| From: Shadow | 20/09/2001
14:52:12 |
| Subject: Time | post id:
421005 |
| I know that this the broadest
question ever but.. How does time work? | |
| From: Paul | 20/09/2001
14:59:35 |
| Subject: re: Time | post id:
421029 |
| It doesn't work, it just is. We
have arbitrarily assigned it certain values, but it existed long before we
did so. cheers, Paul | |
| From: Shadow | 20/09/2001
15:07:17 |
| Subject: re: Time | post id:
421049 |
| Ok then, how does it move? Why
does time move at one second per second? Why is it the way it is? Is it
possible to change it? I heard somewhere that time has bumps on the
quantum level )Or something like that) | |
| From: Grant¹ (Avatar) | 20/09/2001
15:08:51 |
| Subject: re: Time | post id:
421053 |
? I didn't know time moved. | |
| From: Chris (Avatar) | 20/09/2001
15:16:30 |
| Subject: re: Time | post id:
421075 |
Wow. Good questions. The easy one is the second one. Time may or may not be bumpy at the quantum level. Basically the thinking goes like this: We've got a quantum theory of electric fields, which says electric fields at the quantum level are little bumps called photons. We've got quantum theories for the other fundamental interactions (strong and weak nuclear forces). We're trying to come up with a quantum theory for gravity. Now at present gravity is described in terms of space-time (general relativity), so some people suggest that a quantum theory of gravity would mean that at the quantum level gravity is little bumps of space-time. We say that time is quantised. However, as one regular here is fond of insisting, the jury is still out on this one. We don't yet know for sure if time is quantised. On the other question, I think the answer will not come from physics. Physics treats time as a static coordinate or an axis on a manifold. Yet we seem to experience this notion of time passing. Hawking suggests this is the manifestation of an "arrow of time", something which definitively distinguishes past from future. My personal opinion is that our feeling of time passing is tied to the way we organise our memories: taking in data in the present, analysing, time-stamping and storing chronologically. This gives us the impression of events in space-time moving from future (unresolved) to present (observed) to past (stored in memory). An equivalent perception is that we are moving from past to future. Hope this helps! Chris | |
| From: Paul | 20/09/2001
15:17:03 |
| Subject: re: Time | post id:
421077 |
| Time is not a physical thing, it
is abstract. We like to be able to define it so we have devised a means of
measuring it that has one second intervals. cheers, Paul | |
| From: Fatso the Forester | 20/09/2001
15:18:30 |
| Subject: re: Time | post id:
421082 |
| Time only appears because we
choose to assign values to is for measurement purposes. A second is only a
second because we call it a second. As far as bumps and stuff,
? | |
| From: OP (Avatar) | 20/09/2001
15:21:15 |
| Subject: re: Time | post id:
421088 |
| Time only appears because we
choose to assign values to is for measurement purposes. A second is only a
second because we call it a second. As far as bumps and stuff, ? So why can't I have a conversation with my great-grandfather? | |
| From: Fatso the Forester | 20/09/2001
15:23:22 |
| Subject: re: Time | post id:
421093 |
| appears to move(sorry) not
exist. | |
| From: Shadow | 20/09/2001
15:24:39 |
| Subject: re: Time | post id:
421098 |
| Time only appears because we
choose to assign values to is for measurement purposes. So if we didn't have values for it, it would not exisit? :-) | |
| From: Chris (Avatar) | 20/09/2001
15:24:41 |
| Subject: re: Time | post id:
421099 |
Be careful to distinguish between our measurement of time in units (which is arbitrary or abstract) and time itself (which is not). The second is a conveniently defined unit of time for the purposes of measurement. Time itself is a real part of the universe, embodied in relativity. The scale at which time is expected to become discontinuous (if it is quantised) is called the Planck scale, and it is defined independently of the second. However it can be converted into seconds, giving about 10-43seconds. | |
| From: Shadow | 20/09/2001
15:25:00 |
| Subject: re: Time | post id:
421100 |
| Time only appears because we
choose to assign values to is for measurement purposes. So if we didn't have values for it, it would not exisit? :-) | |
| From: Fatso the Forester | 20/09/2001
15:30:35 |
| Subject: re: Time | post id:
421106 |
| Mind you, you could argue the
philosophical question is we don't have a measurement for it does it
really exist, but I think we should leave that to the arts
students | |
| From: B.C. ® | 20/09/2001
15:44:13 |
| Subject: re: Time | post id:
421142 |
| Time only
appears because we choose to assign values to is for measurement purposes.
So if we didn't have values for it, it would not exisit? :-) Time is that which separates events....if there was no time everything would happen together. Time came into existence at the moment of the BB and developed as space expanded. Hawking alluded to three arrows of time...the phycological arrow, this is the direction in which we remember the past but not the future...the thermodynamic arrow, this is the direction in which we see disorder or entropy increase,and finally the cosmological arrow, this is the direction the universe is expanding rather then contracting. Time also passes at a rate that depends on the geometry of the space in that vicinity, or in other words depending on the gravitational well we are measuring it in.Hence it's association with space in what we call the space/time continuum. | |
| From: B.C. ® | 20/09/2001
15:51:25 |
| Subject: re: Time | post id:
421164 |
| ... time is an
illusion. The phenomena from which we deduce its existence are real, but we interpret them wrongly..." I think Einstein said, "Time is an illusion, albeit a stubborn one" Not real sure of the context in which it was said, but have a sneaking suspicion it was a fecetious statement in reply to the above quote Newton said that time was like an arrow shot from a bow, flying straight and true......Einstein said that time was more like a flowing river,creating eddies and whirlpools and speeding up and slowing down | |
| From: Chris (Avatar) | 20/09/2001
15:53:50 |
| Subject: re: Time | post id:
421172 |
In fact, everything you said may be completely wrong. Only time will tell... Yes, that is a possibility. Exciting, yes? :o) I looked at the Balfour link. I don't have his book, so can't read it. I'm interested in his description of his paper "relativity without relativity" which is online, however I fear you may not be interested in my dissection of it. I couldn't see which bits relate to his conclusion that time is only an illusion. | |
| From: tritium ® | 20/09/2001
16:01:03 |
| Subject: re: Time | post id:
421191 |
| I'll add my 2c to this
conversation as well :) Relativity works on a model that treats time in a similar fashion to the spacial dimensions and it is possible to do a rotation where some of the time becomes distance and some of the distance becomes time. Basically it works in 4 pretty much identical dimensions. However this is just a model which gives predictions as to what should be observed. Although this model has been quite successful in predicting what should be observed, there is no guarantee that the mathematical treatment of the time dimension truelly represents how time behaves. One thing is for sure, the model has deficiencies. It has no way of explaining the concept of the present moment, nor a preference in one particular time direction. Whether or not such a concept is just an illusion, or whether it's real is also unknown. However there is definatelly something special about one direction of time (entropy can only increase in one direction and only decrease in the other direction). This doesn't mean relativity is crap and shouldn't be used, it just means that it can't really be used to explain this particular phenomenon. | |
| From: Fatso the Forester | 20/09/2001
16:16:27 |
| Subject: re: Time | post id:
421224 |
| ... time is an illusion. The phenomena from which we deduce its existence are real, but we interpret them wrongly..." I think Einstein said, "Time is an illusion, albeit a stubborn one" Not real sure of the context in which it was said, but have a sneaking suspicion it was a fecetious statement in reply to the above quote Newton said that time was like an arrow shot from a bow, flying straight and true......Einstein said that time was more like a flowing river,creating eddies and whirlpools and speeding up and slowing down Adams said that time is an illusion, lunchtime doubly so, and that eddie was in the time spack continuum | |
| From: spOOk ® | 20/09/2001
16:16:53 |
| Subject: re: Time | post id:
421225 |
| If we took a measurement of
entropy, could we create a general theory of relativity using the concept
of space-entropy, rather then space-time? | |
| From: James R (Avatar) | 20/09/2001
16:47:28 |
| Subject: re: Time | post id:
421275 |
| Why is he
wrong that time is literally an illusion? And doesn't
exist? He's not necessarily wrong. But why single out time? Perhaps everything is an illusion? This is, of course, a philosophical discussion rather than a scientific one. JR | |