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Eternalism and Presentism (Merged)
Posted: 11 May 2011 06:05 PM   [ Ignore ]   [ # 106 ]
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Gnostikosis - 11 May 2011 01:46 PM

Ok, what is time and how do you put your finger on it? (figuratively)

The nature of time is elusive…..is it most fundamental in the universe or is it emergent, is there temporal flow or is it static, is time infinite, i.e. it has no beginning or end, does it exist at all and how does time relate to causality?

The best scientific theories now do not seem to have definite answers to these philosophical questions on the nature of time.

An encouraging scientific approach/research on the quantum nature of time attempts to address these issues comes from causal dynamical triangulation (CDT) whereby computer simulation findings indicate time does exist as most fundamental, it is not emergent and is more fundamental than space, causality must be preserved in the evolution of space/time, it is dynamic, it flows and it persists without beginning or end i.e. it is infinite.

Here is an interesting you tube video on What is time?
by Professor Renate Loll, one of the researchers on CDT

You wrote:

In measuring time what are you actually measuring other then the revolution of a planet or some other cyclic event?

Clocks only measure periodic motions of physical objects, not time itself.

I’m not saying the concept of time is not useful.

Agreed, but an operational definition of time is not time.

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Posted: 11 May 2011 07:13 PM   [ Ignore ]   [ # 107 ]
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kkwan - 11 May 2011 04:13 PM
dougsmith - 11 May 2011 04:03 AM
kkwan - 10 May 2011 11:54 PM

Philosophical problem:

“The present” raises the difficult question: “How is it that all sentient beings experience now at the same time?” There is no logical reason why this should be the case and no easy answer to the question.

This is one of those claims that sounds profound until you realize it’s true by definition and therefore completely content-free.

What it doesn’t do is to say anything about the relativity of simultaneity which makes a hash of whatever metaphysical point the author was trying to get out of it.

It does not refer to the “relativity of simultaneity” because for all sentient beings (presumably human and all are on the earth), simultaneity is local and does not extend to the Andromeda galaxy, neither are they traveling anywhere near light speed (if it is possible) wrt to others on the earth.

It is a philosophical, not a physics problem.

I have no idea what you’re talking about here.

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Posted: 13 May 2011 02:28 PM   [ Ignore ]   [ # 108 ]
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dougsmith - 11 May 2011 07:13 PM

I have no idea what you’re talking about here.

If all sentient beings are on the earth, it is irrelevant to consider the “relativity of simultaneity” because for all practical purposes, they can all be considered to be in one initial frame of reference, i.e. the earth, which is rotating or traveling through space at a miniscule fraction of the speed of light. Thus, there is no need to invoke SR at all wrt simultaneity on the earth. Newtonian time and mechanics is adequate.

OTOH, we don’t know or might never know whether any sentient beings exist, say in the Andromeda galaxy, so it is pure speculation to think that if they do exist and if that is another initial frame of reference wrt the earth, then SR and the “relativity of simultaneity” should be considered. Also in any experiment on simulteneity, it would take 2.5 million light years for information regarding simultaneity to be transmitted or received from the earth to the Andromedia galaxy.  smile

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Posted: 13 May 2011 02:34 PM   [ Ignore ]   [ # 109 ]
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kkwan - 13 May 2011 02:28 PM
dougsmith - 11 May 2011 07:13 PM

I have no idea what you’re talking about here.

If all sentient beings are on the earth, it is irrelevant to consider the “relativity of simultaneity” because for all practical purposes, they can all be considered to be in one initial frame of reference, i.e. the earth, which is rotating or traveling through space at a miniscule fraction of the speed of light. Thus, there is no need to invoke SR at all wrt simultaneity on the earth. Newtonian time and mechanics is adequate.

OTOH, we don’t know or might never know whether any sentient beings exist, say in the Andromeda galaxy, so it is pure speculation to think that if they do exist and if that is another initial frame of reference wrt the earth, then SR and the “relativity of simultaneity” should be considered. Also in any experiment on simulteneity, it would take 2.5 million light years for information regarding simultaneity to be transmitted or received from the earth to the Andromedia galaxy.  smile

oh oh

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Posted: 06 August 2011 02:03 AM   [ Ignore ]   [ # 110 ]
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http://fqxi.org/data/forum-attachments/RoSandBlockworld.pdf
Relativity of Simultaneity and Eternalism: In Defense of the Block Universe
Daniel Peterson and Michael Silberstein
“...two competing notions of time. The first, originally suggested by Heraclitus, is called presentism. (...) ...a good starting definition for presentism is the view that only the present is real; both the past and the future are unreal. This view is close to, but not exactly the same as, possibilism, which states that the future is unreal while both the past and the present are real. Both of these stances claim to adequately capture the manifest human perception of time. We tend to view ourselves as occupying a unique temporal frame that we call the present that always moves away from the past towards an uncertain future. However, with the advent of relativity, a different stance, whose primary ancient proponent was Parmenides of Elea, provided a viable alternative to Heraclitean presentism. This new stance, eternalism, was translated into the language of relativity of Hermann Minkowski in 1908 to suggest that time and space should be united in a single, four-dimensional manifold. Thus arose the notion of a 4D “block universe” (BU) in which the past, present, and future are all equally real. This view is called eternalism, and two arguments by Putnam[18] and Rietdijk[19] allegedly show that SR with its relativity of simultaneity (RoS) implies that only the BU perspective can obtain. (...)
Generalizing from this result, then, one can conclude that a prior event (the stubbing of a toe) is as real as a later event (a shout of pain). If the first event (A, for instance) occurs in the “present”, then A’ occurs in the future and the RoS argument suggests that the future is as real as the present. Likewise, if A’ occurs in the present, then A occurs in the past and the RoS argument suggests that the past is as real as the present. Both of these conclusions contradict the presentist assertion that the present is real while the past and future are not since past, present, and future must share the same ontological status by the above argument. (...)
Though the traditional formulations of the Putnam, Rietdijk and SSC’s RoS argument for the block universe may be ill-defined in certain parts that leave the argument open to attacks by philosophers of language and presentists, we have reformulated the argument with more specific definitions that make eternalism the likely victor over presentism. Thus, the task before the presentist in defending herself has become even grander; she must 1) find a way to dispel the RoS argument, 2)....”

The relativity of simultaneity (RoS) is a consequence of Einstein’s 1905 constant-speed-of-light postulate so “to dispel the RoS argument” is tantamount to showing that the postulate is false. Let us assume that the Lorentz contraction, another consequence of Einstein’s 1905 constant-speed-of-light postulate, is absurd. Given this assumption, the Michelson-Morley experiment UNEQUIVOCALLY refutes Einstein’s 1905 constant-speed-of-light postulate (c’=c) and confirms the antithesis, the equation c’=c+v given by Newton’s emission theory of light:

http://www.amazon.com/Relativity-Its-Roots-Banesh-Hoffmann/dp/0486406768
“Relativity and Its Roots” By Banesh Hoffmann
“Moreover, if light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd: A stone thrown from a speeding train can do far more damage than one thrown from a train at rest; the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton’s laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations. Yet, as we have seen, Einstein resisted the temptation to account for the null result in terms of particles of light and simple, familiar Newtonian ideas, and introduced as his second postulate something that was more or less obvious when thought of in terms of waves in an ether.”

http://www.pitt.edu/~jdnorton/papers/companion.doc
John Norton: “These efforts were long misled by an exaggeration of the importance of one experiment, the Michelson-Morley experiment, even though Einstein later had trouble recalling if he even knew of the experiment prior to his 1905 paper. This one experiment, in isolation, has little force. Its null result happened to be fully compatible with Newton’s own emission theory of light. Located in the context of late 19th century electrodynamics when ether-based, wave theories of light predominated, however, it presented a serious problem that exercised the greatest theoretician of the day.”

http://philsci-archive.pitt.edu/1743/2/Norton.pdf
John Norton: “In addition to his work as editor of the Einstein papers in finding source material, Stachel assembled the many small clues that reveal Einstein’s serious consideration of an emission theory of light; and he gave us the crucial insight that Einstein regarded the Michelson-Morley experiment as evidence for the principle of relativity, whereas later writers almost universally use it as support for the light postulate of special relativity. Even today, this point needs emphasis. The Michelson-Morley experiment is fully compatible with an emission theory of light that CONTRADICTS THE LIGHT POSTULATE.”

So the crucial question is: IS THE LORENTZ CONTRACTION ABSURD? The following references give a straightforward YES answer to the crucial question:

http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
“These are the props. You own a barn, 40m long, with automatic doors at either end, that can be opened and closed simultaneously by a switch. You also have a pole, 80m long, which of course won’t fit in the barn. Now someone takes the pole and tries to run (at nearly the speed of light) through the barn with the pole horizontal. Special Relativity (SR) says that a moving object is contracted in the direction of motion: this is called the Lorentz Contraction. So, if the pole is set in motion lengthwise, then it will contract in the reference frame of a stationary observer…..So, as the pole passes through the barn, there is an instant when it is completely within the barn. At that instant, you close both doors simultaneously, with your switch. Of course, you open them again pretty quickly, but at least momentarily you had the contracted pole shut up in your barn. The runner emerges from the far door unscathed…..If the doors are kept shut the rod will obviously smash into the barn door at one end. If the door withstands this the leading end of the rod will come to rest in the frame of reference of the stationary observer. There can be no such thing as a rigid rod in relativity so the trailing end will not stop immediately and the rod will be compressed beyond the amount it was Lorentz contracted. If it does not explode under the strain and it is sufficiently elastic it will come to rest and start to spring back to its natural shape but since it is too big for the barn the other end is now going to crash into the back door and the rod will be trapped IN A COMPRESSED STATE inside the barn.”

http://www.quebecscience.qc.ca/Revolutions
Stéphane Durand: “Pour mieux comprendre le phénomène de ralentissement du temps, il est préférable d’aborder un autre phénomène tout aussi paradoxal: la contraction des longueurs. Car la vitesse affecte non seulement l’écoulement du temps, mais aussi la longueur des objets. Ainsi, une fusée en mouvement apparaît plus courte que lorsqu’elle est au repos. Là aussi, plus la vitesse est grande, plus la contraction est importante. Et, comme pour le temps, les effets ne deviennent considérables qu’à des vitesses proches de celle de la lumière. Dans la vie de tous les jours, cette contraction est imperceptible. Cependant, si une fusée de 100 m passait devant nous à une vitesse proche de celle de la lumière, elle pourrait sembler ne mesurer que 50 m, ou même moins. Bien sûr, la question qui vient tout de suite à l’esprit est: «Cette contraction n’est-elle qu’une illusion?» Il semble tout à fait incroyable que le simple mouvement puisse comprimer un objet aussi rigide qu’une fusée. Et pourtant, la contraction est réelle… mais SANS COMPRESSION physique de l’objet! Ainsi, une fusée de 100 m passant à toute vitesse dans un tunnel de 60 m pourrait être entièrement contenue dans ce tunnel pendant une fraction de seconde, durant laquelle il serait possible de fermer des portes aux deux bouts! La fusée est donc réellement plus courte. Pourtant, il n’y a PAS DE COMPRESSION matérielle ou physique de l’engin.”

http://www.parabola.unsw.edu.au/vol35_no1/vol35_no1_2.pdf
Parabola Volume 35, Issue 1 (1999)
LENGTH AND RELATIVITY by John Steele
“The Pole in the Barn Paradox. Now we know about length contraction, we can invent some amusing uses of it. Suppose you want to fit a 20m pole into a 10m barn. If the pole were moving fast enough, then length contraction means it would be short enough. (...) Now comes the paradox. According to your friend who is going to slam the barn doors shut just as the end of the pole goes in, the pole is 10m long, and therefore it fits. However as far as you are concerned, the pole is still 20m long but the barn is now only 5m long: length contraction must work both ways by the first postulate. How can you fit this 20m pole into a 5m barn? This paradox is apparently due to Wolfgang Rindler of the University of Texas at Dallas. Of course the key to this is relativity of simultaneity. Your friend sees the front end of the pole hit the back wall of the barn at the same time as the doors are closed, but you (and the pole) do not see things this way. You are standing still and see a 5m long barn coming towards you at some shockingly high speed. When the back of the barn hits the front of the pole (and takes the front of the pole with it), the back end of the pole must still be at rest. It cannot ‘know’ about the crash at the front, because the shock wave travelling along the pole telling it about the crash travels at some finite speed. The front of the barn has only 15m to go to get to the back of the pole, but the shock wave has to travel the whole length of the pole, namely 20m. The speed of the barn is such that even if this shock wave travelled at the speed of light, it would not get to the back of the pole before the front of the barn did. Hence in both frames of reference, the pole fits inside the barn (and will presumably shatter when the doors are closed).”

http://hyperphysics.phy-astr.gsu.edu/Hbase/Relativ/bugrivet.html
“The bug-rivet paradox is a variation on the twin paradox and is similar to the pole-barn paradox…..The end of the rivet hits the bottom of the hole before the head of the rivet hits the wall. So it looks like the bug is squashed…..All this is nonsense from the bug’s point of view. The rivet head hits the wall when the rivet end is just 0.35 cm down in the hole! The rivet doesn’t get close to the bug….The paradox is not resolved.”

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Posted: 06 August 2011 05:15 PM   [ Ignore ]   [ # 111 ]
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I see that Chris Crawford hasn’t gotten here yet, so I’ll do it.

Utter nonsense.

Occam

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Posted: 27 November 2011 12:42 PM   [ Ignore ]   [ # 112 ]
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Assuming Eternalism, I’ve been wondering what it would be like to experience the world without the illusion of time passing or traveling through time.

I can’t see anyway it’s possible without an illusion.

Stephen

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Posted: 27 November 2011 02:10 PM   [ Ignore ]   [ # 113 ]
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StephenLawrence - 27 November 2011 12:42 PM

Assuming Eternalism, I’ve been wondering what it would be like to experience the world without the illusion of time passing or traveling through time.

I can’t see anyway it’s possible without an illusion.

Dunno. At each minute you’re thinking “Time is passing into the future!” and that’s part of the manifold.

There’s also something about the causal arrow here, where we’re privy to information to one temporal side of us but not to the other.

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