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Why does time require matter ?

by phinds
Tags: matter, require, time
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tarbag
#145
Feb29-12, 09:25 AM
P: 19
I think we have expressed the mathematical relationship that links the time to matter. according to general relativity we can write rapidly:
The equivalence principle gives us the expression between the time coordinate and the proper time measured in the entourage of the mass distribution.
dτ=gttc2dt2; dτ is the proper time.
gtt=(1-GM/c2r);
if gtt=0 then the proper time is zero. it happens at the Schwarzschild radius.
I think this expression shows that our time vanishes at this limit. This time is what we measure since the big bang. before the big bang it was another time that has nothing to do with matter. It is just a model.
petm1
#146
Mar2-12, 02:04 PM
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P: 366
Think of emission as the cause and reception the effect of EMR, GPS works because of this relationship, and all I can see is one end of this duration I think of as a photon.
Grimstone
#147
Mar5-12, 02:36 AM
P: 69
So as mass alters space and time, then the space between two SMBH in a death dance. would weaken the space-time barrier?
Chalnoth
#148
Mar5-12, 02:39 AM
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Quote Quote by Grimstone View Post
So as mass alters space and time, then the space between two SMBH in a death dance. would weaken the space-time barrier?
Um, there's no such thing as a space-time barrier. The space around supermassive black holes gets curved in interesting ways, though. Curiously enough, it is the smaller black holes that have more curvature around them, not the larger ones.
Avabew
#149
Mar9-12, 04:44 AM
P: 1
The whole thing about matter degrading from a high entropy to a low entropy helps me understand this further but then you start getting into "is it the start or the begining?" Time would then cease to exist with no lower form of decay without some catalyst to change the matter from its simplest state of existence back into a more complex form... If there is no comparison for degradation does it exist....???? ie If things were all degrading at the same rate (including the observer) there would be no change comparitively to observe......... Ouch
petm1
#150
Mar9-12, 11:26 AM
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What are you going to use as a clock, our anchor to the past, if not matter? How about an observer made out of anything other than the matter anchoring their consciousnesses in the present? The duration of matter and its changes in space-time is how we measure existence, the count of a clock is what keeps it all relative. Does time require matter I would think not but does matter require time, yes.
sigurdW
#151
Mar10-12, 10:36 AM
P: 27
Quote Quote by phasl001 View Post
Yet a theory remains unproven even if it has facts to back it up, therefor it is a highly scientific opinion, because anyone might think otherwise. For example, global warming, many believe that it is cause by increased carbon dioxide levels in the atmosphere. It is fact that carbon dioxide levels have risen and it is also fact that the earth is warmer than it really is. Regardless of the theory, it remains unproven and only a matter of opinion on what exactly is warming the earth. Sorry to go off topic, but I believe you are wrong. Which is my opinion :)

-Phil
You tell only a part of the story,
its a common mistake to believe a scientific theory to be ONLY a matter of opinion:

Theories can only be disproven, but we try honestly to disprove theories
and prefer to use a well tested non-disproved-theory instead of a disproved or untested one!
dpa
#152
Mar12-12, 06:46 AM
P: 149
I will break the discussion here and ask sth new.
1.Suppose there is emptiness, not even vaccum. So no vaccum energy and so forth.
Is there time?.
2. Out of nowhere suddenly a matter pops up.
Does it change or remain till eternity? Now, is there time?

Can this be answered?

And completely unrelated.

3. And, further than that, Do we even know what causes time/change to ask why its arrow is forward?

why it is in forward direction.
sigurdW
#153
Mar12-12, 11:09 AM
P: 27
I will speculate: Because they are definable in terms of each other.
Lensman
#154
Mar12-12, 10:09 PM
P: 17
My humble opinion is that time was invented by us so our farmers knew when it was safe to plant crops without danger of frost. Calendars and so forth.
If we had not invented time then how could we have measured the speed of light?(I'm trying to inject some humor here, folks. Don't take me too seriously.)
C. Bernard
#155
Mar17-12, 09:25 PM
P: 17
Don't we use sound to measure sound, light to measure light, distance to measure distances and motion to measure motions? But time? We use motion to measure time,such as one rotation of the earth, we call a day, one day divided by 24 we call an hour etc...
Without movement time ceased to exist as it were.
An universe without movement is possible as long as it "jump" from one state to the other. In such an universe would time exist?
It seems matter is not so much needed as motion is for time to be detectable by a human or a machine and so have an existence.
Chalnoth
#156
Mar17-12, 11:55 PM
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Quote Quote by C. Bernard View Post
Don't we use sound to measure sound, light to measure light, distance to measure distances and motion to measure motions?
No. Why would you think this?
phinds
#157
Mar18-12, 12:27 AM
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Quote Quote by C. Bernard View Post
It seems matter is not so much needed as motion is for time to be detectable by a human or a machine and so have an existence.
And what motion do you think is possible without matter? Motion of WHAT?
Mark M
#158
Mar18-12, 09:01 AM
P: 526
Quote Quote by dpa View Post
I will break the discussion here and ask sth new.
1.Suppose there is emptiness, not even vaccum. So no vaccum energy and so forth.
Is there time?.
2. Out of nowhere suddenly a matter pops up.
Does it change or remain till eternity? Now, is there time?

Can this be answered?

And completely unrelated.

3. And, further than that, Do we even know what causes time/change to ask why its arrow is forward?

why it is in forward direction.
1. If you define time as thermal evolution, then technically no, there would be nothing to base it on. But, it is impossible to find an area of spacetime that is completely empty, as the uncertainty principle says there always must be some energy, even if it is just a very small amount. So such a situation would never occur.

2. Like I said, there can never be a total vacuum, so that doesn't need to be addressed it simply can't happen.

3. Yes, it appears that time seems to flow "forward" because of entropy. Entropy is the measure of how discorded a particular system is, for example, gas has a far higher entropy than a solid, it's molecules are very jumbled up. The second law of thermodynamics states that entropy will always increase overall. So, if you leave an ice cube out, it will eventually melt into water, then gas, it's more disordered states. So seeing something like a glass coming together, or vapor condensing into an ice cube, doesn't happen because that would be a reduction of entropy.

But, it's possible for entropy to decrease in small flukes, as long as it is compensated for by something else's entropy increasing by a larger amount (such as energy consumption by humans. Your body stores things into more ordered states, but in the process releases energy, so the overall entropy still increases.). So you could see something like an un-shattering glass, but the odds are so low, you probably wouldn't see anything like that if you kept tabs on the universe since the big bang.
C. Bernard
#159
Mar19-12, 08:14 PM
P: 17
To Chalnoth: i was refering to the fact that we use intrinsic properties of things to measure them.
For exemple a meter to measure distance. It seems time has no intrinsic properties which can be used to either measure it or qualify it.


To Phinds: yes you are rigth,matter is needed for motion, but i think motion is needed to even have the idea of time,(which may or may not exist).
DaveC426913
#160
Mar19-12, 08:42 PM
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Quote Quote by C. Bernard View Post

To Phinds: yes you are rigth,matter is needed for motion, but i think motion is needed to even have the idea of time,(which may or may not exist).
I beg to differ.

Matter did not even condense out of energy until between 3 and 20 minutes after T=0. There was both time and movement - and plenty of both - prior to that.
Chalnoth
#161
Mar20-12, 08:09 PM
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Quote Quote by C. Bernard View Post
To Chalnoth: i was refering to the fact that we use intrinsic properties of things to measure them.
For exemple a meter to measure distance. It seems time has no intrinsic properties which can be used to either measure it or qualify it.
Huh? There is nothing intrinsic about a meter. A meter is simply a convenient standard with which we can compare measurements. In fact, the meter is defined today in terms of time.

A second is defined as the amount of time passed to count some number of oscillations of a particular atomic clock. The speed of light is then defined as being a specific ratio of meters to seconds. The meter is defined in terms of the two.

So, for example, when we build an experiment to measure how fast light beams propagate, we are really measuring our convention for the meter.
enosis_
#162
Dec15-13, 11:53 AM
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P: 120
Quote Quote by phinds View Post
I have read in serveral posts here that the concept of time in a total void is meaningless. That is, many scadzillions of years from now, assuming the expansion continues and black holes evaporate, and all goes REALLY dark (yes, I'm talking about a LONG time), the concept is that time loses its meaning because there's no way to measure it.

This really is perhaps one of those silly semantic arguments that I usually do not care for but this one is bugging me for some reason.

I GET completely the fact that you can't MEASURE time without matter but the concept that time just stops passing doesn't make sense to me. It is a somewhat pointless distinction, since even if time goes on, nothing HAPPENS. It's just the concept that "time stops" that bothers me and that SEEMS to be what I'm hearing from some of the threads here.

I'd appreciate any comments anyone has on this? Do you think time doesn't exist if you can't measure it because there's nothing to make clocks out of (and even no subatomic interactions to measure your ticks by) ?

Thanks,

Paul

By the way, I put this in cosmology since I can't think where ELSE to put it ... if a mod wants to move it, fine by me.

Can we step back and look at the big picture for a moment?


First, to expand on what Chronos posted #104
"Time and space are thought to be a consequence of gravity. Theoretically, without gravity, there would be no time or space -
re: http://www.astronomycafe.net/gravity/gravity.html

"Perhaps the most unusual thing about gravity we know about is that, unlike the other forces of nature, gravity is intimately related to space and time. In fact, space and time are viewed by physicists, and the mathematics of relativity theory, as qualities of the gravitational field of the cosmos that have no independent existence. Gravity does not exist like the frosting on a cake, embedded in some larger arena of space and time. Instead, the 'frosting' is everything, and matter is embedded and intimately and indivisibly connected to it. If you could turn off gravity, it is mathematically predicted that space and time would also vanish!""




IF the universe ever stops expanding - THEN shouldn't gravity begin to re-gather all of the lifeless mass into a single point again?

Accordingly - wouldn't time continue to correspond to events?


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