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Blogger George Musser wrote on Jan. 21, 2014 @ 16:31 GMT
Theoretical physicists commonly say their biggest challenge is to unite general relativity with quantum theory. But at this month’s FQXi conference in Puerto Rico,
Carlo Rovelli said they have an even bigger challenge: to unite general relativity with thermodynamics. After all, physicists do have proposed solutions to the first problem, such as string theory and loop quantum gravity, and the rivalry among them is not so bitter that theorists can’t
find the humor in it. Physicists routinely and uncontroversially work with an
effective theory of gravity which, while not the full story, captures quantum corrections to Einstein’s theory.
But it’s one thing to describe the inner workings of gravity, quite another to understand how gravity behaves in big complicated systems, which are the subject of thermodynamics. “We are totally in the dark about the foundations of statistical thermodynamics and general relativity,” Rovelli told his colleagues at the conference. Gravity inverts our usual intuition about thermodynamic concepts such as entropy: a spread-out gas has a high entropy mechanically, but a low entropy gravitationally.
Amadeo Balbi remarked to me, “There is no consensus on how to precisely calculate entropy when gravity is important, except in special cases, such as black holes.” And for black holes, physicists confront the notorious information paradox, whose latest incarnation as the
firewall argument sparked a
suitably fiery debate at the conference.
Perhaps most dramatically, Rovelli has been arguing
for two decades that space and time themselves are not fundamental to nature, but emerge thermodynamically. He made the case in his
prize-winning essay in FQXi’s first essay contest, and others have presented
similar ideas at past FQXi meetings. To advance this broader program, Rovelli’s talk in Puerto Rico went back to basics. He didn’t concern himself with the much-discussed second law of thermodynamics, nor the third law, nor the first. He focused on the
zeroth law. (You’d think that a discipline—statistical mechanics—that prides itself on counting 10
23 molecules at a time would have done a better job of numbering its laws.)
The zeroth law says that a gas or other system that has reached equilibrium has a uniform temperature. This deceptively simple principle underpins the other laws, not least by defining temperature as the collective property that an equilibrium system possesses. Systems that are not in equilibrium do not have well-defined temperatures.
So what’s up with gases in a gravitational field? When they reach equilibrium, they do not have a uniform temperature, but cool off with altitude in a phenomenon known as the Tolman-Ehrenfest effect. As Rovelli and
Matteo Smerlak have showed, the effect is basically a
consequence of gravitational redshift. Light or anything else that climbs away from Earth’s center loses energy, which is tantamount to cooling off.
In practice, we never see this effect. The air temperature does drop when you climb a mountain or fly a plane, but that’s ultimately because of the disequilibrium between the sun-basked ground and the cold of deep space. Imagine the far future of Earth after the sun goes dark, radioactive ores decay away, and the planet comes into thermal equilibrium with the cosmos. The inhabitants of that sorry world will still feel colder when they climb a mountain. The temperature will fall by one part in 10
13 at an altitude of 1 kilometer. Not enough to put on mittens, but more than enough to flout the zeroth law.
To restore the primacy of the law, Rovelli sought a generalized version that holds under all conditions. He noted an interesting fact about temperature. Although we typically measure it in units of degrees or kelvins, according to basic physical laws it really has units of inverse seconds—a rate. One way to see this, Rovelli and
Hal Haggard argued
last year, is Heisenberg’s energy-time uncertainty relation. The time it takes a quantum system to change discernibly is inversely proportional to the spread of its energy, which is proportional to temperature for systems in thermal equilibrium. Thus time is inversely related to temperature, and vice versa. The same goes for classical systems as well.
Specifically, Rovelli argued that temperature is the rate at which systems change their internal state. Air at room temperature, for example, changes state 3 trillion times per second as the molecules feverishly reshuffle themselves. In this spirit, Rovelli proposed defining equilibrium as a condition not of uniform temperature, but of a common rate of changing state. The Tolman-Ehrenfest effect then makes perfect sense. By warping time, gravity mucks with the time standard by which rates are measured. As you climb a mountain, time passes more quickly and rates slow down. The rate at which a gas changes state—and thus its temperature—thus decreases even though the gas molecules are as feverish as ever.
To make the connection to the conference theme, the physics of information, Rovelli suggested thinking of an interaction between two systems in terms of information. Each system gets a glimpse into the internal structure of the other system. If both systems are changing state at the same rate, both gain the same amount of information about each other. And that, Rovelli argued, is what equilibrium really means. The situation is like two poker players reading each other’s expressions. If one poker player is expressionless, while the other is an open book, then the two will be out of equilibrium—which translates, quite tangibly, into a flow of money from the second to the first. But if the two are equally able to read each other, they can play equally well and reach a stalemate.
Rovelli has put so much effort into understanding equilibrium because it is crucial to his program of explaining time as emergent. Traditionally physicists have taken time as a given and expressed all physical change with respect to it. A pendulum swings, a clock ticks, and a heart beats once per second. But Rovelli thinks you could eliminate the little
t and express all these changes with respect to one another. A pendulum swings once per clock tick or heart beat, and vice versa.
 |
External time vs. relational time |
Time here plays the same role that money does in an economy: it provides a convenient medium of exchange, but has no value on its own. In principle, you could shred all the dollar bills and instead perform a complex series of barter transactions. In his charming little autobiographical book
What Is Time? What Is Space?, Rovelli wrote: “Time is an effect of our ignorance of the details of the world. If we had complete knowledge of all the details of the world, we would not have the sensation of the flow of time.”
Quantitatively, Rovelli solves for
t by inverting the equation describing equilibrium states. This is subtle: equilibrium states are not changing macroscopically, by definition, so they seem like an odd choice for defining time. Rovelli argues that time evolution is latent in the statistics of equilibrium states, since a system, if displaced from equilibrium, will return to it. The time evolution given by the second law of thermodynamics builds on how equilibrium states are defined. “I think there’s a clear way of getting time out of a timeless theory,” Rovelli told me.
That said, he has yet to show conclusively that time is a collective phenomenon.
Yasunori Nomura said he shares Rovelli’s general aim of recovering time from correlations within a system, but questions his focus on equilibrium states. There seems little risk that theorists will reach equilibrium on equilibrium anytime soon.
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Robert H McEachern wrote on Jan. 21, 2014 @ 16:55 GMT
"But Rovelli thinks you could eliminate the little t and express all these changes with respect to one another."
All observations and measurements are "with respect to one another". The notion of a "unit" of measurement, such as a "second" or "meter", is nothing more than a shorthand notation for a ratio of measurements. An elapsed time of "10 seconds" simply means that the ratio of the measurement and the arbitrary standard, is equal to 10.
It is arguably more correct to think of Rovelli's concept not as "doing away with non-emergent time", but rather as picking a different standard to use in the ratio.
Rob McEachern
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John Brodix Merryman wrote on Jan. 21, 2014 @ 17:45 GMT
“Time is an effect of our ignorance of the details of the world. If we had complete knowledge of all the details of the world, we would not have the sensation of the flow of time.”
This is nonsense. What if we were to say; If we have complete knowledge of all molecular motions in a body of water, we wouldn't have the sensation of temperature?
Of course we would. Temperature is the average of all the actions.
If we knew both the position and momentum of all parts of the world, there would still be a rate of change and thus effect of time. We would simply know the average rate and thus a potentially universal rate of change.
A universal time is the collective, composite rate of change. There is no blocktime of all those events. The thermodynamic process is explicitly about that dynamic process and its resulting change. If we knew the entire process, we would still have that sum total effect of time/rate of change, not no time.
The real problem is that the idea of blocktime is incompatible with thermodynamics, since blocktime replaces that dynamic process with a static dimension of all events.
Regards,
John M
The state of equilibrium is one where all effects balance out, so only if all those details were to effectively cancel out, then there would be no change/no rate of change and no time.
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Robert H McEachern replied on Jan. 21, 2014 @ 19:06 GMT
"This is nonsense." I agree. The sensation/perception of something is not the same as that something. I do agree that it would be possible to construct a machine that would not have any sensation of the flow of time. So what? WE are not such machines, but we already know how to construct such machines, even without having "complete knowledge of all the details of the world." I'm pretty sure a rock as no sensation of the flow of time either.
Rob McEachern
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John Brodix Merryman replied on Jan. 21, 2014 @ 20:21 GMT
Rob,
"I'm pretty sure a rock as no sensation of the flow of time either."
Yes, there is little rate of change for a rock and the rock doesn't even have complete knowledge of the details of the world.
Would the machine express any change? Or is the issue the question of sensation? What would be the sensation of time? Is it any different from a sensation of action?
Regards,
John M
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Robert H McEachern replied on Jan. 21, 2014 @ 21:37 GMT
John,
The issue is indeed the question of sensation. Since all measurements are "with respect to others", what is your internal passage of time sensation "with respect to"? Surely not the physicist's definition of a second.
Expressions like "It happened in the blink of an eye", explicitly inform you of what that particular event's duration is in respect to. Take it literally - a blink is a single closing and reopening of the eye. If you close your eyes and immediately fall asleep, and do not reopen your eyes until the following morning, then the whole night may result in the sensation of having literally passed within a single blink of the eye - which just happened to take all night.
Or, if you are bored to death, and keep asking yourself "When will this tedium end? "When will this end? When will this end?, then the passage of time, as measured by counting the number of times the question has been asked, may seem very long, as compared to when you are so engaged in something that you never once asked "When will this end?", and consequently, the time flew-by in "no time at all", as measured, literally, by the zero question count.
The passage of time is subjective, because it is subject to our continually changing choice about what to use as a reference.
Rob McEachern
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John Brodix Merryman replied on Jan. 21, 2014 @ 23:04 GMT
Rob,
Very much so. It's all actions and our particular impression of them. We are basically single points of reference, so we experience activity as a sequence of events, rather than a broader field of activity. Our perception of that broader spectrum is what is called emotion, instinct and intuition, those cumulative feedback loops in our subconscious. These we tend to process more as a scalar, like pressure, or temperature, where the outcome is what figuratively rises to the surface of all the input. We use all sorts of scalar terms to describe it, like hot, cold, stress, pressure, lack thereof, etc.
So while we logically think of time as that progression from past events to future ones and which physics treats as measurements of duration, the larger dynamic is the changing configuration of what physically exists, so those events, once formed, dissolve into the next and so recede into the past and memory. The future becoming past.
Regards,
John M
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Thomas Howard Ray replied on Jan. 22, 2014 @ 12:22 GMT
"What if we were to say; If we have complete knowledge of all molecular motions in a body of water, we wouldn't have the sensation of temperature?"
Right, John. We wouldn't.
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John Brodix Merryman replied on Jan. 22, 2014 @ 14:47 GMT
Tom,
How does knowing all the information negate knowledge of parts of it? Temperature is an average of all those motions, so if we had complete knowledge of all the motions, we could calculate a much more precise temperature than simply sticking a thermometer in it.
Regards,
John M
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John Brodix Merryman replied on Jan. 22, 2014 @ 15:29 GMT
Tom,
I would even argue that even if we only know the actions of a single molecule, we could still use it as a thermometer to estimate the temperature in its vicinity, given molecules are interacting with one another and therefore trading energy around, in what amounts to an entropic process. Since that molecule will be loosing energy to slower molecules and gaining it from faster ones, it will settle into equilibrium with its immediate context.
We could also theoretically use it as a rough clock of its context, when it has reached this equilibrium, since its rate of interaction will also be stabilized.
Regards,
John M
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Thomas Howard Ray replied on Jan. 22, 2014 @ 20:46 GMT
"I would even argue that even if we only know the actions of a single molecule, we could still use it as a thermometer to estimate the temperature in its vicinity ..."
You would, but you'd lose.
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John Brodix Merryman replied on Jan. 22, 2014 @ 21:24 GMT
Tom,
A thermometer works by coming into dynamic equilibrium with the medium. Would you argue that in such a medium, all the molecules come towards an equilibrium, ie, the hotter ones cool down and the colder ones heat up? So if you were to examine the actions of a particular molecule after that equilibrium is reached, the odds are that it would be representative?
I'm not saying it is a thermometer, but that it could be used as one, to give an average level of molecular activity in the medium, since the representative molecule has moved towards that average.
Regards,
John M
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Plato Hagel wrote on Jan. 21, 2014 @ 18:55 GMT
"
George Musser:
But at this month’s FQXi conference in Puerto Rico, Carlo Rovelli said they have an even bigger challenge: to unite general relativity with thermodynamics."
The Arrow of time concept was held in mind when I read about Alan Guth's ideas here that I did not see included in your write up. I thought it might be significant to what over all was noted from your perspective of that same event.
"
An arrow of time—the steady growth of entropy with time—has been generated, without introducing any time-asymmetric assumptions.The Universe Began In A State Of Extraodinarily Low Entropy by
Alan Guth"
I would also like to add something for reference.
"
The old version of string theory, pre-1995, had these first two features. It includes quantum mechanics and gravity, but the kinds of things we could calculate were pretty limited. All of a sudden in 1995, we learned how to calculate things when the interactions are strong. Suddenly we understood a lot about the theory. And so figuring out how to compute the entropy of black holes became a really obvious challenge. I, for one, felt it was incumbent upon the theory to give us a solution to the problem of computing the entropy, or it wasn't the right theory. Of course we were all gratified that it did."Black Holes and Beyond: Harvard's Andrew Strominger on String Theory I have to apologize as link is now dead. See instead to follow up:
The Cosmic Hologram "
Holography encodes the information in a region of space onto a surface one dimension lower. It sees to be the property of gravity, as is shown by the fact that the area of th event horizon measures the number of internal states of a blackhole, holography would be a one-to-one correspondence between states in our four dimensional world and states in higher dimensions. From a positivist viewpoint, one cannot distinguish which description is more fundamental.Pg 198, The Universe in Nutshell, by Stephen Hawking"
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Akinbo Ojo wrote on Jan. 21, 2014 @ 19:14 GMT
Again and again, that false statement: "Light ... that climbs away from Earth’s center loses energy, which is tantamount to cooling off". On the contrary, this is what Einstein believed: "...we can regard an atom which is emitting spectral lines as a clock, so that the following statement will hold: An atom absorbs or emits light of a frequency which is dependent on the potential of the gravitational field in which it is situated. The frequency of an atom situated on the surface of a heavenly body will be
somewhat less (not more) than the frequency of an atom of the same, element which is situated in free space ...". If E =hf is still correct, then we can from the quote say, the energy, E of an atom situated in free space will be somewhat more than the energy of an atom of the same, element which is situated on the surface of a heavenly body. These things have been verified experimentally in Pound and Rebka's
experiment and same in the Gravity Probe A. Indeed the
Gravity Probe A claims that at 10,000km a clock should run 4.5 parts in 10
-10 faster than one on the Earth. That is frequency, f and therefore energy, E is higher up and lower down.
So why the false statements persist beats me. Does a falsehood repeated severally become a truth? Or is this a genuine mistake?
Akinbo
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Plato Hagel replied on Jan. 21, 2014 @ 19:26 GMT
You might want to look at the Relativity of Muons. As well,
Seeing Muons!As well, regarding application:
Muons reveal the interior of volcanoes
attachments:
1_cosmics.jpg,
1_mu1.gif
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Akinbo Ojo replied on Jan. 23, 2014 @ 08:44 GMT
Still waiting for a clarification from anyone on the content of my last post. There seems to be a loud silence. In same write up by George Musser I see: "
As you climb a mountain, time passes more quickly and rates slow down". Does time pass more quickly when rates slow down or the opposite? Considering students may be reading this and be misled by the use of language, if not of thought someone out there should edit the post asap.
Akinbo
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John Brodix Merryman replied on Jan. 23, 2014 @ 11:01 GMT
Akinbo,
The difference is between one having to pull away from the gravitational field, vs. one in free space. A clock under acceleration will slow as well, thus the equivalence principle, between acceleration and gravity.
Regards,
John M
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Thomas Howard Ray replied on Jan. 23, 2014 @ 12:51 GMT
"In same write up by George Musser I see: 'As you climb a mountain, time passes more quickly and rates slow down'. Does time pass more quickly when rates slow down or the opposite?"
Akinbo, it means that relative to your position at the foot of the mountain, time passes more slowly, because the farther from a gravity source, the more distance between "ticks" of the clock -- the rate -- that records a time interval.
Sippose you have two super-accurate watches before you start your climb. You synchronize them before you begin, and leave one behind. When you return from your climb, you will find that the watch you took with you will be out of sync with the other; it will appear to have "lost time." Therefore, time will have passed relatively quicker at the point you left than at the top of the mountain.
John's explanation is also correct.
Tom
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Akinbo Ojo replied on Jan. 23, 2014 @ 19:21 GMT
Thanks Tom and James for at least venturing a reply.
Can you for a minute Tom, put "time passes
more slowly, because the farther from a gravity source, the more distance between "ticks" of the clock" alongside "As you climb a mountain, time passes
more quickly..." and claim the two are the same meaning?
Also frequency is like the ticking of a clock, the shorter the distance between wave peaks, the more the frequency but the shorter the period, or the more the distance between ticks, the shorter the frequency and the longer the period. Einstein, Gravity Probe A, etc suggest the distance between ticks are shorter hence higher frequency at a height of the mountain, i.e. time passes more quickly as correctly stated and therefore rates of ticking are faster, not slow down as wrongly stated in the article. That is my quarrel, two contradicting meanings in same sentence.
Your clock analogy is good. Reminds me of the 'twin paradox'.
And John, what do you make of Einstein's statement I quoted above on Jan. 21, 2014 @ 19:14 GMT where acceleration or deceleration is not mentioned at all but only dependence on the potential of the gravitational field in which the clock is situated, i.e. dependence on position not on how the position is attained?
Akinbo
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Thomas Howard Ray replied on Jan. 23, 2014 @ 19:27 GMT
"Can you for a minute Tom, put "time passes more slowly, because the farther from a gravity source, the more distance between "ticks" of the clock" alongside "As you climb a mountain, time passes more quickly..." and claim the two are the same meaning?"
Of course not. The times are *relative.* Time passes more quickly on the ground *relative* to the time up the mountain.
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Akinbo Ojo replied on Jan. 23, 2014 @ 20:01 GMT
So to you, which one is correct, time passing more quickly or slowly as you climb? Not on the ground relative to the mountain top or the mountain top relative to the bottom, "as you climb". I think it is clear George Musser or is it Rovelli have made a grave and I dare say very fundamental error and Einstein and Gravity Probe A are correct. An error which if rectified has far reaching consequences as I have pointed out in other posts.
Regards,
Akinbo
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John Brodix Merryman replied on Jan. 23, 2014 @ 21:17 GMT
Akinbo, Tom,
I also noticed that discrepancy, but was trying to avoid another conflict. I thought it was the higher clock ticking faster and
wikipedia agrees."In addition to this, general relativity gives us gravitational time dilation. Briefly, a clock in a stronger gravitational field (e.g. closer to a planet) will appear to tick more slowly. People holding these clocks would agree on which clock appeared to be going faster."
Regards,
John M
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Thomas Howard Ray replied on Jan. 23, 2014 @ 21:52 GMT
The main point is that because motion is relative, time is not absolute -- "moving clocks run slow."
This means a longer interval between ticks, so that a clock at the top of the mountain runs slower, just as if it were accelerated against the gravitational field. It will therefore have recorded fewer units on its dial than a clock at rest at the bottom of the mountain.
Say for simplicity that the "climbing clock" lost a second in the journey. Then from time zero when the clocks were first synchronized, the clock at rest relative to gravity on the ground will be a second faster than the climbing clock; the climbing clock will be "younger" when they are compared, as in Einstein's twin paradox (which is not really a paradox at all).
The error you are making is thinking of time as something other than scalar, so you think that one or the other clock readings -- fast or slow -- has to be the "real" physical result. They are *both* real, and valid, in their own inertial frames -- the frame that determines the interval between ticks.
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John Brodix Merryman replied on Jan. 23, 2014 @ 22:08 GMT
tom,
There are two effects there; The acceleration and the weaker gravity field. The acceleration is equivalent to gravity and slows it, while the weaker gravity field naturally runs faster because it's closer to being in the vacuum of space, with little to slow it.
Regards,
John M
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Plato Hagel replied on Jan. 24, 2014 @ 04:50 GMT
It is always desirable for me to see the advances made in terms of Relativity which can help me to see these theoretical developments in play.
So one thing really helped was to see satellite projects as they exemplify the technique so as to discern some thing. In this case time differences as they relate to how we see earth other then the pearl it is. So, let us consider the Grace mapping of earth's gravitational field as it would appear from space. Not every place on earth emits the same gravitational strength as another location.
How is this measured that we can see these variances? If you have two satellites in tandem whose distance is recorded by a beam of light how would the earth show such variance?
This gives you clues as to the time differences that places on earth depict. Have a look for a mountain range.
Secondly, it is also desirable to see beam of light in action as it is portrayed in Ligo experiment as to the detection of gravitational waves. How would such gravitational waves be reflected in the beam of light?
attachments:
image.jpg,
1_image.jpg
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Akinbo Ojo replied on Jan. 24, 2014 @ 10:24 GMT
John M, you said you also noticed the discrepancy, but was trying to avoid another conflict. Why? I think someone said somewhere that evil flourishes when good men keep quiet. Thanks for the wikipedia reference. It is an addition to the other evidence Einstein, Gravity probe A, Pound and Rebka's experimental finding (not the conflicting and contradictory closing statement in the paper), etc. But then is this a minor discrepancy, a typo, a genuine error or part of an elaborate conspiracy to emasculate the truth? If the latter, must we let it pass to avoid conflict?
Then Tom, I will let this pass, but certainly what is at issue is not because motion is relative as you said, you might as well be climbing up or climbing down the mountain. Even someone as anti-Einstein as Pentcho has been unwittingly conscripted into the belief that clocks run slower up the mountain than lower down so now on the same side as those he claims to be against in Einsteiniana :(
Akinbo
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John Brodix Merryman replied on Jan. 24, 2014 @ 11:00 GMT
Akinbo,
There are a fair number of potential targets in physics and given my limited time and knowledge, I have to focus on as few as possible. That said, whether he remembers or not, I've been bugging George Musser since the 90's and his early days at SciAm, about problems in cosmology.
Its not evil that is the issue, but increasingly fantastical speculation and as such is it's own worst enemy, given the degrees of skepticism it is arousing.
Regards,
John M
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Thomas Howard Ray replied on Jan. 24, 2014 @ 11:20 GMT
Look guys, relativity has been tested and retested for a hundred years. It is as true as any scientific theory can be, despite your misunderstandings.
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John C Hodge replied on Mar. 26, 2014 @ 18:19 GMT
Akinbo,
The Pound-Rebka experiment involved light going up and\/b] down. the measured effect was redshift and blueshift. A change in potential energy can account for this. General relativity's gravitational redshift involve a square root. Hence only a redshift.
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Akinbo Ojo replied on Mar. 26, 2014 @ 19:09 GMT
John H,
Yes, the Pound-Rebka experiment involved checking frequency changes when light goes up and when light goes down. You can see the paper
here. I have commented at length elsewhere on this site (?Faster than light, ?Ripping Einstein apart), excerpt "
At the top of a tower or at a height, the frequency fu will be higher than the frequency fd at the bottom. Pound and Rebka's experiment showed in ALL their measurements that the frequency of the source is ALWAYS red and below that of the absorber (i.e. all minus sign). Why this should be so is left for other theories like 'tired light', 'extinction', etc. What is important here is that on the difference of averages, the frequency when the source is at the bottom, fd is less than the frequency, fu at the top of the tower by -5.13 x10^-15, which difference can therefore only be attributable to position in the gravitational field. However, despite reporting rightly that fu is more than fd, there is an erroneous statement in the paper that light frequency increases as it falls, which is not corroborated by their own findings. The Gravity probe A gives results that also conform to the prediction from the equation of fu being more than fd.)". Light frequency increases as it goes up (blue shift) and reduces as it falls (red shift) as has been found in ALL the experiments I referenced.
Akinbo
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Thomas Howard Ray wrote on Jan. 22, 2014 @ 23:06 GMT
" ... the representative molecule has moved towards that average."
Or away from it.
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John Brodix Merryman replied on Jan. 23, 2014 @ 01:03 GMT
Tom,
Have there ever been any tests to show how that is possible, given we are talking a representative molecule, not one unlikely outlier? All we are talking about is whether temperature can be estimated from the motion of one molecule, so is the motion of one molecule in a medium in thermal equilibrium representative of the rest? It seems likely to me.
Regards,
John M
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Thomas Howard Ray replied on Jan. 23, 2014 @ 12:53 GMT
John, if motion is relative, what information do you expect to get from the movement of one molecule?
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John Brodix Merryman replied on Jan. 23, 2014 @ 13:24 GMT
Tom,
Necessarily you will have to measure it relative to context, not in isolation, or there would be no evidence it is moving and presumably no temperature, since that is quantitative. The assumption being that in thermal equilibrium, the other molecules will be moving at about the same rate, in context. Not that I know what the translation would be, but if it is moving twenty miles an hour, the temperature would be hotter than if it is moving ten miles an hour.
Regards,
John M
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Thomas Howard Ray replied on Jan. 23, 2014 @ 13:26 GMT
" ... if it is moving twenty miles an hour ..."
Relative to ...?
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John Brodix Merryman replied on Jan. 23, 2014 @ 17:08 GMT
Tom,
The other molecules.
The point is made that at the level of the individual molecules, temperature is not a factor. The argument I'm trying to make is that the effect of entropy means all these molecules trade energy around until they are in a state of equilibrium, so if you measure the interactive energy of just one molecule, it would serve as a thermometer of the larger medium. The point being is that, due to entropy, temperature is not just a statistical measure, but the real energetic equilibrium state of the medium.
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Thomas Howard Ray replied on Jan. 23, 2014 @ 17:54 GMT
"(Relative to ...?)
The other molecules."
So all the other molecules are at relative rest, and the one molecule whose speed you choose to measure isn't? A system in an equilibrium state, John, is isolated from all other systems, by definition.
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John Brodix Merryman replied on Jan. 23, 2014 @ 19:57 GMT
Tom,
It would be isolated by being in a pot.
Regards,
John M
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Thomas Howard Ray replied on Jan. 24, 2014 @ 11:18 GMT
Is the pot still isolated when you dip into it to make a measurement?
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Pentcho Valev wrote on Jan. 25, 2014 @ 13:30 GMT
Akinbo,
"Even someone as anti-Einstein as Pentcho has been unwittingly conscripted into the belief that clocks run slower up the mountain than lower down so now on the same side as those he claims to be against in Einsteiniana"
Too much misstatement. Let me suggest something. We study, carefully, a good relativistic source (without paying attention to other sources) and then restrict the discussion to this source only:
David Morin: "The equivalence principle has a striking consequence concerning the behavior of clocks in a gravitational field. It implies that higher clocks run faster than lower clocks. If you put a watch on top of a tower, and then stand on the ground, you will see the watch on the tower tick faster than an identical watch on your wrist. When you take the watch down and compare it to the one on your wrist, it will show more time elapsed. (...) This GR time-dilation effect was first measured at Harvard by Pound and Rebka in 1960. They sent gamma rays up a 20m tower and measured the redshift (that is, the decrease in frequency) at the top."
Pentcho Valev
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Akinbo Ojo replied on Jan. 26, 2014 @ 10:40 GMT
Pentcho,
It is not a misstatement because I have been reading your posts and sometime ago I took you up on same topic and provided you with references, both theoretical and experimental to which you no longer responded. I am reluctant to restrict the discussion to your source when there are others and when the author of General relativity, Einstein himself has spoken. But let's see
"higher clocks run faster than lower clocks" means frequency higher > frequency lower. This is irrespective of whether you are looking up or looking down. You don't need to look at any other clock but yours to measure its frequency. Frequency is not relative as such. I can measure the frequency of my clock at my location without looking at your clock. It is only when we discuss on phone that we can now start saying my frequency is higher or lower than yours.
Einstein did not say I have to look at your clock to measure my frequency. But having now independently done so, he says very, very, very unambiguously on
p.157,
"Furthermore, we can regard an atom which is emitting spectral lines as a clock, so that the following statement will hold: An atom absorbs or emits light of a frequency which is dependent (only) on the potential of the gravitational field in which it is situated. The frequency of an atom situated on the surface of a heavenly body will be somewhat less than the frequency of an atom of the same, element which is situated in free space (or on the surface of a smaller celestial body)".
And if Planck tells you that E = hf, who is Musser, Rovelli and other Einsteiniana people disagreeing with?
It may help to replace 'g' in your equations with GM/r
2.
Akinbo
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John Duffield wrote on Jan. 25, 2014 @ 18:02 GMT
I'm with Carlo when it comes to time being derived from motion. You can hold your hands up with a gap, a space between them. And you can waggle your hands. That's motion. Space and motion are empirical. But there is no time flowing between your hands or anywhere else. Open up a mechanical clock and you don't see time flowing through it like some cosmic egg-timer. You see cogs and things. Moving. Through space.
And
George, if you're there, when light climbs away from Earth's center, it doesn't lose any energy. Clocks run slower when they're lower, so the frequency looks higher, that's all. Take that clock to the top of a tower and measure the photon frequency, and you measure it to be slower. But it hasn't changed. You clocks have changed instead. And so have you. It takes work to climb to the top of the tower. You have more mass-energy. So it
looks like the photon has less. But it doesn't.
That might sound unfamiliar and even alarming. But imagine you've got a 511keV photon and you direct it into a black hole. The black hole mass increases by 511keV/c². No more. It's the same if you drop an electron into a black hole. Conservation of energy applies. There is no magical mysterious action-at-distance mechanism by which a photon or an electron gains or loses energy on the way down or on the way up. Gravity is not an external force that adds energy to a falling body. There is no force upon that falling body. The principle of equivalence likens the body on the ground to the body accelerating through gravity-free space.
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Pentcho Valev replied on Jan. 26, 2014 @ 09:45 GMT
John Duffield wrote: "...when light climbs away from Earth's center, it doesn't lose any energy. Clocks run slower when they're lower, so the frequency looks higher, that's all. Take that clock to the top of a tower and measure the photon frequency, and you measure it to be slower. But it hasn't changed. You clocks have changed instead."
I don't agree but still let us analyse your hypothesis. We have frequency f at the bottom of the tower and f' at the top, and f > f'. But f=c/L and f'=c'/L', where c and L are speed of light and wavelength at the bottom and c' and L' speed of light and wavelength at the top. How about c and c'? c > c' or c = c'?
Pentcho Valev
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John Duffield replied on Jan. 26, 2014 @ 11:57 GMT
You missed the trick, Pentcho. The E=hf photon energy doesn't change as it ascends, and nor does the frequency. So f=f'. Your clock rate increases as you ascend. So when you re-measure the photon frequency it appears to have decreased. Your clock changed and so did you. But the photon didn't.
Flip it round and think of the black hole scenario. Convert a 1kg brick into photons and direct them into a black hole. The black hole mass increases by 1kg. Or just drop the 1kg brick into the black hole. The black hole mass increases by 1kg. Conservation of energy is not my hypothesis.
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Pentcho Valev replied on Jan. 26, 2014 @ 12:51 GMT
John,
"You missed the trick, Pentcho. The E=hf photon energy doesn't change as it ascends, and nor does the frequency. So f=f'. Your clock rate increases as you ascend. So when you re-measure the photon frequency it appears to have decreased. Your clock changed and so did you. But the photon didn't."
OK, misunderstanding. f and f' are the APPARENT (that is, measured by using the respective clocks) frequencies, at the bottom and at the top of the tower. Then f > f', right? We define c and c' in the same way, so: c > c' or c = c'?
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John Duffield replied on Jan. 26, 2014 @ 15:52 GMT
Pentcho: the apparent speed of light is the same so you might think c = c'. But when you climb to the top of the tower your light clock is going faster because the light is going faster. Light doesn't slow down when it climbs out of a gravitational field. It speeds up. See http://arxiv.org/abs/0705.4507 . Everybody agrees that the coordinate speed of light varies with gravitational potential, and everybody agrees that the locally-measured speed of light is constant. But they don't agree on which is the "real" speed of light. Most physicists and textbooks will say it's the locally-measured speed of light, but IMHO that contradicts Einstein and the hard scientific evidence. There is no literal time flowing in a light clock. It's just light, moving. There's no literal time flowing in a quartz wristwatch either. Or a mechanical clock. Clocks typically "clock up" some kind of regular cyclic motion and show a cumulative display that we call "the time". Check out
A World Without Time: The Forgotten Legacy of Gödel and Einstein. But beware of the blurb that suggests that time does not exist. It does exist, just as heat exists. It just isn't fundamental and empirical like space and motion.
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Anonymous replied on Jan. 27, 2014 @ 09:38 GMT
John D,
Thanks for the paper by J. Magueijo and J.W. Moffat you linked. Very interesting. Before I make a comment, let me first state my agreement with your, "Light doesn't slow down when it climbs out of a gravitational field. It speeds up".
But I have some difficulty with, "The E=hf photon energy doesn't change as it ascends, and nor does the frequency. So f=f'.
Your clock rate increases as you ascend. So when you re-measure the photon frequency it appears to have decreased. Your clock changed and so did you. But the photon didn't".
Suppose the clock you are using, i.e. the 'Your clock', is the frequency of electromagnetic oscillation? In that case, the light frequency itself changes. You can check the Einstein references I earlier posted.
But coming back to Magueijo and Moffat's paper and the statement therein that "The unit of time is defined by an oscillating system or the frequency of an atomic transition, and the unit of space is defined in terms of the distance travelled by light in the unit of time…. But then, within such a framework, neither can the constancy of the speed of light be falsified, thus losing its status as a scientific statement". The current definition of a
second is based on such an oscillating system, that of Caesium atom 133 at 9 192 631 770Hz. Within that framework, if Caesium 133, is found in some situations to oscillate at a higher frequency, then the definition of only the second will change not the metre, and from this the distance light will travel in "one second" will change and the constancy of light postulate in all circumstances can be falsified.
Akinbo
(Since you agree Light speeds up when it leaves a gravitational field, have you considered this as a solution to the Pioneer anomaly, whereby two-way signals were returning to earth earlier than scheduled giving a bluish tinge to the red shift?)
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Anonymous replied on Jan. 28, 2014 @ 16:59 GMT
Your agreement noted, Akinbo. I haven't considered Pioneer I'm afraid. As for "your clock" and frequency, note the definition of the second:
"Since 1967, the second has been defined to be 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..."
The NIST caesium clock uses lasers and a microwave cavity wherein hyperfine transitions cause microwaves. But there's no mention of frequency because that's cycles per second, and we're defining the second here. So what the detectors really do, is count incoming microwave peaks. When they get to 9,192,631,770, that's a second. Then we define the frequency as 9,192,631,770 Hertz "by definition". Then we define the metre as the distance travelled in 1/299,792,458th of a second. So we use the motion of light to define the second and the metre, which we then use to measure the motion of light. Hence we always measure 299,792,458 m/s. It's a dark-age tautology I'm afraid.
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Akinbo Ojo replied on Jan. 28, 2014 @ 19:39 GMT
John D,
Thanks for pointing out the exact mode by which the definition of a second is obtained. I focused on frequency to avoid any talk of light speed as it is still a taboo. But your explanation even makes things worse for a constant light speed going by the methodology. Suppose you take your NIST caesium clock, lasers and a microwave cavity to a gravitational environment less intense than Earth's along with a mechanical clock and you then find that the detectors counted more incoming microwave peaks in the time it takes for your mechanical clock to tick one second, say 9 192 631 776? This will make an electromagnetic phenomenon that takes 1 second on Earth surface (9 192 631 770 peaks), take 0.9999999993 seconds instead. Still very close to 1 second. If you went to this gravitational environment with a rigid one metre rod as Einstein likes to use, and as you say, you want to measure the motion of light, you find the light speed will be about 299,792,458.2087 m/s instead of 299,792,458 m/s. Talking of catching someone in the trap he has set for others...
I propose the Pioneer anomaly as an experimental proof of your statement, "Light doesn't slow down when it climbs out of a gravitational field. It speeds up". If light can speed up to 299,792,458.2087 m/s as I have calculated and which also agrees largely with Einstein's equation 3
here, the two-way signals from earth to the Pioneer spacecrafts will be returning earlier than their scheduled times, which is what is observed. The initial suggested interpretation for this observation used to be that the spacecrafts' motion away from earth was being retarded due an attractive force from the Sun so it was not moving away fast enough (i.e. its redshift had a bluish tinge). But now the current explanation is that the craft were not receding fast enough due to a thermal engine problem. Our agreement that light can speed up and could be catching up with the craft and returning earlier does not feature much as a possible explanation but I intend to push it until falsified.
Akinbo
*John, do you by any means know if the method of a detector counting wave peaks was similar to that used in the
Gravity Probe A experiment which found that a clock 10,000km was 4.5 parts in 10
-10 faster than one on the Earth?
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John Duffield replied on Jan. 30, 2014 @ 17:36 GMT
If you took it all down a mine, the light goes slower so your second is bigger. Then you still "measure" the speed of light to be 299,792,458 m/s. Duh!
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Akinbo Ojo replied on Jan. 31, 2014 @ 10:48 GMT
John,
You said, If you took it all down a mine, the light goes slower so your
second is bigger. Then you still "measure" the speed of light to be 299,792,458 m/s.
That is exactly the point, if you read the definition of the
BIPM second, side by side with the theoretical and experimental evidence presented in previous posts. What your statement implies is that for light to still be measured constantly to be 299792458m/s,
the definition of the second must become adjustable to be bigger or smaller.
So the poison that must now be offered to BIPM or NIST is the choice to swallow a rigid definition of the second and have a variable light speed
OR have a rigid light speed and a variable definition of the BIPM second.
Either way, suicide for a theory or swallowing of the humble pie by BIPM/NIST is guaranteed. And by the way, the idea of a rigid second appears to support Newtonian absolute time, which I think we will still resort to when we get to the bottom of the mine.
Akinbo
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John Duffield replied on Jan. 31, 2014 @ 17:22 GMT
I didn't think it was an issue for BIPM or NIST so much as an issue for people like George Ellis. See http://arxiv.org/abs/astro-ph/0703751 along with http://arxiv.org/abs/0705.4507. IMHO really comes back to
What is time? See http://www.physicsdiscussionforum.org/time-explained-t3.html
for my explanation. I say it's a cumulative measure of motion, and that's all.
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Akinbo Ojo replied on Feb. 1, 2014 @ 12:23 GMT
John D,
I see that you have done some really deep thinking on the nature of time. Really brilliant. Pentcho would also love that list of
crackpots you linked on another blog! Really interesting, the kettle now calling the pot black.
You have devoted so much energy on 'time', which is okay. 'Place' is mentioned severally in your write ups, but place (i.e. space) itself is no less daunting and without it we can't have a complete picture.
Hear this paraphrased from
Newton,p.11 "
...…when a part of space moves, (e.g. a car) it is translated from one place to another. But a car is a part of space, so this implies that the moving part of space (i.e. the car) is translated out of itself, (i.e. a part of place is translated out of its place); unless we postulate that there are two spaces that everywhere coincide, a moving type of place and another one that is stationary, so that the movement of a part of the moving one involves a translation of that item from the corresponding part of the stationary one to a different part of the resting space…". How can a body as a geometric object with the property of place be translated out of its place? If it is translated, what does it leave behind? And where it seems to go to, what happens to or changes in the place now subsequently occupied? Therefore, the same difficulty expressed by the website you linked, (i.e. Nothing Can Move in Spacetime:...irrefutable arguments that show that motion in spacetime is logically impossible. Spacetime is frozen from the infinite past to the infinite future by definition) applies also to and even confronts Space itself. If you are familiar with it these are the logical basis for
Zeno's paradoxes of motion. So not just time or space, but motion itself which we all see needs to be re-conceptualized.
In the Ellis paper, "...In order to be viable, any VSL theory involving a variable speed of photon travel must of necessity be based on some other method of measuring spatial distances than radar. So the question for any specific proposed VSL theory is, What viable alternative proposal for distance measurement is made?". Two-way radar signalling to Venus has been used to
compare light transit times between Earth and Venus WITH the same journey when light grazes the Sun's surface with the Sun in between Earth and Venus and a longer transit time has been reported! The interpretation is either slowing of time by the Sun's gravity or slowing of light speed due to the higher gravitational potential, depending on the point of view. Is Ellis saying for either of these two explanations to be viable some other 'method of measuring spatial distances other than radar' must be done? Lengthening of the earth-sun distance to explain the longer transit time has not featured as at yet as an explanation, so what is Ellis really talking about spatial distance?
Finally from your blog, I think a little error, the higher the gravitational potential, the slower the clock, not "in this situation (a region of low gravitational potential), the light is moving slower". Not just comparison of position in a gravitational field but different gravitational fields of different strengths. Thus Einstein predicted,
p.97 that "We therefore conclude that spectral lines which are produced on the Sun's surface will be displaced towards the red (reduced frequency), compared to the corresponding lines produced on the Earth". The issue of a standard definition for the second should be separated from that of light speed but because of the ulterior motive behind the current definition, there is an attempt to present us with a fait accompli concerning CSL. Luckily, paradoxes, those beautiful things that expose theoretical falsehood come to the rescue. The definition itself indicates that certain things can make the atom oscillate more than 9,192,631,770 cycles in what make one second. For instance a temperature higher than 0K. So 9,192,631,770 cycles/second is not an invariant quantity. If that is not invariant, neither can the distance light travels in the time taken to count up to 9,192,631,770 be invariant in all environments and neither can the speed. To illustrate, given two Caesium 133 atoms in the same room, one at 0K and the other at higher temperature and so oscillating higher than 9,192,631,770, going by the distance light travels, the one timed by Caesium at 0K would travel further than the one timed by the heated up Caesium atom which arrives earlier at 9,192,631,770 oscillations. Paradox: Can the measurement of the travelled 'metre' be affected by temperature? Standardization by itself is okay, but for the second, it has become necessary to add "at Earth surface" since just as temperature does, the counting can be affected by the gravitational environments, where clocks run faster or slower than Earth. The fear in not doing this may lie in the consequence that the light speed of 299792458m/s becomes a terrestrial measurement, not a universal one. Again within space-time logic, space-times flatter than the slightly curved Earth space-time certainly exist and in this light speed must be higher (e.g. free space and on the moon), just as in space-time more curved than Earth's, e.g. on the Sun, light speed (or light transit time as some like to call it) is slower. Einstein doesn't question all this, but his modern day followers do.
On the 'motion' topic I could elaborate more but suffice to speculate that all motion is illusion, the only motion, i.e. the only 'change of place' that is real is absolute in nature and it is the appearance and disappearance of 'discrete places' from nothing. It resolves the paradoxes for motion in a discrete or continuous space.
What is IMHO?
Akinbo
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Akinbo Ojo replied on Feb. 3, 2014 @ 09:04 GMT
More headache for BIPM on the definition of a
second:
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.And at its 1997 meeting the CIPM affirmed that: This definition refers to a caesium atom at rest
at a temperature of 0 K.
Question 1: I thought someone said 0K cannot be
exactly attained due to zero-point energy? If so, can the second be exact? If the second on this basis cannot be exact, then in the definition of the
metre: The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458
of a second, the second in which definition must be an approximation as well since 0K is not exact. Where then does the exact come from when subsequently stating "It follows that the speed of light in vacuum is
exactly 299 792 458 metres per second"? 0K is not exact, therefore second cannot be exact, therefore metre cannot be exact but by magic light speed can be exact? Smells of proceeding from an answer to the question instead of the other way round. Why the desperation for exact, is there an ulterior motive to cover up something and why?
Question 2: I thought someone said at 0K, atoms will be incapable of vibrating, is Caesium 133 atom an exception capable of oscillating 9 192 631 770 times at 0K?
It is certainly a difficult job to cover and patch up what is false, loopholes springing up here and there, perhaps its time to come clean and open up.
Akinbo
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Roger Granet wrote on Jan. 26, 2014 @ 05:19 GMT
To me, Rovelli's position that time is just a function of the spread of its energy, which is due to the physical components of a system changing, seems clearly correct. I'm no physicist, but my sense (or possbily lack thereof) would tell me that if there were no physical change at any level in the universe, there would be no time. So, as mentioned, time is just a way of keeping track of the amount things physically change in a system. And, if the components are more resistant to being changed (e.g. have higher mass?), then time would move slower as relativity shows. This also seems to explain the arrow of time. If time is just a measure of physical components changing, then even if they change in reverse direction back to their original state (e.g. a broken coffee cup reforming itself), the arrow of time is still going forward because as the components reverse their direction, change is still happening, and thus time is moving forward. That is, time can't go backwards because you can't take back the fact that components have changed. Even if you try to take it back, that action is itself change and thus time still moves forward.
Also, it seems like that if the universe started with a single existent entity that could replicate itself to create the multiple existent entities we see in our universe now and if these existent entities could change, this would explain the low entropy at the beginning of the universe. The single initial entity would have very low entropy and due to the changes occurring in the replicated entities, entropy would increase.
This is just what it seems like to an amateur thinker/"crackpot". Thanks for listening!
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Ken Hon Seto wrote on Jan. 29, 2014 @ 14:45 GMT
The only time exists is absolute time or universal time. However there is no clock time unit (including a clock second) that represents the same amount of absolute time in different frames of reference. The observer's clock second represents a specific amount of absolute time. He uses the SR/GR or IRT math to predict the clock time value on a moving clock for an interval of absolute time on his clock.
For example: according to SR one second of proper time on the observer's clock is predicted to have a clock time value of 1/gamma seconds on a moving clock. According to IRT one second on the IRT observer's clock is predicted to have a clock time value of 1/gamma seconds or gamma seconds on a moving clock.
IRT is a new theory of relativity. The math of IRT includes the math of SRT as a subset. Also the math of IRT is valid in all environments. including gravity. A paper on IRT is available in the following link:
http://www.modelmechaniics.org/2011unification.pdf
Ken Seto
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Steve Agnew wrote on Feb. 22, 2014 @ 23:49 GMT
Rovelli's approach is certainly worth an attempt, but I am skeptical about how useful it will be.
In general, temperature is one dimensional and time is one dimensional and since temperature evolves in time, it is perfectly reasonable to back fit time with temperature as well. The real question is whether or not this will be useful. Not only is this approach complex, the action of temperature is now a hodgepodge of quantum action and gravity action and it just seems like it will a much more difficult approach than even the muddle that is space time.
The paper implies that thermodynamics may reveal a hidden connection between gravity and quantum action. It’s possible and worth looking at, but it is much more likely that without a single quantum action from the start, the tensor algebra will be even more onerous that GR. Given the partition functions of statistical mechanics and the fact that the universe has a very large range of temperatures, the back fits to eliminate time look to be really complex.
Temperature is a property of both matter and action. The matter of an object increases if you heat it up and decreases if you cool it down. Action increases and decreases as a temperature gradient increases and decreases as well. Therefore, temperature as time will be convolved with differential changes in both matter and action. That does not sound very pretty.
To further complicate things, an object can have any number of different temperatures for its different ensembles of internal states: kinetic, magnetic, vibrational, rotational, translational, electronic, ion, electron, hole, etc., and that is before we get to nuclear stuff and black holes. These ensembles can be completely separate, partially, or fully connected. So, good luck.
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Yuri Danoyan wrote on Sep. 2, 2016 @ 17:41 GMT
I would like this discussion turn to other direction:
Symmetry without Time
About the Concept of Symmetry.
It seems to me necessary to throw away the notion "time".... from concept of symmetry and use only notion "space”.
Because the natural symmetry.... only static symmetry without motion.
Motion implies “time”...
Continuous symmetry is tautology.Only discrete symmetry is valid.
“Tautology does not have sense”(Ludwig Witgenstein)
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Georgina Woodward replied on Sep. 2, 2016 @ 19:55 GMT
Hi Yuri, you will have to explain more about why you think symmetry can only be static, and timeless. I can imagine a shape with rotational symmetry, rotating over time without tautology. The change of position in space is not affecting the symmetry. I think you must be thinking something very different. You probably will have to explain further if you would like others to discuss the idea. I don't understand what you mean.
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Yuri Danoyan replied on Sep. 3, 2016 @ 00:21 GMT
Georgina
Firstborn symmetry not included time.
Time entered in symmetry thanks to physics.
Return to embryonic symmetry can simplifay many problem of physics to my mind.
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Georgina Woodward replied on Sep. 3, 2016 @ 01:54 GMT
Thanks for your reply Yuri but I still don't understand what problem time is causing symmetry? Is this something to do with the so called symmetry of time ? There is no problem with the notion that information can be received in the order of production or in the reverse order. Though for EM information (without using recording and playback) the reverse order would require over taking the light speed signal, which we can't do. It is only important to remember the hypothetical time reversal is only reversing the information input to an observer and not reversing the passage of time of the material Object universe. That is the universe of sources of information not the visible output from processing of received information. I may be way off what you were thinking about in regard to time and symmetry, Let me know. Happy to think about your comments.
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Georgina Woodward replied on Sep. 3, 2016 @ 02:30 GMT
Yuri, the article seems to be about time and equilibrium states, in a nut shell. Do your thoughts on symmetry have anything to do with that? How can basic geometric symmetry, as you say'simplify many problems of physics?' I think symmetry is responsible for so called entanglement. What areas of physics are you thinking about simplifying and how will that help?
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Yuri Danoyan wrote on Sep. 4, 2016 @ 02:24 GMT
Georgina
Where there is motion, there is also the speed from 0 to C.
From speed depend deformation, according Relativity.Deformation violates symmetry.
It is paradox...Time should be discarded.
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Georgina Woodward replied on Sep. 4, 2016 @ 03:02 GMT
Hi Yuri,
I'm not sure if you are talking about motion of a symmetrical shape or motion of the observer. In any case if the shape is a rigid solid and if there is insufficient friction to alter the state of the material, its form in underlying material reality will not be altered by the motion. What does alter is how the information emitted from the object is received by the observer, giving apparent deformation. The culprit is not time but the manner in which we gain knowledge of the world via our senses. The relativity of the perception is due to the observer seeing the product of processing the received information. The observer does not actually see the material object itself but the generated representation of it. No paradox.
It does not matter that the material shape can be symmetrical yet be seen asymmetrical as the material object and the seen manifestation are different categories of 'Object'. IE not the same thing,
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