Time at the Event Horizon

Lawrence,

"Motion exists independent of measurement. The planets clearly orbited the sun long before people began to measure their celestial positions and velocities."

Exactly. Time is the changing configurations of what exists. As such it is these events going from future potential to past circumstance. It is not some meta-dimension along which the present moves from past to future. We are mobile creatures and thus tend to view the future as the space in front of us, that we are about to traverse and the past as that path which we have already traveled. It is this basic orientation on which the notion of time as an adjunct to space is based.

As I pointed out previously, it is a non-problem for most of the people on this planet whether the sun revolves around the earth, or the earth rotates relative to the sun. Depending on your perspective, it could be argued that both are true. It's just that when you try to make sense of planetary orbits that it becomes necessary to accept the earth rotates relative to the sun. Now we have these physical theories describing time as a form of static block, in which the present's location is as relative as one's location in space. Also theories trying to project deterministic processes onto a probabilistic future and come up with a multi-world scenario in which all possibilities happen, rather than considering it's the probabilistic future collapsing into the determined past, etc.

Motion is relativistic and subjective, yet we try to reduce the cumulative effect down to a one dimensional narrative path. This has been going on since the beginning of history. In fact it is the basis of history. Consider how we have cut the cycles of the moon to fit the solar year. Our religious and civil traditions are a function of creating a narrative storyline that the whole group can think of as their cultural foundation.

E.O. Wilson described the insect brain as a thermostat, in that it essentially reacts to temperature changes. In a very real sense, that is how our right brained parallel processing function works, in that it is reacting to the energies of the present. It is our left brained serial processing function that is essentially a clock, in recording the series of cause and effect circumstances through which we, as individuals pass. We then weave our experiences into that of others and create a group narrative. So it is extremely natural that we should view the process of time as a passage, but that doesn't make an effective explanation for what is happening. There is no fourth dimension along which we travel. It is the changing events which are created and replaced by the sum of activity.

My point is that motion existed prior to anyone measuring it. Also time is something which exists without necessarily measuring the motion of something. Motion is in its simplest form v = dx/dt, and both x and t are geometrical quantities and the velocity intertwines the dx with the dt. One does not proceed from the other. They both just "are." Attempting to get time from motion or motion from time is a "chicken & egg" problem. This is carried further with spacetime where c is an invariant. I think the final state of the universe is an empty Minkowski spacetime. The geometry of the spacetime is such that null directions define a "c," even if there are no photons, and this converts spatial distance into temporal ones. To say anything much further is to get into a thicket of philosophical handwringing.

Cheers LC

Lawrence,

I don't guess I'll not be able to get you out of your thicket either, but maybe one more try;

Lets not say motion, since that implies orientation. Let's just say "activity," as in fluctuation.

If you have a level of activity, then it will qualify as having temperature, whether or not there is someone to measure it. Just as that activity will affect change, whether or not there is someone to measure it. Now it would be impossible to have this activity without it causing change, but the various stages of change do not exist in some extra dimension. They are being created and dissolved by that activity.

Now if you happened to have read many of the various theories of time posted in last years contest on the nature of time, you might have noticed that many of them, by eminent members of the physics community, posted various permutations of the notion generally referred to as "block time," in which that very notion of these events do exist in some other dimension. Many of them where quite inventive, such as how the various dimensions of space and time might manipulated to that we could travel in time, just as we can travel in space. Now if you were to understand time as these events being created and necessarily dissolved, since the same energy is required to manifest the next event, this notion of block time, that that "dimension" is something more than a convenient construct, is ludicrous. Thus understanding why I find the idea worth disputing.

Mr. Crowell, Mr. Merryman,

In looking at the dialogue between the two of you, I can't help wondering whether you've found time to read my essay, 'On the Impossibility of Time Travel.' I believe it addresses some of the questions you're debating, and puts them in a worthwhile perspective. My view of time can be summarized very simply and succinctly: What we've traditionally thought of and referred to as "the flow of time" is, in reality, nothing more and nothing less than the evolution of the physical universe.

Cheers

John And Lawrence

Nice discussion. We all 3 agree on one point: motion is independent on time.

So what is time ?

My definition is: Physical time is run of clocks. Clocks/time are measuring devices invented by man.

Do we still agree on that ?

If yes following question is to be answered: How that we experience motion in linear time ? The answer is: Linear time is a mind construct based on neuronal activity of the brain.

With this question of time is resolved: Universe is timeless. Time/clocks are invented to measure motion.

This is pragmatic solution of time. Barbour would like to abandon time in physics. My opinion is that is not realistic and has no sense.

Time is esential part of physics. We have only to understand it well.

Here Godel vision is fully developed and has concrete results:

Universe is without time, timeless, time is a measuring device merely.

Yours Sincerely Amrit

PS Dear J.C.N. Smith

You say: "the flow of time" is, in reality, nothing more and nothing less than the evolution of the physical universe.

I would not agree with that. Universe is timeless, evolution of universe is timeless too. We measure evolution of thde universe and in this way time enters, but only in our vision in our experience. Universe itself is timeless. Universe is NOW.

Read my essay: Today observer in physics is imprisoned in neuronal linear time. He experiences motion through the neuronal time.

Conscious (awakened) observer is aware of neuronal time. He experience motion directly as is perceived in eyes.

perception of motion - mind processing in neuronal time - experience (unconscious opbserver)

perception of motion - experience (conscious observer)

This is where physics meets with knowledge and awareness of how mind functions, with esence of Bhuddist meditation of watching, witnessing the mind

PS

to read more, see my article on file attachedAttachment #1: 1_Bridging_Observer_and_Observed.doc

sorry here is last versionAttachment #1: Bridging_Observer_and_Observed__amrit_sorli.rtf

The physicist's operational definition of time: Time is that which is measured by clocks.

The physicist's operational definition of a clock: A clock is a device which measures time (often followed by some sort of obfuscating gobbledygook about how clocks are based on a "regular motion," which, of course, one could only determine by using a clock).

Just a wee bit of circular reasoning perhaps? And we still wonder why modern physics is in a state of disarray?

The "mind" is not sufficiently well understood to serve as a credible basis for a theory of physics.

Cheers

Dear Smith

There is no one experimental evidence of physical time existing beyond clocks run. So the new more adequate, correct definition of time in physics is:

PHYSICAL TIME IS RUN OF CLOCKS.

For example clocks run slower in stonger gravity not because 4-th coordinate of space-time there is shrinking, but because this is how universe functions: material change run slower in stronger gravity field.

Shrinking of 4-th coordinate of space-time is only a math description.

J.C.N. Smith,

"Time is measured on a clock," is a reasonable definition of time. I would say that basically this is about all one needs to consider.

There is a whole lot of stuff in physics which has a strange existence, and a little circularity to it. Take Newton's second law F = ma. Here you have a dynamical quantity (force) equal to a kinematic quantity (mass) times a geometrical one (acceleration). From a subtle categorical perspective this is a really funny equation, one which might drive medeival scholastic types nuts. Yet I suspect few physicists lose a lot of sleep over this.

Time and all geometric quantities are I think on some equivalent level, whether these are distance, time, velocity, acceleration and so forth. Now acceleration is a bit different because it is not a proper frame to observe physics from, but to be honest I think advancement in quantum gravity might put acceleration on the same footing as velocity. Which ever is the case distance and time are equivalent and converted into each other by the speed of light and transformed into each other on frames by the Lorentz group.

There really is not a lot of reason to get wrapped up in philsophical ideas beyond this. If time and distance are categorically equivalent, then so is velocity v = dx/dt. There is nothing else beyond this, and no need to get into strange ideas about time not existing, or time as something induced by motion or ... . These are just geometric categories which make physical theories work.

Cheers LC

Distance, velocity and acceleration are primary physical realities independent on observer and measurment.

Time/clock is a measuring device introduced by the observer.

So time you cannot put in same catergory as distance, velocity and acceleration.

yours amrit

""Time is measured on a clock," is a reasonable definition of time. I would say that basically this is about all one needs to consider."

I would have a minor quibble with this. If there is no definable regular motion, we may not be able to assign a set value to units of time, but as long as there is activity and the changing circumstances that result, there will still be past events and the potential for future ones. One of the core principles that relativity makes over Newtonian physics is that there is no absolute measure of time. Even the most regular of cycles will change if variables such as gravity or velocity are changed. Time and measuring time are two different things.

Mrit said, "Time/clock is a measuring device introduced by the observer."

But also is a ruler.

Cheers LC

John you say: Time and measuring time are two different things.

No, there no evidence for that.

Clock (clock run clock motion)is a measuring device for other motions.

All motion run in space.

Physical time is exactly run (motion) of clock.

Space itself is timeless.

We live in NOW.

Mr. Crowell,

You wrote, "There is a whole lot of stuff in physics which has a strange existence, and a little circularity to it. . . . . Yet I suspect few physicists lose a lot of sleep over this."

Perhaps the only physicists who might lose just a tiny little bit of sleep over this sort of inconsequential circular logic silliness are the ones who are trying to understand why General Relativity and Quantum Mechanics don't exactly mesh up?

Cheers

It is not that big a deal really. Think of the old school definition of matter, "Anything that has mass and occupies space." That is sort of circular. To be honest I doubt that much real progress in physics will happen through philosophical debates over definitions. That projects things back into scholasticism.

Cheers LC

"To be honest I doubt that much real progress in physics will happen through philosophical debates over definitions."

On the contrary; it is work which is not guided by clear definitions of terms which will not lead to much progress in physics. Philosophical discussions leading to clear definitions of terms certainly can lead to progress. We obviously will need to agree to disagree on this point.

Cheers

amrit,

We live in now, but there is activity in now and it keeps changing the configuration of now. Think back to when you were a small child. You were every bit as aware of the now as you are today, but what you are aware OF has become much more complex as has your understanding of it.

Time isn't a dimension along which the present moves. It's the process of what is present changing form. Whether it's a clock like metronome, or random activity.

J.C.N,

"My view of time can be summarized very simply and succinctly: What we've traditionally thought of and referred to as "the flow of time" is, in reality, nothing more and nothing less than the evolution of the physical universe."

The point I like to emphasize is that when we understand time as process, rather than dimension, then it goes the other direction. Since we are not traveling the fourth dimension from the past into the future, it is the consequence of process/evolution which turns the future into the past. On the philosophical terms that Lawrence objects to, this means we are integral to the events and not just points of reference navigating them. It doesn't preclude free will, just means reality affects us to the degree we affect reality. We are defined by our limits and limited by our definition.

Sorry I haven't been following the current contest. It's been a time thing and what little internet time I have has been mostly used to clock the debt bomb.