Time

[sithlordaj]

ok, I've been reading alot of books on string theory and loop quantum gravity (not technical. I couldn't even begin to comprehend that deep of math).<br /><br />Anyhow so I got to thinking about time. Einstein said that time is a dimension just like space. up until a while ago, i completely agreed.<br /><br />i was thinking; what is time? if you were able to take every particle in a particular region of space and cause all information between them to stop being exchanged (for this to work the way i propose, information from a particle would not be available to itself either, stoping it from degrading), would time really still be passing for anything within that region of space (note that everything outside this region can function normally)?<br />i dont think it does. I think time itself is the act of information being exchanged between matter. so, gravity would actually just distort the way information is exchanged. it seems to me that time is a product of particle interaction than the geometry of space.<br /><br />but maybe im missing something. what do you all think?<br />if im wrong, is there a better definition of time?

 

[draklorza]

Inter-Dimensional Relation Theory 101:<br />"the concept of a dimension depends on a particle's orientation to a select dimension."<br />"Nothing has a point of origin."<br />"When a dimension is taken away, another will strive to exert it's self."(such as a 2d spider web will be 3d in space.)<br />you define time very well. <img src="/images/icons/smile.gif" /><br />I've been looking for you. <img src="/images/icons/wink.gif" />

 

[alpha_taur1]

Some questions: <br /><br />1. At what stage in the formation of the universe did time become a meaningful concept that could be measured ?<br /><br />I realise that this will depend somewhat on the size of the Hubble constant.<br /><br />2. Question deleted.<br /><br />3. Did time become a meaningful concept suddenly, or gradually? If gradually, is the nature of time still changing at some indeterminate rate? Is there evidence other that the rates of certain atomic processes? <br /><br />4. If the opposite ends of the observable universe are receding from each other, what is the inference for the relative rate of time for each location, and the total time elapsed from the Big Bang from each location? <br /><br />5. Is it possible that time and atomic events are both changing constantly in such a way that the passage of time appears to remain constant from a particular viewframe?<br /><br />I don't have any religious wagon to push. I'm just curious how an Astronomer would answer these questions nowadays.

 

[newtonian]

Alpha_Tauri - Hi!<br /><br />How do you define time?<br /><br />My personal definition:<br /><br />The medium through which cause and effect flow.<br /><br />There are also different types of time, to wit:<br /><br />1. Our universe specific space-time.<br /><br />2. Other universes' space time.<br /><br />3. Primordial time.<br /><br />Your question assumes only one type of time. You seem also to assume time began at the origin of our universe.<br /><br />Our universe specific space-time did begin at the origin of our universe. That is partly because our universes' space began at the origin of our universe - space not being entrrely empty but containing potential energy, including apparently dark energy, aka vacuum energy.<br />However, our universe had a cause in harmony with the scientific principle of cause and effect.<br /><br />Cause and effect cannot proceed without time.<br /><br />Therefore, primordial time had to already exist before our universes' space-time was created by cause and effect.<br /><br />Your question obviously involves the question of whether there was a first cause, or First Cause.<br /><br />And whether primordial time always existed or was created by the first cause.<br /><br />Or, alternately, whether there are an infinite number of causes and effects going back an infinite amount of time - which is possible only if some form of primordial time always existed, of course.<br />On the question of whether other universes exist, it is interesting that you brought up religion in your opening post.<br /><br />In fact, the Bible may allude to such other universes in the following text, which you may choose to consider academically rather than religiously:<br /><br />(1 Kings 8:27) "27 "But will God truly dwell upon the earth? Look! The heavens, yes, the heaven of the heavens, themselves cannot contain you; how much less, then, this house that I have built!"<br /><br />Now, as you are well aware, ancient texts can be interpreted more than one way - but I have pointed out to

 

[yevaud]

Great questions, AT.<br /><br />Well, as Newtonian says, time had to be a factor right from the instant it all began. Causality has no meaning if not. Effect must follow cause.<br /><br />Curious question, that of "did time become a meaningful concept..." All we know for certain is that time as we understand it exists right to the Planck time (10^-43 seconds) after the "Big Bang" (or whatever event this truly was). Prior to that we will likely never know, but my gut feeling is to say refer back to my first answer.<br /><br />There's a Physics joke about this, which really isn't a joke: "time is nature's way of making sure that everything doesn't happen all at once."<br /><br />AS far as the relative rate of time at, say, opposite ends of the universe is the law of "Commonality." It's an accepted given that the laws of physics are the same here as they would be at the opposite side of the universe from you. To believe otherwise would be fruitless, and the universe as we see it would not be what we see, if they were different.<br /><br />Hmmm. Time and atomic events changing such that we wouldn't know. Hmmm...<br /><br />I suppose my answer to that is if you're within a frame of reference, without some outside point to refer to, you'd never know. How would we? That's a tough question.<br /><br />Going to think on this for a while... <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[newtonian]

On #4 - Some astronomers postulate that distant portions of our universe are expanding faster than light (FTL) from us. <br /><br />That has important implications, including the fact that we cannot observe by speed of light methods how time is effected. It would be beyond our light cone, our visibility horizon.<br /><br />One could assume the theory of relativity holds in such a scenario, as Newton probably did for his laws of motion at near speed of light speeds.<br /><br />Time stopping or going backwards - that is probably simply an optical illusion. <br /><br />And an assumption. Observation is far superior.<br /><br />Of course, if dark energy travels faster than light, which it apparently does, and we can construct dark energy telescopes analogous to the various electromagnetic telescopes (using visible light, infra-red, radio, x- ray, gamma-ray), then we may be able to observe these more distant portions of our universe.<br /><br />However, you probably realize that time is relative to reference point - that is, space-time is so relative.<br /><br />Primordial time would, on the other hand, be independent of reference points in our universe since it operates outside of and before our universe.<br /><br />The question is, can we isolate time from our universe specific space-time, perhaps by some interaction with other universes or dimensions, and then match it somehow to primordial time and then observe?

 

[emperor_of_localgroup]

Great question. Another mystery of nature is time. Here is my 2 cents about time. From my younger days I always found there is relation between time and change, any form of change, for example displacements or temperature, etc. Without time there cannot be any change and without change time is meaningless or non-existent. A timesless situation is possible when there's no change, which is unthinkable. Many of you may have already noticed everything, big or small, in this universe is undergoing a constant change internally or externally. I wish i'm a mathematician to put a mathematical dress on my observation. <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[yevaud]

That's "Subjective" versus "Objective" time. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[emperor_of_localgroup]

No, i dont think so. If so, then this is probably one of the few places where subjective and objective views coalesce. <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[yevaud]

Hmm. If I misinterpreted what you were saying, sorry. It sounded like you were describing how different situations a person can be in gives them the subjective experience of different rates of time. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[emperor_of_localgroup]

I really don't feel comfortable when an 'adjective' is used to define any scientific terms such as Time. I'm not quite sure from where the terms Subjective time and objective time came. Must have come from some philosophers. The time we are debating about must be objective. I just wanted to see or read some new ideas about time, we are somewhat aware of the old views of time. I recently heard of a guy from New Zealand, forgot his name, who claims there is no time. I never heard of him again. <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[dragon04]

Wow. Time is complicated. When you really start to think about it.<br /><br />Is there such a thing as "absolute" time?<br /><br />The age of the universe is relative to our 24 hour day. But on a world that rotates twice as fast, or twice as slowly, the age of the universe is very different, relative to them.<br /><br />The same goes for distance. A "light year" would be a very different figure to a Saturnian.<br /><br />Does time behave like both a particle and wave?<br /><br />I think I'll go have a chat with Shroedinger's Cat.<br /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[yevaud]

Enjoy!<br /><br />But don't bother talking to Schroedinger's dog...he'll just &%$#@! about how the cat's getting all of the attention. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[alpha_taur1]

"....time had to be a factor right from the instant it all began. Causality has no meaning if not."<br /><br />Time had to exist for causality to exist, but the question is related to the passage of time during the period of inflation. There was a stage where the laws of physics did not apply, and we think that there was a rapid inflationary period. At some stage matter condensed. <br /><br />Correct me if I'm wrong, but my understanding is that the nature of gravitation also changed during this period, from plasma gravitation through condensation gravitation through the evaporative gravitation which exists today.<br /><br />We know that space and time are inextricably linked, yet we assume that time remained constant during the inflation. Did the rate of time itself change during this period? <br /><br />The rate of time passage would not affect causality. <br /><br /><br />Newtonian - I'll try to decipher your post at some stage. No offense, but the use of Bible references makes it difficult to read. Perhaps you're right, since this is getting into the realm of metaphysics.

 

[yevaud]

Yeah. I wasn't referring to the rate of time, but whether or not it existed - was it a valid concept before the Planck time.<br /><br />Which is why I referred to cause and effect.<br /><br />As far as the laws of physics applying, hmmm. Well, <b>something</b> applied at those kind of energies, and it's hard to see how things could have progressed without some analogy of time present. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[igorsboss]

The SI definition of the second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom at zero kelvins.<br /><br />(from http://encyclopedia.laborlawtalk.com/Second)<br /><br />I take my conceptual understanding of Time from this definition. Although I'm not precicely sure what causes the transition between the two hyperfine levels mentioned above, it seems to me that the transitions correspond to something akin to a vibration of the atom. Maybe it is the electron orbiting the atom, or maybe it is something else. Vibrations are things we can count.<br /><br />Consider then, that all particles or waves which are affected by time must have some kind of teeny tiny pendulum attached to it. A pendulum, in this sense, is any regularly repeating event which can be counted.<br /><br />Also, every one of these teeny tiny pendulums acts locally, according to relativity. Each takes its own path.<br /><br />Time, then, is simply a count of pendulum swings.<br /><br />So, particles in a "fast time" frame of reference undergo more vibration cycles than (otherwise identical) particles in a "slow time" frame of reference. Relativity says that relative motion affects the relative count of pendulum swings.<br /><br />There is no time travel to the past because there are no negative pendulum swings. The count increases monotonically.<br /><br />There is no absolute time because no pendulum is special.<br /><br />Time began when the first repeating event began to happen for the first time.

 

[yevaud]

Which raises the question.<br /><br />Since at Planck energies, all forces were the same thing - symmetry breaking hadn't occurred yet - what, was "time?" What sort of transitional states were occurring.<br /><br />This is an intellectual "dry heave," of course, because there's no real way to know. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[igorsboss]

Working from the "Time is a count of pendulum swings" model, I think I can answer the questions.<br /><br /><font color="yellow">1. At what stage in the formation of the universe did time become a meaningful concept that could be measured ? </font><br /><br />The instant the first regularly repeating event repeated. This would be very very early.<br /><br /><font color="yellow">3. Did time become a meaningful concept suddenly, or gradually? If gradually, is the nature of time still changing at some indeterminate rate? Is there evidence other that the rates of certain atomic processes? </font><br /><br />The concept of a count happens instantly.<br /><br />The progress of the various individual counts change according to relativity.<br /><br />Since counts of repeated atomic processes define time, the evidence will come in the form of statistical analysis of the progress of the various counts. You may measure and compare the counts at your whim.<br /><br /><font color="yellow">4. If the opposite ends of the observable universe are receding from each other, what is the inference for the relative rate of time for each location, and the total time elapsed from the Big Bang from each location? </font><br /><br />Since each teeny part of the universe evolved differently than everywhere else, the inference is that the counts are almost certainly different. Relativity gives a very accurate prediction of how they differ.<br /><br /><font color="yellow">5. Is it possible that time and atomic events are both changing constantly in such a way that the passage of time appears to remain constant from a particular viewframe? </font><br /><br />Yes!<br /><br />For example, the entire universe could come to a complete halt, such that no countable vibration happens anywere, and then restart, and we would not be able to tell that anything happened at all. (!)<br /><br />This implies that an omnipotent and omnicient supreme being could operate on our universe at

 

[alpha_taur1]

I like the analogy of the debugging kernel <img src="/images/icons/smile.gif" />

 

[blueman]

Does gravity stop at -273.15 K? No particles can move, including the graviton, right?

 

[vogon13]

Particles with mass. Photons and gravitons are massless. Additionally, a photon 'automatically' has a temperature per its wavelength. Now, would a photon with zero energy and and an infinite wavelength move? Hard to prove one way or the other in this universe. Not even sure it would exist, 0=0 after all. Not sure how the energy of a graviton is manifested. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[igorsboss]

If photons with zero energy could exist, wouldn't each reaction be able to produce an infinite number of them? Hard to imagine this could work out.

 

[vogon13]

I just speculated such photons couldn't exist. I think you just <i><b>proved</b></i> they can't exist. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[Saiph]

actually, they still can exist.<br /><br />Why? Cause infinite wavelength = 0 energy. And so you can make as many as you'd like.<br /><br />You just can't:<br /><br />A) use any energy from them<br />B) Tell if they move<br />C) Detect them (no energy, no "size" due to being so big)<br /><br />So if they do exist, it doesn't matter. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[vogon13]

Would they be forbidden because of that conservation of information thing that I still don't understand and that has Hawking all worked up (so to speak) about black holes now?<br /><br />This is rapidly going weird on me? What kind of process would yield such particles?<br /><br />Wait!<br /><br />Zero is a precise number! Heisenberg Uncertainty will zorch it! Wavelength is infinite, they ain't here in our universe at all, they are beyond and unbound and forever lost to the infinite infinities of infinitude!<br /><br />Glad I got that out of my system.<br /><br /><img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>