Images that make you laugh

[Elixir]

 

[ZiprHead]

 

[Loren Pechtel]

I don’t think that is how Lorentz contraction would work, sorry.

Because you're asking the wrong guy. Lorentz isn't the guy to be talking to, you need Mr. Doppler.

I said I agreed it would be red. Just not longer.

I'm saying Mr. Doppler is going to make it longer, also. The car gets just as stretched as the photons.

 

[Shadowy Man]

I said I agreed it would be red. Just not longer.

I'm saying Mr. Doppler is going to make it longer, also. The car gets just as stretched as the photons.

And I’m saying that’s incorrect physics. Can you give me any reference or physics theorem that supports your conjecture? Can you outline the transformation equations from the moving car frame to the observer’s frame that show that the length of the car will be expanded, in conflict with the standard Lorentz contraction result?

Basically, length contraction is not a Doppler effect it is a special relativistic effect from reference frame transformations.

 

[skepticalbip]

I said I agreed it would be red. Just not longer.

I'm saying Mr. Doppler is going to make it longer, also. The car gets just as stretched as the photons.

And I’m saying that’s incorrect physics. Can you give me any reference or physics theorem that supports your conjecture? Can you outline the transformation equations from the moving car frame to the observer’s frame that show that the length of the car will be expanded, in conflict with the standard Lorentz contraction result?

Basically, length contraction is not a Doppler effect it is a special relativistic effect from reference frame transformations.

We seem to have learned the same physics. I think you were right earlier in the thread. The cartoon was drawn by a cartoonist, not a physicist, so can be forgiven for being a bit confused about relativistic effects. But, at least, he understood the Doppler effect.

 

[ZiprHead]

 

[ZiprHead]

 

[Loren Pechtel]

I said I agreed it would be red. Just not longer.

I'm saying Mr. Doppler is going to make it longer, also. The car gets just as stretched as the photons.

And I’m saying that’s incorrect physics. Can you give me any reference or physics theorem that supports your conjecture? Can you outline the transformation equations from the moving car frame to the observer’s frame that show that the length of the car will be expanded, in conflict with the standard Lorentz contraction result?

Basically, length contraction is not a Doppler effect it is a special relativistic effect from reference frame transformations.

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

 

[bilby]

And I’m saying that’s incorrect physics. Can you give me any reference or physics theorem that supports your conjecture? Can you outline the transformation equations from the moving car frame to the observer’s frame that show that the length of the car will be expanded, in conflict with the standard Lorentz contraction result?

Basically, length contraction is not a Doppler effect it is a special relativistic effect from reference frame transformations.

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

Yeah, it's an exaggerated example of the Doppler effect.

Indeed one could say a cartoonishly exaggerated example.

 

[SLD]

 

[skepticalbip]

And I’m saying that’s incorrect physics. Can you give me any reference or physics theorem that supports your conjecture? Can you outline the transformation equations from the moving car frame to the observer’s frame that show that the length of the car will be expanded, in conflict with the standard Lorentz contraction result?

Basically, length contraction is not a Doppler effect it is a special relativistic effect from reference frame transformations.

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

That's confusing. Are you saying that, when the car is moving away, the light reflected from the front of the car travels slower than the light reflected from the rear?

The fact that it was drawn by a cartoonist makes more sense to me.

 

[Shadowy Man]

And I’m saying that’s incorrect physics. Can you give me any reference or physics theorem that supports your conjecture? Can you outline the transformation equations from the moving car frame to the observer’s frame that show that the length of the car will be expanded, in conflict with the standard Lorentz contraction result?

Basically, length contraction is not a Doppler effect it is a special relativistic effect from reference frame transformations.

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

Yes. I understand what you are saying. I’m just saying that it is wrong. That is not how relativistic physics works.

 

[none]

loren, not to be confused with lorentz is an expert in rears.

 

[SLD]

 

[bilby]

 

[Wiploc]

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

That's not physics. It's a cartoonist's misunderstanding of physics.

 

[bilby]

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

That's not physics. It's a cartoonist's misunderstanding of physics.

You guys are aware that an approaching blue car doesn't actually appear red after it passes you, in real life.

Aren't you?

 

[Elixir]

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

That's not physics. It's a cartoonist's misunderstanding of physics.

You guys are aware that an approaching blue car doesn't actually appear red after it passes you, in real life.

Aren't you?

It does if the front is painted blue and the back is painted red.

 

[Angry Floof]

You guys are aware that an approaching blue car doesn't actually appear red after it passes you, in real life.

Aren't you?

It does if the front is painted blue and the back is painted red.

What if it's Spiderman?

 

[Shadowy Man]

While there obviously would be a Lorentz contraction involved in the car that's not what the cartoon shows. That is purely the doppler effect at work--the light turns blue because it's compressed, the light turns red because it's stretched out. The image carried by the light is compressed/stretched the same as the photons themselves.

That's not physics. It's a cartoonist's misunderstanding of physics.

My OCD took over and I looked into this more. What one would “see” isn’t as simple as what one would “measure” through Lorentz contraction. The best paper I found on the subject is this one:

https://www.researchgate.net/profil...-moving-objects.pdf?origin=publication_detail

I haven’t tried to work through all the math, but if one were to look or photograph something moving smear the speed of light then in addition to the relativistic length contraction the finite speed of light would need to be taken into account.

The correct answer appears to be not exactly what I was thinking but also not what the simplistic cartoon implies either.

I guess you do learn something more every day.