Black holes

[Farsight]

We know of quite a few coordinate transformations that are definitely forbidden by FGR. Can you give an example of a coordinate transformation that is not forbidden by FGR? Even better: Can you describe an objective way for us to determine which coordinate transformations are forbidden, and which are not?

Sure. Remember that light can't go slower than stopped.

Did you misspeak? As presented by its developer, John Duffield of Poole, FGR is founded upon uninformed arrogance, intransigence, and nonthink.

Nope, there's no such thing as FGR, and what I'm telling you is based on what Einstein said. What's not to like?

You know Clinger, your name is apt. You cling to conviction, and you dodge the bleedin' obvious. Here, let's give you the spotlight. Care to explain why these two light pulses are moving at the same speed? Take care, your mathematical smoke and mirrors doesn't work against hard scientific evidence. And it's trains next.

 

[DeiRenDopa]

Sure. Remember that light can't go slower than stopped.

Brilliant non-answer!

I know we can nominate posts, but is there a category for 'best non-answer by a crank'?

Nope, there's no such thing as FGR, and what I'm telling you is based on what Einstein said. What's not to like?

Did you misspeak? As presented by its developer, John Duffield of Poole, FGR is founded upon uninformed arrogance, intransigence, and nonthink.

You know Clinger, your name is apt. You cling to conviction, and you dodge the bleedin' obvious. Here, let's give you the spotlight. Care to explain why these two light pulses are moving at the same speed? Take care, your mathematical smoke and mirrors doesn't work against hard scientific evidence. And it's trains next.

I'm not W.D.Clinger, and I know you're going to ignore me, Farsight.

However, what I write here may be of some interest, and value, to other readers.

"The bleedin' obvious" is indeed just that; the "two light pulses are moving at the same speed", NOT.

It's bleedin' obvious if you have farlight eyes, and can "see" the light pulses doing their thing in absolute space and time. This is a world in which FGR rules.

However, if you have only ordinary eyes, how can you "see" what the two light pulses are doing?

In the real world - where GR rules (as far as we know, today) - you can only see a light pulse if you detect light that is emitted from it*. So you'd be using light to observe light, and the location of your eye and the path the light takes - from light pulse to your eye - are both important, in terms of working out what you actually see.

Did Farsight specify where your eye is supposed to be, in order to see these two light pulses? No, he did not.

Did Farsight describe the medium through which the light travels, from light pulse to your eye? No, he did not.

Did Farsight provide the math/calculations which allow you to derive - objectively, and in an independently verifiable way - the arrive time of light from the light pulses? No, he did not.

Did ...

What did Farsight do?

Well, he behaved just as W.D.Clinger said: he made an oracular statement, one which cannot be checked, objectively and in an independent fashion.

W.D.Clinger was right, every question about FGR can be answered only by querying the oracle ...

* there are other ways (e.g. you could detect electrons emitted via the photoelectric effect), but they are either equivalent, more complicated, or both

 

[ctamblyn]

Only it's electric permittivity and magnetic permeability.

My mistake: I copied that snippet directly from your post (http://www.internationalskeptics.com/forums/showpost.php?p=8145440&postcount=762) without proof-reading properly.

Yes [latex]Z_0 = \sqrt{\frac{\mu_0}{\varepsilon_0}}[/latex] so you can keep it constant by increasing ε0 in proportion with μ0. But [latex]\varepsilon_0 =\frac {1}{\mu_0 c_0^2}[/latex] and if you insist that c is constant, then if you increase ε0 you have to reduce μ0. So electric permittivity is proportional to the reciprocal of magnetic permeability.

Not quite: if we're saying that Z₀ is constant and insisting that c is constant, then the permeability and permittivity are both constant too.

There aren't any "muon decay clocks", we just see muon decay affected by time dilation just as we'd expect.

Simply take a very large collection number N of muons at rest and count the decays. When N/2 decays have been detected, that's one unit of time. When a further N/4 decays have been detected, that's another unit of time. And so on.

And "we just see muon decay affected by time dilation just as we'd expect" is the point I've been trying to get across to you for some time now. Weak interactions, strong interactions and electromagnetic interactions are all affected identically.

It's like your parallel-mirror light-clock is good for a trillion reflections before it decays. Move it fast and you extend its lifetime as measured by an observer on earth. And if somebody does find that nuclear clocks don't stay synchronised with electromagnetic clocks when you change the elevation, then once somebody replicates it, then it will be accepted physics.

That's something of a moot point, since as far as anyone knows strong and weak clocks are affected in precisely the same way as electromagnetic ones. If they were not, then relativity would be wrong and arguing over the "correct interpretation" of GR would be far less interesting.

You know why light is affected twice as much as matter, don't you?

Also moot. The model I was referring to is incapable of affecting, say, neutrinos at all.

No there isn't. It's just light moving through space. Space isn't falling down. The light curves when it travels through space, that's all.

Re-read what I said, and re-read the paper. In their paper they had a flow described by the vector field V. I am not saying that "real" space is "really" flowing, however useful an analogy that might be in certain circumstances. I am describing the model in the paper you cited in support of your ideas.

 

[ctamblyn]

You've had your empirical data. You dismiss it just as you dismiss Einstein.

That claim is not compatible with the facts. I asked repeatedly for empirical data which shows that "MTW" GR is wrong, but you haven't provided a single piece.

If I am mistaken, then simply link to the post where you provided that evidence.

 

[Reality Check]

How about ben can't address the evidence or face up to what Einstein said, so he tries ad-hominem abuse instead. Gorn, geddoutofit, you've got nothing.

How about Farsight can't state any evidence that his obsession with what Einstein said means anytrhing for the physics of GR?
Farsight: Do you understand the fallacy of argument by authority?
(27 March 2012)
Gorn, geddoutofit, you'e not even wrong, just deluded about what GR states.

So Farsight continues with his fantasies about the actual physics and lies about "ad-hominem abuse". What ben m stated is the obvious - you have a personal fantasy about GR, e.g.

• that one coordinate system is somehow special when GR is specifically coordinate free.
• that the "speed of light varies" which is a dumb statement without specifying which speed of light. The local speed of light is always c. The coordinate speed of light depends on the coordinates.

You cannot provide any evidence to support this fantasy. In fact you insist on citing empirical results that support GR.

 

[Reality Check]

Yes, I said we'd see a flash. Have a read up on GRBs

Yes - you should read up on GRBs

Most observed GRBs are believed to consist of a narrow beam of intense radiation released during a supernova event, as a rapidly rotating, high-mass star collapses to form a neutron star, quark star, or black hole. A subclass of GRBs (the "short" bursts) appear to originate from a different process. This may be the merger of binary neutron stars and perhaps specifically the development of resonance between the crust and core of such stars as a result of the massive tidal forces experienced in the seconds leading up to their collision, causing the entire crust of the star to shatter.[2]

Nothing to do with natter falling into a black hole because there is no optional black hole before the supernova !

and take a look at this physicsworld article ...

Which is about matter being blown away from the accretion disk of Sagittarius A*- no gamma burst there either!

It's meant to be as perfect as the frozen star. It's not the kind of surface you can walk around on.

What it is looks like is the kind of surface where matter piles up to a density comparable to neutron stars. And what do we see on neutron stars - Type 1 X-ray bursts. What do we not see for black holes - Type 1 X-ray bursts!

• Advection-dominated Accretion and Black Hole Event Horizons; Narayan, Garcia & McClintock, Astrophysical Journal Letters 478(2): L79-L82, April 1997.
• Quasi-regular X-Ray Bursts from GRS 1915+105 Observed with the IXAE: Possible Evidence for Matter Disappearing into the Event Horizon of the Black Hole; Paul, et al., Astrophysical Journal Letters 492(1): L63-L66, January 1998.
• New Evidence for Black Hole Event Horizons from Chandra; Garcia, et al., Astrophysical Journal 553(1): L47-L50, May 2001.
• On the Lack of Type I X-Ray Bursts in Black Hole X-Ray Binaries: Evidence for the Event Horizon?; Narayan & Heyl, Astrophysical Journal 574(2): L139-L142, August 2002.
• Observing the effects of the event horizon in black holes; Done & Gierlinski, Monthly Notice of the Royal Astronomical Society 342(4): 1041-1055, July 2003.
• The Rates of Type I X-Ray Bursts from Transients Observed with RXTE: Evidence for Black Hole Event Horizons; Remillard, et al., Astrophysical Journal 646(1): 407-419, July 2006.

 

[W.D.Clinger]

No response from Clinger then. Quelle Surprise.

Gotta go.

You had no answer for DeiRenDopa, and I had nothing to add to what he said.

Not at that time, anyway. Now I see you've provided yet more evidence for DeiRenDopa's thesis:

So don't allow yourself to be distracted by suggestions that you spend years learning differential calculus or that you spend months on the Kerr solution.

FYI: Differential calculus is also called first-semester calculus, or calculus 1. If you had majored in science at a decent university in the United States, you'd have taken it during your first semester---assuming you hadn't already taken it in high school. (In the US, more students study differential calculus in high school than in college.)

We know of quite a few coordinate transformations that are definitely forbidden by FGR. Can you give an example of a coordinate transformation that is not forbidden by FGR? Even better: Can you describe an objective way for us to determine which coordinate transformations are forbidden, and which are not?

Sure. Remember that light can't go slower than stopped.

I'm glad to see you've changed your mind about Kruskal-Szekeres coordinates, and Eddington-Finkelstein coordinates, and Lemaître coordinates, and Painlevé-Gullstrand coordinates. Light never goes slower than stopped in those coordinates, so now you're saying it's okay to use them in FGR.

Since the FGR oracle has given different answers to that same question on different days, I don't see how your answer could possibly give us an objective way to determine which coordinate transformations are forbidden in FGR.

Clinger, Vorpal, your r=6m noted.

Let's note also that no one knows whether that r=6m calculation can be performed within FGR. My calculation used Painlevé-Gullstrand coordinates, which had definitely not been part of FGR until today. Vorpal's calculation did not use an explicit coordinate transformation, but he used some GR theory that Einstein derived from principles of covariance that Farsight had denied in no uncertain terms earlier within this thread.

Before Farsight changes his mind again tomorrow, let's run through the answer that standard GR gives to Guybrush Threepwood's question about what happens to an object that's falling radially into a black hole, starting from rest at infinity.

We'll start by looking at the infalling object's coordinate velocity, as calculated in several different coordinate systems. All of those coordinate systems are okay with Farsight, according to the rule he gave above. (We have to do this quick, before he comes back tomorrow and changes his mind.)

• In rain coordinates, the object's coordinate velocity is zero throughout the fall.
• In Painlevé-Gullstrand coordinates, the object's coordinate velocity at Schwarzschild r is - β = - 2m/r.
• In Schwarzschild coordinates, outside the event horizon at r=2m, the object's coordinate velocity is - β (1 - β²) (as shown in post #875).

Here's a table of (the absolute values of) those velocities for various values of the Schwarzschild radial coordinate r:

r ............ | 0 .... | β ........... | β (1 - β ² )
1000m | 0 | .0447c | .0446c
100m | 0 | .141c | .139c
10m | 0 | .447c | .358c
8m | 0 | .500c | .375c
6m | 0 | .577c | .385c
4m | 0 | .707c | .354c


3m | 0 | .816c | .272c
2m | 0 | 1.000c | 0
1.5m | 0 | 1.155c |
1.0m | 0 | 1.414c |
0.5m | 0 | 2.000c |
0.1m | 0 | 4.472c |

Which of those columns gives the real radially inward velocity of the infalling object?

They all do. This is relativity, so there's more than one way to look at that question.

If you're a passenger on a train, riding along on ribbon rail with all of the windows closed in the cabin, then you may not be aware of any forward movement at all. That's a perfectly legitimate point of view, and it corresponds to the zero column.

If you open a window and calculate your velocity by using your watch to time the interval that passes between mileposts, then you may calculate a nonzero velocity. The β column shows that "milepost" velocity, where I'm assuming mileposts have been planted at fixed values of the Schwarzschild radial coordinate r.

To keep those mileposts planted at fixed values of r, those mileposts have to be accelerated radially outward. Otherwise, they'd fall toward the black hole. For mileposts in the vicinity of the black hole, that acceleration takes a lot of power. For a milepost at the event horizon, it would take infinite power to keep the milepost from falling into the black hole. For mileposts inside the event horizon, it would take more than infinite power to keep the milepost from falling inward. The supraluminal velocities in the β column therefore correspond to a counterfactual calculation of what the milepost velocity would be if it were possible to maintain mileposts at fixed r even inside the event horizon. That's why you shouldn't get upset by those supraluminal velocities.

The β (1 - β²) column shows the infalling object's velocity as observed at infinity, or by an observer being held at some fixed r by radially outward acceleration. That as-observed-at-infinity velocity converges to zero at the event horizon, because light emitted by the object at the event horizon can't escape. The observer at infinity will never see the object pass through the event horizon, and will certainly never see the object once it passes inside the event horizon. To the observer at infinity, it looks as though the object starts to slow down inside r=6m, basically because the observed time dilation is increasing faster than the object's momentum is increasing.

The object continues to fall inward, however, passing the event horizon with no great fuss. Pretty soon, within milliseconds or hours (depending on the size of the black hole), the object reaches the black hole's central singularity. General relativity doesn't tell us what happens there. No one knows what happens there.

I'm glad we were able to talk about this today, while Farsight agrees that all of the coordinate systems mentioned above are allowed by FGR (Farsight general relativity).

I'm pretty sure he'll deny it tomorrow.

 

[Brian-M]

I wouldn't. I'd claim that we'd see a gamma ray burst when an object annihilates at a shockfront before it gets to the event horizon.

Something analogous to a sonic boom?

For God's sake Brian. They're just two pairs of mirrors in front of us with light going back and forth. Stop clutching at straws with this.

I think I've explained the concept clearly enough now. If you still don't understand, so be it.

The thing you call time dilation is just things moving slower

Yes. That's pretty much the definition of time dilation.

No it isn't. One's a rotating ring, one's a gravitational field.

Am I to understand you're claiming that the effect of gravity is different to the effect of acceleration? (This is an old point I tried to make, but you never made your position clear, so I assumed you agreed they were essentially the same thing.)

If gravitational force is different from the force of gravity, how could someone in a sealed room tell whether the downward force they're experiencing is from accelerating through space or from the gravity of a very massive but very distant mass from which they are being held at a fixed distance... so distant that there's no detectable gravitational gradient between the floor and the ceiling of the room.

(Essentially the same question I asked back in post 676.)

 

[Brian-M]

Forget tachyons, Brian. They're the product of another non-real solution. They've been mooted for fifty years plus, there's no evidence for them, and they're way past their sell-by date.

You could say the exact thing about ansibles, which in classic sf use tachyons to communicate. So in the context of ansibles (which is what was being discussed), tachyons are a valid subject.

Modern sf still has the equivalent to ansibles, but they work by different processes (such as subspace, hyperbeam, quantum entanglement, etc) and so they aren't called ansibles anymore.


On a different matter, just one (somewhat silly) thought...

You say that time motion stops completely at the event horizon, that nothing moves. So doesn't that mean that when something falls in, it's blocking the way of everything that falls in afterward?

Wouldn't this cause matter to accumulate in a shell around the black-hole? You'd have the massive singularity in the center, surrounded by empty(?) space until the event horizon where you'd have a shell of matter held back by the barrier of motionless matter at the event horizon.

 

[Vorpal]

If anyone's curious, for radial freefall, if the speed at infinity (rel. to a stationary observer) is more than c/√3 inward, then the Schwarzschild coordinate acceleration d²r/dr² is always repulsive.

• In Painlevé-Gullstrand coordinates, the object's coordinate velocity at Schwarzschild r is - β = - 2m/r.

Typo: -β = -√(2m/r). But everywhere else it occurs, it's right.
Very nice post.

To keep those mileposts planted at fixed values of r, those mileposts have to be accelerated radially outward. Otherwise, they'd fall toward the black hole. For mileposts in the vicinity of the black hole, that acceleration takes a lot of power. For a milepost at the event horizon, it would take infinite power to keep the milepost from falling into the black hole. For mileposts inside the event horizon, it would take more than infinite power to keep the milepost from falling inward. The supraluminal velocities in the β column therefore correspond to a counterfactual calculation of what the milepost velocity would be if it were possible to maintain mileposts at fixed r even inside the event horizon. That's why you shouldn't get upset by those supraluminal velocities.

Naturally: r is timelike in the Schwarzschild interior, so we can't put stationary mileposts any more than we can stop going to the future. I don't disagree with anything here, but it might use some elucidation. In the Schwarzschild interior,
[latex]\[ ds^2 = -\left(\frac{2m}{r}-1\right)^{-1}dr^2 + \left(\frac{2m}{r}-1\right)dt^2 + r^2(d\theta^2 + \sin^2\theta d\phi^2) \][/latex]
we can have mileposts stationary in the spacelike coordinates. Moreover, unlike the exterior, they require no thrust whatsoever--they're geodesics. But of course they still have the singularity in their future; nothing will prevent that. So what we're doing calculating is the rate of coordinate time with respect to proper time, and pretending it's a velocity.

 

[Farsight]

Something analogous to a sonic boom?

Kind of. But remember the pair production and "the wave nature of matter". It's analogous to a sonic boom when you're made out sound waves.

Am I to understand you're claiming that the effect of gravity is different to the effect of acceleration? (This is an old point I tried to make, but you never made your position clear, so I assumed you agreed they were essentially the same thing.)

I'm saying gravity is different to acceleration through space. The latter demands a continual input of energy. As you accelerate your "relativitistic mass" increases. That's your rest mass plus kinetic energy with respect to me. That doesn't happen when you sit in your chair.

If gravitational force is different from the force of gravity, how could someone in a sealed room tell whether the downward force they're experiencing is from accelerating through space or from the gravity of a very massive but very distant mass from which they are being held at a fixed distance... so distant that there's no detectable gravitational gradient between the floor and the ceiling of the room.

They can't. (I assume "gravitational force" should have read "acceleration force"). The principle of equivalence holds good. But that doesn't mean acceleration force is the exact same thing as gravitational force.

(Essentially the same question I asked back in post 676.)

Let me give you analogy that clarifies the distinction. You've got car, with the steering wheel fixed so the car goes straight. We load it up on a flatbed truck and take it to a flat level plain, and you get in and drive it at 60mph. Whilst doing this you notice from distant landmarks that you aren't going straight. The car is veering to the right a little. You stop the car, and I pull up in the truck, and we confer. We notice it's windy, and that this wind is blowing from the left. That's acceleration force. After lunch we carry on, noticing that the wind has now stopped. You get in the car, you drive it at 60mph, and you notice it's still veering right. Again you stop, I pull up, and we confer. I point down to the ground, and show you that on this run, it's muddier on the right than on the left. That's gravitational force. They're totally different, but when you're cocooned in your car, you can't tell.

 

[Farsight]

You could say the exact thing about ansibles, which in classic sf use tachyons to communicate. So in the context of ansibles (which is what was being discussed), tachyons are a valid subject.

Modern sf still has the equivalent to ansibles, but they work by different processes (such as subspace, hyperbeam, quantum entanglement, etc) and so they aren't called ansibles anymore.

Yeah, but it's still science fiction.

On a different matter, just one (somewhat silly) thought...

You say that time motion stops completely at the event horizon, that nothing moves. So doesn't that mean that when something falls in, it's blocking the way of everything that falls in afterward?

Wouldn't this cause matter to accumulate in a shell around the black-hole? You'd have the massive singularity in the center, surrounded by empty(?) space until the event horizon where you'd have a shell of matter held back by the barrier of motionless matter at the event horizon.

Nah. It isn't matter in the usual sense - you can add to the mass-energy of a black hole by shining a light on it. It's more like a solid-space/no-space hailstone of pure primal stress-energy that gets bigger and bigger as energy is added. Yeah I know that sounds like science fiction too, but it relates to the original frozen-star black hole and to the gravastar, so I'm not totally winging it.

 

[Farsight]

You had no answer for DeiRenDopa, and I had nothing to add to what he said.

LOL! Talk about evasion. Do you really think you can get away with slippery mathematics greased with abuse? Here, have another go. Redeem yourself.

...You know Clinger, your name is apt. You cling to conviction, and you dodge the bleedin' obvious. Here, let's give you the spotlight. Care to explain why these two light pulses are moving at the same speed? Take care, your mathematical smoke and mirrors doesn't work against hard scientific evidence. And it's trains next.

I've just been reading the rest of your post. Groan, more than infinite power, supraluminal velocities. See where you end up when you won't face up to the simple evidence?

 

[Brian-M]

Yeah, but it's still science fiction.

I never intended to suggest that tachyons existed.

 

[edd]

I've just been reading the rest of your post. Groan, more than infinite power, supraluminal velocities. See where you end up when you won't face up to the simple evidence?

Oh come on Farsight - he explains quite clearly right in that post exactly why that shouldn't be taken to be physical.

 

[Farsight]

My mistake: I copied that snippet directly from your post (http://www.internationalskeptics.com/forums/showpost.php?p=8145440&postcount=762) without proof-reading properly.

It was Matt Visser who didn't proof-read properly! I copied that from the paper. Did I say it's on page 36? It's on page 37:

An arbitrary gravitational field can always be represented as an equivalent optical medium, but subject to the somewhat unphysical restriction that

[magnetic permitivity] ∝ [electric permeability].

Not quite: if we're saying that Z₀ is constant and insisting that c is constant, then the permeability and permittivity are both constant too.

Sure. But my point is that permittivity is proportional to the reciprocal of permeability. I gave an analogy a week or two back that was carefully worded: permittivity is like how easy it is to bend the spring steel bar, permeability is like how hard it kicks back.

Simply take a very large collection number N of muons at rest and count the decays. When N/2 decays have been detected, that's one unit of time. When a further N/4 decays have been detected, that's another unit of time. And so on.

Just like my factory full of machines that have an average lifetime before they break down. But the point remains that we have atomic clocks, optical clocks, piezoelectric clocks, and so on. But we have no devices that go by the name of "muon clock".

And "we just see muon decay affected by time dilation just as we'd expect" is the point I've been trying to get across to you for some time now. Weak interactions, strong interactions and electromagnetic interactions are all affected identically.

I know about muon decay and why the lifetime is extended when the muon moves fast. I've said this somewhere, saying it's a rotational version of the parallel-mirror time dilation. You simplify the muon down to a circle of light and think in terms of stretching a coil spring. The circle is stretched into a helical segment with a longer light-path length, so a zillion rotations takes longer.

That's something of a moot point, since as far as anyone knows strong and weak clocks are affected in precisely the same way as electromagnetic ones. If they were not, then relativity would be wrong and arguing over the "correct interpretation" of GR would be far less interesting.

It wouldn't be wrong, it would just be that Lorentz invariance wouldn't be absolute. It's no big deal. The principle of equivalence isn't absolute, that doesn't make relativity wrong. We just do the experiment and see if nuclear clocks show any discrepancy with electromagentic clocks, and take it from there. I'm on record as saying a gravitational field is where there's a gradient in the relative strength of the electromagnetic force versus the strong force, so I'm interested. That GRB I was talking about might show features where the electrons went first and the protons last.

Also moot. The model I was referring to is incapable of affecting, say, neutrinos at all.

Ah neutrinos. I think it's a shame Antonio Ereditato and Dario Autiero have resigned. IMHO they were victims of media sensationalism. I read the paper and it played a straight bat reporting experimental results, which I think was the right thing to do. And after all, the speed of light isn't constant, so light can go "faster than light". But they carry the can and fall on their sword like the good guys they are while the media, including the CERN press office, bear no responsibility whatsoever. Anyway, neutrinos should be classed with photons, let's have a thread on them sometime.

Re-read what I said, and re-read the paper. In their paper they had a flow described by the vector field V. I am not saying that "real" space is "really" flowing, however useful an analogy that might be in certain circumstances.

Good. I'm glad we've knocked that one on the head. Watch the Horizon programme again and marvel at how the waterfall garabage is presented as fact. All: read this too.

I am describing the model in the paper you cited in support of your ideas.

It was sol who cited the paper in post #753 on page 19 after I'd said Visser had moved on to gravastars.

 

[Farsight]

I never intended to suggest that tachyons existed.

OK.

Oh come on Farsight - he explains quite clearly right in that post exactly why that shouldn't be taken to be physical.

He's lost in maths edd. And he's trying to bamboozle you with it while evading the scientific evidence. I have to go now and do the parquet, please make sure he tackles this:

 

[edd]

He's lost in maths edd. And he's trying to bamboozle you with it while evading the scientific evidence.

I somehow think he's trying to bamboozle me with maths. For one thing, the maths seems pretty clear to me. For another thing, I'm in agreement with him, so I'm an unlikely target for bamboozlement. For a third thing, I'm not the mathematician some here are, but y'know, I can hold my own, so I'm even less a likely target for that. For a fourth thing, I think the 'scientific evidence' (what little there is for things falling into black holes) is pretty much on the side of me and him.

I have to go now and do the parquet, please make sure he tackles this:

[qimg]http://www.physicsdiscussionforum.org/download/file.php?id=60[/qimg]

I might like to understand exactly how you want this set up for the situation where the lower clock is infalling (the upper clock can do what you want) and I want to know where you think I'm supposed to be watching the clocks from and what it tells me about infalling things before I query anyone else on it.

 

[DeiRenDopa]

Just like my factory full of machines that have an average lifetime before they break down. But the point remains that we have atomic clocks, optical clocks, piezoelectric clocks, and so on. But we have no devices that go by the name of "muon clock".

Indeed.

Just like we no devices which go by the name of "gedanken rope", "gedanken high-speed camera", or light clocks whose light pulses are visible only in farlight.

I know about muon decay and why the lifetime is extended when the muon moves fast. I've said this somewhere, saying it's a rotational version of the parallel-mirror time dilation. You simplify the muon down to a circle of light and think in terms of stretching a coil spring. The circle is stretched into a helical segment with a longer light-path length, so a zillion rotations takes longer.

Ah yes, back to the Farsight world, full of mechanical devices, absolute time and space, and farlight.

So quaint, so Victorian!

Pity that such a neat and tidy world is inconsistent with hard, scientific, objective - and above all - quantitative evidence.

 

[ben m]

Ah yes, back to the Farsight world, full of mechanical devices, absolute time and space, and farlight.

Yep. God forbid Farsight should sink his teeth into the ladder-barn paradox. The ladder is *really* inside the barn, and this is obvious if you read between the lines of Einstein's SR. Look: --|-------|--, it's that obvious. You don't even have an argument, no one is listening to you and your textbooks.