Alternative Explanation Of Absolute Time, think the title says it really...

You need to define which frame you are talking about. The clock of a relatively faster frame is only observed to slow from the frame it is moving relative to, but the "faster" moving frame observes that other frame to be the one moving with its clock being observed to run slower.

Blanket statements like "traveling at higher speeds" are only ever relative, with a reciprocal relationship with the frame it is wrt.


The relativity of simultaneity has nothing to do with the signal delay of the finite speed of light. As you say, we are completely aware of that fact, and we can easily account for it. When we do, events observed as simultaneous in one frame STILL aren't simultaneous in another.

Presentism is a philosophical doctrine that is not anywhere near as empirically rigorous as the relativity of simultaneity. Guess what, it is presentism that would bear the onus of debunking the RoS, not the other way around.

This post has been edited by synthsin75 on Apr 16 2012, 01:17 AM

Having received a gloss on the subject, presentism doesn't sound like it needs to be debunked.

If presentism is the source of mik's problems with Relativity, it is equally the source of his problems with History and Literature, and possibly Current Events.

As stated, I believe that mik's problem is chauvinism and over-reliance on preconceptions, two traits I find distasteful in philosophers. I prefer philosophers engage in a reality with more than one person in it.

[Moderator: A full discussion of length contraction as a natural consequence of accepting the principle of relativity and the Poincaré transformation was made in a previous post. (Click Here). By order of the Moderator, mik and Mazulu are required to read this post, to understand the post, and to ask questions about what things mean if there is any doubt about understanding before any further discussion on the topic of relativity. The penalty for not fully understanding this post before continuing will be a complete loss of faith in your good intentions by the moderator.]

This post has been edited by rpenner on Apr 16 2012, 05:26 AM

rpenner,

I read the required link/post (again.) I am not a mathematician but I am an avid philosopher of science, through which the numbers relate to meaningful concepts and to "the real world" to which those concepts refer.

You say:

Here is a quick review of presentism as contrasted with eternalism and the Block Universe concept of 4-D relativity (starting with the basic ontology of time and review of your quotes on the subject):

me, 4/12:
My "claim" was that time is not 'something' that slows down as we observe clocks slowing down.
...
And "Now" IS the present. It doesn't depend on who sees what and when at whatever distance from the source of light/info and travel time for info about it. "

rpenner:

Also, check out the “Presentism, Eternalism, and The Growing Universe Theory” subsection at the Stanford encyclopedia of Philosophy site, “Time” section.

Also Wikipedia on “four-dimensionalism.

So your four dimensional universe reifies time and space in a way that claims that everything that has ever existed or ever will exist are "equally real."

So "real and present"loses its meaning and the "concept" of "slices of spacetime" can contain past and future as "now present"... conceptually speaking if you ignore that future events are not yet present and past events are no longer present.

Gotta go. Forgot a reference above (the "]Analogously...," quote. Will find it when I come back.

This post has been edited by mik on Apr 16 2012, 09:04 PM

That need not be my position. For example, I may describe things in my personal past light cone (including boundary) as equally real in that my present state can be formulated as a function of this personal past. Or I may treat my personal slice of simultaneity as real-to-me while allowing someone else may with equal validity treat their slice of simultaneity as real-to-them.

Both of these viewpoints are compatible with special relativity that says the meaningful-to-us portion of our past is bounded by our personal past light-cone and our future prospects are bounded by the our future light cone, and that which is outside of the light cones is presently beyond our ability to influence just as we are presently beyond its ability to influence us.

What is solipsism is to deny that the other person is real. What violates the principle of relativity is to claim that the other person is real and still deny that other persons reality is as real as your reality, all things being equal, mutatis mutandis.

Do you have any questions about the above linked post, its use of coordinate system S (with coordinates x and t) and S' (with coordinates x' and t'), on the relativity of simultaneity, the principle of relativity or what ties them all together? Was it clear that a Poincaré transform allows one to relate S and S' ?

This post has been edited by rpenner on Apr 16 2012, 10:44 PM

The main benefit of the methodology of science is that science is progressive -- it gets better over time as more things are added. It's the part of the human civilization that is learning.

http://scienceblogs.com/startswithabang/20...ing_im_wron.php

So when I evaluate claims that "The Big Bang is Wrong" or "Global Warming is Wrong" or "Evolution is Wrong" or "Time does not Exist" or "Maxwell's Equations are Wrong" or "Special Relativity is Wrong" or "I am not a plagiarist" I want to look at some items.

• Does the person show evidence that he fully understands the topic or are they arguing against some sort of straw-man?
• Does the person show evidence that they are making a fair evidence-based argument, or are they just promoting their gut feeling over evidence provided by observation of phenomena?
• Is the viewpoint objective and communicable or does it rely on ephemeral philosophical or semantic distinctions?
• Does the viewpoint lead to a predictive understanding of phenomena or is it just some outlier data that stands outside the collection of the best and most reliable observations?

It means nothing to me that a bunch of crackpots and science outsiders are willing to stand under a common umbrella to rally against the prevailing view. Their ideas must stand or fall on their own. And when they hold contrary positions it is clear that they cannot convince their fellow outsiders of their views, let alone the science-educated mainstream.

It appears that niels' suppositions don't begin to meet the minimum requirements for advancing human knowledge.

This post has been adapted from here for general educational benefit.

This post has been edited by rpenner on Apr 17 2012, 11:11 PM

Great post. Ethan's wisdom will fall on many 'hollow spheres with ears' at physforum.

rpenner,

Please respond to the Wiki quote on four-dimensionalism:

and my comment:

"So your four dimensional universe reifies time and space in a way that claims that everything that has ever existed or ever will exist are 'equally real.' "

Are living dinosaurs and human colonies on Mars “real and present” in some “slice” of “four dimensional spacetime” (a concept) as seen from another frame of reference with each frame of reference having its own 'now' and its own reality?

From your linked post, which I re-read:

Regarding the first sentence, you have never addressed the ontological challenge to the reification of time, making “something” of it besides the obvious “elapsed time” as things move from one point in space to another.
We all know that clocks slow down relative to each other as above yet the challenge to time reification still stands unanswered. The physical process of oscillation slows down in clocks at higher speeds relative to those at lower speeds or in lower gravity fields (higher elevation.)
But what is "time," that "it" slows down?

You never commented on the quote above about “coordinate systems” like 4-D spacetime being in “conceptual space” as distinguished from actual objects moving through space as time passes. Rather, the conceptual coalescence of space and time are taken for granted.

I did not understand why you said, “Ignoring two dimensions of space, we can establish the inertial coordinate system S ...”

Why ignore two dimensions of space?
Space is three dimensional. Time elapses as things move. Call it a fourth dimension but "it" is not an entity combined with space (ontologically speaking.) Everything you wrote beyond the above quote was math. I already said that I am not a mathematician, but I do understand the difference between a coordinate system and the “real world” which it “maps.”

A couple of missing links from yesterday's post:

Stanford Encyclopedia of Philosophy on "Time":
http://plato.stanford.edu/entries/time/

The Reference Frame: Presentism vs Eternalism
http://motls.blogspot.com/2008/05/presenti...eternalism.html

Finally, "real to me" and "real to them" puts priority on frame of reference *as Reality.* Philosophically, beyond that dictum of relativity, things are as they are in the "real world" regardless of frame of reference. "Length contraction" (as per the other thread) is a good example. It is up to science to figure out whether, for instance, earth is a very oblate spheroid, as "seen" from very high speed, or nearly spherical as "seen" from living on it or from orbit around it.

"What is solipsism is to deny that the other person is real. What violates the principle of relativity is to claim that the other person is real and still deny that other persons reality is as real as your reality, all things being equal, mutatis mutandis."

The above statement about "the 'real world' regardless of frame of reference..." does not deny anyone's reality. It elevates "reality" beyond how it is *observed* from different frames of reference. This point has never been addressed here.

I put it to you as I did to synthsin75: Is the flattened earth "equally valid" with the spherical earth just because "another person" flying by at very high speed might see it that way... and we must 'respect his reality'? No.

The philosophy of science called realism says, as above, that the world IS as it IS, not as different frames of reference *see* it. Accordingly, IS means the Present, and the Present IS the Present everywhere, transcending relativity's reification of space, time and spacetime.

Again, please address presentism vs eternalism, the latter of which describes a "block universe" where past, present and future are somehow all Present (depending on frame of reference.) Do you actually believe that?

and my comment:

"So your four dimensional universe reifies time and space in a way that claims that everything that has ever existed or ever will exist are 'equally real.' "

Classically, one should master logic and rhetoric before attempting philosophy. Your insistence that I respond makes little sense when I have already responded and called out that your oversimplification in terms of absolute presentism versus eternal block time is an example of the fallacy of false dilemma and I gave two other possible philosophical viewpoints on what is real. I quote this interaction for your benefit:

And for pedagogical reasons, the text you quote appears to come from here: Wikipedia:Eternalism (philosophy of time)

Real is in scare quotes in this wiki page because the concept is only of metaphysical import. Contrastingly, personal-past-conism limits one to asserting as metaphysically real that which in principle one could discover or physically could influence one, while relativity-informed-presentism involves personal skew realities which are fully commensurable only when the individuals are in the same state of motion (and for the GR-eductation version, in the same place). These philosophies are metaphysical in that those that are compatible with relativity are not distinguishable by physical experiment. They are opinions about intangibles.

The postulated human colonies on Mars seem to require strong, possibly unphysical, assumptions about terrestrial economics. Even if I subscribed to the Wikipedia gloss on Eternalism, living dinosaurs are "knowable, real, and past" while human colonies are "unknowable, potentially real, and future." Both the light cone of physics and English tenses seem adequate to distinguish them from things that conventionally are "real and present."

http://www.physforum.com/index.php?showtop...ndpost&p=516338

Physics does not respect elapsed coordinate time as a fundamental and invariant observable to all observers. Physics does respect elapsed proper time and light cones as fundamental and invariant. From multiple light-cones a geometry of a 3+1 space-time emerges, and that requires a coordinate time to be distinguished if all hypothetical events are to be labelled. The Poincaré transform allows one to relate the labels of one coordinate system to another. Change T' if you want to talk about the coordinate system of "then", change X' if you want to talk about the coordinate system of "over there", change µ' if you want to talk about the coordinate system "passing you by" (omitted are angles required in the 3+1 system in the event the coordinate system is on its head). Empirically, coordinate time is part of models so we can relate measurements to proper time. See also http://www.physforum.com/index.php?showtop...ndpost&p=516449 for other examples of quantities more empirically justified as real than coordinate time.

If coordinate systems S and S' are in relative motion, ( Δx=0, Δt=Δτ ) describes a motionless clock tick, while ( Δx'=vΔτ/√(1 − v²/c²), Δt'=Δτ/√(1 − v²/c²) ) describes the same tick with different clocks and rulers. But from both of these:
(cΔt)² − (Δx)² = c²(Δτ)² = (cΔt')² − (Δx')²
So the physical model of reality speaks to the reality of elapsed proper time even when all we have are the coordinates in which the clock is moving. Elapsed proper time is vital, non-removeable part of all fundamental physical theories.

S has the Δt of its unmoving clocks and S' has the Δt' of its unmoving clocks, but comparing Δt to Δt' is a case of apples and oranges when S likes apples precisely as much as S' likes oranges.

"higher speeds" implies a physically distinguishable absolute standard of rest, which is neither evidenced nor argued for. And in GR it is clock which are lower in a gravity well that tick slower.

We are talking about the ratio of proper time to coordinate time, ∂τ/∂t, which is 1 in the above example for S, and √(1 − v²/c²) < 1, for S' where the clock has a relative motion of v.

Coordinate systems are man-made systems for labeling sections of reality with respect to geometry. The physics that demands the real consequences of light-cones and their interrelations implies that such a geometry is real. It is not, however, Euclidean geometry but hyperbolic. I emphasized this in my April 13th post when I explicitly chose a inhomogeneous hyperbolic rotation with parameter µ'.

I skipped two dimensions because I only needed one time-like dimension and one space-like dimension to talk about velocity and relativity. Additional spatial dimensions would require me to include 5 angles and two more translation parameters to talk about the most general form of the Poincaré transform. This would seem to be a disservice to the reader.

Everything past that point was high school level algebra with all the heavy lifting done for you. I respected your lack of mathematical education.

Today's physical models are currently experimentally indistinguishable from observation. Therefore, on a economic basis where learning costs resources, knowledge of the map is superior to knowledge of the territory because the map describes the whole of the experimental record. While I deliberately used an antique physical model, it passes tests where the influence of gravity is negligible at the parts-per-trillion level. So even crippled by this forum's complete unsuitability to sketch how physically meaningful light cones requires the geometry of light cones to be reflected in reality, exposing you to 1+1 special relativity is a distillation of empirical observation for the case where the relative motion and the direction of length measurement are in the same direction.

Events that happen have an absolute reality that can't be denied just because someone has different clocks and rulers. The geometry of space-time and light cones at least reflects something that is real. Points in space time where nothing happens (also technically called events in SR) are therefore real because the geometry requires the midpoint to exist. The coordinate elapsed time or coordinate distance however are tied necessarily (so physics informs us) to a frame of reference.

Huh? A sphere is mathematical idealization. What something "really is" is also a mathematical idealization. In SR, a sphere at rest is congruent with a flattened sphere moving at high velocity. In that SR reflects the geometry of reality, it is not inconsistent to say the Earth is both an approximate sphere at rest and approximate pancake at high velocity.

The above statement about "the 'real world' regardless of frame of reference..." does not deny anyone's reality. It elevates "reality" beyond how it is *observed* from different frames of reference. This point has never been addressed here.

I put it to you as I did to synthsin75: Is the flattened earth "equally valid" with the spherical earth just because "another person" flying by at very high speed might see it that way... and we must 'respect his reality'? No.

I disagree.

I believe that nothing you have said about Reality is actually informed of by observation of more than the most pedestrian and parochial kind. By studying physical law as modeled by physical theory, I believe that your Reality is more hubris than real.

I don't recognize the philosophy of science as other than methodological empiricism.

Just because you capitalize Reality and the Present, doesn't mean the universe respects your opinion. Einstein went down the path of chasing what was beautiful to him, but in the last twenty years of his life contributed nothing close to important as the theories of his youth. His last hurrah was the EPR paradox -- a thought experiment intended to show that quantum physics was ridiculous; starting in the 1970s experiment and experiment showed that the actual universe was just as ridiculous as Einstein thought the mathematical model of quantum physics was. The universe if it respects reality is not local, and if it respects locality, it is not real.

Why are you insisting on this false dilemma?

RPenner, respectfully, I have, by way of analogy, taken the liberty of rewriting your remarks to reflect what a critic of cubism or post-impressionism or any of many artistic movements might have once have had to say...

-------------------------------------------------------------------------------------
It means nothing to me that a bunch of Bohemian wackos and commercial artist outsiders are willing to stand under a common umbrella to rally against the prevailing artistic views. Their aesthetic notions must stand or fall on their own. And when they hold contrary positions it is clear that they cannot convince their fellow outsiders of the value of their work, let alone the art-educated mainstream.
-------------------------------------------------------------------------------------

It would have been a smart position to take, from the market-place standpoint, but would not have been the manner of position conducive to moving the arts forward. Mainstream scientists "consolidate" and propagate and, yes, even constructively advance the status quo IMHO. And they are far more often right than wrong until they are wrong -- all at once -- when a paradigm shift occurs. But no worries there because there is safety in numbers and there is little downside to being wrong when you have all that company in wrongness. [As opposed, for instance, to the guy who (or so I read) recently resigned after being wrong about faster than light neutrinos]

When did the cubists become popular? Was it before or after 1905? If after, does that mean there were no cubists before that point in time? The failed cubist of 1899, whoever he or she may have been, was the equivalent of a crackpot and scientific outsider.

In other words, what I am trying to gently get at here is that it is faulty logic IMHO to suggest that one's failure to convince others necessarily reflects a failure in one's understanding. It may also reflect a failure in the understanding of others.

One can argue probabilities here, but, without undue explanation, that's an argument that can cut more than one way.

- RF

This post has been edited by Raphie Frank on Apr 18 2012, 09:18 AM

“Yes, it is true that sometimes unusually intelligent and sensitive children can appear to be stupid. But stupid children can sometimes appear to be stupid as well. I think that's something you might have to consider.”
― Douglas Adams, The Long Dark Tea-Time of the Soul

Your analogy is wacko. You put scientific illiterates [crackpots and cranks] in the same group as skilled artists. Cubism wasn't bullshit. Everything the cranky crackpots tout IS useless bullshit. They're not being ignored for any reason other than they're full of crap.

rpenner,
Seems you misunderstand what presentism has to say about the meaning of the reification of time in relativity, specifically how the latter is a case of eternalism in which things past and future are "real" in various frames of reference using the light cone *model.*

But, at this point, I would settle for clarification of the "real shape of earth" in which length contraction insists that a flattened earth is just as real as a nearly spherical one, given that "all frames are equally valid" and a near 'c' fly-by frame might "see"/measure it as a very oblate spheroid.

You said:

Earth *is* nearly spherical. Earth science knows exactly how much longer its diameter is through the equator than through the poles. Earth in the 'real world' does not in fact "flatten" because of mathematical/relativistic considerations.
me:

You disagreed. Because of the "no preferred frames" dictum, you believe that Earth *is* "both an approximate sphere... and approximate pancake" depending on frame of reference, whether at rest or at high velocity. So there is no natural reality to 'the world' independent of frames of reference. The latter create reality. Earth is both nearly flattened and nearly spherical... depending on your point of view. Some philosophy!** (See below)

You continued:

Do you really think that insisting on the well documented, precisely observed and measured Earth described above as the accurate description is "pedestrian and parochial?"

You:
“The universe if it respects reality is not local, and if it respects locality, it is not real.”

Really? Earth is a real local part of the universe. No one is claiming that the universe *is local,* but each part of it is *real* independent of how it is observed/measured.

** It is easy to see how relativity came to endorse the philosophy that reality depends on observation and varies according to how it is observed.

From the Collected Papers of Albert Einstein, Edited by J.J. Stachel and Robert Schulmann
(Princeton Univiversity Press, 1987); Letter to Eduard Study from Albert Einstein
dated Sep 25, 1918:

And so modern relativity adopts the philosophy that there is no "real" world. Reality depends only on what we place in the metaphorical "drawer." We create our own reality.

Yet, if intelligent life never evolved 'the world' (universe and all its parts) would still exist and still have all its intrinsic properties, in and of themselves, without ever being observed or measured... or placed in whatever "drawer" we see fit to call meaningful.

A sphere at rest is defined by a locus of world-lines with respect to it's center world-line so that for any two events, with one on the center world-line and the other on the sphere surface we have in the coordinate system S: u = 0, Δt = 0, (c Δt)²−(Δx)²−(Δy)²−(Δz)² = −R² where R is the proper radius of the sphere.

So we have a center world line:
x = x₀ + 0 t, y = y₀ + 0 t, z = z₀ + 0 t
and a two-parameter (two-dimensional) family of surface world-lines:
x = x₀ + R (cos φ) (cos θ) + 0 t, y = y₀ + R (cos φ) (sin θ) + 0 t, z = z₀ + R (sin φ) + 0 t
Leading to Δt = 0 ⇒ Δx = R (cos φ) (cos θ), Δy = R (cos φ) (sin θ), Δz = R (sin φ)
and (c Δt)²−(Δx)²−(Δy)²−(Δz)² = −R²

Limiting ourselves to motion in the x direction, the S' labels for the same physical system is:
Δz' = Δz = R (sin φ)
Δy' = Δy = R (cos φ) (sin θ)
Δx' = Δx cosh μ' + c Δt sinh μ' = R (cos φ) (cos θ) (cosh μ') + c Δt sinh μ'
Δt' = (1/c) Δx sinh μ' + Δt cosh μ' = (1/c) R (cos φ) (cos θ) (sinh μ') + Δt cosh μ'

Looking at the three-dimensional slices of this with Δt' = 0, we have the following result in the relativity of simultaneity:
v = c tanh μ
Δt = (−v R/c²) (cos φ) (cos θ)
Δt' = 0
Δx' = R (cos φ) (cos θ) √(1 − v²/c²)
Δy' = R (cos φ) (sin θ)
Δz' = R (sin φ)

And so the universal description of a sphere in special relativity is:
Δt = 0 ⇒ (Δx)²/(1 − v²/c²)+(Δy)²+(Δz)² = R²
where v is the motion of the sphere in the x-direction (possibly zero).

This same description describes an unmoving sphere as congruent to a highly flattened sphere moving at high velocity with the same proper radius.

So you refuse to learn anything. Bring out the machete for all those who continuously disrespect or ignore the scientific literature.

So... No comment on the utterly absurd assertion that Earth is both nearly spherical and nearly flattened, depending on how you look at it?

...Or on Einstein's philosophical influence on what relativity theory considers "real?",i.e., the term is meaningless and there is no "real Earth" independent of variations in how it is observed?

... or on the "thought experiment" challenge of a "world" with no intelligent life to "see" it this way or that way?

I guess everything would just disappear if no one were around to bestow "reality" on it by observing and measuring,... as its existence an properties depend on our omnipotent powers of observation and measurement.

Oh well. You all have a right to your opinions, even if you think Earth's shape depends on how you look at it.
Never mind.
Ps: I'm still not a mathematician, but I do know that neither math nor length contraction theory can make Earth flattened, i.e., "in reality", even if Einstein thought reality is just what we choose to stick in a theoretical "drawer"... no such thing as reality.


This post has been edited by mik on Apr 19 2012, 09:49 PM