A question about special relativity

[BadgerBadger92]

I have a question about special relativity, hopefully this isn’t a silly question.

If there are two things, one moving near the speed of light verses the ground, due to time dilation, wouldn’t the traveling body look like everything in it is moving slower according to the frame of reference on earth? Would it appear to be traveling slowly too?

Sorry if I am wording this question oddly, I’m not sure how else to word it

 

[A.T.]

one moving near the speed of light

Would it appear to be traveling slowly too?

It's either "moving near the speed of light" or "traveling slowly" relative to the Earth. It can't be both.

 

[BadgerBadger92]

Thanks for your reply. I do have one more question though

I get now that it will still look like it’s traveling very fast, but what about things in the moving frame of reference? Would they appear to move slowly?

Sorry if my question isn’t clear

 

[Ibix]

Thanks for your reply. I do have one more question though

I get now that it will still look like it’s traveling very fast, but what about things in the moving frame of reference? Would they appear to move slowly?

Sorry if my question isn’t clear

It depends what you mean by "slowly".

If you mean "if I, at rest on the ground, were to take a series of close-up pictures of the fast moving object 1s apart (using a series of stationary cameras spaced along the object's route) and somebody was sitting on the object waving would the images show that his arm hadn't moved much between shots?" then yes, he would be moving slowly in that sense. However, there could be tens of thousands of miles between successive cameras, so in that sense he is moving very quickly.

Avoiding this kind of confusion of language is why we tend to talk about clock rates (or, better, just use maths). Take the man's waving arm as an approximate clock, swinging backwards and forwards about once per second in his rest frame. You would measure the repeat time as longer (possibly much longer) than 1s, while still acknowledging that his hand is moving at a significant fraction of the speed of light.