Frame of Reference as Subject in Subjective Idealism

[Iggy]

Still begging for clarification of relativity of simultaneity as in how it can logically contradict presentism.

 

That relativity and/or a constant speed of light contradict a universal now was proved in post #327 and surrounding posts.

 

Now that you know "universal now" refers to different reference frames rather than locations maybe you could give it another look and it will make more sense.

[Schrödinger's hat]

Still begging for clarification of relativity of simultaneity as in how it can logically contradict presentism.

Yes, and I'd like to give you this, but I need some cooperation. The train of logic is starts at some form of thought experiment involving light beams.

"Even considering different FORs, I know that the past is no longer present and that the future is not yet present, so that leaves us with the reality that what IS happening now IS the present. How can this be wrong?"

 

Since simultaneity means happening at the same time, on what basis does relativity's lack of simultaneity (or "relativity of simultaneity") deny/contradict the above?

Repeating that it doesn't depend on light delay doesn't answer the question.

Again, this requires patient application of logic.

I will happily go through any combination of the assumptions (constancy of speed of light as measured by different observers, no preferred frame, universal and well defined now etc) and describe the logical consequences of taking each as true or false, but I need some indication you understood what I was saying.

This thread is on the philosophy of science, particularly relativity's claims about frames of reference determining reality, or FORs as a qualified* subjective criteria for "reality" as a form of subjective idealism. *(No person or subject required to establish an abstract FOR, reality depends on FOR,... how you look at it.)

Let's drop this for now and focus on why relativity predicts what it does and examining the premises of our arguments, no progress has been made any other time you have claimed this, I doubt responding to it again would have any effect.

This thread poses a philosophical challenge to some of relativity's most absurd assertions based on the theory of length contraction.... specifically, that Earth's diameter, depth of atmosphere, distance from the Sun, and the actual length of a solid meter rod all depend on the frame of reference from which they are observed and measured.

Length contraction of objects is a direct logical consequence of (or logically equivalent to, at least) the relativity of simultaneity. It is much easier to explain relativity of simultaneity, so let's discuss that.

See all versions of realism's rebuttal above. Philosophy of science is appropriately presented in a philosophical "manner", as above. We need not start with the "scientific" dictum "there are no preferred frames of reference" from which to describe "reality." The "world" (let's stay concrete and say Earth) already had a reality of its own (and distance from the sun, varying only a bit in its orbit) before life evolved here, much less intelligent life with nimble minds, clocks, and measuring rods. You still have not acknowledged this fact, upon which realism is based.

Reality does not depend on frames of reference from which it is observed. So science must investigate "reality" and all of its intrinsic properties from the most reasonable frame of reference possible for each object of investigation, be it objects themselves or the distances between them in the real world.

 

Yes, we have a name for the things that are part of objective, non-frame-dependant reality. We call them invariants.

Not all measurements are invariants. This picture you paint is completely consistent with a relativistic world view.

Again you are presenting two options:

Distances are fundamentally representitive of reality and invariant under change of frame.

Distances are fundamentally representitive of reality and vary under change of frame

 

Ignoring the possibility of a third:

Distances are not fundamentally representitive of reality and vary under change of frame. There is another quantity (interval) which is almost indistinguishable from distance when used to describe objects moving at low speed. Describing reality in terms of intervals will give you a result that does not depend on frame of reference.

 

 

Again, you say, "Things that are spatially distant and moving at a different velocity do not share my now."

You (and the relativity of simultaneity in general) claim that there are different, spatially separate "nows" as if the claim itself debunks presentism's claim that the present IS everywhere now, regardless of the space between locations.

Again, I qualified that block with 'according to relativity'. Must you insist that I qualify every statement? I have said that I will show you why relativity posits this, along with the lines of reasoning based on different assumptions that are consistent with experiment. It will require sevaral posts and some level of cooperation.

And the Cap 'n repeats that it (relativity of simultaneity) is not about light delay between FORs, not about the distance between them. Which version is it?

It is not about light delay.

Two objects moving relative to one another have a different now (over most/all of space).

Two objects in the same place and time have the same here and now.

 

Just repeating this over and over again is useless. Let's go through the logic.

 

There is no point in that if you continue to *assume* the primacy of frames of reference for describing reality in direct contradiction to my above arguments.

However, if you will "please" reply as above repeatedly requested, then I will again go 'back to the drawing board' with you.

 

I do not wish to assume that. I was going to examine every combination of assumptions I could think of.

[tar]

Schrödinger's hat

 

Well, I think I finally got it. Thanks to your 423.

 

Perhaps I can take a shot at describing the situation to Owl, since I too was/am considering the meaning of now in a photon lag way.

 

Owl,

 

Relativity assumes a halfgod like now that extends even 100,000 million lightyears from here and beyond. It takes the eyes of a zillion observers scattered all amongst everywhere and gives them all the ability to report what they observe back to us, instantly, using halfgod radio, that operates instantaneously, with no consideration that any speed limit such as C exists. But ALL these observers are stationary in respect to us, they have no velocity toward us, away from us, or tangent to us. They are all in our frame of reference. Events anywhere in the universe will happen in a particular order at particular distances from each other. All the reports will agree on this order and the distances involved. And always the speed of light is the measured, and found to be 300,000,000 meters per second.

 

Now imagine something that is moving at 299,900,000 meters per second, relative to us, and our frame of reference.

All of our zillion observers would clock it moving at 299,900,000 meters per second. But this object has a pilot, who being very industrious has also sent out a zillion observers to all corners of the universe, to report their observations back at halfgod like radio instantaneous speed. This pilot considers himself stationary, all his observers, and he, measure the speed of light at 300,000,000. All his observers are in HIS frame of reference, and are in his halfgod like now. His observers report, and he notices, the Earth passby at 299,900,000 meters per second. The halfgodlike now, that he and his zillion observers consider now, extends throughout the universe. However, the order of events, and the distances between them ARE NOT THE SAME as for us and our halfgod like observers.

 

Since objective reality exists and a real event that happens happens in both frames of reference, and the speed of light is ALWAYS 300,000,000 meters per second, the equations and geometries of space time give us the transformations between our FOR and another FOR. The other FOR looks at ours from a different angle and distances and times are consistantly not in agreement. Same the other way 'round.

 

There is not an objective fullgod frame of reference that can extend its observers out appropriately to account for every possible velocity and every possible extended halfgod like now. Except for SR, which can take it one FOR at a time, make the transforms, between, and thusly "see" objective reality, from at least two halfgodlike nows, which I suppose adds up to a full godlike view of "objective" reality.

 

Regards, TAR2

[Schrödinger's hat]

Well, I think I finally got it. Thanks to your 423.

 

Congrats. Also your post explaining it was very well put.

@Owl this fullgod frame tar speaks of is what we mean when we speak of a preferred reference frame.

[tar]

Well thanks to umlaut hat, iggy, MD2020, the cap'n, and that pot smoking flock of swans, who repeated themselves consistently, the several hundred times required, against the "strawman" arguments of Owl and I, I now know the "meaning" behind the formulae, which is what I was after.

 

Sincere thanks to all who have posted on this thread.

 

Regards, TAR2

 

P.S. At least for SR. GR with space deformed by mass. I don't know what that means.

[Schrödinger's hat]

Well thanks to umlaut hat, iggy, MD2020, the cap'n, and that pot smoking flock of swans, who repeated themselves consistently, the several hundred times required, against the "strawman" arguments of Owl and I, I now know the "meaning" behind the formulae, which is what I was after.

Good to see that repeating ourselves over and over again isn't completely in vain.

Next time you'll probably make much faster progress if you take the attitude 'these scientists are crazy, but let's take their assumptions as true for now, and see where it leads'.

[tar]

sort of like reading a map

 

if you don't believe the map maker knew what he/she was doing you can't prove it by saying that the "blue lines can't be rivers! They are not wet and they don't flow!"

 

You have to read the ledgend and see what the symbols mean, see what scale the map is drawn in, understand what type of map it is and what it is supposed to depict and what it leaves out, AND hold it the right way so real North and the little arrow point the same way.

 

Best regards, TAR2

 

and probably a good idea to check the date on the map, if you are looking for a road that was recently constructed

 

or a feature recently discovered

[Iggy]

Schrödinger's hat

 

Well, I think I finally got it. Thanks to your 423.

 

Perhaps I can take a shot at describing the situation to Owl, since I too was/am considering the meaning of now in a photon lag way.

 

Owl,

 

Relativity assumes a halfgod like now that extends even 100,000 million lightyears from here and beyond. It takes the eyes of a zillion observers scattered all amongst everywhere and gives them all the ability to report what they observe back to us, instantly, using halfgod radio, that operates instantaneously, with no consideration that any speed limit such as C exists. But ALL these observers are stationary in respect to us, they have no velocity toward us, away from us, or tangent to us. They are all in our frame of reference. Events anywhere in the universe will happen in a particular order at particular distances from each other. All the reports will agree on this order and the distances involved. And always the speed of light is the measured, and found to be 300,000,000 meters per second.

 

Now imagine something that is moving at 299,900,000 meters per second, relative to us, and our frame of reference.

All of our zillion observers would clock it moving at 299,900,000 meters per second. But this object has a pilot, who being very industrious has also sent out a zillion observers to all corners of the universe, to report their observations back at halfgod like radio instantaneous speed. This pilot considers himself stationary, all his observers, and he, measure the speed of light at 300,000,000. All his observers are in HIS frame of reference, and are in his halfgod like now. His observers report, and he notices, the Earth passby at 299,900,000 meters per second. The halfgodlike now, that he and his zillion observers consider now, extends throughout the universe. However, the order of events, and the distances between them ARE NOT THE SAME as for us and our halfgod like observers.

 

Since objective reality exists and a real event that happens happens in both frames of reference, and the speed of light is ALWAYS 300,000,000 meters per second, the equations and geometries of space time give us the transformations between our FOR and another FOR. The other FOR looks at ours from a different angle and distances and times are consistantly not in agreement. Same the other way 'round.

 

There is not an objective fullgod frame of reference that can extend its observers out appropriately to account for every possible velocity and every possible extended halfgod like now. Except for SR, which can take it one FOR at a time, make the transforms, between, and thusly "see" objective reality, from at least two halfgodlike nows, which I suppose adds up to a full godlike view of "objective" reality.

 

Regards, TAR2

 

Huzzah! I do believe you have it, Sir.

 

I haven't read the replies yet, so I may be repeating someone, but I would add only to where you say "There is not an objective fullgod frame of reference that can extend its observers out appropriately to account for every possible velocity and every possible extended halfgod like now." just that space-time accomplishes exactly that. It combines all the frames into a single entity.

 

Very nice post, and very well worded.

[md65536]

Relativity assumes a halfgod like now that extends even 100,000 million lightyears from here and beyond. It takes the eyes of a zillion observers scattered all amongst everywhere and gives them all the ability to report what they observe back to us, instantly, using halfgod radio, that operates instantaneously, with no consideration that any speed limit such as C exists. But ALL these observers are stationary in respect to us, they have no velocity toward us, away from us, or tangent to us. They are all in our frame of reference. Events anywhere in the universe will happen in a particular order at particular distances from each other. All the reports will agree on this order and the distances involved. And always the speed of light is the measured, and found to be 300,000,000 meters per second.

Schrödinger's hat and Iggy are probably each more knowledgeable than I, and it sounds like you've figured out some important aspects of relativity...

 

but I don't think this analogy is a good one, for developing a solid understanding of relativity. There are complications that can make it invalid -- namely "updates to simultaneity", which happen if you change inertial frames, say by accelerating. An update to simultaneity relative to something should happen I think any time that you change length contraction to that something. Since simultaneity is relative, it can be changed, and that can sometimes imply weird things... which I won't get into except to say that the "instantaneously communicated" observations of your zillion eyes can change; these instantly communicated observations are not always valid.

 

There's a reason that SR implies that no information can travel faster than c. If you do thought experiments using your analogy, or anything that involves information transmitted faster than c, you'll be able to derive contradictions and paradoxes.

 

If you modified your analogy to say that only the instantaneously made observations that eventually reach us (at a speed of c) are valid observations, then I think it'd be okay. If that ruins your analogy so that it no longer makes intuitive sense, then the analogy (at least your above paragraph of it) might not be that useful.

 

An intuitive understanding of SR will coincide with an intuitive understanding that c is a universal speed limit for all information.

 

 

But don't worry! There are always "further complications" no matter how well you understand relativity, and that shouldn't detract from the aspects that you do understand!

[owl]

Nobody here is willing to consider the thread topic as pertains to "the world" as naturally occurring phenomena independent of different frames of reference (observers with different velocities) from which they are observed. No "takers" on discussing the nature and properties of the world and distances between objects with no intelligent life or observers traveling at different velocities. (An objective world without the quasi-subjective pseudo-reality of how it is all seen from different velocities and locations.)

 

Schrodinger's hat insists:

Length contraction of objects is a direct logical consequence of (or logically equivalent to, at least) the relativity of simultaneity. It is much easier to explain relativity of simultaneity, so let's discuss that.

 

That gets hung up on presentism (everything is happening now) vs lack of simultaneity (now depends on velocity of observers.) I say time is simply how long it takes anything* to happen (not an ingredient in "spacetime")... *say traveling from here to there at whatever velocity... an hour to travel 60 miles at 60 mph. (spelling edit.)

 

I said (repeated for reference below):

This thread poses a philosophical challenge to some of relativity’s most absurd assertions based on the theory of length contraction.... specifically, that Earth’s diameter, depth of atmosphere, distance from the Sun, and the actual length of a solid meter rod all depend on the frame of reference from which they are observed and measured.**

 

I understand that FOR depends on velocity as well as location (which changes with movement, of course.)

But, how does going faster, for instance, make distance traveled shorter? It doesn't. At 120 mph, the above 60 miles will stay the same distance, covered in half the time, 1/2 hour. (In the real world, that is.) And whizzing through our solar system at near 'C' does not make the distance between Earth and Sun shorter, just because it might look shorter than from at rest with Earth. This statement is based on realism, in which FOR does not determine reality.

 

[second edit; an interjection; Regarding all those graphs, including my "laser jousters" word experiment version: Maybe the confusion is due to applying math to the impossibility of cumulative velocity of light and its fast moving source. Since the velocities can not be cumulative, one might assume that distance traveled must become shorter, or length contracted. This is solved in my mind by realization that light can not be pushed faster than 'C.' The rockets/observers/lasers in my experiment are traveling through the light beams they are shining ahead. The supposed "length contracted" distance (required by math) is actually absorbed as the lasers travel at 1/2 'C' through the tail end (closest to the lasers) of the very beams they are projecting ahead. ]

 

How do different FORs from which all above examples are observed make the objects and distances themselves** (as they are, sans intelligent life observing and measuring them) different?

In the real world, how does high speed observation change the shape of Earth, Earth-Sun distance, length of a meter rod, etc? It doesn't.

Until this objection is addressed the rest is argument about manipulating models of the world (not the real world), spacetime*** coordinates, FORs at different velocities "seeing" the world differently, and denial of an omnipresent Present. (No matter what velocity an observer is traveling, now is now, same now everywhere.)

 

*** Whether just an abstract non-entity, a metaphorical "rabbit pelt" or a malleable medium as supposed in GR.

Edited September 28, 2011 by owl

[Iggy]

[second edit; an interjection; Regarding all those graphs, including my "laser jousters" word experiment version: Maybe the confusion is due to applying math to the impossibility of cumulative velocity of light and its fast moving source. Since the velocities can not be cumulative, one might assume that distance traveled must become shorter, or length contracted. This is solved in my mind by realization that light can not be pushed faster than 'C.' The rockets/observers/lasers in my experiment are traveling through the light beams they are shining ahead. The supposed "length contracted" distance (required by math) is actually absorbed as the lasers travel at 1/2 'C' through the tail end (closest to the lasers) of the very beams they are projecting ahead. ]

 

That's funny. Your assumptions can't be wrong so it must be math's fault

[Cap'n Refsmmat]

[second edit; an interjection; Regarding all those graphs, including my "laser jousters" word experiment version: Maybe the confusion is due to applying math to the impossibility of cumulative velocity of light and its fast moving source. Since the velocities can not be cumulative, one might assume that distance traveled must become shorter, or length contracted. This is solved in my mind by realization that light can not be pushed faster than 'C.' The rockets/observers/lasers in my experiment are traveling through the light beams they are shining ahead. The supposed "length contracted" distance (required by math) is actually absorbed as the lasers travel at 1/2 'C' through the tail end (closest to the lasers) of the very beams they are projecting ahead. ]

At no point in my diagrams (or anyone's diagrams, I think) was light pushed faster than c in any reference frames. Could you point to an example where it was?

[Schrödinger's hat]

Nobody here is willing to consider the thread topic as pertains to "the world" as naturally occurring phenomena independent of different frames of reference (observers with different velocities) from which they are observed. No "takers" on discussing the nature and properties of the world and distances between objects with no intelligent life or observers traveling at different velocities. (An objective world without the quasi-subjective pseudo-reality of how it is all seen from different velocities and locations.)

Every time someone does discuss this (according to their model, which is consistent with SR) you respond with:

NOPE I DON'T BELIEVE YOU LALALALALALALALA

 

They then tell you that you're basing your arguments on assumptions that are inconsistent and offer to show you why, to which you respond with another post like this one -- telling everyone that they refuse do discuss it.

 

How do different FORs from which all above examples are observed make the objects and distances themselves** (as they are, sans intelligent life observing and measuring them) different?

Changed speed of observation along with constant observed speed of light, results in changed observation of simultaneity and distances.

This is an irrefutable logical fact.

You can't just say "no it doesn't".

What these observations mean and whether they pertain to reality, or to a distorted view of reality is debatable -- even if doing so goes in the face of a century of science, this is philosophy after all -- but do do so you have to understand why to do so.

In addition to this, claiming that such observations are incorrect has its own logical consequences. You should understand what these are before claiming presentism.

 

 

Until this objection is addressed the rest is argument about manipulating models of the world (not the real world), spacetime*** coordinates, FORs at different velocities "seeing" the world differently, and denial of an omnipresent Present. (No matter what velocity an observer is traveling, now is now, same now everywhere.)

 

My most recent 'manipulation of models' was intended to be a backdrop to show you the consequences of various assumptions, and the mechanism behind simultaneity/length contraction.

Edited September 28, 2011 by Schrödinger's hat

[tar]

#434 Today, 11:42 AM md65536

 

 

If you modified your analogy to say that only the instantaneously made observations that eventually reach us (at a speed of c) are valid observations, then I think it'd be okay. If that ruins your analogy so that it no longer makes intuitive sense, then the analogy (at least your above paragraph of it) might not be that useful.

 

md65536,

 

Yes, I meant that. The visualization of something happening "now" a lightyear from here, is of course accompanied by the realization that we won't actually have any proof it actually happened till a year from now. We just assume that as we see now what happened there during our year ago simultaneous moment, we will see a year from now what happened there in this simultaneous moment.

 

Didn't you know that you are always supposed to listen to what I mean, not what I say?

 

However, it does bring up an interesting "notion" I have been entertaining. We (us humans) are really in no better or worse position than any other entity in the universe to experience the universe. There are some direct analogies between what we are and do, and what a "non thinking" entity is and does. We absorb and record the universe that arrives here, now. It might even be argued that any entity is "created" by the sum total, the history of the patterns, that have accumulated here and now (which ever here and now you consider). 'Cause every here and now occupies a particular unique position in spacetime, that no other entity but it, occupies, and the arrangement of the rest of the universe around it, is not duplicated ever, anywhere or any time else.

 

It is argued mathematically that somewhere in space and time there is a duplicate TAR. I totally disagree. It is not possible. Cause if he where to point at me, and I were to point at him we would be pointing in opposite directions in space and time, making us each unique at least in the direction we would have to point. Nevermind the fact that I would be pointing from the Milky Way and he would be pointing AT the Milky Way.

 

Anyway this "notion" leads me in the direction of considering what "arrives" here now is of great importance, greater importance than what we imagine will arrive here later. We are making the later up (even though it might actually prove out) and its really not going make any difference to our reality, til later, sometime much later or even so much later, that "who cares" if it is right or wrong. What really matters, what reality really is, is what the universe is actually doing, here, now. That photon, that left Alpha Centuri 4 1/2 years ago, is REALLY hitting my eye NOW, being focused by my lense on some rods and cones that are sending chemical and electrical signals to a brain which is "recording" the event, by physically rearranging synapses and connections, inhibiting and promoting firings that "duplicate" the event in an analog way, and compares it against the "model" of the world already built by past "experiences" such as this.

 

What the universe is really like, could very well be exactly what we experience it to be. If we imagine a view that is NOT from here and now, it is by definition imaginary in nature, and need not actually be the case.

 

Regards, TAR2

Edited September 29, 2011 by tar

[owl]

Just a near lightspeed fly-by without having read recent (since my last post) replies.

 

What if “reality” did not depend on frames of observational reference, at whatever speed or location relative to the part of “reality” being observed? Just “what if?” for a moment, OK?

What if the cosmos (or our local system) were not being “observed” from all possible “frames of reference?”

 

How drastically would it change if not observed by us oh-so-intelligent beings. Not at all really. All cosmic objects would have their intrinsic shapes regardless of how observers saw them and their relationships in space. The distances between them would not change at all but for “natural causes” like out- of- round orbits and such or due to the expanding cosmos in which the 'distances' between galaxies is increasing at an accelerating rate (still a mystery as to the dynamic.) That expansion (distance between galaxies, etc.,) is not effected by observation.

That’s it for now. I will read recent posts tomnorrow.

[Schrödinger's hat]

Just a near lightspeed fly-by without having read recent (since my last post) replies.

 

What if "reality" did not depend on frames of observational reference, at whatever speed or location relative to the part of "reality" being observed? Just "what if?" for a moment, OK?

What if the cosmos (or our local system) were not being "observed" from all possible "frames of reference?"

 

For the umpteenth time, reality doesn't depend on frame of reference, but distance is not defined without one.

 

If I give you two lines like so:

And ask "What is the distance between these two lines?"

The question is nonsense. It's undefined.

If, however, I define a plane ('now' in some frame of reference) which intersects both these lines and ask:

"What is the distance between the point at which these two lines intersect the plane?"

You can answer.

But if I change the angle of the plane (analogous to changing velocity), it changes.

If I move the plane along its normal (analogous to allowing time to pass, and having some objects move), it also changes.

You can also answer "What is the width of the blue line in the direction perpendicular to its length?". This would be the rest-width or proper width of the blue object.

But you can't answer "What is the width of the blue line?". As this requires the direction we mean by 'width' to be defined.

 

But no matter what plane we pick, it does not change the lines. The lines are perfectly real without the plane.

 

You can say that the lines are not in fact lines, but points intersecting a single plane that moves (this would be the philosophy of presentism in this analogy), but then you have to define that plane.

 

This is why we keep asking you 'what is the preferred frame?'. Your answer of 'at rest with whatever is measured' (in other words, no universal single preferred frame) is logically inconsistent with presentism.

 

 

You can't have constant observed¹ speed of light in all frames, presentism, and lack of a universal preferred frame for all measurements.

 

Constant observed speed of light is experimentally verified, so to debate this, you'd have to provide experimental results.

 

No experiment we've done to detect a universal preferred frame of reference has worked. So either it's not there (things are lines through all time, not points at now), or it's undetectable (Lorentz Ether theory).

 

Again, the logic behind this can't be summarised in a single post, and I need some small measure of cooperation to explain it.

 

 

¹I say observed, because in Ether theories, the moving person still measures light to be moving at c, but their measurements are wrong.

[md65536]

However, it does bring up an interesting "notion" I have been entertaining. We (us humans) are really in no better or worse position than any other entity in the universe to experience the universe. There are some direct analogies between what we are and do, and what a "non thinking" entity is and does.

 

This is why when we speak of an "observer" we don't speak of a human, but instead of an abstract prototypical observer. It doesn't need to be a physical thing or "alive" or a human with all the connotations and assumptions that come along with that. All the assumptions should be defined, and so minimized.

 

It is argued mathematically that somewhere in space and time there is a duplicate TAR. I totally disagree. It is not possible. Cause if he where to point at me, and I were to point at him we would be pointing in opposite directions in space and time, making us each unique at least in the direction we would have to point. Nevermind the fact that I would be pointing from the Milky Way and he would be pointing AT the Milky Way.

Apologies for this off-topic reply, but... in most models if it's mathematically possible that another exact TAR exists it's statistically certain that an infinite duplicate TARs exist. So your duplicate TAR could be pointing in the same direction, toward the next one in line (and another would be pointing at you). But then there would be an infinite number of TARs that are pointing in different directions, or are picking their noses instead, etc. I don't think these models are correct, either.

 

Anyway this "notion" leads me in the direction of considering what "arrives" here now is of great importance, greater importance than what we imagine will arrive here later. We are

YES. I'm not going to try to talk about "updates to simultaneity" but this intuition of yours is true and a very important part of it. I imagine Einstein having similar insights and being guided by them while figuring it all out for the first time.

 

(This can also be seen as an insight into how reality, and what is observed, are very closely connected.)

[owl]

At no point in my diagrams (or anyone's diagrams, I think) was light pushed faster than c in any reference frames. Could you point to an example where it was?

I could have been more clear. We all know that light can not go faster than c, even when its source is going 1/2 c or whatever. I was just thinking that the apparent “length contraction” could be accounted for by the distance the rockets and their lasers travel *through* the tail end of their projected beams. So even though, in my experiment, each light beam travels over 5/8ths the one Au distance in just over 5 minutes, the lasers/observers themselves travel just over 5/16ths the distance in the same time... the time and distance it takes for each jouster to see the other’s light. No length is contracted and light maintains c velocity throughout, not 1&1/2 c.

Back for more replies soon.

 

Schrodinger's hat:

For the umpteenth time, reality doesn't depend on frame of reference, but distance is not defined without one.

 

If I give you two lines like so:

Posted Image

And ask "What is the distance between these two lines?"

The question is nonsense. It's undefined.

 

Also for the umpteenth time, the philosophy of realism posits that there is a (slightly variable) distance between Earth and Sun which does not require our "definition" (like one Au or 93 million miles... in whatever units) or depend on frame of reference.

Your lines in a box is an abstraction you created. The space (linear in this case) between Earth and Sun is a fact of nature which only varies with position in orbit (91 to 94.5 million miles.) No frame of reference or definition of distance is required for the dynamic orbit of Earth around Sun, all by its natural "self", or to create the space/distance between them.

 

Of course, astronomy has measured this distance very precisely from our at rest frame, naturally.

 

You still don't get realism's "world/cosmos" as is, sans any/all possible frames of reference or definitions.

 

Ps, yet again (still hammering on the fallacy/absurdity of length contraction as per Cap 'n R's and Swansonts repeated assertions):

In the real world, how does high speed observation (near c FOR) change the shape of Earth, Earth-Sun distance, length of a meter rod, etc?

Alternatively, if FOR doesn't change the above (the Cap 'n's assertion), then does length contraction theory assert that we (science) can not know which shapes and measurements of the above are accurate.

 

I will shut up and go away* IF someone will answer this to my satisfaction.

*"Away" is relative. I still want to know what curves when GR claims that gravity curves spacetime. And if "spacetime" is a non-entity concept, the thread title still applies to the question of the "reality factor" of spacetime.

Edited September 29, 2011 by owl

[Iggy]

Also for the umpteenth time, the philosophy of realism posits that there is a (slightly variable) distance between Earth and Sun which does not require our "definition" (like one Au or 93 million miles... in whatever units) or depend on frame of reference.

Can you give us a source establishing that realism rejects a notion of distance that's relative to frame of reference, please?

[Cap'n Refsmmat]

I could have been more clear. We all know that light can not go faster than c, even when its source is going 1/2 c or whatever. I was just thinking that the apparent “length contraction” could be accounted for by the distance the rockets and their lasers travel *through* the tail end of their projected beams.

That's how I explained it, yes. From an observer's point of you, the light source is moving at half the speed of light, so it "chases" the projected light beam. In one second, the light moves half a light-second away from the flashlight, since the flashlight is chasing it.

 

Now, what does the light source observe? From the light source's perspective, it's not moving -- if you measure your velocity relative to yourself, you get 0. After one second, how far away is the light?

 

In the real world, how does high speed observation (near c FOR) change the shape of Earth, Earth-Sun distance, length of a meter rod, etc?

Alternatively, if FOR doesn't change the above (the Cap 'n's assertion), then does length contraction theory assert that we (science) can not know which shapes and measurements of the above are accurate.

Any well-done measurement is accurate in that reference frame. It just disagrees with other accurate measurements taken in other reference frames.

 

I will shut up and go away* IF someone will answer this to my satisfaction.

Ha.

 

I can explain the course of this thread via a simple analogy:

 

Us: Let's explain how to make an omelet. First, you crack a few eggs into a bowl.

You: What?! I'm not eating raw eggs! That's disgusting!

Us: ...no, no, they won't be raw when we--

You: That makes no sense. Look. Imagine I put some raw eggs in a bowl and leave for an hour. When I come back, they'll still be raw. Right?

Us: ...yes, but we're going to cook--

You: How can eggs be both cooked and uncooked? That's nonsense! Realism demands eggs be either one or the other. Anything else is a result of drinking too much cooking sherry.

Us: But they're never both cooked and uncooked -- they're raw at one time, and cooked later.

You: No, that's not what I see in my example. Put some raw eggs in a bowl and they stay raw.

Us: Right, but you can cook them.

You: So now the eggs are both cooked and uncooked, are they?

Us: Uhm, no.

You: You're absurd.

 

If you'd let us cook the eggs, you might understand.

[Schrödinger's hat]

Also for the umpteenth time, the philosophy of realism posits that there is a (slightly variable) distance between Earth and Sun which does not require our "definition" (like one Au or 93 million miles... in whatever units) or depend on frame of reference.

Your lines in a box is an abstraction you created. The space (linear in this case) between Earth and Sun is a fact of nature which only varies with position in orbit (91 to 94.5 million miles.) No frame of reference or definition of distance is required for the dynamic orbit of Earth around Sun, all by its natural "self", or to create the space/distance between them.

This is an empty assertion. Show me an example of (or even logic that shows me that I could discover) a distance that has measured without a frame of reference and I'll happily run over to my nearest university and tell them that relativity is complete nonsense.

You still don't get realism's "world/cosmos" as is, sans any/all possible frames of reference or definitions.

NUHUH! YEHUH! NUHUH! YEHUH! Will get us nowhere.

I don't get realism+presentism+constant speed of light+postulate of relativity because it doesn't make any sense.

 

I do get realism+postulate of relativity+constant speed of light perfectly well.

 

I also get realism+presentism+constant (measured) speed of light. I just think the resulting theory is too convoluted for it to be likely that it's true.

 

In the real world, how does high speed observation (near c FOR) change the shape of Earth, Earth-Sun distance, length of a meter rod, etc?

Alternatively, if FOR doesn't change the above (the Cap 'n's assertion), then does length contraction theory assert that we (science) can not know which shapes and measurements of the above are accurate.

 

I will shut up and go away* IF someone will answer this to my satisfaction.

*"Away" is relative. I still want to know what curves when GR claims that gravity curves spacetime. And if "spacetime" is a non-entity concept, the thread title still applies to the question of the "reality factor" of spacetime.

 

Capn voiced my frustration at this very well. The showing involves diagrams and/or careful application of logic in small steps to make sure we're not leaving anything out. It is exactly what we've been trying to do for the entire thread, but you keep interrupting the process with 'NO SHOW ME HOW IT WORKS'.

 

Just to recap. Respond to the jousters diagram/post I made. Can you read it okay? Explain anything you don't understand. Does it display the situation you were trying to explain?

Note that it doesn't try to demonstrate anything about length contraction or simultaneity, it's just intended to be the situation you outlined (two things moving towards one another emitting a beam moving at twice their speed).

[owl]

Cap 'n R:

If you'd let us cook the eggs, you might understand.

 

Trying to make my challenge look very stupid and ridiculous does not answer the question I have posed many times. Swansont insists that length is NOT an invariant property, that is changes with different Frames of reference. The diameter of Earth is a "length" and so is the space/distance between Earth and Sun, and so is a solid meter rod. So I understood him to say that the shape of Earth changes according to the FOR from which it is observed, and same with the other two distances mentioned.

You, on the other hand, after much argument back and forth with me said definitely that Earth does not change shapes (from 1000 mi to 8000 mi diameter) that Earth does not move closer to Sun (to within 12 million miles or so) as observed from that famous near c fly-by, and that the meter rod does not likewise "morph" to 12 cm as observed from a similar FOR. Rather, you said that there is no way to know which frame of reference is correct... what I call the standard, Earth science measures of all of the above or the measures taken from the infamous near c fly-by FOR. (Your statue as seen from front and back was another illustration of your claim (relativity's claim) that "There is no preferred frame of reference."

 

A little humor here in response to your ridicule: Poor science! It doesn't even know the true shape of our home planet or how far it is from here (now) to the Sun or how long a meter rod is...

(like surveying the surface quadrant of Earth from equator to pole to derive a 10 millionth of it for the sake of establishing a standardized Earth to human commensurate measure of distance was a waste of time!)

 

So PLEASE go ahead and cook those eggs if you will and quit trying to make me look stupid/ridiculous with an absurd cooked up or left raw example.The "if you will" is dubious but I am sincerely asking, and IF you will, thanks. (more editing)

Edited September 30, 2011 by owl

[Cap'n Refsmmat]

I can exactly describe the "true shape" of our home planet. It just happens to live in four dimensions.

 

The absurdity you point out is entirely normal.

[md65536]

That's how I explained it, yes. From an observer's point of you, the light source is moving at half the speed of light, so it "chases" the projected light beam. In one second, the light moves half a light-second away from the flashlight, since the flashlight is chasing it.

 

Now, what does the light source observe? From the light source's perspective, it's not moving -- if you measure your velocity relative to yourself, you get 0. After one second, how far away is the light?

That's an interesting question and I'm wondering where you're going with it. I don't think it should be ignored and brushed under the rug along with everything else in this thread.

 

From the observer's perspective, the light should move one light-second in one second, and the source flashlight moves half a light-second in one second, so the light is half a light-second away from the flashlight, after one second.

 

From the flashlight's frame of reference, the light should move one light-second in one second (as with any observer since the speed of light is c in every frame of reference), and the flashlight is not moving relative to the observer, so the light is one light-second away from the flashlight after one second.

 

Does anyone disagree?

 

 

 

[tar]

Owl,

 

A meter is the distance light travels in 1 300millionth of a second.

 

A second is the time it takes light to travel a meter.

 

We find this to be the case, no matter what direction we measure in.

 

We define length by the velocity of light.

We define time by the velocity of light.

 

Light goes one lightsecond of distance in one second.

Light takes a second to travel a lightsecond of distance.

 

True for me and you, and true for the flyby guy.

 

Only works if we are not moving in reference to the A and B we are measuring the distance and time between.

Only works if the flyby guy is not moving in reference to the A and B he is measuring the distance and time between.

 

 

A is real for both us and the flyby guy.

 

B is real for both us and the flyby guy.

 

A and B are only one real distance and time apart.

 

A spacetime interval.

 

Regards, TAR2