Yes, You Can Go Faster Than Speed Of Light

[OceanBreeze]

Here's the excerpt from Baez.  It basically explains what absolute means.  In this context it has nothing to do with an "absolute frame" (I suspect you're trying to say "preferred frame")

 

 

 

 

 

You "maintain" (i.e. perceive) that it is going faster on the ceiling IF you're on the floor. You also maintain that the speed is c in YOUR frame, if you're on the floor, because it is.  So you perceive the light on the ceiling to be faster than in your own frame if you're on the floor, because it is.

 

If the situation were reversed and you were on the ceiling, then you would perceive the light on the floor to be going slower, because it is.

 

 

Yes, I just finished reading all of that.

 

I’m not sure I totally buy what Baez is saying there, either but I am not a physicist.

 

It may just be a matter of him communicating his ideas poorly but to say that light near the ceiling is faster than c just doesn’t make any sense to me. It may be faster at the ceiling than at the floor as observed by observers who are observing the speed relative to each other. But it cannot be faster than c if by c he means the speed of light measured locally in a vacuum free of any influence of gravity.

 

My take on it, and I may well be wrong, is that the speed of light can only be slower than c, as I have just defined it, and never faster, if you measure it at a distance in a gravity well.

 

To try and put numbers on it, they both will measure the speed of light near to them as 186,000 miles/second.

The observer on the ceiling will see the speed as slower than 186,000 miles/second let’s say he sees 180,000 miles/second at the floor, due to the gravity well.

 

The observer on the floor may see 183,000 mile/second at the ceiling because there is also a gravity well there but it is less there than at the floor.

 

So, both of them see the speed locally as c and none of them see it faster than c, but they do see a difference when taking relative readings due to the gravity well they are in.

 

And, I may have that totally screwed up, so maintain the sense of humor people!

[OceanBreeze]

Whose right?

 

To say anyone is right, is to say there is some preferred frame, no?

They are both right, that is relativity for you!

[Moronium]

Here's an analogy to what Baez is saying with respect to motion in SR.

 

What does it mean to say that in SR acceleration is "absolute?"  Hint, this too has nothing to do with an absolute or preferred frame.

 

It's the same thing.  If B is acclerating relative to A, then A will see B as accelerating and B will ALSO see himself as accelerating.   They agree.  There is no dispute.  It's not relative motion, it's absolute motion.  Absolute motion is NOT an absolute frame, it is absolute motion, that's all.  They're not the same thing.

 

That said, the accelerating clock is no longer in a frame where the speed of light is constant, or even c.  And he will see A's clock going FASTER, not slower, as he did when he was inertial.

Edited July 10, 2018 by Moronium

[Moronium]

You say:

 

Light is always measured at the speed of light, the gravitational field of the ceiling is not enough to affect our measurement of the speed of light.

 

 

If you would keep up, you would know that we can now detect a time difference if one clock is raised only one foot higher than the other.  And an observer can see both clocks at once.  He sees the different readings, not two identical readings. The difference is absolute, not relative, and not reciprocal.  That''s because gravitational dilation is absolute.

Edited July 10, 2018 by Moronium

[Moronium]

If you were standing on the ground and you saw a spacecraft with a lazer inside of it, bouncing up and down from two parallel points, and sat stationary you would see a straight line made by the photon. As soon as the spacecraft moves, the lazer you are measuring will be seen at a slant. In your frame of reference, you now measure a longer distance for light to move, but is still moving at the speed of light, Moronium, do you understand this so far?

 

Sure.

[Moronium]

Since you mentioned light clocks, Dubbo, let me ask you a related question. And anyone else who may care to answer.

 

Here's the scenario. 

 

1. I'm hanging out down on the corner, guzzling a 40,  with a light clock next to me.  It's going straight up and down, OK?

 

2.  I spot a guy overhead who also has a light clock next to him. It looks "slanted," as you say, to me.

 

3.  Presumably, my clock looks slanted to him and his clock is going straight up and down for him, OK?  With me so far?

 

4.  I conclude that I'm stationary and that he's moving.

 

Here's the question:

 

How would it look the least bit different (to me) from it already does if I were the one moving?

Edited July 10, 2018 by Moronium

[Moronium]

I'll tell you because if you quote him true, he's a total wack job.

 

What it means to have some absolute frame, requires that physics be fundamentally different in some frame, meaning essentially that there is a simpler form of physics for some frame...

 

 

Do you understand that? Do you also realize there is no evidence that the laws of physics are different in any frame?

 

Both your assertions (embedded in he form of question) and the conclusion you draw from them are dubious.

 

Do some research:  Find out what the experts say.  Acceleration in SR is absolute.  Time dilation due to your proximity to the center of gravity in GR is absolute.

 

That's what the experiments show.

 

If you think that implies a preferred frame and/or what you've been calling an "absolute frame," then you don't understand the relevant concepts.

 

Edit: Well, I take that back.  One meaning of "preferred frame" would tell you that, as between the two, the inertial frame is PREFERRED over the accelerating frame.  But that meaning is not the one you've been trying to argue against, i.e., some absolutely stationary rest frame which is acknowledged as such by all other observers.

 

BTW, that meaning also completely demolishes your repeated, blanket assertions that THERE ARE NO PREFERRED FRAMES!

Edited July 10, 2018 by Moronium

[GAHD]

This is the also the paper I had in mind earlier (but couldn't find at the time) when I spoke of Einstein's comments on the issue of whether the train or the tracks are moving.  Here's the verbatim passage I was thinking of:

 

 

Unless you're going to totally reject Newton's laws it is obvious that the power of a locomotive cannot set the whole earth in motion (F=MA)  Yet Einstein wants to stand on principle that it "could be" the other way around.  Where exactly this "principle" came from is not that clear, except for the fact that SR REQUIRES the engineer to regard the train as stationary and the "landscape" as moving.  Without that assumption the theory self-destructs.  He states the "principle" this way:

 

 

Sorry, Al, but the two are mutually exclusive.  Either (1) the train is moving relative to the tracks, or (2) the tracks are moving relative to the train.  It can't be both, as a matter of objective reality.  Common sense and all pertinent physical laws eliminate (2). That leaves us with (1), so now we know which one is moving. Nor are they truly "equivalent" under SR, because it forces us to say that (2) is the case and that (1) is NOT the case. We can't "choose" on "utilitarian" or any other grounds in SR.  So the "principle" is violated right there   

 

Sorry, SR, but I aint buyin it.  You can keep your bogus "principle" to yourself if you like it, but, me, I'm sticking with common sense and all other known physical laws.

 

Just a couple small points point here:

"Newton's laws it is obvious that the power of a locomotive cannot set the whole earth in motion (F=MA)" Wrong, it's just going to be a very small value. It's like machinists treating pi as 3.1 or 3; not that important to ignore the small values on a macro scale, but still ignoring a truth.

 

 

Either (1) the train is moving relative to the tracks, or (2) the tracks are moving relative to the train.  It can't be both, as a matter of objective reality.  Common sense and all pertinent physical laws eliminate (2). That leaves us with (1), so now we know which one is moving.

In objective reality, neither is stationary, and the only reason you ever treat one as such is the exact same reason machinists use 3 or 3.1 for pi; it eliminates a bunch of extra operations that are "close enough" in the end result when you ignore them. if you add up all the angular momentum we can currently calculate into the equation(both are circling sol, circling the milky, circling a possible universal epicenter while also gaining momentum relative to that center via expansion...) it "evens out" to a point where you CAN write either as stationary to just get a damned-close approximation of the end Derivitives. They're both moving relative to each other, it's just less calculation to ignore small changes when your possible fidelity of measurement is worse than that level of precision to begin with.

 

Minor side rant there, but it's important to understand why conventions are there and how they ARE "white lies"

 

 

 

[Moronium]

Yeah, good points, GAHD.  I don't always make it explicit, but in cases like this I always mean moving (faster) relative to the other.  Of there's always also the possibility that both objects are moving, like, for example, two objects approaching each other at a relative velocity of .5c with one going .2c and the other .3c.  But in the train/tracks example, that's not a likely possibility.

 

By the way, thanks for the sentiments displayed when you posted that video.  To be honest, I only watched 4-5 minutes, then lost interest, but I still appreciate the thought.

Edited July 10, 2018 by Moronium

[Super Polymath]

 if you add up all the angular momentum we can currently calculate into the equation(both are circling sol, circling the milky, circling a possible universal epicenter while also gaining momentum relative to that center via expansion...)

 

Bizarre, just last night I had a dream that illustrated what you just described, I often dream about everything in infinitely dynamic free-fall somehow being the source of all forces in nature. Indeed the inner structure of the smallest quarks could be made of infinite smaller objects with same dynamical complexity in angular momentum of the entire universe. I once had a dream that a mathematician was playing with a Hoberman sphere to describe my cyclic model of both the universe and a subatomic constituent of it.

 

https://www.youtube.com/watch?v=9XSKQ4cCFoY

 

[GAHD]

Yeah, good points, GAHD.  I don't always make it explicit, but in cases like this I always mean moving (faster) relative to the other.  Of there's always also the possibility that both objects are moving, like, for example, two objects approaching each other at a relative velocity of .5c with one going .2c and the other .3c.  But in the train/tracks example, that's not a likely possibility.

 

By the way, thanks for the sentiments displayed when you posted that video.  To be honest, I only watched 4-5 minutes, then lost interest, but I still appreciate the thought.

Keep in mind: if you add up all the values, the train CAN be going net-slower than the tracks in an absolute reference frame, all it needs to do is "accelerate" against it's net-vector relative to the other body.

 

Too bad you stopped 4 mins in. try it on 2x speed and just watch the animations, or skip through with the right-arrow on yer keyboard, The guy's good at conceptualizing visually what exactly happens with various, as my father would say derisively, "Mathemagics." it certainly helps when the abstract codes used for notation get confusing and become a barrier to entry

 

Bizarre, just last night I had a dream that illustrated what you just described, I often dream about everything in infinitely dynamic free-fall somehow being the source of all forces in nature. Indeed the inner structure of the smallest quarks could be made of infinite smaller objects with same dynamical complexity in angular momentum of the entire universe. I once had a dream that a mathematician was playing with a Hoberman sphere to describe my cyclic model of both the universe and a subatomic constituent of it.

 

.Heh, Your dream reminds me of N-dimensional polytopes...Enjoy digesting that one. ;)

(the digestive cookie explanation of them)

[Moronium]

Keep in mind: if you add up all the values, the train CAN be going net-slower than the tracks in an absolute reference frame, all it needs to do is "accelerate" against it's net-vector relative to the other body.

 

 

As far as clock retardation goes, they have found that it is not correlated to some distant or Absolute (with the capital A) reference frame but rather with motion relative to the local dominant gravitational field.  What is "local" is relative to the scale you're dealing in.  For earth it would be the ECI; on Mars it would be the MCI;, for the solar system the solar barycenter; for the universe the CMB.  So it doesn't seem necessary to take into account the net sum of ALL motions to predict the degree of clock retardation that will occur in local conditions.

Edited July 11, 2018 by Moronium

[Moronium]

Yes, I just finished reading all of that.

 

I’m not sure I totally buy what Baez is saying there, either but I am not a physicist.

 

It may just be a matter of him communicating his ideas poorly but to say that light near the ceiling is faster than c just doesn’t make any sense to me. It may be faster at the ceiling than at the floor as observed by observers who are observing the speed relative to each other. But it cannot be faster than c if by c he means the speed of light measured locally in a vacuum free of any influence of gravity.

 

 

I won't address what you said in the remainder of this post, Popeye, other than to say you're saying something different than Baez, and, if he's right, you're wrong.  The question is why?

 

You have properly noted the bolded words above: "if by c he means the speed of light measured locally in a vacuum free of any influence of gravity."

 

That's NOT what he means.  The very reason the speed of light varies in this context is because it is NOT free from any influence of gravity.

 

That's what gravitational time dilation is all about.  Time slows down the closer you are to the center of gravity. It speeds up as you recede from it.  This is an absolute phenomenon, not a relative one.  That means that it won't be "seen" differently depending on your frame of reference. It will be seen the same in all frames of reference.  It is frame-independent (absolute) not frame-dependent (relative).

 

Baez is right.  As I said earlier, Einstein said the same back around 1918:  In GR the speed of light is NOT constant.

 

Once again, this is not a case where we're dealing with two different observers and trying to say what another might see.  There's only one observer, i.e., YOU, on the floor.  When you look at the ceiling, you are not looking at "another guy in another frame."  You are just looking at light.  When you do that, YOU (not some other guy) will measure the speed of light "up there" to be faster than yours.  Why? Because it IS faster (it's absolute, not relative).

 

Again, when you look at the ceiling, you are not looking at "another guy in another frame."  The guy on the ceiling WILL see the speed of light in his frame to be c, but you're not him, and he's not you.  And, in his case, he will see the speed of light on the floor to be slower than it is in his frame, because it IS slower there.  Either way, the speed of light varies in GR--it is not constant for all observers. 

Edited July 11, 2018 by Moronium

[Moronium]

This whole exchange about floor/ceiling light speed in GR is actually a good springboard for a further analysis of SR.

 

Start at the beginning.  Why is the speed of light the same in all inertial frames?  Why?

 

My claim is that you get a much more consistent, explanatory, objective, and reasonable theory of motion if you don't claim that.  I would therefore say that the speed of light in NOT the same in all inertial frames.

 

So why does "everyone else" (I'm far from alone in my opinion, but let's forget that) say otherwise?

 

Because Einstein (SR) said otherwise.

 

Well, OK, then, why did Einstein say otherwise?  I've been through all this in other posts, as far as his personal motivations go, and I won't try to say it all again in this post.  So let's ask the question in another way.

 

Did the empirical evidence compel him to say that?  NO!  Absolutely not.  And he explicitly said as much.

 

Then how did he come to make that assertion, if not based on evidence?  By, he said, his own imagination and his own free will.  He chose to say it. It's a theoretical postulate, not an empirical fact.

 

Well, but it's since been proven to be a fact, right?  NO!  Absolutely not, as any theoretical physicist worth his salt will tell you.

 

Many of you believe otherwise.  You think this postulate is a proven fact.  It aint.  If you think otherwise, do some research.

 

Now, let's go back to the floor/light thing for a minute.  In GR, as an absolute matter, light is faster on the ceiling.  That's the presumed "fact."  It's not just a matter of individual perspective.  

 

Well, then why did I say that the guy on the ceiling says that light is still c in the ceiling frame?  I didn't. SR says that.  I don't even agree, but I know that everyone I'm talking to here does.

 

The question here is this:  How can both A (a guy on the floor) and B (a guy on the ceiling) both see light in their own frame to be 186,000 if it's actually different?

 

The short answer is:  Because they're "seeing" what SR tells them to see.  No other reason.  That doesn't mean they're right, as a matter of actual fact.  They're simply making an assumption.

 

I've said why I think their assumptions are mistaken many times over, in great detail in other posts.  In short it's this:  Because they are making measurements of both time and distance (which they need to derive their speed) with different instruments.  So, given the LT, they will measure the speed to be the same even when it isn't.  I will elaborate on this in my next post.

Edited July 11, 2018 by Moronium

[Moronium]

The question here is this:  How can both A (a guy on the floor) and B (a guy on the ceiling) both see light in their own frame to be 186,000 if it's actually different?

:

Because they are making measurements of both time and distance (which they need to derive their speed) with different instruments.  So, given the LT, the will measure the speed to be the same even when it isn't.

 

 

 

I'll elaborate on this a little more in this post by examining the lorentz transformations.  

 

It's good to remember that the LT were lifted by SR FROM a preferred frame theory.  That's what they were designed to work in, NOT a relative theory.  So, why were they invented?

 

The MM experiment could NOT detect that the earth was in any way moving.  Does that mean it is NOT moving, and that the sun, the fixed stars, and the whole universe is revolving around us?  That would invalidate everything we think we know, if true!

 

So, now what?

 

Lorentz said:  The earth IS moving, we just don't measure it to be, in our own frame.

 

Why don't we measure it to be moving, if it is?

 

Because our measuring instruments have been distorted by virtue of our motion, Lorentz said.  And he worked out his transformation equations to quantify the amount of distortion required, in each frame, depending on speed, for light to ALWAYS be measured to be the same in all inertial frames (even though it actually isn't).  Hence, the Lorentz transforms, which he had basically worked out (with some later refinements) in 1892, a full 13 years before Einstein published his SR paper.  SR later high-jacked these, because they are necessary to make sense in any viable theory of relative motion.

Edited July 11, 2018 by Moronium

[OceanBreeze]

I won't address what you said in the remainder of this post, Popeye, other than to say you're saying something different than Baez, and, if he's right, you're wrong.  The question is why?

 

You have properly noted the bolded words above: "if by c he means the speed of light measured locally in a vacuum free of any influence of gravity."

 

That's NOT what he means.  The very reason the speed of light varies in this context is because it is NOT free from any influence of gravity.

 

That's what gravitational time dilation is all about.  Time slows down the closer you are to the center of gravity. It speeds up as you recede from it.  This is an absolute phenomenon, not a relative one.  That means that it won't be "seen" differently depending on your frame of reference. It will be seen the same in all frames of reference.  It is frame-independent (absolute) not frame-dependent (relative).

 

Baez is right.  As I said earlier, Einstein said the same back around 1918:  In GR the speed of light is NOT constant.

 

Once again, this is not a case where we're dealing with two different observers and trying to say what another might see.  There's only one observer, i.e., YOU, on the floor.  When you look at the ceiling, you are not looking at "another guy in another frame."  You are just looking at light.  When you do that, YOU (not some other guy) will measure the speed of light "up there" to be faster than yours.  Why? Because it IS faster (it's absolute, not relative).

 

Again, when you look at the ceiling, you are not looking at "another guy in another frame."  The guy on the ceiling WILL see the speed of light in his frame to be c, but you're not him, and he's not you.  And, in his case, he will see the speed of light on the floor to be slower than it is in his frame, because it IS slower there.  Either way, the speed of light varies in GR--it is not constant for all observers. 

 

 

You should address the rest of my post because it is all required for context.

 

Baez did use two different observers, one on the ceiling and one on the floor, and Baez agrees that both will see the speed of light as c, locally in their own respective frame s of reference.

 

Quoting him directly: “Light travels faster near the ceiling than near the floor.  But where you are, you always measure it to travel at c; no matter where you place yourself, the mechanism that runs the clock you're using to measure the light's speed will speed up or slow down precisely in step with what the light is doing.  If you're fixed to the ceiling, you measure light that is right next to you to travel at c.  And if you're fixed to the floor, you measure light that is right next to you to travel at c.”

 

I agree with all of that, because the room is a gravity well and light at the bottom of the well will travel slower than light at the top of the well, but relative to whom?

 

Both observers, on ceiling and on floor, measure light to be moving at c, locally, and they are both right!

 

We also know that in the gravity well light travels more slowly at the bottom of the well than at the top, and that is also right!

 

Where Baez goes off the rails is when he says this: “But if you are on the floor, you maintain that light travels faster than c near the ceiling.  And if you're on the ceiling, you maintain that light travels slower than c near the floor.”

 

Only the second sentence is correct! In a gravity well, light travels slower than the free-space velocity of light in a vacuum. The light at the ceiling is still in a gravity well, referenced to the free-space velocity of light and must be slower than c in free space. It can never be faster than c!

 

Baez is confused, or at the very least, his use of language is confusing. The light at both the ceiling and the floor is slower than c, as they are both in a gravity well. However, all observers measure the speed of light as c, locally.

The resolution to this is when measured non-locally, the light at the ceiling is faster than the light at the floor but still slower than the free-space speed of light, which is c.

 

There isn't any light, especially in a gravity well, that moves faster than the free-space velocity of c. If you want something that is Absolute, that is it!

[Moronium]

Both observers, on ceiling and on floor, measure light to be moving at c, locally, and they are both right!

 

We also know that in the gravity well light travels more slowly at the bottom of the well than at the top, and that is also right!

 

Where Baez goes off the rails is when he says this: “But if you are on the floor, you maintain that light travels faster than c near the ceiling.  And if you're on the ceiling, you maintain that light travels slower than c near the floor.”

 

Baez is confused, or at the very least, his use of language is confusing. 

 

1. I agree with your first sentence in a qualified way.  See my most recent two posts.  I agree that they will both MEASURE the speed to be the same in their own frame.  I don't agree that both are right, except in a trivial sense.  Both have made correct measurements with the instruments they have.  They are "both correct" in that sense.  But they are not "both correct" as a matter of fact. See your own second sentence as posted above.

 

2.  I don't agree that he "goes off the rails" at this point.  Please read my post (the one this is responding to) carefully to see why I don't agree.

 

3.  I do agree that his language in the first passage you posted is ambiguous and therefore confusing.  But he's OK in the second passage (where you say he goes "off the rails").

Edited July 11, 2018 by Moronium