Length of Moving Rod Relative to Frame S

[Snip3r]

Consider a rod of length 1 m and I are in frame S. Now i move at a velocity considerable to velocity of light wrt S. I take the rod with me (with its length parallel to motion). Now when i measure the length of the rod what will it be?i think it will still be 1 m for me but just wanted to confirm

 

[Doc Al]

Yes, since the rod remains at rest with respect to you, you'll measure it to have its rest length of 1 m.

 

[Qzit]

Hi Doc Al

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Yes, since the rod remains at rest with respect to you, you'll measure it to have its rest length of 1 m.

If you shoot light out from the rod in a perpendicular direction to the spaceship does it remain perpendicular when it hits the space ship? Does the distance matter?

 

[Doc Al]

If you shoot light out from the rod in a perpendicular direction to the spaceship does it remain perpendicular when it hits the space ship?

As seen by observers in the spaceship, the light path is perpendicular to the rod and the ship.

Does the distance matter?

What distance?

 

[Naty1]

If you shoot light out from the rod in a perpendicular direction to the spaceship does it remain perpendicular when it hits the space ship? Does the distance matter?

Doc Al...how did you ever interpret this??
Is the 'perpendicular' to the rod or the spaceship or both? What direction is the spaceship moving relative to the rod? Is it accelerating or moving with a constant velocity [fixed speed and direction]?

As seen by observers in the spaceship, the light path is perpendicular to the rod and the ship.

if the ship is moving at constant velocity parallel to the rod, right??

 

[HallsofIvy]

I can't speak for Doc Al, but I assumed that the "space ship" Qzit was referring to was the one on which the Snip3r was carrying the rod. Since they are all (Snip3r, the rod, and the spaceship) are all motionless with respect to each other, it really does not matter whether is arranged in the direction the spaceship is moving.

 

[Naty1]

The conclusion here seems different...is it?? Now I'm not sure...time to think a bit more!

https://www.physicsforums.com/showthread.php?t=562144

 

[Naty1]

HallsofIvy...oh good grief, no wonder...I did not think of that scenario...
Thank you!

That also answers my post #7...
and to all a good night!

But that thread relates...a different perspective...so I'll leave it...

 

[Doc Al]

I can't speak for Doc Al, but I assumed that the "space ship" Qzit was referring to was the one on which the Snip3r was carrying the rod.

Exactly. (If Qzit wants to discuss a different scenario, let him define it.)

 

[HallsofIvy]

The conclusion here seems different...is it?? Now I'm not sure...time to think a bit more!

https://www.physicsforums.com/showthread.php?t=562144

The discussion in that link doesn't seem to have anything to do with this topic. There, you are moving at high speed relative to a mirror and shining as light at it, here, you are measuring a stick you are carrying with you.

 

[Naty1]

The discussion in that link doesn't seem to have anything to do with this topic. There, you are moving at high speed relative to a mirror and shining as light at it, here, you are measuring a stick you are carrying with you.

i agree... that's why I said a "different perspective" above ...maybe I should have said different frames of reference or different situation.