Alternate definitions of time

[Didymus]

Preface: A second used to be defined by 1/86,400th of a solar day. This wobbles a bit, so a more stable definition was given as 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. Fine and dandy. This is presumably because, unlike the earth's rotation, which can wobble and is slowly slowing, cesium always behaves the same, no matter what... it is what it is and it doesn't change.

 

So, my question is mostly a philosophical one. I understand the supporting evidence for the math showing that these atoms slowed down, but why is it preferable to believe that these atoms are incapable of being inaccurate and that time is malleable? Obviously, because the definition of a second is based on the clock, we can logically say that a "second" has slowed down... but with the old definition of a second, if the earth's revolution were to slow, we wouldn't assume time to be slowing, but the earth's rotation (as evidence by the fact that we realized that the earth's rotation altered rather than assuming that time was slowly slowing down).

 

 

Realistically, it makes little difference, the math stays the same even if you say "time stays the same, but everything (including atomic actions) slow down by a certain factor." ... but I wonder why the definition einstein chose is so preferred.

[ajb]

let us be careful here: you have definitions of a second, which is a measurement of the passage of time rather than a definition of time itself.

Preface: A second used to be defined by 1/86,400th of a solar day. This wobbles a bit, so a more stable definition was given as 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. Fine and dandy. This is presumably because, unlike the earth's rotation, which can wobble and is slowly slowing, cesium always behaves the same, no matter what... it is what it is and it doesn't change.

The definition of a second also includes at rest, and approaching the theoretical temperature of absolute zero.

 

The atom must be very cold as to eliminate radiation effects and all measurements are in the rest frame of the atom.

Realistically, it makes little difference, the math stays the same even if you say "time stays the same, but everything (including atomic actions) slow down by a certain factor." ... but I wonder why the definition einstein chose is so preferred.

The key to the modern definition is that it is in reference to the rest frame of the atom. That gives us a standard clock in any inertial frame, i.e. a way of defining a second, but the clocks in different inertial frames need not agree with each other.

[swansont]

The problem with the earth rotation definition was that other observable oscillators were not changing — the sun's revolution about the sun, and various clocks we had devised. So it's not simply a matter of saying that time has slowed if your measurements do not all agree that this has happened.

[Didymus]

The change in the definition of a second wasn't intended to be the question, but a preface. The question is... when we observe that under certain circumstances, the atoms we use to define time change... why do we prefer to interpret this as the clock being immutable and time itself changing vs. the atomic processes changing.

(i.e. the "jets flying around the world with cesium clocks" and "muons observed to last longer at high speed" ... how do we know that the muons are still decaying at their infallible rate and that time is stretching as opposed to "when they move fast, they don't decay as fast,")

 

Functionally, it would make little difference, because the rate at which they slow down would match the math of SR... but the explanation of that math would eliminate a LOT of currently paradoxical variables if we consider it a change in how the moving object behaves, rather than a change in space and time around that moving object. i.e. use the same formula, but define the variables differently.

[swansont]

The change in the definition of a second wasn't intended to be the question, but a preface. The question is... when we observe that under certain circumstances, the atoms we use to define time change... why do we prefer to interpret this as the clock being immutable and time itself changing vs. the atomic processes changing.

 

(i.e. the "jets flying around the world with cesium clocks" and "muons observed to last longer at high speed" ... how do we know that the muons are still decaying at their infallible rate and that time is stretching as opposed to "when they move fast, they don't decay as fast,")

 

Functionally, it would make little difference, because the rate at which they slow down would match the math of SR... but the explanation of that math would eliminate a LOT of currently paradoxical variables if we consider it a change in how the moving object behaves, rather than a change in space and time around that moving object. i.e. use the same formula, but define the variables differently.

 

Because the clocks follow a consistent law, independent of the type of clock. If it's an atomic process that's changing, it is not doing so in any systematic way that depends on the atomic interaction or the atom's properties. The change does, however, depend on speed, and on the gravitational potential. Just as theory predicts.

[Didymus]

Let's go to one of Einstein's thought experiments... I have this button that changes time. I press it and time is now moving at 1% it's normal rate. In every way, the universe is now moving at 1% it's former rate and all processes (including the revolution and orbit of the earth, atomic processes and biological processes)... How do you detect it?

 

Now I press another button and time is moving at 20times it's former rate.... Because we now think faster and observe everything going faster... We won't notice any difference.

 

Basic as this may seem.... If a cesium clock inalterably tells time.... Were time to change it couldn't be noticed because if time slowed by any factor, the everything down to the atoms would have slowed by that same factor. If X nanoseconds went by relative to the ground clock, the same number of nanoseconds must have passed on the moving clock... Even if this number of nanoseconds seemed longer.

 

Basically... A mechanism can't measure something "more accurately" than the thing it's measuring.

[ACG52]

Were time to change it couldn't be noticed because if time slowed by any factor, the everything down to the atoms would have slowed by that same factor

.The change could only be noticed from a different reference frame. No reference frame ever sees it's own proper time as altered.

 

If X nanoseconds went by relative to the ground clock, the same number of nanoseconds must have passed on the moving clock.

 

No, relative to the ground clock, fewer nanoseconds have passed on the moving clock.

Edited February 22, 2013 by ACG52

[Didymus]

But during each of those nanoseconds, the plane could view the earth and people on the ground could view the plane. The same number of nanoseconds passed on both frames of reference, they just disagree as to the duration of each nano second.

 

Unless you believe that during some nanoseconds, the planes all stopped existing momentarily?

[ACG52]

The same number of nanoseconds passed on both frames of reference

 

The people on the ground would see the people on the plane counting fewer nanosecond while the ground counted more.

 

That's what time dilation is about.

Edited February 22, 2013 by ACG52

[swansont]

Let's go to one of Einstein's thought experiments... I have this button that changes time. I press it and time is now moving at 1% it's normal rate. In every way, the universe is now moving at 1% it's former rate and all processes (including the revolution and orbit of the earth, atomic processes and biological processes)... How do you detect it?

 

Now I press another button and time is moving at 20times it's former rate.... Because we now think faster and observe everything going faster... We won't notice any difference.

 

Basic as this may seem.... If a cesium clock inalterably tells time.... Were time to change it couldn't be noticed because if time slowed by any factor, the everything down to the atoms would have slowed by that same factor. If X nanoseconds went by relative to the ground clock, the same number of nanoseconds must have passed on the moving clock... Even if this number of nanoseconds seemed longer.

 

Basically... A mechanism can't measure something "more accurately" than the thing it's measuring.

 

If time changed its rate for everything you couldn't measure it. But that's not an accurate representation of relativity, so it's moot.

[Didymus]

The people on the ground would see the people on the plane counting fewer nanosecond while the ground counted more.

 

That's what time dilation is about.

 

So, do you believe that, since more nanoseconds "happened" on earth than on the plane, there were some nanoseconds during the plane's trip where the plane did not exist? It's not that "51 nanoseconds didn't happen" on the planes..." SR states that EVERY nanosecond had a slightly shorter duration. Thus, biological functions happened a bit slower. atomic functions happened a bit slower and thus the clock ticked a bit slower. But the same number of nanoseconds would have passed because both frames of reference could view the other one during each nanosecond.

[michel123456]

If time changed its rate for everything you couldn't measure it. But that's not an accurate representation of relativity, so it's moot.

If time changed instantly, yes we couldn't measure it. But if time changed over distance, we could. It would appear as the diagram below from Ned Wright's tutorial

 

"If we now "stretch" the time axis near the Big Bang we get the following

space-time diagram which has straight line past lightcones:"

 

 

 

 

 

Edited February 22, 2013 by michel123456

[swansont]

If time changed instantly, yes we couldn't measure it. But if time changed over distance, we could. It would appear as the diagram below from Ned Wright's tutorial

 

But that's not we're talking about.

[ACG52]

So, do you believe that, since more nanoseconds "happened" on earth than on the plane, there were some nanoseconds during the plane's trip where the plane did not exist?

I'm not really sure what you're talking about. When the planes clock and the earths clock are brought into the same frame of reference and compared, the planes clock will have ticked off fewer nanoseconds than the earth's clock.

[michel123456]

He says that there is no absolute 'tick".

 

If the rate of the "tick" changes universally, nobody would notice anything.

 

 

------------------

And what i say is that if the "tick" changes universally (yes) but not everywhere "at the same instant" then we would notice the change.

Edited February 23, 2013 by michel123456

[md65536]

So, do you believe that, since more nanoseconds "happened" on earth than on the plane, there were some nanoseconds during the plane's trip where the plane did not exist? It's not that "51 nanoseconds didn't happen" on the planes..." SR states that EVERY nanosecond had a slightly shorter duration. Thus, biological functions happened a bit slower. atomic functions happened a bit slower and thus the clock ticked a bit slower. But the same number of nanoseconds would have passed because both frames of reference could view the other one during each nanosecond.

More nanoseconds passed on Earth, but each of those nanosecond was shorter, relative to a nanosecond measured on the plane. --- err, on average that is, when you include relative simultaneity...

 

Yes, both observers could potentially constantly observe the other's clocks. Both plane and ground observer see the same number N nanoseconds elapsed on the plane's clocks, and both observers see the same number N+51 nanoseconds elapsed on the ground clocks. Everyone agrees on any single clock, but different relatively moving clocks don't record the same elapsed time.

Edited February 24, 2013 by md65536

[Delta1212]

Yes, you could simply say that all physical processes slow down as speed increases, rather than saying that it's time. But since time is just a measure of the comparative rates of physical processes and there are no processes that do not slow down to compare them with, I'm not sure how that means time isn't "really" slowing down.

[Didymus]

It's just the difference between stating that "space moves" vs. "the objects within a space move." One is a rather extraordinary claim that leads to paradoxes and holes in logic... and one is common sense.

Likewise, to state that there's an atomic change, moving at relativistic speeds... sure. For some reason, how these atoms behave slows down when moving. Perhaps muons simply can't give off energy in order to decay under the forces of such high rates of speed. Perhaps these high rates add to their stability somehow. The measure by which they're stabilized match the numbers predicted in SR, and this is completely intuitive. But, to say that this material can not be changed under any circumstances... and when we find a circumstance where they appear to have changed... that's just because these immutable objects are traveling through curved time.

One assumes time to be a physical, alterable fabric... the other defines time as an abstract idea by which humans describe the order of events. Something that can not be changed because it doesn't exist as some magic fabric. ... just an idea to differentiate what has happened (and how long ago) from what will happen.

[swansont]

Likewise, to state that there's an atomic change, moving at relativistic speeds... sure. For some reason, how these atoms behave slows down when moving. Perhaps muons simply can't give off energy in order to decay under the forces of such high rates of speed. Perhaps these high rates add to their stability somehow. The measure by which they're stabilized match the numbers predicted in SR, and this is completely intuitive. But, to say that this material can not be changed under any circumstances... and when we find a circumstance where they appear to have changed... that's just because these immutable objects are traveling through curved time.

But there is no evidence to support the notion that this is a physical effect on individual particles. No experiment, and no theory. A physical effect would require an absolute frame of reference.

[Didymus]

... basically any test intended to prove time dilation could more simply be explained by a physical change. Specifically cesium clocks running slow and muons decaying slower. The absolute frame in reference being either their speed relative to the medium through which they travel, or if traveling through a vacuum, their speed relative to their source.

[swansont]

... basically any test intended to prove time dilation could more simply be explained by a physical change. Specifically cesium clocks running slow and muons decaying slower. The absolute frame in reference being either their speed relative to the medium through which they travel, or if traveling through a vacuum, their speed relative to their source.

 

They could be, if there was a mechanism, and any evidence that there is a preferred frame of reference. There is neither, though, and people have done experiments to test for this. So appealing to either is a non-starter.

[swansont]

!

Moderator Note

Non-mainstream relativity link split http://www.scienceforums.net/topic/73388-alternate-relativity-split-from-alternate-definition-of-time/

[Didymus]

So, you say that there is 0 evidence for a preferred frame of time and thus, the idea of high speed causing physical change to be unorthodox.

 

This implies that time as an inalterably fabric has been sufficiently proven to override the more intuitive concept of time being an abstract concept rather than a universal, yet inconsistent fabric.

 

Other than the observation of muons, the clocks on a plane and the GPS lag, what evidence has been collected that time is alterable? Not thought experiments. What numbers support it that don't have a much simpler physical explanation?

 

I.e. why are the rates of atomic transitions considered able to tell time "more accurately" than time itself? When we see atomic transitions happen at a slower rate on jets or satellites or muons... What evidence is there that time changes in stead of those rate of change in atomic states?

[swansont]

So, you say that there is 0 evidence for a preferred frame of time and thus, the idea of high speed causing physical change to be unorthodox.

 

This implies that time as an inalterably fabric has been sufficiently proven to override the more intuitive concept of time being an abstract concept rather than a universal, yet inconsistent fabric.

 

Other than the observation of muons, the clocks on a plane and the GPS lag, what evidence has been collected that time is alterable? Not thought experiments. What numbers support it that don't have a much simpler physical explanation?

 

I.e. why are the rates of atomic transitions considered able to tell time "more accurately" than time itself? When we see atomic transitions happen at a slower rate on jets or satellites or muons... What evidence is there that time changes in stead of those rate of change in atomic states?

 

There is no mechanism to slow these rates. You have to have atomic systems and nuclear systems and subnuclear particle interactions — all with different coupling strength — affected in an identical fashion. There is nothing in the models that would allow for this. There is also no experiment that is consistent with one. If there is a preferred frame, then clocks would vary throughout the course of the day, owing to the earth's rotational speed. They would vary even more over the course of a year, owing to the revolution about the sun. Both scenarios can be tested. It doesn't happen.

 

You don't get to throw out science by saying you have a simpler explanation. That explanation has to have testable implications, as with all science.

 

Tests of time dilation (pdf)

http://www.worldscientific.com/doi/pdf/10.1142/S0217732305017202

 

That's a subset of tests of relativity, because there's a whole bunch of atomic physics that depends on the inclusion of relativity into QED. And the part about how all of electrodynamics demands that c be invariant. Every time someone uses a radio or cell phone in a car, they are confirming this.

 

I see nothing about this that implies that time is an "inalterably (sic) fabric" considering that the basic implication is that time is relative.

[Didymus]

Swanson... which of these are anything more than an aether drift experiment? These show quite well that light moves at a constant speed relative to it's source (each mirror). Doesn't give any logical confirmation of time's mutibility... let alone that this explanation is more viable than a physical change that is "real" in all inertial frames.

You say: "There is no mechanism to slow these rates. You have to have atomic systems and nuclear systems and subnuclear particle interactions — all with different coupling strength — affected in an identical fashion. There is nothing in the models that would allow for this."

Yet, you seem to have come to the same conclusion and accepted it as fact... that these subnuclear particle interactions are somehow defined by the flow through a fabric of time as opposed to time being a way to universally describe an order of operations. That leap of faith is what I question. The experiments you listed seem to all be a bunch of remakes of Michelson-Morley....