Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: mxplxxx on 21/10/2016 06:11:10
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Relativity states that matter moving at different speeds ages at different rates. Given this fact, why is the universe so ordered?
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Because the laws of physics are the same in inertial frames? Also because these time differences are relative and far from being chaotic are highly predictable.
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Why is the universe not chaotic because of time differences?
Because we are not yet trying to run an intergalactic train network.
When trains were first introduced in England, each town kept its own time, by its own town clock.
- You could have a train arriving at one station before it left the previous station! You could call this somewhat chaotic...
- This made it hard to print train timetables, because you needed a different timetable for each town.
- This led to a system of standard timezones, with a common time reference in the whole UK, for example.
We have subsequently introduced air travel, where different airports need to be in different standard timezones.
- A number of times I have taken a flight where I arrived several hours before I left. It sure saves time getting through customs!
- While it is somewhat disorienting to our body clock, we generally cope
- apart from the ocasional telephone call in the middle of the night from a contact who doesn't know that you are on the other side of the world
- Our smartphones are able to automatically change to the new timezone
- The world hasn't yet descended into chaos
If and when we introduce an intergalactic train service, I expect that it will be even more challenging to our body clocks and social networks, but our even-smarter phones will cope just fine, just like GPS copes today.
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Why is the universe not chaotic because of time differences?
Because we are not yet trying to run an intergalactic train network.
When trains were first introduced in England, each town kept its own time, by its own town clock.
- You could have a train arriving at one station before it left the previous station! You could call this somewhat chaotic...
- This made it hard to print train timetables, because you needed a different timetable for each town.
- This led to a system of standard timezones, with a common time reference in the whole UK, for example.
We have subsequently introduced air travel, where different airports need to be in different standard timezones.
- A number of times I have taken a flight where I arrived several hours before I left. It sure saves time getting through customs!
- While it is somewhat disorienting to our body clock, we generally cope
- apart from the ocasional telephone call in the middle of the night from a contact who doesn't know that you are on the other side of the world
- Our smartphones are able to automatically change to the new timezone
- The world hasn't yet descended into chaos
If and when we introduce an intergalactic train service, I expect that it will be even more challenging to our body clocks and social networks, but our even-smarter phones will cope just fine, just like GPS copes today.
Thx. Intelligence has allowed us to adjust to the different timezones. Are you suggesting that the Universe is intelligent (something I believe in and can propose reasons for but not here:))?
I see the universe behaving similarly to a finite-state machine which doesn't need time to function. Then there is the quantum of action with its constant value (Planck's constant) which may act to smooth out time differences.
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We have subsequently introduced air travel, where different airports need to be in different standard timezones.
NO they don't. For some reason civilians seem to think that they need to wake up at 0700 so they invent time zones so that it's light at 0700, and then muck about withthe zones so it gets light at 0600 in summer except in Arizona, some parts of Australia, and Spain which is mostly west of London but adopts European summer time so it's still dark at 0700. And of course it's nonsense in Norway Canada and New Zealand - in fact in every civilised country - where daylight begins at 0300 in summer and never in winter.
So scientists, aviators, mariners, military units, polar explorers and space travellers, use UTC, Greenwich or Zulu time, always and everywhere. Right now it's 01:45 Z everywhere in the universe except where you are.
And who said the universe was not chaotic? The observable universe consists of stuff a few light-nanseconds away right up to stuff that happened a zillion years ago, and we have absolutely no idea of where everything is right now and what it is going to do next.
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And who said the universe was not chaotic?
And who said it was?:)
Particles, molecules, planets, stars, solar systems, galaxies, galactic clusters all seem ridiculously ordered considering they started in a big-bang. It is a well-known fact in physics that the entropy of the universe is decreasing resulting in increasing order/complexity. Hence we appear! Unfortunately this won't always be the case and we are doomed some time in the distant unless we can arrest the increase in entropy.
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That all depends upon the granularity of the observations. On cosmic scales it may appear as though the universe is becoming more ordered. While on a microscopic scale entropy increase appears to win out. How you observe things always has a bearing on the results you obtain.
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Why is the universe not chaotic?
The universe is chaotic (in the mathematical sense).
Even the Solar System is chaotic, as it is an example of the "n-body problem".
- In practice, this means that on long timescales (200 million years), planets could collide, fall into the Sun or get ejected from the Solar System.
- It could happen a lot sooner if there are outside influences (eg a star passing close to the Solar System, as they all bob up and down in their various elliptical orbits around the galaxy).
The galaxy and clusters of galaxies are also chaotic n-body systems.
See: https://en.wikipedia.org/wiki/Stability_of_the_Solar_System
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Where ever you are in the universe, the universe is basically stationary just as we are. A far off planet may look to us to be moving at close to the speed of light C due to the expansion of the universe. However it is moving as slow as we are.
As I see it, the particular gravitational fields equilizes the clock and ruler relative to where they are. If you look for contributions from all other fields, they are reduced by the distance squared. We are basically concerned with the Earths field and the suns field and nearby planets. The galaxy field centered at the center of the galaxy is relatively small and all the other galaxies count for nothing.
The differences in clocks primarily show up at the atomic levels but as photons and particles travel toward us they encounter conditional relativity. Thus the light from a far star changes color as it leaves its star and then as it travels through its galaxy. By the time it reaches our galaxy it is very red. Then it passes to our sun and finally the Earth. All the while it changes color. Relativity thus has many steps depending upon how many gravitational fields it encompasses.
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Because the laws of physics are the same in inertial frames?
Beautifully expressed. The laws are the same 'everywhere'. If they weren't we would all be in for a 'magic universe' of sorts, one where you suddenly might find yourself becoming a 'singularity' to the ones left behind, not obeying the laws of physics as we know them. We built our understanding of the universe on it.
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As you know, I stand for the idea of 'locality'. Local definitions, observer dependent. In such a universe it doesn't matter how 'infinite' one think it to be. In fact it's much smaller than one might expect, as it rests on locality. That's also why QM and the rest of the physics 'shrinking' this universe, scaling it down, gets my vote. That is what locality is about physically, some few ground rules. The rest of it, 'time dilations' and Lorentz/Fitzgerald contractions are to me between 'frames of reference'. That's another very difficult thing to decide, what is a 'frame of reference' when you start to think that way? NIST has clocks showing you time dilations at elevations of centimeters, is that a physical proof of different 'frames of reference? How about you, as you stand up?
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And looking at it this way, those few groundrules has to be the same, everywhere, for this universe to communicate.
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Can add one thing. I would expect time dilations and Lorentz/Fitzgerald contractions to end where we can't measure anymore, presuming 'perfect instruments'.
Theoretically that is at Planck scale to me.
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All time references can coordinate with each other, because they all use the same ground state. As an analogy, all the water on the surface and atmosphere of the earth use sea level as the ground state. If possible, water, any place on earth, will continue to flow until it reaches sea level. All rivers and streams act on their own, while nevertheless heading toward sea level.
In the case of time references, the ground state is the speed of light, which is the same in all references. At the speed of light time slows to zero, thereby making the speed of light the reference of lowest time potential; C-level.
If you look at larger atoms, like gold, the electrons move at relativistic speed, while the nucleus is more or less stationary. This area of science is called relativistic quantum chemistry. Such atoms occupy two time references, which coordinate by both references coordinating to the ground state, creating Heisenberg uncertainty.
Heisenberg uncertainty can be explained with an analogy found in photography called motion blur. Motion blur occurs when the speed of the action is faster than the shutter speed. In the case of the atom, the nucleus is analogous to the camera and the election is the action speed. Since a still picture stops time, the difference in speed; d/t, is conserved in the photo and expressed as uncertainty in position; blur.
In the picture below, we can determine the position of the cyclist, but we can't tell his momentum. On the other hand, we can sense the momentum of the background, but we can't determine its position due to uncertainty in position; time to distance conversion. The still photo of the motion blur analogy is created by our quantum universe. Our quantum universe steps between states, in zero time. Our quantum universe sort of creates an on-off affect in time, which allows time and distance to merge as space-time; time and motion blur.
(https://www.smashingmagazine.com/images/motion-blur/biker.jpg)
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If you tell me the time of exposure and the mass of the bike and the man, I can tell you the momentum... (nice analogy by the way puppy)
What is an inertial frame and why all electrons have the same properties? Something is missing in the GR-SR picture...
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If you tell me the time of exposure and the mass of the bike and the man, I can tell you the momentum... (nice analogy by the way puppy)
What is an inertial frame and why all electrons have the same properties? Something is missing in the GR-SR picture...
I agree that the time of exposure is critical in the photo of the cyclist.
In the photo, the cyclist looks sharp, and the background blurred. But isn't this only because the photo was taken with a relatively long exposure-time, perhaps 1/500th sec?
Suppose the exposure-time had been much shorter, say, 1/500,000th sec. Then wouldn't both the cyclist, and the background, look equally sharp.
Would that prove anything.
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I have to differ with some ideas.
#op. Time doesn't cause anything and therefore doesn't affect the behavior of the universe.
#1,#9. If the physical laws varied between frames, that would imply an incomplete knowledge of them, that they are more complex than originally thought. One universe, one set of laws.
#2: Coordination of activities, clock synchronization, etc. results from human thinking. The universe works without it.
#3. A computer shows evidence of intelligent design, but it has no intelligence.
#4. A universal time would require a constant simultaneous clock synchronization. The last sentence of the post explains why it can't be done.
#5,#6. For a continuous decrease of order, a few things would have to be eliminated like:
star and galaxy formation by gravity, formation of elements in stars, plant growth from seeds, life forms from DNA.
#10. The earth is a rotating gravitational mass. Within the context of SR consider it a composite frame of reference.
#13. Position and momentum can't be measured simultaneously, Position requires one measurement of t and x. Momentum requires two measurements of t and x.
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phyti, what are those #1-#13 referring to? As for time not causing anything, that seems a deeply philosophical question. Either 'time' is what allow 'change' to exist, or 'change' is 'time' to us. As if time on one side would be stream we're immersed in, on the other as if 'time' would be a artifact created out of 'change'. The last one will demand one to explain 'change' though, and doing so one might find oneself instead becoming immersed in 'change'
A variant of a snake biting its tail when one gets to that point :)
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And 'puppypower', what do you mean by 'Our quantum universe sort of creates an on-off affect in time, which allows time and distance to merge as space-time; time and motion blur.'?
you lose me there
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I think the answer is simple: Because it JUST ISN'T.
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I think the answer is simple: Because it JUST ISN'T.
That's a dramatic way of cutting the Gordian Knot! It appeals by its simplicity. But is it fully satisfactory from a scientific viewpoint?
I mean, suppose you were asked "Why isn't the speed of light infinite, instead of 300,000 kps?"
And you said "Because it JUST ISN'T".
Um, actually, thinking about it, you might have a good point..........
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phyti, what are those #1-#13 referring to? As for time not causing anything, that seems a deeply philosophical question. Either 'time' is what allow 'change' to exist, or 'change' is 'time' to us. As if time on one side would be stream we're immersed in, on the other as if 'time' would be a artifact created out of 'change'. The last one will demand one to explain 'change' though, and doing so one might find oneself instead becoming immersed in 'change'
The '#' refers to the post #. It's finding fault with the statements and not with the poster.
If you study the history and application of 'time', it reveals itself as a convenient record keeping system. Since it requires a form of measurement, a standard uniform periodic event is used. The clock (in whatever form) provides this beat. The best practical example I know of is the metronome.
Notice the observer assigns a clock event (time) after detecting an event of interest via an image. For local events there is no significant difference between time of detection and time of occurrence. For astronomical events the time of occurrence is in the past according to distance. The time will vary for different observers. One event, multiple times! Which time, if any, caused the event? See how nonsensical it becomes.
Time is in the mind, just as motion in a movie, or the motion of an image on a computer screen.
SR experiments have demonstrated subjective time, with each observer having their own local clock. Medical research has shown people with memory issues have impaired ability to judge time intervals.
There is also the misinterpretation of space-time drawings as motion in a space dimension and a time dimension when in fact it is a history of speed.
The more opinions I see about time, the more it seems to be a security thing. The continuation of 'time' is synonymous with the continuation of life. People want to cling to the idea of an invisible something behind the scenes making things happen.
In quantum physics, you have probabilities of events. From the decay of X, sometimes you get a+b, or b+b or a+c, but never c+c. Here time has no role, i.e. the process is independent of time, just like flipping a coin. The value of such processes is the enrichment of the world with variety.
The ultimate issue, as usual, is ignorance. No one knows what factors determine the half-life of a particle, or why light speed is c and not c+7. We do, know based on current knowledge, that the factors determining the behavior of the universe were here before the appearance of life forms. Thus the world works in an amazing way without us, and we have to be content with mental models.
There is lots more, but prefer to keep posts short.
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You're not alone taking that stand phyti. It's about 'time' as an illusion, right? Then again, clocks measure it, and measurements makes physics. What I think Einstein saw as a illusion wasn't that time didn't exist, rather that it had no 'global' consistency as Newtons ideas of an 'absolute 'universal' time', unless using Lorentz transformations. If one think of those then 'local time' has a logic that is translatable though. With a pure illusion I don't see this as necessary, it would make ones age a question of magic, instead of ones wristwatch measuring it. It's ('time' as an illusion) a result of ones local 'clock', comparing it relative other frames of reference. But it can't be a illusion unless one also include the clock one compare those other 'frames' with. Doing so we now question all ideas we have of physics existing, or anything being able to be agreed on.
The values and rates one sets for measuring won't matter for 'c' being 'c', it will still be a constant. And you can split 'c' at your leisure, getting to ones local time keeper (a clock).
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I think Phyti's right in suggesting that our human preoccupation with Time is a "security thing". It comes about because we're born, live a pitifully short number of years, 70+ perhaps, then die. And we don't like the idea of that. Or the personal experience of getting older and watching our bodies get wrinkled and worn-out. We fear death.
To us "time" is synonymous with "life".
But suppose we had much longer lives, lasting 700, or 7,000, or 7,000,000 years. Or especially - if we were immortal, and lived as long as the Universe exists - we wouldn't be bothered about Time. We'd just say, Time is one thing happening after another, so what?
Hopefully, we'll soon be able say this, as Science will by 2050, eliminate human death and make us immortal.
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A 'probability' is something that has its base in statistics as I see it. You measure events (and you need that wristwatch for it) finding that different outcomes comes with different probabilities, that becomes its base. From such, assuming a logic, it might be possible to extrapolate probabilities for other situations. When I think of time and probabilities I think of QM, and QM is to me scale dependent.
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So yes, going down in scale time becomes questionable to me too. It might seem a 'artifact' at that scale, but it's no illusion. If it is a constant, then QM shouldn't matter for it though. Why I look at it this way is because I think of constants as 'properties', they are what SpaceTime is presumed to rest on. It's also a question of how one think, 'time' as 'quanta' might create one type of experiments, and experimenter. 'Time' as a 'constant' might make another. Local time defined through its probability of happening should be a 100%, at least macroscopically. And the problem, from a point of scaling it down, is that a experimenter always uses his 'wristwatch', and it never stops ticking.
one could ask oneself this, is 'c' scale dependent? Will it stop being 'c' at some scale? Why should the scale of it matter? What I understand to happen is that at some scale/point you can't get a consistent answer anymore, but does that imply that the 'property' of this constant also must be gone? I don't think that can be if one want to join QM with relativity.
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Psychological time zx16?
that exist too. To me that's a result of consciousness, although has little to do with ones wristwatch.
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Psychological time zx16?
that exist too. To me that's a result of consciousness, although has little to do with ones wristwatch.
Obviously you're right, psychological time does exist. Like when you go to sleep, and lose consciousness (intermittently) for 6, or 7 or 8 hours. Those hours seem to pass more quickly than if you'd been awake. That seems fairly easy to account for.
But is psychological time only a result of "consciousness". For example, don't you find that being on the computer makes time seem to pass more quickly, even though you ARE awake - and conscious - all the time you're on it?
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You can also argue the opposite zx16 :)
That it is your consciousness 'psychological time' that makes it feel as if the time passing at your computer goes faster.
You want even more ideas :)
Try Resetting the Clocks (http://www.nytimes.com/2013/05/05/books/review/time-reborn-by-lee-smolin.html)
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Now, how Smolin think and how I see it is different :)
And he's a theoretical physicist.
But we both think 'time' is real
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yor_on;
For a ruler, there is space between the uniform marks.
For a clock, what's between the ticks?
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For a ruler, there is space between the uniform marks.
We know that this space exists, because we can measure it with a smaller ruler, having even more-closely spaced marks.
For a clock, what's between the ticks?
Time.
We know that this time exists, because we can measure it with a faster clock, having even more-closely timed ticks.
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Phyti, solve those and I expect you to be guaranteed a Nobel prize. You have two obvious choices (there might be more, possibly both, depending on from where you look). One is that everything is 'quantized', the other that it just continues as you scale it up (a 'flow'). If we assume that it is 'quanta', we meet the question you ask 'what's between the ticks?' and then the same can be asked for the ruler.
I'm open for both possibilities, more or less depending on my mood for the evening :)
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I do have a weakness for quantizing though, it makes it handleable. Although it still leaves you to define the 'background' it 'exist' in. It's also where the snake biting its tail comes in. If properties creates SpaceTime' for example, those questions should become wrongly asked/defined.
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One way would then be to assume properties to exist as a origin, from it coming both clocks and rulers. Then those belong to a 'inside', which are exactly where we are too. I don't think properties are 'measurable' in the same way as a 'quanta' might be. Not that we can measure either btw.
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Perhaps our modern obsession with "quantising" is powerfully influenced by digital technology, where everything is either "0" or "1", with no intermediate shades.
As yor_on says, this makes things " handleable". As witness the digital computers upon which we're handling this discussion.
However I don't think reality can be "handled" in such a simplistic binary "1-0" "on-off" way. Certainly our brain-cells don't seem to work like that. Every brain-cell has hundreds of connections forming "synapses". These aren't binary but work along flexible analogue lines, influenced by richly-varying chemical inputs.
That's probably why we haven't yet created "artificial intelligence". We're trying to do it with simple transistors. But even if these transistors are programmed to act in "neural nets", the individual components of the nets don't reproduce the complexities of an organic brain-cell.
It's like building a very realistic waxwork dummy of Dr Crippen, then expecting it to walk about and murder his wife.
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Yeah, I'm leaning to the same conclusion zx16. The world is non-linear, mathematics are non-linear, physics are non-linear. It's not the Newtonian road anymore. Although, it's those guys, and gals naturally, that we stand on trying to decipher nature.
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Although, there has been some pretty cool ideas coming with analog solutions to 'walking' etc. allow for a multitude and principles will materialize. well, as I think then :)
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Time is just changes of positions?