Questions about time

[sol invictus]

Time as an observational unit within which we view material change exists, this doesn't make time a thing that can be travelled along. Therefore, it's not a dimension in the same way that space is.

It's certainly not the same as space, that's obvious. But it is indeed a dimension, or at least that's what physics tell us.

 

[Merton]

Thanks, fuelair! I think my embarrassment is more due to the fact that I'm a newbie on a skeptic forum... and this isn't exactly how I wanted to start things off! lol

 

[Farsight]

It's certainly not the same as space, that's obvious. But it is indeed a dimension, or at least that's what physics tell us.

It's a dimension in the sense of measure rather than freedom of movement. Here's a bit of etymology:

dimension late 14c., "measurement, size," from L. dimensionem (nom. dimensio) "a measuring," from pp. stem of dimetri "to measure out," from dis- (see dis-) + metiri "to measure" (see measure). Meaning "any component of a situation" is from 1929. Related: Dimensional; dimensions.

Temperature used to be thought of as a dimension, but nowadays it isn't generally considered to be a dimension per se, because the word dimension tends to be thought of in the context of freedom of motion - and everybody knows you can't literally climb to a higher temperature. However time hasn't shifted in the same way, and people still tend to think that you can literally travel to a different time. Or at least that such is theoretically possible. It isn't. Because whilst temperature is akin to an average measure of motion, time is akin to a cumulative measure of motion. It isn't something that you can actually move through.

 

[keyfeatures]

If we trace back to the Newton vs. Leibniz debate, I'm inclined to side with Gottleib (although taking God out of the mix). Neither time nor space are discernible things with attributes. Unfortunately, Leibniz was probably too busy doing vanity family trees for Royals and so Newton ultimately won by popularity vote.

 

[RobDegraves]

Time as an observational unit within which we view material change exists, this doesn't make time a thing that can be travelled along. Therefore, it's not a dimension in the same way that space is.

You can travel along time, however only forward.

Like falling... you can only fall down.

Obviously the reality is a fairly complex one. A lot of modern physics is based on time being a dimension (again, oversimplification obviously), there is a reason for this and that is because it works.

Just you and Farsight saying it isn't real does not change what is currently understood in physics, nor is your assertion obviously based on an in depth understanding of the science involved.

If you have a serious model of physics in which time does not exist that can replace the current models, please do present it.

 

[Beerina]

It's a dimension in the sense of measure rather than freedom of movement. Here's a bit of etymology:

dimension late 14c., "measurement, size," from L. dimensionem (nom. dimensio) "a measuring," from pp. stem of dimetri "to measure out," from dis- (see dis-) + metiri "to measure" (see measure). Meaning "any component of a situation" is from 1929. Related: Dimensional; dimensions.

Temperature used to be thought of as a dimension, but nowadays it isn't generally considered to be a dimension per se, because the word dimension tends to be thought of in the context of freedom of motion - and everybody knows you can't literally climb to a higher temperature. However time hasn't shifted in the same way, and people still tend to think that you can literally travel to a different time. Or at least that such is theoretically possible. It isn't. Because whilst temperature is akin to an average measure of motion, time is akin to a cumulative measure of motion. It isn't something that you can actually move through.

That would be news to Einstein. IANAP but wasn't his theory that you are always moving throuh the spacetime continuum at c?

A result of this was that gravity and inertial resistance to acceleration weren't just similar phenomenon, but were in fact the exact same phenomenon? That gravity was warped space and time and you were accelerating while not actuall moving throuh space, to maintain c?



As for the larger subject that time doesn't really exist in the freedom of movement sense, as if we exist in a solid state across the 4d continuum, I point out an argument from computer science -- certain computations, which we can do, cannot be solved in any way significantly fqster than "try all possibilities". Hence his 4d solid cannot have come to exist with said computations in it, as is currently understood.

Hence something must actually be calculating, which requires actual interaction in a time sense. The Church Turing thesis is that the Turing machine represents the concept of most powerful computational model hat can perform, at most, a finite number of operations in a finite time.

And said model, which actually exists, cannot short-circuit these calculations no matter how cleverly programmed.

So if time didn't exist, something else like it must, or there is something infinite in capacity about the universe, either of which are also interesting.

 

[keyfeatures]

How would you judge time without movement?

How would you judge units of time without consistent movement?

A sense of time is only achievable because we have the capacity for memory and recall. The memory of the world being different allows us to conceive of a past. Putting ourselves in this memory also allows us to project to a future. However, to judge the progress of this difference we use consistent movements and the memory of how many such movements have occurred since a particular prior memory state existed. This allows us to say that 'time' has passed. This is why time apparently dilates with gravity / speed - because what actually dilates is movement / space.

 

[ctamblyn]

How would you judge time without movement?

How would you judge units of time without consistent movement?

A sense of time is only achievable because we have the capacity for memory and recall. The memory of the world being different allows us to conceive of a past. Putting ourselves in this memory also allows us to project to a future. However, to judge the progress of this difference we use consistent movements and the memory of how many such movements have occurred since a particular prior memory state existed. This allows us to say that 'time' has passed. This is why time apparently dilates with gravity / speed - because what actually dilates is movement / space.

As I mentioned earlier (possibly in another thread), I have a few problems with treating motion as somehow being the basis of time.

First: how do you define or model motion without first having a concept of time?

Second: is the resulting picture really any better than the conventional one? For example, does it make better predictions, or is it somehow simpler to work with?

Third: how do you account for processes such as muon decay? Obtain a muon, sit it in front of you and start observing it. It will happily sit there for a while (about 2 microseconds, on average, but it is a random process). Then, without warning, it will decay into other particles. There is a passage of time from the start of your observation to the moment of decay, and yet nothing in the muon moved (it has no internal structure that we know of).

 

[Perpetual Student]

It's a dimension in the sense of measure rather than freedom of movement. Here's a bit of etymology:

dimension late 14c., "measurement, size," from L. dimensionem (nom. dimensio) "a measuring," from pp. stem of dimetri "to measure out," from dis- (see dis-) + metiri "to measure" (see measure). Meaning "any component of a situation" is from 1929. Related: Dimensional; dimensions.

Temperature used to be thought of as a dimension, but nowadays it isn't generally considered to be a dimension per se, because the word dimension tends to be thought of in the context of freedom of motion - and everybody knows you can't literally climb to a higher temperature. However time hasn't shifted in the same way, and people still tend to think that you can literally travel to a different time. Or at least that such is theoretically possible. It isn't. Because whilst temperature is akin to an average measure of motion, time is akin to a cumulative measure of motion. It isn't something that you can actually move through.

Time travel is the creation of science fiction writers with no support among the physics community. But it does seem to be your favorite straw man. The etymology of any modern scientific word is interesting but irrelevant to any question concerning its accepted modern scientific definition. Quaint outdated usages like "temperature as a dimension" are also irrelevant to any modern scientific discussion. Spacetime (with time being a fourth dimension) is a productive concept with strong experimental support and is a key aspect of our best scientific models of the universe. Pseudo-scientific claims that time is some emergent property with no meaningful model or evidence to support it is mere sophistry. Such notions are often the result of cultists, engineers and computer programmers attempting to play physicist.

 

[Merton]

Just because I want to see answers here, I'm going to play devil's advocate.

First: how do you define or model motion without first having a concept of time?

Couldn't we make an analogy to space? "How do you define or model space without first having a concept of distance?" If distance is the metric for space, time is the metric for motion.

Second: is the resulting picture really any better than the conventional one? For example, does it make better predictions, or is it somehow simpler to work with?

No, no better picture. Just a different way of thinking about it.

Third: how do you account for processes such as muon decay? Obtain a muon, sit it in front of you and start observing it. It will happily sit there for a while (about 2 microseconds, on average, but it is a random process). Then, without warning, it will decay into other particles. There is a passage of time from the start of your observation to the moment of decay, and yet nothing in the muon moved (it has no internal structure that we know of).

The muon has no internal structure that moves, but it is spinning, right? Would this not be its motion?

 

[keyfeatures]

As I mentioned earlier (possibly in another thread), I have a few problems with treating motion as somehow being the basis of time.

First: how do you define or model motion without first having a concept of time?

Topological or geometric relation to other 'things' and the change observed in this.

Second: is the resulting picture really any better than the conventional one? For example, does it make better predictions, or is it somehow simpler to work with?

Why wouldn't it? It may not fit so well with human intuition.

Third: how do you account for processes such as muon decay? Obtain a muon, sit it in front of you and start observing it. It will happily sit there for a while (about 2 microseconds, on average, but it is a random process). Then, without warning, it will decay into other particles. There is a passage of time from the start of your observation to the moment of decay, and yet nothing in the muon moved (it has no internal structure that we know of).

If there is an observed change in the state of the muon then something moved. You haven't observed time passing. My own sense it that there is a real difference in quantum states that isn't just statistical interpretation. Just as the coin toss 'prepares' the heads or tails.

 

[Michael C]

First: how do you define or model motion without first having a concept of time?

Topological or geometric relation to other 'things' and the change observed in this.

This sends us round in circles. How do you define "change observed" without reference to the time dimension along which the change is observed?

 

[punshhh]

How would you judge time without movement?

How would you judge units of time without consistent movement?

A sense of time is only achievable because we have the capacity for memory and recall. The memory of the world being different allows us to conceive of a past. Putting ourselves in this memory also allows us to project to a future. However, to judge the progress of this difference we use consistent movements and the memory of how many such movements have occurred since a particular prior memory state existed. This allows us to say that 'time' has passed. This is why time apparently dilates with gravity / speed - because what actually dilates is movement / space.

Perhaps it helps to see time as part of a relative system. This relative system has time and space as described by physics from the moment of the Planck epoc.

 

[Farsight]

You can travel along time, however only forward.

Like falling... you can only fall down.

Obviously the reality is a fairly complex one. A lot of modern physics is based on time being a dimension (again, oversimplification obviously), there is a reason for this and that is because it works.

Just you and Farsight saying it isn't real does not change what is currently understood in physics, nor is your assertion obviously based on an in depth understanding of the science involved.

Garbage. It's based on an in-depth understanding, patent scientific evidence, and on A World Without Time: The Forgotten Legacy of Godel and Einstein. You can travel in space. You can jump forward a metre, and you can jump back a metre. You can climb a ladder a metre, and then you can descend a metre. But there is no way you can travel through time. Just sitting there in your armchair isn't like falling at all.

If you have a serious model of physics in which time does not exist that can replace the current models, please do present it.

It isn't my model. Now go and read A World Without Time: The Forgotten Legacy of Godel and Einstein. And if you have evidence of travelling through time, please do present it. After that you can show us all your time machine.

 

[keyfeatures]

This sends us round in circles. How do you define "change observed" without reference to the time dimension along which the change is observed?

Numerical order.

 

[Kwalish Kid]

Garbage. It's based on an in-depth understanding, patent scientific evidence, and on A World Without Time: The Forgotten Legacy of Godel and Einstein. You can travel in space. You can jump forward a metre, and you can jump back a metre. You can climb a ladder a metre, and then you can descend a metre. But there is no way you can travel through time. Just sitting there in your armchair isn't like falling at all.

The questionable work of a non-scientist about science notwithstanding, it is foolish to say that the coordinates in time where one finds oneself are not different now than they were in the past. If we want to actually do physics, we have to acknowledge that there are time coordinates and that the position according to these coordinates change in regular ways that we can study and predict.

It isn't my model. Now go and read A World Without Time: The Forgotten Legacy of Godel and Einstein. And if you have evidence of travelling through time, please do present it. After that you can show us all your time machine.

Farsight is well-known for presenting his own version of Einstein inconsistent with Einstein's work and biography and for being almost completely ignorant of the relevant physics written by Einstein (see any of his threads for examples).

 

[Kwalish Kid]

First: how do you define or model motion without first having a concept of time?

It is fascinating to see how Maxwell talks about this in Matter and Motion. He pretty much goes along without explicitly defining time, but then stops and admits what he's doing, provides a working definition and essentially lays down the gauntlet for anyone who might replace that definition that their definition must get a physics at least as good as the one that he is working with.

Later Einstein would do just that, in pretty much exactly the places that Maxwell identifies are the most dubious assumptions.

 

[Farsight]

That would be news to Einstein.

See above. Honestly, it wouldn't be.

IANAP but wasn't his theory that you are always moving through the spacetime continuum at c?

You could say that, but in a slightly different way. Light is always moving through space at c. And see pair production. We can make an electron (and a positron) out of light. The electron has spin, and c features in the Dirac equation. It's "a wave equation, formulated by British physicist Paul Dirac in 1928. It provided a description of elementary spin-½ particles, such as electrons". You're made out of electrons, and electrons are waves, and light waves are waves. You can diffract them both. So think of yourself as being made up of waves that are always moving at c. This is why the Simple inference of time dilation due to relative velocity works. And that's just Pythagoras's theorem really. It really is that simple.

A result of this was that gravity and inertial resistance to acceleration weren't just similar phenomenon, but were in fact the exact same phenomenon? That gravity was warped space and time and you were accelerating while not actually moving through space, to maintain c?

No probs re gravitational mass and inertial mass, but he didn't actually say that gravity was warped spacetime, and it was only the principle of equivalence, not the fundamental law of equivalence. Standing on the ground is like accelerating through space, but it's a little bit different in that no work is being done and no energy is being transferred.

As for the larger subject that time doesn't really exist in the freedom of movement sense, as if we exist in a solid state across the 4d continuum, I point out an argument from computer science -- certain computations, which we can do, cannot be solved in any way significantly fqster than "try all possibilities". Hence his 4d solid cannot have come to exist with said computations in it, as is currently understood.

The 4D solid or block universe doesn't exist in a real sense. Like I was saying it's a bit like filming a red ball traversing the room, then cutting the film into into individual frames and stacking them up. The ball now appears as a red streak embedded in the block. There's no motion going on. It's a representation of space and time, or space and motion, but in itself it isn't something real.

Hence something must actually be calculating, which requires actual interaction in a time sense. The Church Turing thesis is that the Turing machine represents the concept of most powerful computational model hat can perform, at most, a finite number of operations in a finite time.

And said model, which actually exists, cannot short-circuit these calculations no matter how cleverly programmed.

I have a degree in Computer Science, I know about all this. The main thing to remember is that for something to be calculating, something has to be moving. Beads on an abacus, electrons in a circuit, impulses in a brain, there's always something moving in there.

So if time didn't exist, something else like it must, or there is something infinite in capacity about the universe, either of which are also interesting.

It's motion. Without it it would be a strange universe indeed. No light. No way to tell the time. No way to tell distance. No way to see. No expansion of the universe. Without it, it's hardly a universe at all. And yes, it's really interesting.

 

[Farsight]

How would you judge time without movement?

How would you judge units of time without consistent movement?

A sense of time is only achievable because we have the capacity for memory and recall. The memory of the world being different allows us to conceive of a past. Putting ourselves in this memory also allows us to project to a future. However, to judge the progress of this difference we use consistent movements and the memory of how many such movements have occurred since a particular prior memory state existed. This allows us to say that 'time' has passed. This is why time apparently dilates with gravity / speed - because what actually dilates is movement / space.

Well said, keyfeatures.

 

[Michael C]

Numerical order.

I don't see how "numerical order" is a definition of "change observed". Could you elaborate on what you mean?