Time is it moving slower than it was in the young universe?

[validity]

Originally Posted by prothero

I thought time was always relative and observer dependent. So time is moving slower where relative to whom?

Time is measured to be passing at a different rates for A and B whenever there is relative motion between A and B and/or A and B are in different gravitational potentials.

In the case that the observers are in relative uniform motion, and far away from any gravitational mass, the point of view of each will be that the other's (moving) clock is ticking at a slower rate than the local clock. The faster the relative velocity, the more is the rate of time dilation.

There is another case of time dilation, where both observers are differently situated in their distance from a significant gravitational mass, such as (for terrestrial observers) the Earth or the Sun

See http://en.wikipedia.org/wiki/Time_dilation

Just remember there is no preferred reference i.e. the experiences of A and B are both equally valid, even though these experiences may be different from one another.

sorry bit rushed for time at the mo, will provide other examples later is needed

Okay back now...

My favorite example of relative velocity time dilation is muons. Muon Experiment in Relativity I like this worked example as it was the first one that I understood the application of time dilation. From the earth frame the muons passage of time is running slower than the earths, which allows it to reach the ground i.e. its half life is spread over a larger distance. The trick to understanding this is that from the muons frame the distance is shorter than the distance viewed from the earths frame.

An everday example of different gravitational potentials is in GPS. Effects of relativity on GPS - Wikipedia, the free encyclopedia From the GPS satellite point of view time passes slower down on the ground and this effect needs to be accounted for in the design of GPS for GPS to work.

[Alan McDougall]

Samm read my post 41

I will respond to your post later!

[Samm]

Originally Posted by prothero

I thought time was always relative and observer dependent. So time is moving slower where relative to whom?

Hi, prothero! If time were observer-dependent it could only exist in the present since no-one ever observed anything in the future or the past. No? And if time is relative to anything, it must be relative to the changes it measures. And since change can also only occur in the present...

Einstein said that time moves slower in a frame of greater acceleration or gravity and therefore, says Alan McDougall, time should appear to be moving slower as we look back (in time and across space) nearer to the big bang when the universe was denser and gravitational effects were stronger. That would be time "appearing" to move slower to us here today as we look back into the time immediately after the big bang. So "where" is very long ago and "to whom" is us. I think.

Samm

[pagan]

hmmm....

i think i am questions point that time is not physical is interesting as a blatant contradiction to the visualised (by 3d proxy) four dimensional space time in the minds eye when we consider relativity. But it seems to me that such a point is in danger of philosophically undermining materialism per se (which is generally the basis for scientific inquiry) because the argument that we don't measure time but we imply/create it from measuring change in physicality can be applied to physicality itself. ie We objectively imply/create physicality from change in scientific information. We subjectively imply/create physicality from change in sensory experience.

Moreover the example with regard to comparing the position of watch hands to measure mind created non physical time is very visually centered. ie We see watch hands never time. Such an argument is in danger of saying that space does exist because we can see it directly and time doesn't because we cant. However, suppose we consider an auditory being. You could only imply the existence of space from change in sound tone and volume. You cannot hear space directly. (And that last point is made upon the shakey assumption that we do indeed perceive space directly in a visual sense.)

(Now i am not criticising such a point of view in disagreement, i think it is interesting and worth exploring philosophically.......... its just that i get the intuition that the implications go a lot further than the 'realisation' that time is not physical. I am open minded on this.)

But really shouldn't we be asking "do we see space directly? Do we see physicality directly? Do we percieve time directly?" Has not the general relativity scientific model (its always a model and not the thing in itself) told us that there are connections between matter, energy, space, time, force, velocity, etc that we could not concieve of without science? That we didn't suspect. That we cannot mentally feel, hear, picture subjectively. That can only be read in detail objectively using special language (mathematics)? Becomes practical through the same medium?

I have started another thread of which only i am question has replied, called the experimental evidence for 'now'. As it happens a different angle on the same general theme i am question raises here. The point being there that i cannot find any concievable way that we can prove scientifically that the 'now' exists. This is similar to i am question deducing that time does not have a physical existence .... but not the same methinks. I also make points about science with regards to universality and thus time, and how in a sense that does indeed throw time out of the equation. Or perhaps more accurately, out of concievable direct study and into the equation..... which is related to i am questions point.

When we imply that something exists (or is real) from whatever source subjective/objective ....... are we not necessarily being creative? How can we know any truth about reality without the creative leap of implication? This includes undermining what we thought we knew 'directly' without implication!

[validity]

Originally Posted by pagan

i think i am questions point that time is not physical is interesting as a blatant contradiction to the visualised (by 3d proxy) four dimensional space time in the minds eye when we consider relativity. But it seems to me that such a point is in danger of philosophically undermining materialism per se (which is generally the basis for scientific inquiry) because the argument that we don't measure time but we imply/create it from measuring change in physicality can be applied to physicality itself. ie We objectively imply/create physicality from change in scientific information. We subjectively imply/create physicality from change in sensory experience.

Moreover the example with regard to comparing the position of watch hands to measure mind created non physical time is very visually centered. ie We see watch hands never time.

Without knowing which specific definition of materialism you are referring to, I will generalise and say that materialism believes that mental objects and events can be reduced to physical objects and events. I do not see the contradiction, as mental constructs are allowed in the framework of materialism, are they not?

The precise periodic change of watch hands provide a standardised interval. From this standard a sense of time is generated. I see this as consistent with materialism.

Originally Posted by pagan

Such an argument is in danger of saying that space does exist because we can see it directly and time doesn't because we cant. However, suppose we consider an auditory being. You could only imply the existence of space from change in sound tone and volume. You cannot hear space directly. (And that last point is made upon the shakey assumption that we do indeed perceive space directly in a visual sense.)

(Now i am not criticising such a point of view in disagreement, i think it is interesting and worth exploring philosophically.......... its just that i get the intuition that the implications go a lot further than the 'realisation' that time is not physical. I am open minded on this.)

But really shouldn't we be asking "do we see space directly? Do we see physicality directly? Do we percieve time directly?" Has not the general relativity scientific model (its always a model and not the thing in itself) told us that there are connections between matter, energy, space, time, force, velocity, etc that we could not concieve of without science? That we didn't suspect. That we cannot mentally feel, hear, picture subjectively. That can only be read in detail objectively using special language (mathematics)? Becomes practical through the same medium?

For me describing space without using objects is like attempting to describe time without change. Regardless of not being able to hear space directly, you can not see space directly either. You can measure relative distance between objects and from this construct the concept of space.
I am not aware of the general relativity scientific model stating that concievability of the relations between matter, energy, space, time, force, velocity, etc is not possible without science. Where specifically have you drawn your comment?

[pagan]

hi validity

Without knowing which specific definition of materialism you are referring to, I will generalise and say that materialism believes that mental objects and events can be reduced to physical objects and events. I do not see the contradiction, as mental constructs are allowed in the framework of materialism, are they not?

The precise periodic change of watch hands provide a standardised interval. From this standard a sense of time is generated. I see this as consistent with materialism.

oh yeh i agree it can be. Like you say it depends upon which specific materialism we are considering. I was exploring i am questions opinion that time is not physical and that by leaving it out of QM/relativity synthesis equations then the maths is simpler. And maybe time is an illusion in the objective sense. The trouble with such an argument is that materialism itself could be subject to the same logic.

For me describing space without using objects is like attempting to describe time without change. Regardless of not being able to hear space directly, you can not see space directly either. You can measure relative distance between objects and from this construct the concept of space.

Well yes maybe, but how do we construct the concept of space without being highly influenced by an internal abstraction directly influenced by vision? After all what is geometry? Is it pure mathematics in the sense that a non visual being could concieve of it?

I am not aware of the general relativity scientific model stating that concievability of the relations between matter, energy, space, time, force, velocity, etc is not possible without science. Where specifically have you drawn your comment?

unfortunately i have the tendency to explore openly and often get confused with putiing a point of view forward. I certainly believe that such relations are possible outside science..... although we shouldn't be unaware of the influence of science upon our conceptions generally, even upon those who do not study it but pick up the scientific concepts through popular culture. Which relates to the point i was making ....

Has not the general relativity scientific model (its always a model and not the thing in itself) told us that there are connections between matter, energy, space, time, force, velocity, etc that we could not concieve of without science?

i am not saying that we cannot have relationships between these concepts without science, but i am saying that science can have a radical effect. eg spacetime 4 d geometry.

You seem to believe for example that we don't see space directly ..... but there are many that would disagree. For most such people it is extremely unlikely that they would concieve of 4d spacetime without science. In fact it is often a delight and wonder to them!

[validity]

Originally Posted by pagan

hi validity

oh yeh i agree it can be. Like you say it depends upon which specific materialism we are considering. I was exploring i am questions opinion that time is not physical and that by leaving it out of QM/relativity synthesis equations then the maths is simpler. And maybe time is an illusion in the objective sense. The trouble with such an argument is that materialism itself could be subject to the same logic.

I will look again for the post by "i am", but meanwhile I will post here and not directly to you, that the phrase "time is not physical" needs some further development. For example, to say that the flow of time is an illusion does not necessarily negate the distinction of “cause and effect”, “before and after” etc.

Originally Posted by pagan

Well yes maybe, but how do we construct the concept of space without being highly influenced by an internal abstraction directly influenced by vision? After all what is geometry? Is it pure mathematics in the sense that a non visual being could concieve of it?

They are good questions. Firstly the definition of vision needs clarification to understand what a non-visual being is i.e. the difference in “a vivid mental image” and “visual perception”. I use the distinction in this way. Echolocation, for example, can be used to construct a concept of space without visual perception i.e. it is a vivid mental image. Geometry uses visual perception to build a concept of space i.e. geometry is not a vivid mental image. The concept of space is not dependant on any one method of construction, a bat can equally navigate a forest as a ranger with a map (and a torch). So what do you mean by a non-visual being?

Originally Posted by pagan

i am not saying that we cannot have relationships between these concepts without science, but i am saying that science can have a radical effect. eg spacetime 4 d geometry.
You seem to believe for example that we don't see space directly ..... but there are many that would disagree. For most such people it is extremely unlikely that they would concieve of 4d spacetime without science. In fact it is often a delight and wonder to them!

To better clarify what I mean when I say we don’t see space directly i.e. without anything intervening, I will use an analogy. Say you are taller than me. Your "tallness" is a property of us, not you specifically. I cannot see your tallness without my height intervening.

[pagan]

validity -

Echolocation, for example, can be used to construct a concept of space without visual perception i.e. it is a vivid mental image. Geometry uses visual perception to build a concept of space i.e. geometry is not a vivid mental image. The concept of space is not dependant on any one method of construction, a bat can equally navigate a forest as a ranger with a map (and a torch). So what do you mean by a non-visual being?

i hadn't thought of that, its a good point .... it might indeed suggest that we do not percieve space directly. (If space exists at all). Similarly for time. (if time exists at all)

"tallness" is a property of us, not you specifically. I cannot see your tallness without my height intervening.

which might imply relativity, or relationship generally, as say in before and after. In general relativity theory of course, there are events that cannot be determined to be in the same order for all observers. In particular for space time connection between two events that is always greater than c, which are deemed outside cause and effect in the 'material' sense.

.... but i guess that returns me to my point that when we imply that something exists (or is real) from whatever source (subjective/objective) we are being creative. Are space and time mental constructs (from sensory/rational mind) or are they more than that because they are real? More like a mental construction as a revelation.

With regard to time being slower for some observers, or high gravity environments from the past say, as far as i understand these are time frame comparisons and not differences in direct experience. Time only appears to slow down from outside the different time frame, within it it is the same, even for atomic clocks. But i guess that by instead of direct experience you would interpret it as something else? An instinctive measure between experiences?

So when time appears to slow down for a different frame of reference, that appearance is no more or less direct than before, since directness is not the question. It is always measured relationship?

I have to apologise validity but my brain is slowing down, so i am probably way off .... it is late and i have been overloaded by an intense few weeks. I will get back to you.

[Samm]

'Scuse me guys, but this conversation seems to have gone a few miles past the drop point. There are abstractions here that seem utterly to confuse the realities of which we are speaking. Oh, my aching head! :-0

Samm

[I am question]

Of course, that is time. All it is is a measurement, nothing more.