Change

[FrumiousBandersnatch]

... it seems to me time is a property of the motion of material things. The apple you mentioned is present whether I measure its dimensions or not. It's an apple. But time isn't present unless I measure it - only the material motion is present apart from the measurement.

If time is, as you say, a property of the motion of material things, then an apple 'experiences' time whether you measure it or not, as, even in isolation, its material constituents are vibrating, behaving like tiny clocks. You will have noticed this (particularly with pears) as fruit often goes off when you're not observing it.

 

[essentialsaltes]

However, what if I don't care about a position in space?

Then you are not interested in the number of spatial dimensions.

If I am wrong, show me time apart from a measurement of it.

Well, time is certainly not material in the usual sense.

 

[FrumiousBandersnatch]

Certainly not. All of these clocks are rated to particular accuracies.

It always seemed to me that, for the master clock, they're aiming at increased precision rather than accuracy - they want to get minimum variability of the frequency, whatever it may be. [/pedant] I may have this wrong...

 

[Resha Caner]

Then you are not interested in the number of spatial dimensions.

I may or may not be depending on the context.

Well, time is certainly not material in the usual sense.

So it's spiritual? That's a joke. I realize you didn't meant that. But if it's not material, what is it? Does physics deal with things that aren't material? I didn't think so. We're back to my first question: What is time?

 

[Resha Caner]

If time is, as you say, a property of the motion of material things, then an apple 'experiences' time whether you measure it or not, as, even in isolation, its material constituents are vibrating, behaving like tiny clocks. You will have noticed this (particularly with pears) as fruit often goes off when you're not observing it.

Touche' ... though you cast my post differently than I meant it.

 

[essentialsaltes]

So it's spiritual? That's a joke. I realize you didn't meant that. But if it's not material, what is it? Does physics deal with things that aren't material?

It deals with things that are physical.

What is time?

Let's try a different question.

What is weight?

Weight is a physical property of objects.
We measure it with a scale. Yes, a physical scale.

It seems to me weight is a property of material things. The apple you mentioned is present whether I measure its weight or not. It's an apple. But weight isn't present unless I measure it - only the material apple is present apart from the measurement.

If I am wrong, show me weight apart from a measurement of it. Show me a weight without an apple or a scale.

 

[Resha Caner]

It deals with things that are physical.

I chose the word "material" for a reason. In my worldview to be physical is to interact. The words are nearly synonymous. Further, there is no underlying assumption that the things interacting need be material.

However, I don't see "time" as one of those things. Time does not interact with the apple, but is a measure of the motion of the apple with respect to some other thing (cesium). Likewise, distance is not a measure of space, but a measure that relates 2 things.

If you see "physical" differently, you'll need to define it.

Let's try a different question.

What is weight?

You seem to reinforce my point with this, so I must be missing what you're getting at. I don't think weight is a thing either. It is, as you say, a measured property of the apple.

This can spin off into the philosophical if we're not careful, and I'm trying to avoid that. It gets into the question: What is a thing apart from its properties? I think we can circumvent that philosophical digression by noting that any property we "perceive" is an interaction of one thing with another. If I use a scale, weight is a measurement of the distance traveled by the supporting plate as the gravitational force of the apple acts against a spring. Weight is not a thing in itself, but a description of how particular things interact.

 

[FrumiousBandersnatch]

Touche' ... though you cast my post differently than I meant it.

Ah, OK; in that case, I don't really know what you meant. Can you rephrase it?

 

[essentialsaltes]

You seem to reinforce my point with this, so I must be missing what you're getting at. I don't think weight is a thing either. It is, as you say, a measured property of the apple ... a description of how particular things interact.

No, I think we're in agreement, but maybe have different ideas of what 'real' or 'physical' means, as opposed to material.

 

[FrumiousBandersnatch]

Time does not interact with the apple, but is a measure of the motion of the apple with respect to some other thing (cesium). Likewise, distance is not a measure of space, but a measure that relates 2 things.

Seems to me a distance measures the separation of two positions in space - which may be abstract, i.e. not relate to any physical (interacting) thing.

I don't think weight is a thing either. It is, as you say, a measured property of the apple.

Such measures often have two meanings, the value that we measure, and the corresponding property or relationship that can be measured.

If I use a scale, weight is a measurement of the distance traveled by the supporting plate as the gravitational force of the apple acts against a spring. Weight is not a thing in itself, but a description of how particular things interact.

Or a label for a particular kind of interaction.

Not really seeing where this is going...

 

[Resha Caner]

Not really seeing where this is going...

Many seem to view time as if it is independent of everything - as if it can stand alone. If so, I am challenging those who think that way to defend their position. So, if distance is a measure between 2 points in space, show me those points or that space independently of anything material.

If, however, time is contingent on the material ... and if the parameters associated with those things (alpha, c, etc.) could possibly change, then time would change with them.

No, I think we're in agreement, but maybe have different ideas of what 'real' or 'physical' means, as opposed to material.

Care to elaborate on where you think we differ on "physical"?

 

[Justatruthseeker]

I know this is somewhat old news, so my first question is whether there have been any recent developments in the discussion on possible variations in certain physical parameters (fine structure constant, alpha) etc.

https://www.newscientist.com/article/dn19429-laws-of-physics-may-change-across-the-universe/
https://www.newscientist.com/article/mg18324541-100-if-the-speed-of-light-can-change/

Has this idea been largely accepted or rejected? Or is it still something that is unfolding?

But then, my second question would be: If it is possible some of these parameters change, what implications does that have?

I see nothing problematic in this. being that we also are beginning to suspect none of the constants are constant.

http://news.stanford.edu/news/2010/august/sun-082310.html

The problem is people simply do not understand the speed of light. Measuring devices and all things sharing a frame of reference change with acceleration.

Time, distance and the speed of light is like kinetic energy. In a bullets frame it reads zero velocity and zero kinetic energy, even if in our frame we read both a velocity and a kinetic energy for the bullet. Likewise in our frame we read zero velocity and zero kinetic energy for us. Zero points are reset as energy is added to or subtracted from all things sharing a frame dependent upon acceleration or deceleration. Energy is lost or gained and the zero points are reset proportionally.

This is evident in that a bullet reads zero kinetic energy in its frame - and if slowed down to stationary in our frame, will still read zero kinetic energy. There is no such thing as a backwards moving clock or a bullet with negative kinetic energy. Zero points are constantly reset proportional to the energy gained or lost.

The problem is people still try to use the same times and distances from this frame and apply it to other frames. This can not be done, because the zero points in the other frame have been reset proportionally to the energy gained. This is why light will always calculate to c regardless of one's velocity. Zero points have been reset proportionally to the energy gained or lost due to that change in velocity. The speed of light is not mysterious or magical. It is simply a proportional measurement based upon the energy gained or lost due to changes in one's velocity.

Changes to those measuring devices can never be detected from within the frame - but only to frames not sharing our same relative velocity. You can never reach the speed of c using your own clocks and rulers, because they will always read your velocity as zero as the zero points are reset with changes in energy. Those changes in energy exactly compensate for the changes in velocity, so that light will always calculate to c regardless of your velocity.

Look at the second hand of a clock. A point near the hub (stationary frame) does not read the same elapsed time or distance that a point near the tip (accelerating frame) does. Like kinetic energy the zero points will reset depending on your frame of reference. The point near the tip sees the same thing as the point near the hub does, because the zero point has shifted when you shift to the other frame. Both will observe the same proportional arcs of time and distance. To the point near the tip all his measuring devices instead say he is the point near the hub. When in the tips frame, you must shift the entire zero point to that frame, not leave it in the other frame. It is this confusion that leads to thoughts of backwards moving clocks, or even clocks that stop. Both are a complete impossibility. The same impossibility of the thought of a bullet with negative kinetic energy. It will never happen.

 

[FrumiousBandersnatch]

.. if distance is a measure between 2 points in space, show me those points or that space independently of anything material.

I can't show you them if they're abstract; clearly there has to be some initial physical referent, but the points between which the distance is being measured don't have to represent anything physical. For example, a point 3 miles above the centre of the White House is a distance x from a point a mile above the North Pole. A distance can be calculated between any two designated points in space without having to specify anything particular at each point.

If, however, time is contingent on the material ... and if the parameters associated with those things (alpha, c, etc.) could possibly change, then time would change with them.

The observed time is dependent on the position and/or motion of the observer; observers in different inertial frames will measure time outside their frames differently.

 

[FrumiousBandersnatch]

I see nothing problematic in this. being that we also are beginning to suspect none of the constants are constant.

http://news.stanford.edu/news/2010/august/sun-082310.html

That is contradicted by more recent work: Decay rates of radioactive substances are constant.

 

[Resha Caner]

A distance can be calculated between any two designated points in space without having to specify anything particular at each point.

That can only be done as an abstract exercise. If a true absolute vacuum could be achieved, how would you ever complete a measurement in that vacuum? You have to mark the points somehow. And in the real world there is no way to do it without using a material marker. Real measurements of distance are contingent upon the material. That you can abstract the concept of measurement doesn't make space real.

Have you ever been in a boat with no land in sight on a cloudy day? No sun. No stars. No instruments. No GPS. It's an eerie feeling as you realize you have no way to determine whether you're drifting, in what direction, or how fast. People in such situations misjudge all the time.

The observed time is dependent on the position and/or motion of the observer; observers in different inertial frames will measure time outside their frames differently.

Yes, I understand that. That's not the type of change I'm talking about. You can still calculate how those inertial frames will relate. And what parameter is key to that calculation?

 

[essentialsaltes]

Care to elaborate on where you think we differ on "physical"?

No, because I fear it will turn into philosophy, and I'm unarmed. After a tiny amount of google-fu, all I've learned is that "a property is physical if and only if it either is the sort of property that physical theory tells us about or else is a property which metaphysically (or logically) supervenes on the sort of property that physical theory tells us about".

 

[juvenissun]

When is a parameter 'supposed to be' constant? I don't think we have any a priori reason to suppose that anything is constant. But when the evidence rolls in, those determinations can be made. We might suppose that the temperature is constant, but then we see it goes up and down. Not a constant after all. Finding that alpha varies would be more interesting (and unexpected) than finding that the temperature varies, but I don't see how it would be connected to 'our ideas of time'.

Glad to hear that. Haven't you already forgot the argument on the decay constant of radiometric element? Or what you said here is the real bottom line in your heart.

 

[Resha Caner]

No, because I fear it will turn into philosophy, and I'm unarmed. After a tiny amount of google-fu, all I've learned is that "a property is physical if and only if it either is the sort of property that physical theory tells us about or else is a property which metaphysically (or logically) supervenes on the sort of property that physical theory tells us about".

Too bad. I think it would have been fun. It wouldn't have to be a philosophical discussion, and you might learn something. It can be a struggle to define terms that have been taken for granted, but I think the exercise brings a deeper understanding.

If it's a simple matter of posting a question in the philosophy forum, I can do that. But it seems you're simply not interested. OK.

 

[essentialsaltes]

Glad to hear that. Haven't you already forgot the argument on the decay constant of radiometric element?

You mean that young earth creationists hypothesize that it has changed, but the evidence shows that it hasn't? I don't need to forget it, since it does not contradict my statement.

 

[FrumiousBandersnatch]

That you can abstract the concept of measurement doesn't make space real.

No, quite. Is that what this is about, whether space is 'real'?

Have you ever been in a boat with no land in sight on a cloudy day? No sun. No stars. No instruments. No GPS. It's an eerie feeling as you realize you have no way to determine whether you're drifting, in what direction, or how fast. People in such situations misjudge all the time.

True, people misjudge things; I don't see the relevance.

That's not the type of change I'm talking about. You can still calculate how those inertial frames will relate. And what parameter is key to that calculation?

I don't know what you're getting at. Care to explain?