The Twin Paradox Made Simple

[Moronium]

What are you referring to?  Why does the MM experiment have anything to do with the fact that your claim is demonstrably false?

 

With any intelligent poster asking in good faith, I would respond to a question like this.

 

But you aint that.

[JMJones0424]

Your high horse is faulty.  You claimed that which is false was true.  You claimed to quote instances from a source I cited that were not in the source I cited.  You are a liar.  You cannot even support the claims you made to support the lies you made.

[Moronium]

I don't know what your level of education is, JM but it's been observed that education has different effects on different kinds of people:

 

 

"Education, n.: That which discloses to the wise and disguises from the foolish their lack of understanding." (Ambrose Bierce)

 

[Moronium]

I will take a minute to explain something that a lot of people (here, anyway) don't seem to understand:

 

If I pick a single frame of reference (the barycenter of the solar system, for example) and use it to calculate the speed of multiple objects (like the Sun and all the planets, for example), then I am NOT using SR.  I am NOT positing relative simultaneity, and I am implicitly rejecting the notion that "all motion is relative."

 

An unsophisticated relativist will deny this.  He will say that I am just employing SR in a "convenient" frame of reference.  But, in fact, SR would, by it's postulates, strictly forbid this procedure.  I have explained how and why it forbids this many times, but those explanations get ignored.

 

Anytime I pick one frame of reference to assess the motion of various objects I have, theoretically speaking, undertaken to assign absolute motion to them, not relative motion.  The frame of reference I pick could be that of my dog in my backyard, and it would be no different in this sense.  Picking the dog in my backyard as a "preferred frame" would be senseless and would produce "absolute values" with no particular significance, but I would still be assigning absolute motion to all other objects I compared him to (the dog-catcher's truck driving by, a stranger coming into my yard, whatever).

 

The frame of reference I pick could be me.  In that case, I would be the preferred frame. Absolute motion would then be imputed to all objects which are moving relative to me. So, de facto, SR always employs a preferred frame too, notwithstanding it's general denial that this is a proper procedure.  This is just another inconsistency in SR.  It does not adhere to its own purported precepts in practice.  

 

In order to be true to itself, SR would have to assert that any possible answer to any possible question asked about any possible motion is both unknown and unknowable.  Unfortunately, that would make it utterly useless as a scientific theory of motion, so it can't possibly do that.

Edited May 4, 2018 by Moronium

[Moronium]

Let's take a classical view for a minute.  Let's say I am going down the road at 50 mph.  Using the earth's surface as a chosen preferred frame, I would then say that *I* am going 50 mph.  If I then asked how fast the car in front of me (which is receding from me at the rate of 20 mph in the same direction that I am going) I would say that it is going 70 mph.  Here again the preferred frame is the earth's surface, not ME.  If I was the preferred frame I would have to say that the car in front of me is going 20 mph and that the earth, and everything attached to it (houses, stop signs, bystanders along the roadside, whatever) are all moving away from me at the (absolute) speed of 50 mph (well, or toward me, if I they have not passed me yet).

 

Of course, if I chose myself being the preferred frame, then I am going "zero."  So is the shotgun and the carton of cigarettes which are on the seat beside me.

 

But how do I "know" that I am motionless with respect to everything else in the universe?  Answer:  I don't.  I just posit it, that's all.  With SR I am absolutely free to posit anything I want to as a preferred frame, see?  Well, no, not really.  Not if you subscribe to SR, anyway.  In SR you are NOT "free" to posit that the earth's surface is motionless, as you did initially,  because that's not YOU.  You can never posit that you are moving.in any way.  SR don't play dat..

 

So, in SR, I always know my speed, absolutely.  It's zero.  But, wait, SR says you can never know that anything is "at rest."  Aww, well, just forget what SR says.

Edited May 4, 2018 by Moronium

[Moronium]

As the graphic explains, because of the transformed space and time lines, each observer is actually reading the other’s clock in the past!

 

 

 Corrections for signal delays due to travel time can, should be, and routinely are applied to any calculations for (assessment of) "time dilation."  Therefore they don't have any effect on that concept.  David Hogg, a physics professor at Princeton who wrote a book on SR, explains this as follows:

 

 

A common confusion for students of special relativity is between that which is real and that which is apparent. For instance, length contraction is often mistakenly thought to be some optical illusion. But moving things do not “appear” shortened, they actually are shortened. How they appear depends on the particulars of the observation, including distance to the observer, viewing angles, times, etc.  The observer finds that they are shortened only after correcting for these non-fundamental details of the observational procedure.....

 

Observing time dilation... it is important to distinguish between what an ideally knowledgeable observer observes and what an ordinary person sees.  As much as possible, the term “to observe” will be used to mean “to measure a real effect with a correct experimental technique,” while “to see” will be reserved for apparent effects, or phenomena which relate to the fact that we look from a particular viewpoint with a particular pair of eyes.

 

....In order to correctly measure the rate of D’s clock, E must subtract the light-travel time of each pulse (which she can compute by comparing the direction from which the light comes with the trajectory that was agreed upon in advance). It is only when she subtracts these time delays that she measures the time between ticks correctly...

 

http://cosmo.nyu.edu/hogg/sr/sr.pdf

 

So, as I am reading Hogg, it would be a mistake to say that a clock reading that does NOT correct for light delay is a "real effect."  It would only be an "apparent one." That's one (of many) reason(s) why I say that these minknowski diagrams don't tell you anything about the "real" world.

 

Hogg says here that the word "observes" must be distinguished from "sees" in order to get a correct understanding. Among other things, in order to make an "observation, one must be "an ideally knowledgeable observer," according to Hogg.  "Apparent effects" must be eliminated in order to properly talk about an "observation."  Some posters here seem unable to follow that advice and/or make that distinction.

 

For that matter, Einstein himself failed to do that, when convenient for his purposes.  I have noted in my thread on relative simultaneity that he deliberately deprives his train passenger of "ideal knowledge" and leaves him ignorant of his own motion.  The train passenger is compelled to insist that he is absolutely "at rest" even though Einstein has previously established, by postulation, that he is moving.  This hardly makes him "an ideally knowledgeable observer," eh?

 

The routine and regular mixing of real vs apparent effects is the main ingredient of sophistical arguments purporting to "demonstrate the truth" of SR.   Such arguments rely heavily on employing the "fallacy of equivocation.'

 

Coming back to your post, Popeye, you say:   "...each observer is actually reading the other’s clock in the past!"  That may be true, but it's hardly a good ground for concluding that reciprocal time dilation is "true," as you seemingly do.

Edited May 4, 2018 by Moronium

[Moronium]

Illustrations using light clocks are often used to (purportedly) prove that time dilation is "reciprocal," but these examples only assume what they purport to "prove."

 

Assume that I'm looking at a light clock (call it A) that is moving with respect to me, OK?  Now, I ask you, how would it look (appear) to me if I were motionless?  Now, then, how would it look to me if I was moving at the speed I end up imputing to it, and IT was actually motionless?  What would the difference in what I "see" be?

 

Could what I see possibly tell me whether [a] I am moving,  it is moving, or [c] we are both moving?

 

Let's call my light clock B.

 

Now it should be obvious that if both A and B agree that (for example) A is motionless and B is moving, then nobody will claim that time dilation is "reciprocal."  Both will agree that B's clock has slowed down and that A's hasn't.

 

What you "conclude" strictly depends on what you assume as  premises to begin with.  Your "conclusion," standing alone, proves nothing about the "real world."  It just shows what your subjective assumptions (right or wrong) are.

Edited May 4, 2018 by Moronium

[Moronium]

In the book I just cited, Hogg also says:

 

 

The first principle of relativity ever proposed is attributed to Galileo, although he probably did not formulate it precisely. Galileo’s principle of relativity says that sailors on a uniformly moving boat cannot, by performing on-board experiments, determine the boat’s speed. They can determine the speed by looking at the relative movement of the shore, by dragging something in the water, or by measuring the strength of the wind, but there is no way they can determine it without observing the world outside the boat. A sailor locked in a windowless room cannot even tell whether the ship is sailing or docked.

 

 

I made this same point in an earlier post.  In response, cheerleaders like A-wal, reflexively shouted that I was lying (or something similar).

 

Hogg also says something else that I have referred to, to wit:

 

On a day-to-day basis we are not aware of the motion of the Earth around the Sun, despite the fact that its orbital speed is a whopping 30 km s−1 (100, 000 km h−1). We are also not aware of the Sun’s 220 km s−1 motion around the center of the Galaxy (e.g., Binney & Tremaine 1987, Chapter 1) or the roughly 600 km s−1 motion of the local group of galaxies (which includes the Milky Way) relative to the rest frame of the cosmic background radiation (e.g., Peebles 1993, Section 6). We have become aware of these motions only by observing extraterrestrial references (in the above cases, the Sun, the Galaxy, and the cosmic background radiation). Our everyday experience is consistent with a stationary Earth.

 

 

What Hogg refers to as a "fact" is merely the earth's motion "relative to" the Sun and other preferred frames, such as the CMB.  What Hogg doesn't explicitly say is that motion relative to a preferred frame is absolute (not relative) motion.  Earlier I also provided substantial authoritative support for the accepted modern view that the CMB actually IS a legitimate preferred frame, not just an arbitrary or "convenient" one.  It is a preferred frame in (one of)  the sense(s) that wiki describes, i.e:

 

In theoretical physics, a preferred or privileged frame is usually a special hypothetical frame of reference in which the laws of physics might appear to be identifiably different (simpler) from those in other frames.

 

 

The conclusions of prominent (e.g., nobel prize winning) physicists pertaining to preferred frames and special relativity were also reflexively denied by posters like A-wal, of course, who suggested that they were "highly stupid" (in contrast to him, needless to say).

 

Another interesting excerpt from Hogg:

 

2.1 Time dilation: Consider two observers, Deepto (D) and Erika (E), moving relative to one another in spaceships. D measures E’s speed to be u with respect to D’s rest frame. By symmetry, E must also measure D’s speed to be u with respect to E’s rest frame. If this is not obvious to you, notice that there is no absolute difference between D and E. If they did not measure the same speed, which one of them would measure a higher speed? In order for one to measure a higher speed, one of them would have to be in a special or “preferred” frame; the principle of relativity precludes this.

 

. 

 

Note that Hogg does NOT claim that  there is, or can be, no preferred frame.  He simply notes (accurately) that SR precludes one.

 

I wonder how many here who inform me that I just "don't understand" SR, have actually carefully read authoritative books on the topic, such as this one published by Hogg (the emphasis being on the word "carefully").

 

What any competent professor of SR says to his students is this: "I am here to teach what the implications of SR's postulates are.  I am not here to tell you that those postulates are "true."  Unfortunately, there seems to be a great number of SR "teachers" who do otherwise.

Edited May 4, 2018 by Moronium

[Moronium]

What any competent professor of SR says to his students is this: "I am here to teach what the implications of SR's postulates are.  I am not here to tell you that those postulates are "true."  Unfortunately, there seems to be a great number of SR "teachers" who do otherwise.

 

 

 

David Morin, a professor of physics at Harvard who I have cited before, says this in his book on the topic, for example:

 

11.2 The postulates

 

Let’s now start from scratch and see what the theory of Special Relativity is all about. We’ll take the route that Einstein took and use two postulates as the basis of the theory. We’ll start with the speed-of-light postulate:

 

• The speed of light has the same value in any inertial frame.

 

I don’t claim that this statement is obvious, or even believable. But I do claim that t it’s easy to understand what the statement says (even if you think it’s too silly to be true).

 

 

 

http://www.people.fas.harvard.edu/~djmorin/chap11.pdf

 

I agree with Morin.. I can "understand" what the postulates (and their implications) of SR are, even if I don't believe them to be "true."  Some posters here  (A-wal, for example) take the opposite position and assert that "if you don't believe the postulates of SR are true, then you don't (and can't) understand them."

 

I don't think so.  Homey don't play dat.

 

People taking A-wal's position quickly turn SR into an "unfalsifiable" (per Popper) pseudo-scientific metaphysical proposition,  Popper singled out "theories" such as Freudian psychology and Marxist economics (dialectical materialism) for special mention as pseudo-scientific because, he said, such "theories" immunize themselves from any potential criticism by building in ad hoc refutations.  Things like "if you don't believe, it's only because you don't and can't understand it." ya know?

 

That's kinda what all the mystics say, aint it?  You will know their speculations are true, but only if you are "enlightened."  If you don't "know" it, that does not detract in the least from the glorious truth.  It merely proves that you are "unenlightened.'

 

It's not the same, but it brings to mind Feynman's notorious statement about QM:  Anyone who understands QM doesn't understand it.

Edited May 5, 2018 by Moronium

[OceanBreeze]

David Morin, a professor of physics at Harvard who I have cited before, says this in his book on the topic, for example:

 

 

http://www.people.fas.harvard.edu/~djmorin/chap11.pdf

 

I agree with Morin.. I can "understand" what the postulates (and their implications) of SR are, even if I don't believe them to be "true."  Some posters here  (A-wal, for example) take the opposite position and assert that "if you don't believe the postulates of SR are true, then you don't (and can't) understand them."

 

I don't think so.  Homey don't play dat.

 

People taking A-wal's position quickly turn SR into an "unfalsifiable (per Popper) pseudo-scientific metaphysical proposition,  Popper singled out "theories" such as Freudian psychology and Marxist economics (dialectical materialism) for special mention as pseudo-scientific because, he said, such "theories" immunize themselves from any potential criticism by building in ad hoc refutations.  Things like "if you don't believe, it's only because you don't and can't understand it." ya know?

 

That's kinda what all the mystics say, aint it?  You will know their speculations are true, but only if you are "enlightened."  If you don't "know" it, that does not detract in the least from the glorious truth.  It merely proves that you are "unenlightened.'

 

It's not the same, but it brings to mind Feynman's notorious statement about QM:  Anyone who understands QM doesn't understand it.

 

 

I don't disagree with Morin, or with you, for that matter. Notice that when I posted that graphic I didn't make any claim that it is "True". I posted it as an example (a good one, I think) of what SR claims about relative motion and reciprocal time dilation.

I accept the claims of SR as true in the sense that SR is falsifiable (including reciprocal time dilation) but so far it has never been falsified, as far as I know. So it is a good theory, unlike the theory that there exists a red swan which is not falsifiable and therefore not scientific and in fact, a useless theory.. SR is falsifiable because it makes predictions, and those predictions can be, and have been, tested and verified.

 

If you have evidence of an instance of SR being falsified by any experiment, and not just an opinion, I would be interested in reading about that.

 

And yes, the vast majority of people who say they understand SR, and act as its staunchest defenders, really do not understand it at all, as you have already seen.

Edited May 4, 2018 by OceanBreeze

[Moronium]

 

If you have evidence of an instance of SR being falsified by any experiment, and not just an opinion, I would be interested in reading about that.

 

 

 

I have already done that on numerous occasions, Popeye, and it's not just my opinion (if you want to call it an opinion) but one shared by a large number of physicists.  I'll see if I can find a few and post links to them here.   

 

I've looked a little.  But the truth is, I've made so many posts, in so many different threads, many of which are many pages long, that at times it's almost easier to start all over with a simple post than to find and link much more detailed posts in other threads.

 

The clock readings of the H-K experiment prove that there is, in fact, NO reciprocal dilation.  If you don't care at all about clocks, but are only you're looking for disproof of what some hypothetical observers putatively "sees" or "thinks" then that has been addressed at some length too, even in the last few posts I've made in this thread, also.

 

Of course any fool can "think" almost anything, but that doesn't make it the least bit sensible.

 

I would assert that any subjective "claim" purportedly made by some hypothetical observer that suggests that clock retardation is "reciprocal" makes no sense.  That's not quite the same as proving it's "untrue" of course.

 

What kind of "disproof" any you looking for, exactly, Popeye?

 

UPDATE:  Here's one thread I've found where the "logic" of reciprocal dilation is addressed and which is directed primarily at subjective thoughts.

 

http://www.scienceforums.com/topic/30741-what-the-observer-saw/  (posts 9 and 11)

 

A similar analysis is presented in post 55 of THIS thread.  http://www.scienceforums.com/topic/30976-the-twin-paradox-made-simple/page-4

 

Here's another, where the focus in primarily on the motions of the objects themselves, rather than observers, per se:

 

http://www.scienceforums.com/topic/31081-preferred-frame-geometry/?do=findComment&comment=355943  (post #3)

 

With regard to a more general "disproof" of SR, did you look at post 99 of this thread?:  http://www.scienceforums.com/topic/30976-the-twin-paradox-made-simple/page-6

Edited May 4, 2018 by Moronium

[A-wal]

I can't be bothered right now to point out all the mistakes you keep making, you never learn from them anyway. Your biggest problem seems to be that you get stuck on this:

I would assert that any subjective "claim" purportedly made by some hypothetical observer that suggests that clock retardation is "reciprocal" makes no sense.  That's not quite the same as proving it's "untrue" of course.

You simply can't see how object 2 is length contracted and time dilated from object 1's frame while object 1 is length contracted and time dilated from object 2's frame. You think that they can't both be right one frame must be preferred. There's no contradiction here, regardless of the that fact that these are just two arbitrary frames and there's no reason to expect either to be a magical preferred frame.

 

Let me know where you get lost...

 

1. Object 1 and object 2 accelerate away from each other. Object 2 is length contracted and time dilated from object 1's frame while object 1 is length contracted and time dilated from object 2's frame.

 

2. Object 1 accelerates into object 2's frame. Less time has passed on object 1's watch than on object 2's because object 1 is now in a frame in which they were time dilated and length contracted before accelerating into this frame. They then sync their watches.

 

3. Object 1 and object 2 accelerate away from each other again. Object 2 is length contracted and time dilated from object 1's frame while object 1 is length contracted and time dilated from object 2's frame.

 

4. Object 2 accelerates into object 1's frame. Less time has passed on object 2's watch than on object 1's because object 2 is now in a frame in which they were time dilated and length contracted before accelerating into this frame. They then sync their watches.

 

5. Object 1 and object 2 are joined by object 0. Object 1 and object 2 accelerate away from each other again, object 0 doesn't accelerate. Object 2 is length contracted and time dilated from object 1's frame and so is object 0 but to a lesser extent. Object 1 is length contracted and time dilated from object 2's frame and so is object 0 but to a lesser extent. Objects 1 and 2 are length contracted and time dilated from object 0's frame by the same amount as object 0 is length contracted and time dilated from the frame of both object 1 and object 2.

 

6. Object 1 accelerates into object 0's frame. Less time has passed on object 1's watch than on object 0's because object 1 is now in a frame in which they were time dilated and length contracted before accelerating into this frame.

 

7. Without syncing watches, Object 1 accelerates into object 2's frame. Less time has passed on object 1's watch than on object 2's because object 1 is now in a frame in which they were time dilated and length contracted before accelerating into this frame and the difference in elapsed time is greater than the difference in elapsed was between object 1 and object 0. They then sync their watches.

 

8. Object 1 and object 2 accelerate away from each other again. Object 2 is length contracted and time dilated from object 1's frame while object 1 is length contracted and time dilated from object 2's frame.

 

Note that they are now in motion relative to object 0, every time they accelerate away from each other they do it from a different frame than the last time they accelerated away from each other and it makes no difference.

 

If Object 1 accelerates into object 2's frame then less time will have passed on object 1's watch but if object 2 accelerates into object 1's frame then less time will have passed on object 2's watch.

Edited May 4, 2018 by A-wal

[Moronium]

You think that they can't both be right one frame must be preferred. There's no contradiction here, regardless of the that fact that these are just two arbitrary frames and there's no reason to expect either to be a magical preferred frame.

 

 

If you want to talk about what makes "sense" to some fool, then I can't dispute that.  If he believes he's an elephant, then he does, and that much is "true."  Of course it's not true that he actually is an elephant, but that's just a matter of objective fact (which doesn't even exist for a solipsist).

 

People can be reasonably mistaken about their own motion too, that's a known fact (although the illusion is generally quite temporary).  Either way, that's not even what I'm talking about.

 

It's "unreasonable" to suggest that a trained astronaut would actually think he was absolutely motionless on his way to the moon, but that's not even what I'm talking about, either, in this context, at least.

 

I'm just saying that, if there is such a thing an as objective reality (and I believe there is) then they cannot BOTH be right as a matter of objective reality.  They can both "believe" they're right all year long, sure, and that's OK.  But, still, at least one of them must be wrong, as an objective matter.They cannot BOTH be "at rest" as SR requires them to assume.  Not if they're really moving, relative to each other, anyway.

 

You want to say A thinks he's at rest, B thinks he's at rest, they both agree that they're moving relative to each other, and BY GOD, they're BOTH RIGHT!!!

 

A solipsist might find that to be a "rational" proposition, but...

 

I don't think so!  Homey don't play dat.

Edited May 4, 2018 by Moronium

[A-wal]

Only a fool would accept that SR is a logically consistent model and then attack it based on nothing more than their distaste of multiple frames being equally valid despite all evidence to the contrary.

 

Solipsism has nothing to do with this. You keep bringing it up, presumably in the hopes of trying to somehow discredit me but it has zero baring on the validity of SR. That kind of ad hocism stinks of desperation.

 

A trained astronaut or any other observer can only be in motion relative to any other object, including the moon. To claim that the astronaut is in motion while the moon is motionless is to claim the the moon is at absolute rest and that either the astronaut's motion is relative to the moon's frame regardless of the astronaut's destination or that the absolute rest frame of the universe somehow depends on the astronaut's choice of destination. You need to think about what the implications would be of the claims you're making and how absurd they actually are.

 

Whether or not reality is objective or entirely subjective, it is self-consistent. In a universe where light moves at the same velocity relative to all inertial observers there can be no preferred frame. If you want to try claiming again that any theoretical physicist worth their salt agrees with a model in which the speed of light is variable then this is simply a false claim. It's been shown that the relative velocity of light is independent of the motion of inertial observers. SR describes this universe, the real one, not a make believe one with magical reference frames giving them priority over other frames.

 

Both objects in relative motion are time dilated and length contracted from the frame of reference of the other object and either one will have experienced less proper time if they accelerate into the frame of the other. Neither one has a more valid claim about the true reality than the other. You can choose to either accept this or to continue to deny it, but it's the only logically consistent model that works with a constant speed of light. If the speed of light isn't constant then SR isn't a true description of reality, nobody is denying that, but your claim that "one of them must be wrong" is false.

Edited May 4, 2018 by A-wal

[Moronium]

You say A thinks he's at rest, B thinks he's at rest, they both agree that they're moving relative to each other, and BY GOD, they're BOTH RIGHT!!!

 

A solipsist might find that to be a "rational" proposition, but...

 

I don't think so!  Homey don't play dat.

 

 

 

 

If you actually understand SR then you would understand why SR REQUIRES them to make such contradictory, mutually exclusive claims.  SR would self-destruct if they didn't.

 

But that nonsense is NOT a point which "proves the truth of SR."  On the contrary, it basically proves that SR CAN'T be true, as an objective matter.

[Moronium]

Only a fool would accept  that SR is a logically consistent model and then attack it based on nothing more than their distaste of multiple frames being equally valid despite all evidence to the contrary.

 

 

You just demonstrate, once again, than you cannot grasp the very elementary proposition that "logical validity" can never prove existential soundness.

 

Exactly what  is to be expected from a hard-core, stone-cold, extremely gullible solipsist like you, A-wal.

Edited May 4, 2018 by Moronium

[A-wal]

If you believe that the picture of reality painted to you by your senses is more than your minds interpretation of reality and that there is in fact an external reality that exactly matches your internal one despite having nothing to go on other than your internal picture than I'm afraid you're the one who's truly gullible. That's faith based thinking.

 

The validity of SR (or any other physical model for that matter) is entirely unaffected by the validities of the solipsism/materialism philosophies. That's like saying someone shouldn't be able to vote because they support ManU, a great idea if you hate ManU as much as I do but not a rational link to make.

 

 

You say A thinks he's at rest, B thinks he's at rest, they both agree that they're moving relative to each other, and BY GOD, they're BOTH RIGHT!!!

 

A solipsist might find that to be a "rational" proposition, but...

 

I don't think so!  Homey don't play dat.

If you actually understand SR then you would understand why SR REQUIRES them to make such contradictory, mutually exclusive claims.  SR would self-destruct if they didn't.

 

But that nonsense is NOT a point which "proves the truth of SR."  On the contrary, it basically proves that SR CAN'T be true, as an objective matter.

The most fundamental concept that SR is built on is that they can make no mutually exclusive claims about their inertial motion. SR certainly doesn't require that they do so. What a silly thing to attempt to claim.