Personal Topic

[Moronium]

Well, Popeye, if I "ran you out of the thread" by talking with Marco, I regret it.  Obviously I'd rather converse with reasonable people, like you.  It's just that I haven't run across many here who seem to be very opened minded.  By and large posters here just want to assert their preconceptions, and don't care to "discuss" anything.

 

I was curious to see if you disagreed with this post, from a few pages back, and if so, why.  Care to respond?

 

 

Minkowski says that "lengths" don't change.  Only distance (space) does.   You're with Minkowski, I see.  He couldn't distinguish one from the other either.

 

Say I have a football field with goal posts at each end.  The space between those two posts is the distance.

 

Now I say I have two rulers with "lengths."  One is 12" one is only 6" long (but I think it's 12)

 

With the short ruler I will measure the distance to be 600 feet.

 

With the long ruler, I will measure the distance to be 300 feet.

 

The distance is the same, and has not changed.  The only thing that changed is my measurement of it.  That's because the lengths of my measuring instruments are different, not because the two goal posts have moved first farther apart, and then closer together, when I change rulers.

Edited February 17, 2019 by Moronium

[OceanBreeze]

Well, Popeye, if I "ran you out of the thread" by talking with Marco, I regret it.  Obviously I'd rather converse with reasonable people, like you.  It's just that I haven't run across many here who seem to be very opened minded.  By and large posters here just want to assert their preconceptions, and don't care to "discuss" anything.

 

 

 

You didn’t run me out.

 

I am very busy right now and don’t have much time for any discussion forum. Soon I will be gone for a couple of months, so no need to be concerned about what I think of the discussion.

 

 

I was curious to see if you disagreed with this post, from a few pages back, and if so, why.  Care to respond?

 

 

Minkowski says that "lengths" don't change.  Only distance (space) does.   You're with Minkowski, I see.  He couldn't distinguish one from the other either.

 

 

Can you please provide a link to support your statement here?

My understanding is the spacetime interval (total distance in spacetime between events) measured in any frame is the same as that spacetime interval measured in any other frame.

 

Stated another way, in Minkowski spacetime, all frames of reference will agree on the total distance in spacetime between events.

 

This is not the same as saying that there is no length contraction in Minkowski spacetime. In fact, Minkowski used the Lorentz factor to determine length contraction in much the same way that Einstein did.

 

This seems to be just the opposite of what you have written.

 

To clarify this; Say that the spacetime interval is represented by a plate of food in a frame “at rest”. As seen in a frame moving with respect to the first one, the plate of food shrinks (length contraction in one direction) but since time slows down, it lasts longer. So, the total food, representing the spacetime interval, is the same in any frame. Not the greatest analogy but maybe it gets the point across.

 

 

 

 

 

Say I have a football field with goal posts at each end.  The space between those two posts is the distance.

 

Now I say I have two rulers with "lengths."  One is 12" one is only 6" long (but I think it's 12)

 

With the short ruler I will measure the distance to be 600 feet.

 

With the long ruler, I will measure the distance to be 300 feet.

 

The distance is the same, and has not changed.  The only thing that changed is my measurement of it.  That's because the lengths of my measuring instruments are different, not because the two goal posts have moved first farther apart, and then closer together, when I change rulers.

 

 

Of course, that is correct but I don’t see where it has anything to do with relativistic effects. Relativistic effects are not the same as measurement errors.

[Moronium]

Popeye, I've now made 4 consecutive posts in response to yours.  I think that what I'm trying to say will be clearer if you read them all before responding to any.

 

I'll start by re-pasting a post I made earlier. which contains a reference to an article which talks about a "widespread view."  In his thread Ralf just posted a video featuring Brian Greene, where Greene raves about the radical changes in space and time which SR implies. This paper is worth reading if you're that interested (which you probably aren't, I know).

 

 

 

 

It is widely believed that the principal difference between Einstein’s special relativity and its contemporary rival Lorentz-type theories was that while the Lorentz type theories were also capable of “explaining away” the null result of the Michelson–Morley experiment and other experimental findings by means of the distortions of moving measuring-rods and moving clocks, special relativity revealed more fundamental new facts about the geometry of space-time behind these phenomena.

 

 

According to this widespread view, special relativity was, first of all, a radically new theory about space and time. This is however not the case.  In comparison with the pre-relativistic Galileo-invariant conceptions, special relativity tells us nothing new about the geometry of space-time. It simply calls something else “space-time."...Special relativity and the Lorentz theory are identical theories about space and time in all sense of the words.

 

http://philsci-archive.pitt.edu/9896/1/leszabo-lorein-preprint.pdf

 

What!?  You mean calling time a "fourth dimension" doesn't make it one?  Like, who knew, I ask ya?

 

What a disappointment.  Hell, now we're back to that boring 3 + 1 spacetime.  What fun is that?

 

Your post (which I can't see right now, because I didn't quote it) talks about "spacetime," and "spacetime intervals," which is NOT talking about either space or time independently.

 

Lorentz said that measurement had virtually everything to do with relativistic effects (or at least understanding them), but you say it has nothing to do with it.  You obviously accept SR unconditionally, and don't tend to think in alternate terms.

 

Per Minkowski, clock retardation and length contractions are mere illusions.  They don't really occur.  Lorentz says the opposite.

Edited February 19, 2019 by Moronium

[Moronium]

Of course, that is correct but I don’t see where it has anything to do with relativistic effects. Relativistic effects are not the same as measurement errors.

 

I'm glad that you agree that this is correct.  But this is the same principle which you rejected in the time (vs clocks) example we talked about before.  You did not think it was the same interval.  But I could substitute the word "interval" in that example for the word "distance" in this example and the point would be the same. The interval is the same, even if certain measurements of it are not the same.

 

"Time" is an abstraction, and therefore harder to talk about than tangible things like football fields and rulers.

Edited February 17, 2019 by Moronium

[Moronium]

The ship's crew members also calculate the particulars of their trip from their perspective. They know that the distant star system and the Earth are moving relative to the ship at speed v during the trip. In their rest frame the distance between the Earth and the star system is εd = 0.6 × 4 = 2.4 light years (length contraction), for both the outward and return journeys

 

https://en.wikipedia.org/wiki/Twin_paradox

 

This is an excerpt from wiki to illustrate the point.  According to that article, in the earth frame, the distance is 4 light years.  Of course a a light year is a measure of distance, not time.

 

So now we have two different distances, 4 and 2.4 (this article takes the Minknowski interpretation).

 

Lorentz would say the distance is the same.

 

Suppose these two observers, one going .6c and one "at rest," happen to be side-by-side at the moment, each looking at a distant star.  Lorentz would say that the distance to that star is the same, regardless of whether you're moving or not.

 

Lorentz would say that the fast observer "measures" the distance to be 2.4 light years, but that it is not.  That's just his "measurement," not a fact.  Minkowski says that IS the distance.  The idea is essentially that "space" shrinks for one guy, but not the other.

 

But the point here is to respond to your request for a link.  I didn't go into all of the details of the wiki example, but you can look for yourself.  Apart from the conclusion that the distance has shrunk to 2.4 years, there is no further analysis involving "time dilation" for the traveler.  There is no calculation of clocks slowing down  There is no consideration of measuring rods shrinking.  Those physical changes just play no part in the analysis or explanation. It's all simply explained by space "shrinking, which they misleadingly call "length contraction."  The LT are just assumed to directly affect time itself (not clocks) and space (distance) itself (not length).  In effect, using my football field example. they are saying the the goal posts moved closer together for the traveler, not that his measuring rods were different.

 

Here's one more excerpt from that same wiki article:

 

In the relativity of Poincaré and Hendrik Lorentz, which assumes an absolute (though experimentally indiscernable) frame of reference, no twin paradox arises due to the fact that clock slowing (along with length contraction and velocity) is regarded as an actuality, hence the actual time differential between the reunited clocks.

 

 

 

The clear implication, of course, is that clock retardation and length contraction are NOT "regarded as an actuality" in Minkowski's interpretation.

Edited February 19, 2019 by Moronium

[Moronium]

Here's another prior post that relates to this same issue, Popeye.  My conclusion is that I have travelled 50 miles to Podunk whatever speed I travel at.  I have not travelled "only" 25 miles because I got there in half the time the guy said it would take.  Do you agree with that?

 

 

If I asked two people how far Podunk is from here, one might say "about 50 miles" and one might say "about an hour."

 

Of course an hour has nothing, per se, to do with distance, but you can think of it in those terms if you want.  Assuming that a guy is travelling at the rate of 50 mph (usually a totally unwarranted assumption), then Podunk is "an hour" from here.  Time and distance are both required to calculate speed, so they are all, to that extent, interrelated.

 

But guys like Minkowski thought this inter-relationship was somehow an "independent reality" as opposed to a mere restatement of a mathematical relationship.  What do you expect?  He's a damn mathematician, not a physicist.  What does he know about "independent reality?"

 

If I decided to mash down on that accelerator and hold it at 100 mph all the way to Podunk, thereby getting there in a half an hour instead of an hour, I certainly wouldn't claim that I had traveled a "shorter distance"  than 50 miles.  Only an SR disciple could possibly think that, I figure.

 

Here I might add that if I had badly worn tires, thereby reducing their circumference, then my odometer might tell me I had gone 54 miles, instead of only 50, when I got to Podunk.  But that would not mean that I had "actually" traveled 54, even if I felt sure that I did.  It wouldn't change the distance, it's merely a mismeasurement.

Edited February 19, 2019 by Moronium

[Moronium]

This is not the same as saying that there is no length contraction in Minkowski spacetime. In fact, Minkowski used the Lorentz factor to determine length contraction in much the same way that Einstein did.

 

 

It should be clear that I don't agree with this.  Minkowski did not actually "use" the LT in any literal sense at all.  The physical changes contemplated by the LT are not taken literally by Minkowski.  For him, they are merely illusory, and don't play any part in his explanation. Minkowski took the math from the LT (he had to), but rejected the ideas behind them.  That creates it's own contradiction, but I won't go into that again here.

 

Remember the LT were developed by Lorentz, in conjunction with his theory.  Al lifted them.  As I've said before, Einstein did not view time as a 4th dimension in 1905.  That came with Minkowski in 1908.  At first, anyway, Einstein regarded Minkowski's spacetime to be what he called "superflous over-learnedness."

Edited February 17, 2019 by Moronium

[marcospolo]

 

 

 Of course a a light year is a measure of distance, not time.

 

So that distance is the distance traveled by light in one year... OK,

but "one year" is scientifically defined as  the time taken for light to go such and such a distance...

 

So we cant know a distance unless we know light speed, (d = v*t) and we can't know that speed unless we know that distance...

Measuring Velocity requires two minimum values, one is distance and the other is time.

 

The definition is circular and therefore totally meaningless.

 

The official definition of how long a meter is, according to the brainy physicists, is its the distance that light will travel in one 300000000ths of a second.

 

So now we have a circular definition of length and time, we cant ever measure light speed as anything else can we?. Even if it was changing wildly from day to day, we can no longer measure it.

 

Oh crap, I forgot, I'm ignorant. My criticisms are irrelevant.

[Moronium]

The official definition of how long a meter is, according to the brainy physicists, is its the distance that light will travel in one 300000000ths of a second.

 

So now we have a circular definition of length and time, we cant ever measure light speed as anything else can we?. Even if it was changing wildly from day to day, we can no longer measure it.

 

I agree with this post, Marco.  Using those definitions, you could never even test, forget prove, the speed of light to be anything other than what you already declared it to be.

 

This is a typical, and regretable, example of taking an unproven hypothesis and treating it as fact.

Edited February 18, 2019 by Moronium

[Moronium]

First Statement:  We measure the speed of light to be the same in every inertial frame.

 

Minkowski:  I agree

 

Lorentz: I too agree

 

====

 

Second Statement:  So the empirical facts prove that the speed of light is constant.

 

Minkowski:  Exactly!

 

Lorentz:  Wrong.

 

======

 

Minkowski:  Lorentz, you old fool.  You just contradicted yourself.

 

Lorentz:  No I didn't.  I agree that we measure it to be the same, but that is only due to inaccurate measurement.  In truth, the speed of light is NOT constant in every inertial frame.

 

Minkowski:  Are you really trying to say that you don't accept Einstein's Postulate as being indubitably true!?

 

Lorentz:  Yes, that's exactly what I'm trying to say.

Edited February 18, 2019 by Moronium

[marcospolo]

I added some stuff.

First Statement:  We measure the speed of light to be the same in every inertial frame.

 

Minkowski:  I agree

 

Lorentz: I too agree

 

Marco:  I don't agree

 

====

 

Second Statement:  So the empirical facts prove that the speed of light is constant.

 

Minkowski:  Exactly!

 

Lorentz:  Wrong.

 

Marco; Yes Lorentz, you are correct in your conclusion, the second statement is wrong. We only differ on the reason why.

 

======

 

Minkowski:  Lorentz, you old fool.  You just contradicted yourself.   and Marco, Lorentz and I are not going to ask why you think that, we will simply ignore you.

 

Lorentz:  No I didn't.  I agree that we measure it to be the same, but that is only due to inaccurate measurement.  In truth, the speed of light is NOT constant in every inertial frame.

 

Marco: Again Lorentz, you are right, its just your reason that is an incorrect assumption. But the speed of light is certainly different in inertial frames that are moving at different speeds.

 

Minkowski:  Are you really trying to say that you don't accept Einstein's Postulate as being indubitably true!?

 

Lorentz:  Yes, that's exactly what I'm trying to say.

 

Marcos: Me too!

 

 

Why does Marco disagree that "we measure light to be going the same speed in all inertial frames"?

 

Well, in the previous post, that Moronium admitted was correct, we just got through explaining that light speed, distance and time are all defined as a circular argument, so it won't matter what light may really be doing, we must always get a consistent, prearranged answer.

The measurements are invalid. (possibly the right results, but NOT provable, and besides the concept defies logic and reason that light will have the same measured value irrespective of the motion of the observer, even if moving with or against the direction of the light beam! The measurement CANT possibly read the same.

Edited February 18, 2019 by marcospolo

[marcospolo]

I agree with this post, Marco.  Using those definitions, you could never even test, forget prove, the speed of light to be anything other than what you already declared it to be.

 

This is a typical, and regretable, example of taking an unproven hypothesis and treating it as fact.

Hey Moronium, The definition of the meter is set by unanimous agreement  of a committee of the worlds best physicists, you know that guys I'm supposed to totally believe as they are educated better than I am, and they don' suffer from ignorance or the Kruger-Dunning effect like I do.

 

Yet clearly they are too stupid to see that they have a simple impossible circular definition here.

Sorry, but you just blew every claim of superiority made on their behalf, based on education and knowledge.

 

My view of Physics is at the least, as useful as theirs.

 

But my view is rational.

 

They come up with shite like parallel universes, things being in two place at the same time.... its all a bunch of garbage I'm afraid.

(not ALL physics, just the irrational stuff)

[Moronium]

“If the principle of relativity were not valid we should therefore expect that the direction of motion of the earth at any moment would enter into the laws of nature, and also that physical systems in their behavior would be dependent on the orientation in space with respect to the earth.” Ref: A. Einstein, Relativity, the Special and General Theory, 1920, P. 17-18.

 

Yeah, that's what we would expect.  And that's exactly what we get as soon as an object accelerates.  Then the relativity principle no longer applies.  The "laws of nature" get changed by motion. The speed of light changes, and is no longer constant. We have to "complicate" things by introducing fictitious forces, etc.  But, hey, we still manage just fine.  It's all just part of "science.," and the science of physics doesn't suddenly disintegrate.

 

The relativity principle is not sacred, and, even according to Einstein, it's certainly not universally applicable.  For that matter, it may not be applicable anywhere, inasmuch as non-inertial motion seems to be ubiquitous.

 

One might even conclude that all motion, not just motion in accelerating systems, is absolute, as Lorentz said.

Edited February 18, 2019 by Moronium

[marcospolo]

Yeah, that's what we would expect.  And that's exactly what we get as soon as an object accelerates.  Then the relativity principle no longer applies.  The "laws of nature" get changed by motion. The speed of light changes, and is no longer constant. We have to "complicate" things by introducing fictitious forces, etc.  But, hey, we still manage just fine.  It's all just part of "science.," and the science of physics doesn't suddenly disintegrate.

 

The relativity principle is not sacred, and, even according to Einstein, it's certainly not universally applicable.  For that matter, it may not be applicable anywhere, inasmuch as non-inertial motion seems to be ubiquitous.

 

One might even conclude that all motion, not just motion in accelerating systems, is absolute, as Lorentz said.

 

Are you intending to reply to my two posts, #883 and #884?

In them I prove that you would be wrong to claim that I have no ability to criticize the masters of Physics.

And so you cant just dismiss my observations on any grounds other than by showing me where they are wrong. Not just pointing me to some paper of some supposed expert from 1840. Or saying I cant understand, or I would agree with you. That's not science, its arrogance.

 

That proves nothing.

I can't PROVE I'm right, but if I'm wrong, you sure as hell should be able to prove it.

[marcospolo]

Yeah, that's what we would expect.  And that's exactly what we get as soon as an object accelerates.  Then the relativity principle no longer applies.  The "laws of nature" get changed by motion. The speed of light changes, and is no longer constant. We have to "complicate" things by introducing fictitious forces, etc.  But, hey, we still manage just fine.  It's all just part of "science.," and the science of physics doesn't suddenly disintegrate.

 

The relativity principle is not sacred, and, even according to Einstein, it's certainly not universally applicable.  For that matter, it may not be applicable anywhere, inasmuch as non-inertial motion seems to be ubiquitous.

 

One might even conclude that all motion, not just motion in accelerating systems, is absolute, as Lorentz said.

What are you saying, "the speed of light changes"?

Since when? I thought its probably constant in an absolute sense. Not affected by the motion of the source, and certainly its not going to be measured as the same value irrespective of the motion of the observer, let alone when we consider his direction of travel compared to the direction of travel of the light.

 

Please clarify, "the speed of light changes".

[Moronium]

Are you intending to reply to my two posts, #883 and #884?

 

 

No

[Moronium]

 

Please clarify, "the speed of light changes".

 

 

The speed of a baseball changes when you throw it.

 

Even in SR acceleration is deemed to be absolute motion (not frame dependent)

 

Light is no longer considered to be travelling at the same speed in each direction.  It is no longer considered to be "isotrophic."

 

The whole Einstein scheme of reciprocal time dilation, etc. no longer works out.  An accelerating object will "see" an inertial clock as running faster, not slower.

Edited February 18, 2019 by Moronium