Relativity And Simple Algebra

[Moronium]

The bottom line is that the velocity addition formula of SR is brought in as an enforcer.  It prohibits certain viewpoints from being held.  It's a cop, stopping people from breaking the law.

 

What is it enforcing?

 

SR's postulate that the speed of light is constant in every inertial frame that's what.

 

If you reject that postulate, which is a perfectly reasonable and coherent thing to do, consistent with all known empirical fact, then there is no need for the enforcer.  Kinda like if you repeal a law that says blacks cannot attend the same schools as whites, then there is no need to have cops at the schoolhouse door giving DNA tests to all the kids before they are allowed to enter.

 

Like I said, Popeye, my interest here is to compare and contrast viable, but competing, scientific hypotheses.  Apparently that is tantamount to entering the "twilight zone" to you.  You don't seem to be capable of even considering that the postulates of SR could possibly be wrong.

Edited February 22, 2019 by Moronium

[OceanBreeze]

This is also confirmed by wiki:

 

 

Same link as last.

 

Show me where anything I have said disagrees with the Wiki quote.

 

I have said and will say this for the last time:

 

The velocity of one thing moving relative to another cannot be more than c.

 

However, two things moving at almost 1c relative to their center of mass, going in opposite directions, can have a distance between them that grows (according to an observer at rest at the com) at almost 2c.

 

That distance that is increasing in time is a closing or opening speed. That distance does not have a specific direction. It is not a velocity.

 

No individual physical object can have a velocity of over 1c in Special Relativity

 

Closing speeds and similar such constructions of distance/time can be useful to understanding, but it’s important to understand that they are not to be used or confused with velocities as defined in Special Relativity.

 

By repeating your self over and over you are just wasting your time and mine, and no more of mine.

[OceanBreeze]

The bottom line is that the velocity addition formula of SR is brought in as an enforcer.  It prohibits certain viewpoints from being held.  It's a cop, stopping people from breaking the law.

 

What is it enforcing?

 

SR's postulate that the speed of light is constant in all inertial frames, that's what.

 

If you reject that postulate, which is a perfectly reasonable and coherent thing to do, consistent with all known empirical fact, then there is no need for the enforcer.

 

 

You are a science denier and a waste of time.

[Moronium]

You are a science denier and a waste of time.

 

You just proved my point, Popeye.  I guess I mistook you for someone who took science as science, rather than religion.

[Moronium]

I have said and will say this for the last time:

 

The velocity of one thing moving relative to another cannot be more than c....No individual physical object can have a velocity of over 1c in Special Relativity

 

 

Why are you purporting to tell me that?  I've said it many times myself (in the context of SR)

Edited February 22, 2019 by Moronium

[Moronium]

That distance that is increasing in time is a closing or opening speed. That distance does not have a specific direction. It is not a velocity.

 

 

 Yes, you've chanted that mantra quite frequently.  What you have not done is explain what difference it makes.  I mean, you tried to, by saying that it meant there was no physical motion involved in a closing speed, but that's clearly wrong, so.....

 

I mean think about what you're saying.  On the one hand you say the doppler readings are real and accurate, and then you say there is no physical motion involved.

 

You can't see the contradiction?

Edited February 22, 2019 by Moronium

[Moronium]

You just proved my point, Popeye.  I guess I mistook you for someone who took science as science, rather than religion.

 

The point I am referring to here is this:

 

Like I said, Popeye, my interest here is to compare and contrast viable, but competing, scientific hypotheses.  Apparently that is tantamount to entering the "twilight zone" to you.  You don't seem to be capable of even considering that the postulates of SR could possibly be wrong.

 

 

And when I say "viable" alternate theory, I don't mean some crackpot pseudo science,  It's a viability that Einstein himself always acknowledged, as has every theoretical physicist worth his salt up to this very day.

 

And yet you call ME a science denier, eh?  Who's the denier here, really?

.

Edited February 22, 2019 by Moronium

[ralfcis]

Oh no, now I'm back to being confused again.

 

"The velocity of one thing moving relative to another cannot be more than c." and then "No individual physical object can have a velocity of over 1c in Special Relativity"

 

The 1st statement is correct but then the 2nd seems to contradict it. No individual physical object can have any relative velocity (it needs a 2nd object) so you're saying a single object can have a speed and that speed is measured as distance over time but with no direction? You're measuring the speed of the growing distance between 2 objects. I don't get how it's possible to measure the speed of a single object.

 

Ok, here's where I'm confused. 2 ships are leaving earth at .8 c relative to earth in opposite directions, the relative velocity between the two ships is .9756c, not 1.6 c. The 3rd party observer on the earth  would measure each ship at a relative velocity to him at .8c. He can't get a radar gun reading from one ship to another but he can get a televised picture of what one ship sees of the other. He can see from the images,  the doppler shift ratio confirms their relative velocity is .9756c But he would also see the space between them is growing at 1.6c from his perspective. The ships are going in a line away from him which defines relative velocity to him. But if they were just comets streaking across the sky parallel to him there would be no relative velocity even though they streak across the entire length of his horizon.  The space is also expanding in a line parallel to him so it's expanding at 0 relative velocity to him so the speed of expansion is unrelated to him. So if you're looking at light from the side, you're looking at it's non-relative velocity (speed) and when you're looking at it head on, it becomes a relative velocity.

 

I don't get that meaning from these next 2 statements though

 

"However, two things moving at almost 1c relative to their center of mass, going in opposite directions, can have a distance between them that grows (according to an observer at rest at the com) at almost 2c.

 

That distance that is increasing in time is a closing or opening speed. That distance does not have a specific direction. It is not a velocity."

 

But is does have a specific direction, sideways. Without that specific direction, it would be a relative velocity.

Edited February 22, 2019 by ralfcis

[ralfcis]

Yay I just put conway and polymmoth on permanent ignore in my settings. I'd like to put moronium on ignore as well but sometimes he says relevant things so I'll put up with his tsumani posts.

[Moronium]

 The 3rd party observer on the earth  would measure each ship at a relative velocity to him at .8c. He can't get a radar gun reading from one ship to another but he can get a televised picture of what one ship sees of the other. He can see from the images,  the doppler shift ratio confirms their relative velocity is .9756c 

 

 

 

 

It's not possible for E to physically measure by doppler shift the speed between A and B.  Watching TV won't change that.  There is no confirmation that they are "really" moving at .975c relative to each other.  That's a supposition that is derived from the velocity addition formula.  In other words, it is derived from theory, not  actual measurement.

Edited February 22, 2019 by Moronium

[Moronium]

That distance that is increasing in time is a closing or opening speed. That distance does not have a specific direction. It is not a velocity."

 

 

Whether it's a velocity or not is totally irrelevant, as far as I can see.  If I said that B was going east and A was going west, then then the closing speed would have a direction, and therefore be a "velocity."  But that doesn't add anything significant.  The speed is the same either way. As I said to Popeye:

 

What you have not done is explain what difference it makes.  I mean, you tried to, by saying that it meant there was no physical motion involved in a closing speed, but that's clearly wrong, so.....

 

I mean think about what you're saying.  On the one hand you say the doppler readings are real and accurate, and then you say there is no physical motion involved.

 

You can't see the contradiction?

Edited February 22, 2019 by Moronium

[Moronium]

The question here is about relative speed.  Velocity and speed are used as synonyms is this context.  Watch Greene.   He keeps talking about speed (only) and then when he goes to his formula, he puts the speed in where "v" (for velocity) is present.

 

The point is not to get confused by terminology.

[ralfcis]

I know I might as well try to explain a picture of Ramen noodles but here is the math version of what I said above:

 

http://www.sciencechatforum.com/download/file.php?id=5442&mode=view

 

 This is the STD representing Greene's little story about the train at .6c and the platform. When the middle of the train hits the middle of the platform, it triggers the light to go off. When the middle of the train hits 1, the people's clock on the platform hits 1.25 according to time dilation. Their clock is at 1.25 simultaneously across the platform and the train's clock hits 1 across the entire length of the train. So my time units at both ends of the train are incorrect. I can't edit them on the drawing but I can list the corrections here:

 

At the front of the train where the president of backwardland sits, the orange numbers are not 0,1,2,3 but -.8, .2, 1.2.

At the back of the train where the president of forwardland sits, the orange numbers are not 0,1,2,3 but +.8, 1.8, 2.8.

 

I hope I did the Lorentz transform arithmetic correctly. If someone could maybe double check my results.

 

The train moves forward and the light hits the president of forwardland at .625  platform time (1.2  train time). The light has to travel a lot longer and a lot farther to hit the president of backwardland which it does at 2.5 right platform time (1.2 train time). I know it's confusing but the Lorentz transforms are forcing how the train time and platform times are labelled. The result confirms that from the train's perspective, both presidents are hit by the light simultaneously at 1.2 train time after the train's clock was sync'd to the platform clock when the middle of the train crossed the middle of the platform.

 

The result also shows the light hits on the presidents are not simultaneous from the platform's clock perspective. Although the clocks start simultaneously, more time passes on the train's clock (1.2) than on the platform's clock (.625) for when the light hits the president of forwardland. Relativists use this result to state the platform people are able to see into forwardland's future and that the past present and future must all happen concurrently for this view into the future to be possible. You don't believe me? Just look at Greene's 2 videos about the concurrency of past present and future. Some real nutjob stuff is being concluded from the relativistic assumption that the present is subjective.

 

A third result is that less time passes on the president of backwardland's clock (1.2) than on the platform clock (2.5) (even though the two clocks were sync'd at the start and the light takes a lot longer to reach the president) when the light hits his eyes. Relativists use this as proof that their present is concurrent with his past just from the difference in clock readings. The only thing that's stopping them from altering his past, and therefore their own present, is the light delay of the speed of information over the distance between them. I'm not making this sh!t up. Just look at the videos, that's also straight from Einstein where he states past, present and future are nothing more than illusion. His nutty assumption that the present is subjective from different perspectives makes his crazy conclusion possible and unavoidable. 

 

Edited February 23, 2019 by ralfcis

[Moronium]

 His nutty assumption that the present is subjective from different perspectives makes his crazy conclusion possible and unavoidable. 

 

Yes, and it is that type of forced subjectivism which supposedly proves that simultaneity is relative.  It's a crazy notion that generates all kinds of inconsistencies.  A PFT posits that simultaneity is absolute, not relative.  That eliminates all the craziness.

Edited February 22, 2019 by Moronium

[ralfcis]

Yes well I have a better explanation than that and that is what I'm slowly working up to in this thread.

[Moronium]

Yes well I have a better explanation than that and that is what I'm slowly working up to in this thread.

 

I doubt it.  Your explanation will incorporate the notions of absolute simultaneity and absolute motion if it's sensible and better than SR.  I don't doubt that it's better than SR if you do that, though.

Edited February 22, 2019 by Moronium

[ralfcis]

Oh so you can see the future too? That's very relativist of you.