Assertion of an "absolute now" from "What is 'spacetime' really"

[Pyrotex]

Here I am, with a brain the size of a planet, and they send me to fetch the aliens out of the airlock. :)

[Michael Mooney]

This will be my finale' unless a miracle of understanding happens.

 

First I'll wrap up the IQ thing.

Many of you are scientists.

What do you think is the probability that the Stanford-Benet Intelligence Scale, which I took in 1957 (scoring 170) and the Weschler Adult Intelligence Scale which I took in 1968 (scoring 178) together reflect an "administrative erro"r in accurate scaling of my IQ?

(I'll set aside the insinuation for the moment that I am lying.)

 

My guess is that the probability is fairly close to zero when considered in conjunction with the fact (not previously mentioned) that my Graduate Record Exam score, as an undergraduate in 1967 was at the 99th percentile. (That is as high as it goes, to state the obvious.)

 

Next... regarding the ontology of "spacetime":... I have been accused of having nothing to teach on ontology. I studied ontology in some depth in my course of study for my master's degree in philosophy.

 

The question, "What is Spacetime, Really?" is an ontological question appropriate to this "Philosophy of Science" section. I was originally wary of such placement of my question, for good reason as it turned out. Hardcore materialistic scientists don't have much "use for" such "metaphysical" inquiries as "What is it, really?"... a kind of a 'foo-foo' realm for those whose only focus is empirical evidence and mathematical quantification of theoretical 'quanta'... often with no observable referents in the "world."

 

So almost all of my references to the ontological inquiry into the actual nature of space, time, and "spacetime" as entities with certain properties were, by-and-large ignored, usually with no reply at all...

 

And often there were long lists of reference to relativity cites that I "should study" before questioning such "established entities" as "curved, expanding, shaped" non-Euclidean space (now *so* well established as Truth), "dilating time" and the wedding of the two as (the Emperor's New Fabric) "spacetime", which all intelligent scientists can "see" quite well and admire with very sophisticated relativity equations.

 

As I have mentioned, one of my "gifts of genius" (I have no "modesty" nor do I aspire to acquire it)... is to recognize nonsense wherever I see it, even if it is proposed by celebrity-level credentialed scientists.

 

Case in point:

I saw nonsense in Hawking's "singularity cosmology" and called him on it. ("Infinite mass density in zero volume" as the origin of the Big Bang... for those not familiar.) He 'recanted' several months after I revealed the absurdity of the concept... on "Myspace." This is a chronological fact whether or not he or his staff ever saw my posts there debunking his cosmology from a singularity. I also hit hard on the "something from nothing" nonsense in those critical posts... but the forum response, as usual, was that "the laws of physics break down in a singularity" and "where all the material came from" is beyond all possible theory. (Not really. The revised Bang/Crunch I have proposed explains it very reasonably.)

 

Other examples of "nonsense" as i see it:

That there is no "empty space." There is no void... even that is full of "stuff.""It's all stuff."

(and it curves, expands, has shape... yawn!... does tricks in response to mass... etc.)

 

That time is an entity.That there are local time environments around clocks in different inertial frames of reference as accelerated to different velocities or at different altitudes with different gravitational forces upon them... or around muons giving them longer lifespans (than measured under other conditions) as they approach earth in their natural environment.

 

In my own "deluded" mystical mind, I have no doubt that all of the above ontological issues will eventually be resolved by unbiased scientists not under the "spell" of relativity and the limits of "local perspective" upon which it is based (and for which it is an excellent tool... which, as stated, seems to blow everyones mind here. Like I just don't understand relativity as is obvious in all of the above.)

 

Good bye. I wish you all good progress in getting over the absolute hypnotic certainty that, as with Einstein and Minkowski (and so succinctly stated by Modest), "Everything is relative."

 

Maybe I'll do a little intro to transpersonal psychology in the psychology section before I go. My career in this field is well established, and I may never get to all those on my waiting list. (I'm getting old and my wisdom is in high demand. (Such arrogance! Nobody here has an ounce of understanding of or respect for radical honesty.) Seems my gift is serving not only me but my clients very well in the "real world"... more than 'withstanding" the severe criticism i have suffered in this little narrow minded forum.

 

So long. I really do wish you all well.

(An after thought: I have never visited the psychology forum. I really do hope that the same moderators are not also the last word on Truth and Reality there!)

 

Ed: Corrected "mass *density*" plus... That "the laws of physics break down in a singularity" is as lame as it gets in "science."

Yet my assertion that the laws of relativity are transcended in the Universal Now is seen aS metaphysical gibberish.

Right... The laws of relativity (as seen from local perspectve) are transcended in realization that the ongoing present *is* always Now for cosmos as a whole.

Simple... What is is everywhere simultaneously. What hasn't happened yet (anywhere) is not present. What has already happened (wherever) is not now happening. There you go... your Universal, Absolute Present.

"So what?"... you might ask. So "Everything" is not "relative." Now is absolutely now everywhere... Oh, and have I mentioned that. space and time are not things, not entities, having no existential reality "of their own"...?

THE END

Michael

[Buffy]

So you're arguing that having a high IQ is perfectly correlated with being correct about everything?

 

Success is a lousy teacher. It seduces smart people into thinking they can't lose, :phones:

Buffy

[Boerseun]

Okay Michael - here goes:

 

Whatever your issue with your IQ may be, and however high your IQ might be, as far as this discussion is concerned, it's irrelevant.

 

As far as the "Bang/Crunch" model you propose, the Big Bounce Theory is nothing new. It changes no jot or title in the fact that either there was stuff before the Big Bang or there was nothing - in the current "incarnation" of the universe, there is no possible means to probe what came before the last "Bang" cycle - whether there was "stuff" before or not won't change the way the universe looks today.

 

As far as your assertion goes that there is a "universal now", i.e. that every moment is the same moment throughout the universe, that is simply not true. Consider, for instance, the following:

 

Let's say we have three points on an equilateral triangle ABC, each side of the triangle a light year long. Let's say we have an observer on each point of the triangle. Instant communication is, needless to say, impossible. But, in order to illustrate your point, the observer at A turns on a light. Exactly one year later, B and C sees the light at the very same moment, and turns on their own lights at the same time. Observer A would then, another year later, see B and C's lights turn on at the same moment, whilst B would wait another year after seeing A's light before seeing C's light turn on. The fact that A saw both B and C reply simultaneously kinda proves your assertion that there is a "universal now", doesn't it?

 

Unfortunately not. You see, the fact that we're talking an equilateral triangle here, in other words, the distances between observers never changes, they are locked apart at the same distance for however long the experiment takes, clearly shows that they are in the same frame of reference. They will have the same "now", even if communication between them seems odd with the year difference between signals. If even one of them had a velocity different than the others, he would be in a totally separate frame of reference, and will not experience a simultaneous "now" moment with the rest of them. For instance, if A was sending a signal once a second, B would receive it once a second. But if C was travelling at relativistic speed away or towards A, then C would, for instance, receive a signal once every minute or ten times a second - time dilation would negate any possibility of there being a "now" that's applicable to all three when the frames of reference get separated.

 

And, unfortunately, whether you agree with this or not is immaterial. It happens. It has been proven. Particle accelerators make provision for the increase in mass as particles approach the speed of light. Atomic clocks lose time in flight. If the GPS system didn't explicitly make provision for relativistic effects then you'd see a lot of airplanes land in the bush.

 

A body travels in a straight line unless some force acts on it. This is sixth grade science, but it took a guy like Newton to figure it out. A body in orbit travels in a straight line as far as its concerned. There is no "force" acting on the body, it's merely following a straight line in space until further notice. It's space itself that's getting bent by gravity. A photon is a massless particle, classical physics would have it that gravity cannot interfere with something without mass. Yet, a photon follows the curvutare of space around the mass of a star. As far as the photon is concerned, it followed a straight line. And, once again, wether you agree with this, or can or can't visualise it, is immaterial. It's simply what happens. That's the deck we're dealt with.

 

Nobody here is under the "spell" of relativity. Science, by definition, is self-correcting and self-criticizing. If the next guy comes up with a theory that blows relativity completely out of the water, each and every single scientist on the face of this planet will have a simultaneous orgasm and the new theory will become Standard. But as yet, nothing has the explanatory and predictive power that relativity has.

 

There's no requirement for any theory, be it relativity or any competing theory, to be intuitive in the human sense. No theory is required to make sense to the human mind. Because, after all, the human mind is a mish-mash of blood and gore, the result of millions of years of evolution, that only has to kill, eat, have sex and die to lead a perfectly normal life. What we're discussing here is so far removed from the everyday human experience that whether the individual can understand it or not is immaterial.

 

And, once again, the fact that you acknowledge your lack of mathematical insight might hamstring you a bit. Because, relativity mostly blows competing theories out the water because the math works out.

 

I do recommend you go and read up some more on relativity, and how it explicitly implies that there is no, and cannot ever be, a universal "now" moment.

 

As far as your objections towards the "total mass of everything in a zero-sized space" is concerned, the following:

 

You might object to it because, once again, you can't visualize it. But remember that mass and energy is interchangeable. At the moment of the "Big Bang" (and wether or not it was the result of a prior "crunch" is immaterial), it wasn't a situation where all mass was in a zero space - it was energy. Everyday massed atomic particles you see around you didn't even begin to form out of the plasma until much later.

 

That, once again, is freshman stuff. And that, once again, is why I recommend you go and buff up on basic relativity and basic physics before you try and debunk it.

 

And really - you repeatedly say that "it can't happen, because I said so in post #x". That simply cuts no mustard here, or anywhere anybody serious about science congregate.

[Essay]

....Catchy title, tho, no?

 

PhilSci Archive - Minkowski space-time: a glorious non-entity

 

Here is another book that caught my interest recently... yet to study in depth, but here is a link and intro:

The Absolute Present

David Larkin

The Absolute Present: Chapter Summaries

...this work is not so much about an ultimate objective-truth of physical theory or the philosophy of time, but is more a quest for re-evaluation in the face of esoteric, complex theories founded upon the ‘near mystical’.

??

Michael, the goal of that polemic was clear enough!

...however....

 

 

Suffice it to say that the whole universe exists (present tense), i.e., *is present* right now "as is" prior to any discussion of information transmission via light and the whole electromagnetic spectrum over whatever distances.

 

Michael

I don't think anyone is disputing your description as above, but what use is it--is the question. In order to calculate or predict or explain things, one needs a system.

 

I notice that your other link seems to speak in terms similar to yours, but I don't think they are leading to the same conclusions.

I'm not sure at what level they are referring to "kinematical effects," but it sure sounds like a different "system."

 

Minkowski space-time: a glorious non-entity

Harvey R. Brown (Oxford), Oliver Pooley (Oxford)

(Submitted on 17 Mar 2004)

Abstract: Einstein distinguished between "principle" and "constructive" theories in physics, and although he thought the latter were more explanatory than the former, he regarded his 1905 formulation of special relativity theory as a principle theory. Some have claimed that Minkowski space-time can serve as the deep structure within a constructive reformulation of special relativity. We criticise this claim, and argue that a satisfactory constructive version of special relativity must involve a dynamical treatment of the forces holding together the constitutive parts of moving rods and clocks.

 

You can get a fairly good preview of the "paper" here:

The ontology of spacetime - Google Book Search

"...the question of the possibility of a fully constructive rendition of SR, and in particular the possibility of a constructive explanation of the "kinematical" effects associated with length contraction and time dilation." -p.74

 

Sometimes I wish I had devoted my life to understanding this stuff, but most of the time I'm glad that it stayed a joyful hobby--while I focused more on biophysics. Whatever that "deep structure" really is, we're stuck here on this round, relatively biophysical structure.

 

~ :phones:

 

p.s. ...hoping to see you on the psychology forum some day....

[Pyrotex]

Goodbye Michael.

I'm sorry things didn't work out for you the way you wanted.

But you really have only yourself to blame.

'Radical Honesty' is a recipe for disaster, Michael. It's not a virtue, but a curse.

The day you are willing to give up RH and learn how to say 'please' and 'thank you', is the day the world will open up to you, and the day your abilities will be acknowledged.

Pyro

[Michael Mooney]

Damn! A toothache that just won't go away.... and this doesn't even qualify as the required miracle of communication to "make me" post again in this thread. Forgive me.

Boerseun:

As far as your assertion goes that there is a "universal now", i.e. that every moment is the same moment throughout the universe, that is simply not true. Consider, for instance, the following:

 

"Simply not true?"

MM:

...The laws of relativity (as seen from local perspectve) are transcended in realization that the ongoing present *is* always Now for cosmos as a whole.

Simple... What is is everywhere simultaneously. What hasn't happened yet (anywhere) is not present. What has already happened (wherever) is not now happening. There you go... your Universal, Absolute Present.

 

This is about the absolute present, not about who "sees" what and when from local perspectives, whether equidistant or not.

 

In what way is my above statement "simply not true?" Stating that as a fact does not in fact invalidate what i said. And your "for instance" was more of Modest's "observer A and observer B" (add an observer C) argument warmed over yet again... that relative perspective is in fact the one true and absolute perspective.

 

The first sentence of my reiteration above addresses this point directly, and is not refuted by your assertion that it is simply not true. "The laws of relativity (as seen from local perspectve) are transcended in realization that the ongoing present *is* always Now for cosmos as a whole."

Michael

[Boerseun]

Well Michael, I'm sorry if you don't "get" it.

 

And if my previous post was just Modest's argument warmed up again, then I'm glad - I don't know which post you're referring to, but if I echoed Modest's sentiments, then at least I know I'm in good company here.

 

The "universal now" concept you're alluding to, appeals to common sense because it makes "sense".

 

That's about as clever as defending a flat earth - the earth being flat also appeals to common sense. And look where that got us.

 

If you have an observer A ten light-years away from observer B (OH MY GOD!!! HERE WE GO AGAIN!!!) then they either are in the same frame of reference or not. That stands to reason. If they are in the same frame of reference, it implies that they are moving in the same direction at the same speed as related to a third point, C. But that is besides the point. The point I'm making, is that there is no way for points A and B to interact unless ten years have passed.

 

It's important that you think about the implications thereof.

 

There is nothing that A can do that B will know about for at least ten years. That also stands to reason. But it doesn't seem as if you read my previous analogy. If there was a third party, C, also in the same frame of reference, on an equilateral triangle ABC, and it shines a light simultaneously towards A and B, then it would receive a return signal exactly 20 years later from both A and B at the same time. This actually supports your hypothesis, meaning that A,B and C share a universal "now" moment.

 

But it's not because there is one - it's merely because they are locked in the same frame of reference by being locked in equilateral triangle ABC, where all three points on the triangle stay the same exact distance from each other by virtue of the entire system having the same velocity.

 

Reality is a bit different.

 

Imagine a photon.

 

The universe is filled with the little buggers.

 

Photons are everywhere.

 

Yet, from a photon's perspective, there is no such thing as "time". For a photon, the Big Bang and the eventual end of the universe (whatever and whenever that might be) is the exact same moment. Yet, we interact with photons every second of every day. What "universal now" moment do we share with photons?

 

A clock slows down as velocity increases. This is an established, demonstrated, proven fact. What "universal now" do you share with a speeding clock, when you can't even agree on the length of a second? Not that the observer travelling with the clock will notice anything untoward - as far as he's concerned, the problem lies with your clock, which seems to have speeded up for him.

 

I can't help you if you're not interested in learning the most basic, proven facts of relativity. And if you can't wrap your head around "observer A and observer B" (add an observer C)" examples, then nobody can help you.

 

There is no "universal now". There wasn't even a "universal now" at the moment of the Big Bang.

 

Look at the tip of your left index finger. That is the exact spot where the Big Bang took place. Now, look at the tip of your right index finger. That is, too, the exact spot where the Big Bang took place. But I've got news for you - I'm sitting at the Southern tip of Africa, and here, right to the left of my coffee mug on my desk, is the exact spot where the Big Bang took place.

 

Your problem in visualizing the universe, which leads you to conclude that there might be such a thing like a "universal now", is that you see the universe as flat three-dimensional space with time added. But the universe is actually a hypersphere, where time and space is tightly interconnected. All points in the universe was the exact spot where the Big Bang happened, and each and every point on this expanding, unfolding hypersphere have a perfectly valid claim to being the Center of the Universe. Even if they have a velocity component that might make them not being in the same frame of reference as you. Which means that there is a limited "now", the limitations being everything that is in the same frame of reference, will experience the same "universal now". But everything else on this unfolding hypersphere will experience a "now" that is purely unique to themselves.

 

I don't know how else to explain this to you. I've done my bit. If you're not willing to familiarize yourself with the most basic ideas and terms of relativity, then neither I nor anybody else can help you.

 

And if please read and comprehend "observer A, B and C" arguments before you dismiss them. Who knows, you might just learn something from us mere mortals.

[freeztar]

Michael posits that our "now" ten years ago is the same "now" that began at a star 10ly away from us. Hence, a supernova that we observe as 250mya is not happening in our "now", of course. Yet, at some point in time, in our reference frame, Earth, it was occurring. At that point, we shared the same "now". This is what I believe Michael is referring to as the "absolute now".

 

Michael seems to have not grasped the idea that ontology can be built upon any number of assumptions that lead to either different, or the same, results. In Michael's view of spacetime, "space" and "time" do not expand or contract. I can empathize with this argument. Nonetheless, when we consider 4 dimensional spacetime, we're left with a system that does an amazing job of explaining universal phenomena.

 

I don't think the universal now needs to be dismissed by science, much like my preference for spacetime. Philosophical views will persist, but Science continues on with what can be observed and measured. If we one day reveal the true nature of gravity and it causes us to abandon our "blanket of spacetime", all the better. Until then, Science will continue to lead the way in evolving tangible understanding while philosophy struggles upon the same ageless problems.(not to imply that philosophy is meaningless!)

[Boerseun]

Michael posits that our "now" ten years ago is the same "now" that began at a star 10ly away from us. Hence, a supernova that we observe as 250mya is not happening in our "now", of course. Yet, at some point in time, in our reference frame, Earth, it was occurring. At that point, we shared the same "now". This is what I believe Michael is referring to as the "absolute now".

...and that's exactly the problem.

 

Because, the "now" we see on a star that's 250 light years away is 250 million years in our past, but not necessarily 250 million years ago in the star's past - once again because there are no "universal frames of reference". It might only be 200 million years ago for the star, due to how it's traveling through space relative to us.

 

Because there is no universal frame of reference, there can be no "universal now".

 

I have illustrated above where three points ABC on an equilateral triangle with sides 10 light years long can illustrate the idea of a universal "now" existing, but also pointed out in my example that it only works when all points share a frame of reference; i.e. the three points on a non-changing triangle. The moments their velocities change relative to each other, pop goes the weasel.

[maddog]

Michael seems to have not grasped the idea that ontology can be built upon any number of assumptions that lead to either different, or the same, results.

It is as though Michael got his definition of "Ontology" from a Cliff Notes on Ontology and

not a standard Webster's or Oxford Dictionary definition. Michael has spent no time

defining terms or declaring assumptions he has made. Michael has just simply made claims, unfounded.

I don't think the universal now needs to be dismissed by science, much like my preference for spacetime. Philosophical views will persist, but Science continues on with what can be observed and measured. If we one day reveal the true nature of gravity and it causes us to abandon our "blanket of spacetime", all the better. Until then, Science will continue to lead the way in evolving tangible understanding while philosophy struggles upon the same ageless problems.(not to imply that philosophy is meaningless!)

I don't mean to dismiss "universal now" entirely -- just to NOT exalt it such high standard

as a corroboratable theory such as SR or GR. A Universal Now is an empirical idea,

like "water is wet" as voiced by Aristotle in the classical greek period.

 

However, a Universal Now is as abstract as they come. Where water being wet, and

observation can come into play. A Universal Now -- all sensibility is all based on "hidden"

assumptions made by the positer. This has No basis in fact.

 

maddog

[maddog]

Because there is no universal frame of reference, there can be no "universal now".

With this you hit the nail on the proverbial head. No now in any way "universal" can be

validated with evidence.

 

Yet as this and the previous thread has demonstrated, such an idea as a "universal now"

can be argued in a NONrigorous way just as much as an old midieval debate:

 

"How many Angels can dance on the head of a pin" ?

Earlier in the other thread, I answered with

Same as the number of Devils... :eek2:

 

In that way of arguing - who is to "prove" me wrong. My point is the argument on such

nonrigorous information is Really Meaningless.

 

maddog

[modest]

An event is a real thing. We can give it ontology and say it exists. For example, a warm plate of sodium ejecting a photon—that's an event. It happens at a specific location and a specific time and it's real. We can call it event-A.

 

I believe we can rephrase the "absolute now" question to: what is the "right now" for event-A", and is it "absolute"? Any event contained in event-a's right now will be simultaneous with event-a. Relativity gives a system of answering that question. The result, which has been well-established in this thread, is that simultaneity of two events (a and :eek2: is not absolute, but depends on the velocity from which it is considered. If the laws of physics work the same in more than one inertial reference frame (a.k.a. the principle of relativity) then there can be no absolute simultaneity and thus no absolute "right now" according to special relativity.

 

If Michael or anybody else wants to declare an absolute now it behooves them to describe a system which answers the same questions as SR, but includes absolute simultaneity. I don't think this is impossible. It very-well could be done. I've just skimmed over: 18861 and I think Doctordick makes a strong case that such a system is possible. In the wider world of physics I believe it would go by the name "euclidean relativity". I also think it has some problems which is perhaps why it has never caught on.

 

I would just like Michael to acknowledge that such an explanation is required. Saying "there is an absolute right now" is not enough to establish any validity of such a thing. You have to show how the system works.

 

~modest

[Michael Mooney]

Boerseun:

Because there is no universal frame of reference, there can be no "universal now".

 

A consideration from a philosophical perspective as pertaining to science:

That the universe *as a whole* transcends local "frames of reference" and as such *for the universe* now is simply the ongoing present. (Future not yet present... past not still present.... That only leaves NOW... see?... *for the universe as a whole* if anyone can "wrap his/her mind around it."

 

In this sense, time is not a thing but the *concept* of "event duration" as in "elapsed time" for whatever specified event to happen as "designated" by the observer's arbitrary "beginning and ending of the observed event".) What relativity is really good at is comparing this relative perspective with that one and taking into account "signal delay" and different velocities creating different relative frames of reference in information propagation from one location to another, given the speed limit of light.

 

We *All* know that earth doesn't "see" light from the sun for 8.3 minutes, but now *is* now both there and here.... and everywhere.

 

Anyone "get it" yet?

 

I just edited out the rest of this post and put it back in the original spacetime thread, as it is back to the ontology of space, time, and spacetime, yet again in reply to the assumptions made by my critics in this thread.

(What a run-around!)

Michael

[Pyrotex]

Michael,

 

are you having fun yet? :surprise:

 

I see your penchant for disagreeing universally with everything that is said, indeed, with every new turn of phrase, is just as egregious now as it ever was.

 

Why don't you pick your battles, and ignore the finer shades of gray that don't really matter?

 

You know, if I were you, I would stop bemoaning all the many times you already said this or that. I would scan those older posts myself and summarize them in as small a post as possible. Throw out all the rhetoric and verbiage, and just boil down what it is that you are trying (so unsuccessfully) to say. That would be a really great exercise, and would save you so much time and grief in the long run.

 

But I get the feeling that you have little interest in saving yourself either time or grief.

 

Why is that Michael? Good luck! :naughty:

 

And hold your temper in check Michael. I will be watching.

[AnssiH]

I've just skimmed over: 18861 and I think Doctordick makes a strong case that such a system is possible.

 

Yeah, and I must say that it is very surprising to me that people don't see it as abudantly obvious that such a system is possible. Of course it is possible, we cannot be "here" and "there" simultaneously to find out anything about simultaneity (without assumptions about the one way speed of information). All natural observers are, by our definitions, manifestations of electromagnetic phenomena, so if you wish, you can look at relativity as a description of how the natural observes are related to each others temporally (by their own measurements) due to them and their internal behaviour being constrained by that electromagnetic phenomena.

 

I mean, if you look at spacetime as a static structure, like a "web of events", then any sort of simultaneity you imagine in there is completely immaterial. What defines relativistic simultaneity is the assumption that light speed is isotropic, which can be taken as something that natural observers MEASURE (as oppose to something that just "IS" ontologically, over and beyond our definitions).

 

When you read the above, perhaps you tried to picture something like an electromagnetic canvas and think about naturally occurring events (that give rise to the motion of a clock). DON'T DO THAT. I am not condoning a specific ontology here. I am just trying to point out that the essential relationships of relativity can be seen in many different ways, as long as you really understand how the relationships are tied together.

 

I have also only skimmed the the analytical-metaphysical thread myself (but I mean to walk it through after the Schrödinger's Equation part), but what I just cannot stress enough is that DD's presentation is NOT an argument about a specific ontology. It is an argument about the epistemological reasons of the relativistic time behaviour of the objects that we've defined.

 

Most people view reality as a set of objects flying around in space and time, but try to instead take a step back, and look at all those objects as some patterns (of some unknown nature) that have temporal "identity" to them only because we defined those patterns as "things with persistent identity" (i.e. "they move" or "are stationary" instead of being "different stuff all the time"). See where I'm getting at?

 

What DD's treatment boils down to, is "how do we define objects", and how we then unavoidably end up defining things in such a way that there are objects in space, they are moving, and their time behaviour against each others is exactly what you get with the normal relativistic description.

 

So, I don't think anyone should view the "analytical-metaphysical take on special relativity" as something that's offered as an alternative theory to the theory of relativity. View it instead as an exploration that's aiming for deeper understanding of relativity. Just, one consequence of understanding those logical roots is very explicit awareness of how unnecessary the idea of relativistic spacetime/simultaneity really is (in any ontological sense). It is very much an arbitrary choice to view it as a spacetime construction (and of course further leads to all kinds of curious ontological questions in one's mind about the "now")

 

People just take the argument that "relativistic simultaneity is unnecessary" as an attack against their worldview, because they've come to see it as the only reasonable conclusion for some reason. Perhaps it's a consequence of the natural tendency of viewing space and time as something that just "are" out there. I mean, to think that space and time and objects ontologically just "are", and don't have anything to do with us first defining all sorts of "identities" to an unknown reality. I find that disturbingly thoughtless.

 

-Anssi

[freeztar]

...and that's exactly the problem.

 

Because, the "now" we see on a star that's 250 light years away is 250 million years in our past, but not necessarily 250 million years ago in the star's past - once again because there are no "universal frames of reference". It might only be 200 million years ago for the star, due to how it's traveling through space relative to us.

 

Do you agree that we can use SR and GR to pretty accurately determine when both the Earth and the distant star shared a simultaneous existence?

Even if one believes this can not be done, it does not invalidate the fact that they both had simultaneous existence (as long as we assume that the Earth is ~4.5 billion years old and do not assume simultaneous events with the distant star before this time.

 

Because there is no universal frame of reference, there can be no "universal now".

Indeed. But this is only true in scientific and empirical relativity.

Of course, I absolutely love Relativity Theory and am not arguing against it scientifically. I find it interesting to explore alternative philosophical aspects though. An absolute now can be argued philosophically, not scientifically.Well, actually, as Modest points out, it can be argued, but it requires Euclidean geometry.

 

I have illustrated above where three points ABC on an equilateral triangle with sides 10 light years long can illustrate the idea of a universal "now" existing, but also pointed out in my example that it only works when all points share a frame of reference; i.e. the three points on a non-changing triangle. The moments their velocities change relative to each other, pop goes the weasel.

 

Indeed. There's no way for any observer to agree on a preferential frame in which all events occur simultaneously, be it a triangle, a square, or whatever geometric form one envisions.

 

But, absolute now is non-empirical philosophy. It's a thought experiment.