Terrell Revisited: The Invisibility of the Lorentz Contraction

[PAllen]

Well those things I know. I was talking about apparent this and apparent that, by which I meant what the observer sees.

But I noticed that the general opinion here seems to be that an approaching rod appears to be contracted, and when the rod starts to recede, it contracts more. So my heuristic argument is not needed.

Visually, an approaching rod appears expanded.

 

[Ken G]

We know a couple things from the Terrell analysis, for rods that take up a small solid angle (and can appear distorted in the way PAllen described above, where one side looks closer to us so has expanded looking tickmarks which I erroneously disputed, but here I'm just talking about the appearance of the full length of the rod). The key point is that the observer who sees the rod in motion can never see anything in an instantaneous image that some observer moving with the rod cannot also see in such an image, the only question is which moving observer is the right one to use. So PAllen's analysis has quantified which observer to use, but it turns out to be the one that is in the same place and time as the stationary observer! But more to the point here, the stationary observer will see a series of images that correspond to comoving observers' views that start out being ahead of the rod, then are straight across from the rod, then are behind the rod. The one thing I'm not clear about is that Baez says there can be distortions in the overall scale when you compare those images, so I'm not clear if that will mess up the argument, but assuming there is indeed a comoving observer that sees the same thing, then we can tell the stationary observer will see a rod getting both closer and less foreshortened at first, will see the maximum length when it looks like an unforeshortened rod at its closest distance (but that will come before the image reaches closest approach), with the image at closest approach being foreshortened by the Lorentz factor.

 

[JDoolin]

Here's an animation I made of "what a person would see" of three square elements of dots moving at 0.866c.

It uses 25 red+20 blue +20 purple worldlines of objects following [itex]x=.866 t + \frac{x_0}{\gamma}[/itex]

The object's "comoving" length is half the distance between the green fence-posts.

To me, it looks very clear in the animation that

(1) Lorentz Contraction is clearly visible when the view passes the middle sphere, as it's apparent length is about 1/4 of the distance between the fence-posts
(2) the red plane of dots appears stretched greatly as it is oncoming. In the first few frames of the animation the red dots cover a distance of several fence-posts. It is hard to tell exactly how many, but it's a lot.
(3) The view of the three planes does NOT appear like it would if the cube were simply rotated. Rather, the front and back face are approximately the shape that one would expect to see from a stationary cube, but always tilted back in a hyperbolic shape.I feel confident that PAllen's equation [itex]t = T + csc \theta[/itex] and my equation: [itex]t=T-\sqrt{x^2+y^2+z^2}[/itex] are derived from exactly the same ideas. So we're not disagreeing on the math.

So when Ken says:

The key point is that the observer who sees the rod in motion can never see anything in an instantaneous image that some observer moving with the rod cannot also see in such an image, the only question is which moving observer is the right one to use.

I'm trying to figure out how I can agree with him, because my first impression is that there is practically NOTHING in that animation that looks "the same" as it would in the perspective of a comoving viewer. I would say instead "the observer who sees the rod in motion can never see any event in an instantaneous image that some observer moving with the rod cannot also see in such an image"

However, there is major disagreement on the positions and time where and when those events occurred. The differences in positions make it so that the shape appears warped. And that apparent difference could NOT be mistaken for ordinary rotation--at least not in the case of a cubic object.

As far as spheres and disks go, though, they have particular symmetries that may come into play. I look forward to making another set of animations with the dots in spherical and disk patterns to see. I don't know the mathematical elegance with which Roger Penrose showed that the sphere stayed looking like a sphere, but I will brute force it with software.

I would have to do quite a lot more work to figure out how a shadow would appear--I think you'd have to take into account the position the velocity of the light-source would have... But it would create a more complicated problem than I want to think about right now. I'd rather focus on the light that is coming directly off the moving body toward the observer.

 

[JDoolin]

And that apparent difference could NOT be mistaken for ordinary rotation--at least not in the case of a cubic object.

Well, I shouldn't say it couldn't be mistaken for ordinary rotation... It's going by pretty quick, and you might not have the presence of mind to measure the length of the parallel side, and watching it shrink against the fence-posts as it goes by... It could be mistaken for ordinary rotation, but I don't understand why you would stress the fact that you COULD mistake it for ordinary rotation when you should be stressing the DIFFERENCES which clearly indicate that it is different from ordinary rotation.

 

[PAllen]

I think there is something interesting and useful about the Terrell/Penrose rotation idea, as long as it is not mis-represented.

1) It can provide a computational shortcut such that you never have to explicitly worry about light delays. Compute a stationary image, and apply SR aberration to each of its image angles. This is an exact procedure, without limit to size or shape, and will also handle surface features. To me, this result is computationally and conceptually interesting.

2) It immediately follows from the above that what might be called the 'stationary basis' image for a given viewing angle of a moving body corresponds to a different viewing angle. This gives rise to a first order visual effect that looks like rotation.

3) But since the rotation analog is only first order accurate, the larger the object the more distortion there is from pure rotation.

4) I think we all have consensus (including Penrose) that introducing other reference points in the scene (fence posts, tracks, etc.) makes rotation rather than contraction an untenable visual interpretation, but if all you saw was a movie of an isolated moving object without any knowledge of context, and it subtended small angle at closest approach, it would appear very close to an image of the rest object that was rotating as it moved.

 

[Ken G]

Yes, I see that as a good summary of the situation. What's ironic is that if we take the speed of light to infinity, or slow down the object, what we see becomes more familiar, and fits better with Galilean relativity. But in that limit, Galilean relativity and Lorentzian relativity don't make different predictions, and both would look weird at speeds approaching that of light (JDoolin-- feel like doing a contrasting picture under Galilean relativity?) so we really have no right to say that one is more familiar than the other. What's more, even if we take c to infinity so both look "normal", we still see something that looks like a rotation-- it's just that the right relativistic answer looks like the rotation is happening in a strange way that seems impossible. But wouldn't Galilean relativity also create a rotation that looked impossible, just due to light travel-time effects? So I'm not sure we can claim that weird looking things tell us we are seeing relativistic effects.

 

[PAllen]

Yes, I see that as a good summary of the situation. What's ironic is that if we take the speed of light to infinity, or slow down the object, what we see becomes more familiar, and fits better with Galilean relativity. But in that limit, Galilean relativity and Lorentzian relativity don't make different predictions, and both would look weird at speeds approaching that of light (JDoolin-- feel like doing a contrasting picture under Galilean relativity?) so we really have no right to say that one is more familiar than the other. What's more, even if we take c to infinity so both look "normal", we still see something that looks like a rotation-- it's just that the right relativistic answer looks like the rotation is happening in a strange way that seems impossible. But wouldn't Galilean relativity also create a rotation that looked impossible, just due to light travel-time effects? So I'm not sure we can claim that weird looking things tell us we are seeing relativistic effects.

I think my post #118 is of interest here.

 

[Ken G]

I didn't quite follow the anti-boost idea, it sounds like you are trying to take advantage of the conformal properties of the Lorentz mapping between observers to generalize what would be seen under non-conformal conditions like the Galilean transformation. What seems like a possibility is that Galilean relativity would look even weirder at speeds close to that of light, putting us in the ironic position of being able to tell that our universe length-contracts from how much less distorted that makes fast-moving objects appear.

 

[PAllen]

I think you are missing some of my points. As I see it, Lorentz versus Galilean transform transform is irrelevant for analyzing imaging in one frame accounting for light speed. All that matters is coordinates description of the moving object. Where a transform would matter is if you go from a frame where light speed is assumed isotropic to another frame. With Galilean, you would have to accept anisotropy in such other frame. What I am doing, though, is simply assuming we are in the preferred frame where light speed is isotropic and c, by fiat. Then, per Galilean relativity, we assume that the coordinate description of a body never changes from its rest description. Then ask, how would such an object look? This is indistinguishable from all the direct signal display computations we have been discussing except we unilaterally use the rest description of the object when it is moving. Irrespective of this, the Terrell-Penrose work establishes how to compute images of an object in motion from images of the object at rest assuming the respective coordinate descriptions are related by Lorentz transform. So given, by fiat, the rest frame object description being used for the moving object, to apply Terrell-Penrose, all we need is a rest frame description that would Lorentz transform into that. That is what I am calling an anti-boost. Please try to think about this more. I am certain my method is correct for my stated assumptions, and would answer precisely the question of how an object would look if there were no length contraction (but all else held the same, e.g. isotropic light speed).

 

[Ken G]

It sounds like you are looking for a simpler way to get what it would look like in a Galilean universe than just doing the time-of-flight ray tracing. Either way, we say the stationary camera is in the isotropic-c frame, and then the time-of-flight effects are the same in either the Galilean or Lorentzian universe. The sole difference will then be the absence of length contraction. So if G is what it looks like in the Galilean universe, and L is what it looks like in the Lorentian universe, and A is the anti-boost that removes length contraction, then you are saying G = AL, where L is easy because we can use a comoving camera. That all sounds correct, though since JDoolin already has a ray-tracing calculation, he can probably just go in and get the Galilen result G by removing the appropriate expressions that trace to the Lorentz transformation instead of Galilean. But you are saying that we can picture what it's going to end up looking like by taking what he has now, and apply the anti-boost, which is just a constant stretching in the longitudinal direction, prior to rotation.

That sounds right, so it means that instead of just seeing a rotating cube, we will see a rotating stretched-cube. If so, I think we can argue that would indeed look more strange-- so we have the odd result that we can tell we are in a Lorentzian universe by the fact that the speedy cube looks less weird than it would in a Galilean universe. Penrose's point that the wheels wouldn't look right against the rails is also true in the Galilean case, so you could tell it's not actually a rotation, but the only reason you would even be tempted to imagine it was a rotation is that it otherwise does look like a rotation in the Lorentzian case, where it is more obviously not a rotation in the Galilean case, so you wouldn't even have to ask the question in a universe like that. Non-contraction in a Galilean universe would be more obvious than length contraction is in a Lorentzian universe!

(By the way, note that wheels would be especially weird, because the point where the wheel touches the rail is presumably not moving instantaneously, so it would not be rotated-- actual wheels would look tortuously twisted, but the point where they meet the rail would indeed line up properly. Relativistic wheels not only look weird, they would be experiencing significant internal stresses due to the acceleration. It sounds like a Born-rigid wheel is an interesting problem in its own right, but that's fodder for a different thread.)

 

[m4r35n357]

Wow, on reading this thread I'm glad I just did the calculations and let the computer deal with what things look like ;) However, I'm a bit puzzled at talk of weirdness in Galilean relativity. I was under the impression that Galilean relativity is characterized by infinite light speed, in which case there is no time dilation or length contraction, and no speed is sufficiently great to cause aberration effects.

What have I misunderstood??

 

[PAllen]

Wow, on reading this thread I'm glad I just did the calculations and let the computer deal with what things look like ;) However, I'm a bit puzzled at talk of weirdness in Galilean relativity. I was under the impression that Galilean relativity is characterized by infinite light speed, in which case there is no time dilation or length contraction, and no speed is sufficiently great to cause aberration effects.

What have I misunderstood??

Nonsense. Galilean relativity says nothing about lightspeed. In incorporates no theory of light. In the 1700s, the finite speed of light had already been determined. A sufficiently brilliant physicist at the time could have then computed there would be perverse visual effects for rapidly moving objects (a sphere would look like a long oval, and you would see the 'wrong' surface features compared to expectation from viewing angle). If you look at the website linked early in this thread (by AT, I believe), they have visualization of what would happen for finite light speed assuming Galilean spacetime. What is true of Galilean spacetime is that there is no way to have finite invariant speed. Thus, objects moving rapidly relative to you would depend on your frame dependent (and possibly non-isotropic) light speed. All in all, it would be much more weird and complex than SR.

[edit: as for aberration, Bradley originally derived this assuming Galilean relativity and finite light speed based on Newton's corpuscular model. For stars, so far as I know, it is still impossible to observe the high order corrections relativity makes to this formula (though the derivation in SR is obviously more sound, in that Bradley had to assume that source speed affected light speed is frame dependent.]

 

[m4r35n357]

I'm familiar with the history of light-speed measurement; I most certainly did not claim that the speed of light was thought to be infinite! Also some of us have recently discussed various parts of this article in other threads. I took from this chapter that most of the pre-relativity confusion regarding light was due to a fundamental mismatch between the properties of light (including very specifically aberration) and the Galilean transform, which was resolved only by SR in 1905. Or perhaps I'm just confusing the "top speed" and the speed of light.

 

[Ken G]

Yes, the Galilean transform can be achieved by taking the top speed to infinity, but keeping the speed of light the same. Perhaps you were not seeing that what we were talking about is what things look like, which includes the finite speed of light-- so using Galilean relativity and the finite speed of light, one could still figure out the illusions one would see (assuming you are in the ether frame). In what we might consider to be among the many great ironies of relativity (another being the constant wavelength shift of Compton scattering), the assumption of Galilean relativity, which might seem like an obvious form of relativity pre-Michelson-Morley, objects at speeds approaching c would look even weirder because they would combine rotation with stretching effects. The remarkable thing about Lorentzian relativity is that it removes any weird stretching-- so all you see is the apparent rotation. This points out something completely missing from the usual explanations about how bizarre Lorentzian relativity is! I can remember great hay being made of how relativity causes objects to look rotated, as if that was due to relativity and not just the finite speed of light. But actually, all relativity does is remove some of the distortions, it is certainly not the source of the rotation effect. That's my takeaway message from the "invisibility" of length contraction, a point that I believe PAllen was making much earlier in the thread and which is nicely demonstrated in JDoolin's final simulations.

 

[PAllen]

I'm familiar with the history of light-speed measurement; I most certainly did not claim that the speed of light was thought to be infinite! Also some of us have recently discussed various parts of this article in other threads. I took from this chapter that most of the pre-relativity confusion regarding light was due to a fundamental mismatch between the properties of light (including very specifically aberration) and the Galilean transform, which was resolved only by SR in 1905. Or perhaps I'm just confusing the "top speed" and the speed of light.

Light 'could' have had finite speed and been consistent with Galilean relativity in a different universe. Yes, I think the issue is that in Galilean relativity the only invariant speed is infinite. Thus light could have had frame dependent speed under an aether model, whence it would isotropic only in one frame, and you would have a preferred frame relative to the aether - but this need NOT be viewed as problematic any more than the speed of sound is isotropic only in a frame at rest relative to air. OR, light could have behaved per Newton's corpuscular model, when its speed would be both source speed dependent and frame dependent exactly as bullets are. The difficulties hit more and more in the 1800s was that some phenomena (e.g. aberration) seemed to fit much better with corpuscular model, while most others fit better with the aether model, and way to try to handle both were getting more and more baroque (aether drag, but then that wasn't enough). SR solved all these issues in a conceptually simple way.

 

[m4r35n357]

Yes, the Galilean transform can be achieved by taking the top speed to infinity, but keeping the speed of light the same.

That's where I lose it I think ;) I can't deal with the concept of a higher top/invariant speed than light because I don't have a mental model of physics that can handle frame dependent light speed. (OK let's not get all GR about this!).

 

[JDoolin]

I don't think you can really say there is any single Galilean construction. Once you throw out the idea of the Lorentzian model, you have to say something along the lines of what is preserved. If not an observer dependent speed of light, is it an infinite speed of light, as Galileo (I think) believed, or is it a source-dependent speed of light? Or do you wish to preserve the speed of light but remove length contraction?

If you try to have a non-finite but constant observer dependent speed of light, that not Galilean Relativity. You have to either have source-dependence, or infinite speed of light.

 

[JDoolin]

Thus light could have had frame dependent speed under an aether model, whence it would isotropic only in one frame, and you would have a preferred frame relative to the aether - but this need NOT be viewed as problematic any more than the speed of sound is isotropic only in a frame at rest relative to air.

Except it wouldn't be Galilean relativity...

 

[PAllen]

Except it wouldn't be Galilean relativity...

Do you believe the behavior of sound violates the POR? It is isotropic only in a frame without substantial motion relative to air. If an 1800s scientist viewed aether as strange form of matter (many did), they would (and did) think there was no issue with respect to the POR. For mechanics (or things not involving light) you had direct observance of POR. For light, there was a preferred frame only because of the presence of aether, just like the presence of air. Oh, and they even explored ideas of aether wind, and the the frame picked out be aether could vary from one place to another (due to motion of the aether).

 

[JDoolin]

Do you believe the behavior of sound violates the POR? It is isotropic only in a frame without substantial motion relative to air. If an 1800s scientist viewed aether as strange form of matter (many did), they would (and did) think there was no issue with respect to the POR. For mechanics (or things not involving light) you had direct observance of POR. For light, there was a preferred frame only because of the presence of aether, just like the presence of air. Oh, and they even explored ideas of aether wind, and the the frame picked out be aether could vary from one place to another (due to motion of the aether).

Okay... Good point. That would be another version of Galilean Relativity.

Once you throw out the idea of the Lorentzian model, you have to say something along the lines of what is preserved.

If not an observer dependent speed of light, is it

(1) an infinite speed of light, as Galileo (I think) believed, or

(2) is it a source-dependent speed of light?

(3) A constant speed of light embedded in luminiferous Aether.

So those would be three different models consistent with Galilean Relativity, right?

 

[PAllen]

Okay... Good point. That would be another version of Galilean Relativity.

Once you throw out the idea of the Lorentzian model, you have to say something along the lines of what is preserved.

If not an observer dependent speed of light, is it

(1) an infinite speed of light, as Galileo (I think) believed, or

(2) is it a source-dependent speed of light?

(3) A constant speed of light embedded in luminiferous Aether.

So those would be three different models consistent with Galilean Relativity, right?

Yup, those would be the variants with significant historical basis.

For the purposes talking about observability of length contraction, I therefore made explicit I was talking about a frame where light speed happened to be c and was isotropic, but that object's geometry was unaffected by motion. Thus (3), in the aether frame. (1) would be trivial, (2) would be more complex as would (3) in any frame other than the aether frame. In any case, what I proposed is the clearest way to contrast what you would see without length contraction.

 

[Ken G]

Yes, I think the natural "Galilean relativity" circa the Michelson-Morley experiment would just be what they expected when they did that experiment-- an infinite top speed, but a speed of light of c in the aether frame. That's what PAllen and I have been talking about, assuming our camera is in the aether frame where Maxwell's equations hold good. Remember, in 1900 they thought they were looking for the aether frame, it was quite a shock to essentially everyone that Maxwell's equations worked in all frames.

 

[JDoolin]

Yay!

I finally had a morning to work on my animations!

Changes:
(1) I made up an algorithm to give me a set of points in a circle.
(2) I switched to using Mathematica's "Sphere" instead of "Point" which renders a lot better. However, the sphere's here don't undergo the same transformationAnimation 1: A circle moving along within the plane of the fence at 0.866c

Animation 2: (Shown Above) The red circle is in the plane of the fence, the purple is in the plane normal to the direction of propagation. The blue is the flat plane. The perspective really plays tricks with you here, because it never really looks to the eye like the red plane is in the plane of the fence. It's much more clear in animation 1.Animation 3: Here is the animation without length contraction of the original figure. This is what you would expect to see in a Luminiferous Aether theory, where you were in the "Aether Frame" and the ball was passing through at 0.866c.

I think what's happening in animation 2, is that the figure is flattened in the direction

 

[PAllen]

Fantastic stuff, JDoolin!

 

[Ken G]

That's really cool, it totally shows that things look even weirder without length contraction. How ironic-- length contraction is invisible only if you are not expecting it!

 

[JDoolin]

Glad you liked those.

The sphere is obviously a special case. In ordinary rotation, a featureless smooth sphere looks identical regardless of how it is rotated. You could say, then, that "rotation of a smooth featureless sphere is 'INVISIBLE'" But the sphere is unique in that geometric quality. You couldn't say "rotation is invisible" in general. If there are any markings on the sphere, then the rotation can be detected by watching the markings. And the more the object differs from a perfect smooth sphere, the more obvious rotation would be.

I think, for Lorentz Contraction an analogous description could be made. If you have a spherical shape, it will appear to remain spherical, though the markings on that sphere may appear to be Lorentz Contracted, the overall shape of the sphere will remain spherical.

http://www.spoonfedrelativity.com/web_images/ViewFollowing14.gif (Animation 2, above)Since I had red blue and purple orthogonal circles all sharing a common center, I wondered what would happen if I spread out these circles so that they formed the walls of a cube, and produced two further animations.

http://www.spoonfedrelativity.com/web_images/ViewFollowing17.gif (6-sides)

and

http://www.spoonfedrelativity.com/web_images/ViewFollowing18.gif (3-sides)

I think these show that there is a noticeable distortion of shape for non-spherical objects.I also wanted to address Ken G's comment.

That's really cool, it totally shows that things look even weirder without length contraction. How ironic-- length contraction is invisible only if you are not expecting it!

I think it should also be noted that in this animation:

http://www.spoonfedrelativity.com/web_images/ViewFollowing13.gif (Animation 3, above)

... could happen in at least two different scenarios:
(1) A spherical shape passes by at 0.866c in a universe where the observer is stationary within a luminiferous ether.
(2) An oval shape (with length twice as great as its width and height) passes by at 0.866c in a Special Relativity universe (i.e. the real universe)

So if you have an oval shape, things would look exactly that weird. It's just that if you have a universe occupied almost wholly by perfectly spherical objects, (...which we do... such as stars and planets) they're not going to look as weird.

 

[JDoolin]

I had to ask, does it still work at 99% of the speed of light?

It looks like it does.
Sphere Animation at .99c
The spherical shape still looks spherical.

Cube Animation at .99c
The cube still doesn't look cubic.

 

[Ken G]

I think these show that there is a noticeable distortion of shape for non-spherical objects.

I think that might just be because the solid angle of the image is not small, so we are seeing the kinds of distortions that can happen around the edges of conformal mappings. To strictly hold to the idea that the effects are "invisible", the objects need to occupy only a small solid angle.

I think it should also be noted that in this animation:

http://www.spoonfedrelativity.com/web_images/ViewFollowing13.gif (Animation 3, above)

... could happen in at least two different scenarios:
(1) A spherical shape passes by at 0.866c in a universe where the observer is stationary within a luminiferous ether.
(2) An oval shape (with length twice as great as its width and height) passes by at 0.866c in a Special Relativity universe (i.e. the real universe)[/qute]

So if you have an oval shape, things would look exactly that weird. It's just that if you have a universe occupied almost wholly by perfectly spherical objects, (...which we do... such as stars and planets) they're not going to look as weird.

Yes, I think you have a good point there, which gibes with PAllen's "anti-boost" idea. If you don't know the shape you are supposed to be seeing, you can't tell if it has been anti-boosted (as in a Galilean universe) or if it is just seen from some angle it would be seen from in a comoving reference frame. What all this means is that there is never any way to tell if you are in a Lorentzian or Galilean universe simply by visual inspection of small objects moving at constant speeds, without knowing the intrinsic shapes of the obects you are looking at. And if you do know those intrinsic shapes, it is the Galilean universe that will show distortions, not the Lorentzian universe. I think that's a remarkable fact, though we can agree that calling it "invisibility" of length contraction isn't a great way to carry this point across.

Now of course the key question is, what is it about length contraction that cancels out time-of-flight distortions, to produce an undistorted image? Is there some reason our universe works like that?

 

[Mentz114]

Yay!

I finally had a morning to work on my animations!Animation 2: (Shown Above) The red circle is in the plane of the fence, the purple is in the plane normal to the direction of propagation. The blue is the flat plane. The perspective really plays tricks with you here, because it never really looks to the eye like the red plane is in the plane of the fence. It's much more clear in animation 1.Animation 3: Here is the animation without length contraction of the original figure. This is what you would expect to see in a Luminiferous Aether theory, where you were in the "Aether Frame" and the ball was passing through at 0.866c.

I think what's happening in animation 2, is that the figure is flattened in the direction

Terrific !

Surely one could set up an experiment to see if measuring a moving object results in a contracted reading ? Your sim predicts something photographable.

 

[JDoolin]

I think that might just be because the solid angle of the image is not small, so we are seeing the kinds of distortions that can happen around the edges of conformal mappings. To strictly hold to the idea that the effects are "invisible", the objects need to occupy only a small solid angle.

Here's a stack three balls high, moving by at .866c

http://www.spoonfedrelativity.com/web_images/ViewFollowing21.gif

More noticeable distortion in the vertical line, but the balls still appear spherical.

 

[Ken G]

Here's a stack three balls high, moving by at .866c

http://www.spoonfedrelativity.com/web_images/ViewFollowing21.gif

More noticeable distortion in the vertical line, but the balls still appear spherical.

Yes, I think that shows pretty clearly the distortion is only on larger angular scales. In a Galilean universe, distortion would be apparent on all scales.

 

[PAllen]

Terrific !

Surely one could set up an experiment to see if measuring a moving object results in a contracted reading ? Your sim predicts something photographable.

The basic issue is getting macroscopic objects at significant fraction of c relative to observer. So far as I know, this basic thing has not been achieved. Even at speeds of the fastest meteorite ever detected, you would not be able to see any of the Galilean distortion, should it exist.

 

[JDoolin]

http://www.spoonfedrelativity.com/web_images/ViewFollowing25.gif
Now the whole figure is smaller than your fist held at arm's length, and the vertical distortion is hardly noticeable.

Move in closer (about halfway) and you can see noticeable vertical distortion.
http://www.spoonfedrelativity.com/web_images/ViewFollowing24.gif

Halve the distance again, and the vertical distortion is even more pronounced.
http://www.spoonfedrelativity.com/web_images/ViewFollowing23.gif

Here is the same, but the figure only shows the balls along the fence-row.
http://www.spoonfedrelativity.com/web_images/ViewFollowing22.gifFinally, here is the "plus sign" configuration back to the longest distance again.
http://www.spoonfedrelativity.com/web_images/ViewFollowing26.gif
You can see that the vertical distortion isn't noticeable, but if you realize that all the objects lie in the plane of the fence, then the Lorentz Contraction "distortion' is very noticeable, even though the vertical distortion is gone.

 

[Mentz114]

The basic issue is getting macroscopic objects at significant fraction of c relative to observer. So far as I know, this basic thing has not been achieved. Even at speeds of the fastest meteorite ever detected, you would not be able to see any of the Galilean distortion, should it exist.

Very true. My friend at CERN said there was no chance of me borrowing the LHC one weekend when they weren't using it.

 

[PAllen]

Actually I was curious about maximum speed observed or produced near Earth for a macroscopic object. So far as I can find, no such object has been observed or created with relative speed greater than .0003 c, way way too slow for visual effects from finite light speed.

That is actually a good thing. It is worth remembering that to get a 1 gram object up to .866c would require giving it a kinetic energy greater than the atomic bomb that blew up Nagasaki (21 kilotons of TNT worth of KE per gram is required for .866c). To get a baseball going at .866 c would require giving it the KE of a large H-bomb (3 megatons of TNT).