

 

[Dale]

Refer the second to the first. Or make the second absolute. Then refer the first to the second.

Do you not see the blatantly obvious problem here? As you noticed there is no physical basis on which to choose one over the other. Therefore neither can be absolute.

 

[The Dagda]

Perhaps an agreed definition of absolute time may be useful here.

Matheinste

Since such a definition cannot by dint of SR model reality it is superfluous, like I say and Dalespam^ is also saying the definition given is useless. In fact any Galilean time as it's sometimes called is not what we observe in the real world nor it seems ever could.

People need to understand what is meant by there are no discreet frames of reference.

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

Reference frames, coordinates and the Lorentz transformation

Relativity theory depends on "reference frames". A reference frame is an observational perspective in space at rest, or in uniform motion, from which a position can be measured along 3 spatial axes. In addition, a reference frame has the ability to determine measurements of the time of events using a 'clock' (any reference device with uniform periodicity).

An event is an occurrence that can be assigned a single unique time and location in space relative to a reference frame: it is a "point" in space-time. Since the speed of light is constant in relativity in each and every reference frame, pulses of light can be used to unambiguously measure distances and refer back the times that events occurred to the clock, even though light takes time to reach the clock after the event has transpired.

For example, the explosion of a firecracker may be considered to be an "event". We can completely specify an event by its four space-time coordinates: The time of occurrence and its 3-dimensional spatial location define a reference point. Let's call this reference frame S.

In relativity theory we often want to calculate the position of a point from a different reference point.

Suppose we have a second reference frame S', whose spatial axes and clock exactly coincide with that of S at time zero, but it is moving at a constant velocity v\, with respect to S along the x\,-axis.

Since there is no absolute reference frame in relativity theory, a concept of 'moving' doesn't strictly exist, as everything is always moving with respect to some other reference frame. Instead, any two frames that move at the same speed in the same direction are said to be comoving. Therefore S and S' are not comoving.

 

[hartlw]

Define this particular frame and the distance and time interval as absolute. Proceed from there.

You have to be practical. Like the std meter and the std mass.

Accelerate the std meter in Paris to .75c and then call it the standard (absolute) meter. The real problem is communicating (measuring) between frames. An absolute reference allows you to do this. Just define one as absolute.

 

[The Dagda]

You have to be practical. Like the std meter and the std mass.

Accelerate the std meter in Paris to .75c and then call it the standard (absolute) meter. The real problem is communicating (measuring) between frames. An absolute reference allows you to do this. Just define one as absolute.

You can't it's one of the fundamental laws of SR, that's the point. If you could then it would destroy SR, and Einstein's theory would be thrown in the trash.

The problem is that to understand why you need more than a cursory understanding of special relativity. But reading any link or book on it will establish why quite completely such a concept is fundamentally flawed, if you understand the maths it will be even more obvious. yes you could define an absolute, but it would be only practical in philosophy because space-time simply doesn't work that way and never has to all appreciable understanding. Thus even knowing when time began precisely, if you even could would be worthless, unless you are God and are not subject to the laws of nature but exist outside of them.

You have to be practical and that is it in a nutshell, to all practical intents such an arbitrary concern is worthless.

 

[matheinste]

I agree with you The Dagda. Such a thing as absolute time does not exist in SR and so is undefinable in SR. However hartlw obviously has his own example of what he considers to be absolute time so it may be worth asking for his general definition rather than a specific example.

Matheinste.

 

[The Dagda]

I agree with you The Dagda. Such a thing as absolute time does not exist in SR and so is undefinable in SR. However hartlw obviously has his own example of what he considers to be absolute time so it may be worth asking for his general definition rather than a specific example.

Matheinste.

Sure I have no problem with that as long as we understand it is philosophy in its purest sense because it is pure abstraction and pure maths.

 

[hartlw]

The most general definition I can think of is absolute time is the distance of a spherical light wave from its center.

 

[hartlw]

If we want to totally abstract ourselves from reality then time, distance, and mass are symbols with certain mathematical properties.

 

[The Dagda]

If we want to totally abstract ourselves from reality then time, distance, and mass are symbols with certain mathematical properties.

Ah but then I feel a need for a thread move. If that is the case then are these values independent of conscious thought, or are they a consequence of it? If the former then there is an absolute time, if the latter then not. It would start to move towards an argument over whether maths has always existed or it is an extension of us. That question is messy, but most people believe that maths is conscious dependent, or put another way not created by a god, or the universe. What is is, it is fundamentally written into reality, and maths is just our flawed way of getting to grips with it.

 

[Dale]

The most general definition I can think of is absolute time is the distance of a spherical light wave from its center.

And which law of physics is different in such a reference frame?

 

[hartlw]

And which law of physics is different in such a reference frame?

I assume you mean a reference frame at the center of a spherical wave. Assuming the spherical light wave is not influenced by gravity, my first thought was a frame at the light center should function as an ineertial reference frame, avoiding for now the problem that there is no such thing as an inertial reference frame in the sense that an object in the frame couldn't possibly move with constant velocity unless you assumed there was no gravity field. But there would be no way of knowing if the frame were spinning wrt to the spherical wave of light.

This got me thinking about the Earth spinning about its axis. How does the Earth know its spinning about its axis? Suddenly the explanation struck me:

THE ANGULAR MOMENTUM OF THE UNIVERSE IS CONSTANT. This implies the existence of absolute space and time, starting with an inertial frame fixed at the center of the "big bang," and the CONSTANT equal to zero.

 

[atyy]

I assume you mean a reference frame at the center of a spherical wave. Assuming the spherical light wave is not influenced by gravity, my first thought was a frame at the light center should function as an ineertial reference frame, avoiding for now the problem that there is no such thing as an inertial reference frame in the sense that an object in the frame couldn't possibly move with constant velocity unless you assumed there was no gravity field. But there would be no way of knowing if the frame were spinning wrt to the spherical wave of light.

Isn't one way of getting the metric of special relativity to consider a bunch of inertial frames with light spreading out from a point (eg. their coincident origins at t=0)?

 

[Dale]

I assume you mean a reference frame at the center of a spherical wave. Assuming the spherical light wave is not influenced by gravity, my first thought was a frame at the light center should function as an ineertial reference frame, avoiding for now the problem that there is no such thing as an inertial reference frame in the sense that an object in the frame couldn't possibly move with constant velocity unless you assumed there was no gravity field. But there would be no way of knowing if the frame were spinning wrt to the spherical wave of light.

This got me thinking about the Earth spinning about its axis. How does the Earth know its spinning about its axis? Suddenly the explanation struck me:

THE ANGULAR MOMENTUM OF THE UNIVERSE IS CONSTANT. This implies the existence of absolute space and time, starting with an inertial frame fixed at the center of the "big bang," and the CONSTANT equal to zero.

The angular momentum of the universe is constant in all inertial frames, so this does not imply absolute space or time.

You still have yet to identify any physical law (e.g. Maxwell's eqts.) which is different (i.e. different form or constants) in one inertial frame vs. another. Until you do so you do not have an absolute time or space.

 

[hartlw]

THE ANGULAR MOMENTUM OF THE UNIVERSE IS CONSTANT.

And that explains, for me, the rotation of the Earth about its axis. It also implies there is the Newtonian Universe (Cosmos) of large objects and small speeds, and the universe of small objects and large speeds. Confusion seems to arise when we put reference frames in between.

I can't get beyond this question. If a light wave is instantaneously emitted from a particle, does it have the speed of the particle? If the aether is "nothing" then it doesn't make sense that it should somehow have the ability to limit the speed of a wave, like water or air does. It makes more sense that light (or EM radiation) would travel with a speed proportional to the energy of expulsion. But then different colors would arrive at different times and so to get them to arrive at the same time you keep the speed constant and put the energy into frequency (color).

Let's assume that a pulse of light is created when an electron jumps from one energy level to another, and it does so with spherical symmetry, and no longer influences the light wave once the process is complete. Then we could have a spherical light wave with an identifiable center.

Two identical particles moving wrt each other emit identical pulses of light at the instant they are at the origin of a coordinate system. What happens? Will the light reach a marker on an axis in the direction of velocity at the same tiime?

In an "aether," yes.

The leading edge of the light wave is created at the instant the electron starts its jump. So regardless of the relative speeds, at this instant the light waves should be identical. The trailing edge of the light wave is created at the instant the electron reches its new energy level. Since one particle has moved with respect to the other, the trailing edges will be spherical but offset. This has some interesting implictions.

But the fundamental question is whether both light waves hit a marker on the axis at the same time. If the leading edges of both light waves are created instantaneously, can the leading edges "know" about the speed of the particle? If not, the leading edges would arrive at the same time but the trailing edge wouldn't.

 

[hartlw]

The angular momentum of the universe is constant in all inertial frames, so this does not imply absolute space or time.

An inertial reference frame is one in which an object on which no forces act moves with constant velocity. Where is there a reference frame in which no forces act on an object? You can identify frames in which an object moves with constant velocity, but you can't satisfy the requirement that no forces act on the object, unless you dispense with gravity (the universe).

 

[Dale]

Now you are just trying to weasel your way out of answering the question. An inertial reference frame can be defined even in the case where there are no inertial objects considered.

The point remains, as it has for the past 3 dozen posts or so, if you cannot identify a physical law that has a different form or different constants in an inertial reference frame then you have no physical basis for selecting one over another and calling one "absolute". I think it should be clear that there is no such law and you are just trolling.

Don't bother posting unless you can address the core issue.