Yes, You Can Go Faster Than Speed Of Light

[Moronium]

No you already said that they're moving at .9c relative to each other. If there were a third object between them so that from this third objects perspective the other two are moving at 4.5c relative to each other then they wouldn't be moving at 4.5c relative to each other from their own perspectives because this is where you need to apply the velocity addition formula. It would probably come out at around .75c (as a guess

 

 

So, if you insert a third object between them, the doppler shift readings they were getting before were wrong? Does inserting a third object change their readings?  Is it simply that the readings were correct before inserting a third object between them, but that, as soon as that third object  is inserted, their respective doppler shift readings are instantly changed? Once changed, the new readings are now "correct," that the idea?    Either way, that seems like a pretty magical third object, eh?  

 

SR tells us, that as between the two, we MUST treat one as motionless to get the "relative velocity."  Previously you said there could only be one "true" relative velocity.  Which is it this this case?  .9c or  (approx) .75c?  Let me guess--BOTH ARE CORRECT, right?

Edited June 24, 2018 by Moronium

[Moronium]

Just to make sure we understanding each other, I'll give some specifics.  We have two objects, A and C.  Let's look at this from A's perspective.  He sees C moving away from him at .9c.  And, of course, C will also see A receding from him at .9c, because that's their relative velocity, right?

 

Now then, let's say that A notices object B, which is between him and C.  He sees B as going in the same direction as C, except that B is receding from him at the rate of only .45c.

 

What will B see?   He will see  A receding from him at .45c, right?  He has to, because that's how A sees him. That's their relative velocity. He will also see C receding from him at the rate of .45c, but in the opposite direction, right?

 

Going back to A's perspective, because he noticed B, A no longer sees C receding from him at .9c.  A now sees C receding from him at the lesser speed of (approx) .75c, right?  With respect to C, A's doppler readings have now changed, right?

 

But, if B suddenly explodes, and ceases to exist, A will once again see C receding from him at .9c, right?

 

We know all this because the velocity addition formula tells us it's true, and because we know that formula has been CONCLUSIVELY PROVEN to be true.  What A sees doesn't matter at all.  It's what B tells us that A will see that is "really true."

Edited June 24, 2018 by Moronium

[Farsight]

What crap.

You don't know what you're talking about. See Hans Ohanian’s 1984 paper what is spin? He said this: “the means for filling the gap have been at hand since 1939, when Belinfante established that the spin could be regarded as due to a circulating flow of energy”.

[A-wal]

 Football's coming home! :)

 

So, if you insert a third object between them, the doppler shift readings they were getting before were wrong?

Nope. The presence of a third object in no way affects the readings of the other two.

 

Does inserting a third object change their readings?

Nope. It does not.

 

Is it simply that the readings were correct before inserting a third object between them, but that, as soon as that third object  is inserted, their respective doppler shift readings are instantly changed?

Nope. Their readings are unaffected by the presence of a third object.

 

Once changed, the new readings are now "correct," that the idea?    Either way, that seems like a pretty magical third object, eh? 

Nope. The third object in no way affects the readings of the first two. Strawman supremus does it again! Seriously, this is really pathetic Moronium.

 

Just to make sure we understanding each other, I'll give some specifics.  We have two objects, A and C.  Let's look at this from A's perspective.  He sees C moving away from him at .9c.  And, of course, C will also see A receding from him at .9c, because that's their relative velocity, right?

Correct, obviously.

 

Now then, let's say that A notices object B, which is between him and C.  He sees B as going in the same direction as C, except that B is receding from him at the rate of only .45c.

Okay.

 

What will B see?   He will see  A receding from him at .45c, right?  He has to, because that's how A sees him. That's their relative velocity.

Of course. He will also see unequivocally that football is indeed coming home to England.

 

He will also see C receding from him at the rate of .45c, but in the opposite direction, right?

No! You said that A sees C moving away at .9c and that A sees B moving away at 4.5c. That means that A and C are not moving away from B at equal velocities.

 

What will B see?   He will see  A receding from him at .45c, right?  He has to, because that's how A sees him. That's their relative velocity. He will also see C receding from him at the rate of .45c, but in the opposite direction, right?

 

Going back to A's perspective, because he noticed B, A no longer sees C receding from him at .9c.  A now sees C receding from him at the lesser speed of (approx) .75c, right?  With respect to C, A's doppler readings have now changed, right?

 

But, if B suddenly explodes, and ceases to exist, A will once again see C receding from him at .9c, right?

 

We know all this because the velocity addition formula tells us it's true, and because we know that formula has been CONCLUSIVELY PROVEN to be true.  What A sees doesn't matter at all.  It's what B tells us that A will see that is "really true."

All based on previous strawman.

 

It's coming home, it's coming home, it's coming, football's coming home!

[Moronium]

No! You said that A sees C moving away at .9c and that A sees B moving away at 4.5c. That means that A and C are not moving away from B at equal velocities.

 

  Why, praytell, would it mean that?

 

I can guess your answer.  It will beg the question and merely restate the premise you are pretending to prove, but go ahead.

Edited June 25, 2018 by Moronium

[DaveC426913]

  Why, praytell, would it mean that?

 

I can guess your answer.  It will beg the question and merely restate the premise you are pretending to prove, but go ahead.

Because SR is one of the most thoroughly tested theories in the history of science. It has passed every test with flying colours. There is no competing theory that explains what we observe as well as SR does. That is not begging the question; that is what the universe is telling us, through evidence.

 

Science is not about trying to prove what reality "is"; science is about observing, theorizing and then making models of what we see. If the model describes current observations and accurately predicts observations not yet made, it has done its job.

 

And SR has unequivocally done that.

 

If you want to talk about what reality "is" - without connecting it to what we study and observe - the religion forum and philosophy forum are right down the hall.

Edited June 25, 2018 by DaveC426913

[Moronium]

Because SR is one of the most thoroughly tested theories in the history of science. It has passed every test with flying colours. There is no competing theory that explains what we observe as well as SR does. That is not begging the question; that is what the universe is telling us, through evidence.

 

 

Well, Dave, you condescend to call others "naive" but that statement is not just false, it is completely naive and shows that you know very little about either modern mainstream views pertaining to  SR or the history of science.  Einstein himself knew better, as did (and does) every prominent physicist at and since his time.

Edited June 25, 2018 by Moronium

[Farsight]

Well, Dave, you condescend to call others "naive" but that statement is not just false, it is completely naive and shows that you know very little about either modern mainstream views pertaining to  SR or the history of science.  Einstein himself knew better, as did (and does) every prominent physicist at and since his time.

Einstein did know better. That's why he said special relativity is "nowhere precisely realized in the real world".

 

See the Einstein digital papers: https://einsteinpapers.press.princeton.edu/vol7-trans/156?

Edited June 25, 2018 by Farsight

[OceanBreeze]

 

So "Using the red shift of distant galaxies puts them at velocities far greater than the speed of light."

 

 

 

No. As I just finished explaining, using the redshift of galaxy GN-z11, the calculated recession velocity is 98.6% of the speed of light. Since galaxy GN-z11 is the most red-shifted object that has been observed, it clearly shows your claim that “using the red shift of distant galaxies puts them at velocities far greater than the speed of light” is false.

 

We may infer that GN-z11 is now travelling FTL, but the redshift can’t tell us that! In fact, we can only see redshift from galaxies that are travelling less than the speed of light, which should require only common sense to understand.

 

 

 

If an object is moving away from an observer at .9c and a second object is moving in the opposite direction at .9c away from the same observer then those two objects are moving away from each other at 1.8c from the perspective of that central observer. Don't start this again!

 

 

 

Nothing in the observable universe has a relative velocity greater than the speed of light! If we were to observe two galaxies such as GN=z11, each moving in opposite directions at 0.986c, from our viewpoint, then each galaxy would observe the other moving away at 0.9999c using the relativistic velocity addition formula.

 

If you naively add the velocities together to get 1.972c, you have just made a rookie mistake as there can be no relative velocity greater than c in the observable universe. 

 

What you can do, is add the magnitudes of the velocities (the speeds) together (295,800,000 m/s + 295,800,000 m/s) to get the rate of change in distance between the two. That is, you get ~591,600,000 m/s and there is no violation of SR because the Closing Speed (or opening speed) as seen by an observer in the center, is not a velocity in a single inertial frame.

 

For example, If the two objects were heading towards each other instead of away, they would collide with a relative velocity of 0.9999c NOT 1.972c even though the closing speed as seen by a central observer was ~591,600,000 m/s.

[A-wal]

No. As I just finished explaining, using the redshift of galaxy GN-z11, the calculated recession velocity is 98.6% of the speed of light. Since galaxy GN-z11 is the most red-shifted object that has been observed, it clearly shows your claim that “using the red shift of distant galaxies puts them at velocities far greater than the speed of light” is false.

 

We may infer that GN-z11 is now travelling FTL, but the redshift can’t tell us that! In fact, we can only see redshift from galaxies that are travelling less than the speed of light, which should require only common sense to understand.

If we can infer from the redshift of distant galaxies that they're moving away faster than the speed of light then “using the red shift of distant galaxies puts them at velocities far greater than the speed of light”. You're just saying the exact same thing in a different way and claiming I'm wrong, and making a complete idiot of yourself. I've reported your post for being argumentative for the sake of trying to get me banned.

 

Nothing in the observable universe has a relative velocity greater than the speed of light! If we were to observe two galaxies such as GN=z11, each moving in opposite directions at 0.986c, from our viewpoint, then each galaxy would observe the other moving away at 0.9999c using the relativistic velocity addition formula.

 

If you naively add the velocities together to get 1.972c, you have just made a rookie mistake as there can be no relative velocity greater than c in the observable universe. 

 

What you can do, is add the magnitudes of the velocities (the speeds) together (295,800,000 m/s + 295,800,000 m/s) to get the rate of change in distance between the two. That is, you get ~591,600,000 m/s and there is no violation of SR because the Closing Speed (or opening speed) as seen by an observer in the center, is not a velocity in a single inertial frame.

 

For example, If the two objects were heading towards each other instead of away, they would collide with a relative velocity of 0.9999c NOT 1.972c even though the closing speed as seen by a central observer was ~591,600,000 m/s.

Again, you're arguing for the sake of it and making no sense whatsoever. Nothing you said in any way changes the fact that if an object is moving away from an observer at .9c and a second object is moving in the opposite direction at .9c away from the same observer then obviously those two objects are moving away from each other at 1.8c from the perspective of that central observer!

 

That's okay, keep embarrassing yourself. Do you still think acceleration isn't part of SR? :)

[OceanBreeze]

If we can infer from the redshift of distant galaxies that they're moving away faster than the speed of light then “using the red shift of distant galaxies puts them at velocities far greater than the speed of light”. You're just saying the exact same thing in a different way and claiming I'm wrong, and making a complete idiot of yourself. I've reported your post for being argumentative for the sake of trying to get me banned.

 

 

 

Do you have a persecution complex? I could not care less whether you get banned or not and I had nothing to do with you getting banned in the past. My only interest in posting is to correct the many wrong things you say about physics and SR in particular.

 

Red shift cannot tell us anything about a galaxy that is travelling FTL away from us because we would not be able to see the light coming from such a galaxy! We can only see redshift from galaxies that are travelling slower than light speed at the time the light was emitted.

 

Any inference we can make about a galaxy going FTL away from us is based on other information, such as the size of the observable universe and the Hubble Radius among other things. Your statement that "using the red shift of distant galaxies puts them at velocities far greater than the speed of light” is wrong and needs to be corrected.

 

 

Again, you're arguing for the sake of it and making no sense whatsoever. Nothing you said in any way changes the fact that if an object is moving away from an observer at .9c and a second object is moving in the opposite direction at .9c away from the same observer then obviously those two objects are moving away from each other at 1.8c from the perspective of that central observer!

 

 

 

I am simply trying to clarify the difference between a velocity, which has both magnitude and direction, and a Closing Speed, which has only magnitude. It is important for understanding that there is no relative velocity in the observable universe that is greater than c. The fact that you refuse to understand this and routinely posit 1.8c which is a velocity, shows how little you understand this subject and you will never learn because of your attitude.

 

 

 

That's okay, keep embarrassing yourself. Do you still think acceleration isn't part of SR?  :)

 

 

 

Well, acceleration takes on a new definition under SR because it is much more complicated. 

 

You may be interested to know that the much respected HyperPhysics.com has to say:

 

The basic question about whether time dilation is real is settled by the muon experiment. The clear implication is that the traveling twin would indeed be younger, but the scenario is complicated by the fact that the traveling twin must be accelerated up to traveling speed, turned around, and decelerated again upon return to Earth. Accelerations are outside the realm of special relativity and require general relativity.

[A-wal]

Do you have a persecution complex?

I have a low tolerance for people like you.

 

I could not care less whether you get banned or not and I had nothing to do with you getting banned in the past. My only interest in posting is to correct the many wrong things you say about physics and SR in particular.

I haven't said anything wrong about SR. Those are just your pathetic attempts to fabricate errors.

 

Red shift cannot tell us anything about a galaxy that is travelling FTL away from us because we would not be able to see the light coming from such a galaxy! We can only see redshift from galaxies that are travelling slower than light speed at the time the light was emitted.

 

Any inference we can make about a galaxy going FTL away from us is based on other information, such as the size of the observable universe and the Hubble Radius among other things. Your statement that "using the red shift of distant galaxies puts them at velocities far greater than the speed of light” is wrong and needs to be corrected.

BS! Redshift is used to model distant galaxies as moving away from us at velocities much greater than c. That fact that other information is also used in no way alters this fact.

 

I am simply trying to clarify the difference between a velocity, which has both magnitude and direction, and a Closing Speed, which has only magnitude. It is important for understanding that there is no relative velocity in the observable universe that is greater than c.

If an object is moving away from an observer at .9c and a second object is moving in the opposite direction at .9c away from the same observer then obviously those two objects are moving away from each other at 1.8c from the perspective of that central observer!

 

The fact that you refuse to understand this and routinely posit 1.8c which is a velocity, shows how little you understand this subject and you will never learn because of your attitude.

:) If an object is moving away from an observer at .9c and a second object is moving in the opposite direction at .9c away from the same observer then obviously those two objects are moving away from each other at 1.8c from the perspective of that central observer! 

 

Knock it off!

[A-wal]

This is all just to cover up your embarrassment at an error you made months ago thinking that when two objects are moving in opposite directions towards a central object you have to apply the velocity addition formula to get their closing velocity on each from the perspective of that third object.

This shows a complete misunderstanding of the most basic aspects of SR and is a symptom of being a pathetic wiki parrot with no ability to actual grasp the relationships, just as your recent fundamental error of thinking that SR doesn't include acceleration because you read it somewhere is another symptom of the same condition.

 

So now you're trying to make out I'm wrong by saying the exact same things as I'm saying but saying them in a different way and claiming that they're not the same.

 

Redshift is used to infer that distant galaxies are receding faster than c and if an object is moving away from an observer at .9c and a second object is moving in the opposite direction at .9c away from the same observer then obviously those two objects are moving away from each other at 1.8c from the perspective of that central observer. Nothing you've attempted to use in your ridiculous attempts to invent errors where none exist in any way invalid these two obviously true statements.

 

That's why if I were to tell you what I really think of you I'd be banned a thousand times over but I hope and I think it's obvious to everyone what you're doing and what kind of person you are, pathetic!

Edited June 25, 2018 by A-wal

[Moronium]

Popeye said:

 

Red shift cannot tell us anything about a galaxy that is travelling FTL away from us because we would not be able to see the light coming from such a galaxy! We can only see redshift from galaxies that are travelling slower than light speed at the time the light was emitted

 

.

Wiki says:

 

There are many galaxies visible in telescopes with red shift numbers of 1.4 or higher. All of these are currently traveling away from us at speeds greater than the speed of light. Because the Hubble parameter is decreasing with time, there can actually be cases where a galaxy that is receding from us faster than light does manage to emit a signal which reaches us eventually. 

 

 

https://en.wikipedia.org/wiki/Faster-than-light

 

How you measure time and distance (and therefore speed) also depends on the assumptions you make before measuring.

 

The expansion of the universe causes distant galaxies to recede from us faster than the speed of light, if proper distance and cosmological time are used to calculate the speeds of these galaxies....Rules that apply to relative velocities in special relativity, such as the rule that relative velocities cannot increase past the speed of light, do not apply to relative velocities in comoving coordinates...  

 

https://en.wikipedia.org/wiki/Comoving_and_proper_distances#Uses_of_the_proper_distance

 

A "co-moving coordinate" is one that treats the CMB as a preferred frame (which violates the taboo of SR) and is co-moving with the CMB.  It is used by astronomers, astro-physicists, cosmologists. etc.  SR is NOT used.  As you can see, the "velocity addition formula" (along with other so-called "facts") goes out the window when you quit treating SR as absolute truth. 

 

The "it depends on your assumptions (theory)" point is one I've been trying to make here.  But people tend to treat their initial assumptions as indubitable fact, so it's hard to even discuss that consideration with people who have been indoctrinated with the assumptions of SR, and treat them as sacrosanct.

Edited June 25, 2018 by Moronium

[Moronium]

Cosmological time is identical to locally measured time for an observer at a fixed comoving spatial position, that is, in the local comoving frame. Proper distance is also equal to the locally measured distance in the comoving frame for nearby objects....It is important to the definition of both comoving distance and proper distance in the cosmological sense (as opposed to proper length in special relativity) that all observers have the same cosmological age...If one divides a change in proper distance by the interval of cosmological time where the change was measured (or takes the derivative of proper distance with respect to cosmological time) and calls this a "velocity", then the resulting "velocities" of galaxies or quasars can be above the speed of light, c.

 

 

https://en.wikipedia.org/wiki/Comoving_and_proper_distances#Uses_of_the_proper_distance

Edited June 25, 2018 by Moronium

[Moronium]

A "co-moving coordinate" is one that treats the CMB as a preferred frame (which violates the taboo of SR) and is co-moving with the CMB.  It is used by astronomers,astro-physicists, cosmologists, etc.  SR is NOT used.  As you can see, the "velocity addition formula" (along with other so-called "facts") goes out the window when you quit treating SR as absolute truth. 

 

The "it depends on your assumptions (theory)" point is one I've been trying to make here.  But people tend to treat their initial assumptions as indubitable fact, so it's hard to even discuss that consideration with people who have been indoctrinated with the assumptions of SR, and treat them as sacrosanct.

 

I keep wondering..,is there ANYBODY who even understands what I'm saying here?  Anybody at all?  Surely someone must understand that the conclusions you reach are strictly dependent upon the assumptions (postulates) you start with.  And surely someone must understand that your starting assumptions can never be proven.  You take them as a given (whether right or wrong) and go from there. Where they take you may persuade you to abandon them (i.e., they can be "disproven"), but the fact that you don't (or won't) abandon them doesn't prove that they are "true."

Edited June 25, 2018 by Moronium

[OceanBreeze]

I have a low tolerance for people like you.

 

 

 

You mean people who try to correct your errors?

 

Like the following:

 

 The relative velocity limit in the case of two objects other than the observer is 2c.

 

There is no such thing as a relative velocity of 2c anywhere in the observable universe.

 

Despite your arrogance, at least you are now starting to use the proper terminology of Closing Speed. So maybe you are finally starting to learn something from my posts.

 Great!