Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Steve Colby on 10/09/2009 14:30:03

Title: Does eyesight change at speed due to Lorentz contraction of the eyeball?
Post by: Steve Colby on 10/09/2009 14:30:03

Steve Colby  asked the Naked Scientists:
   
I have recently discovered the Naked Scientists podcasts (http://www.thenakedscientists.com/HTML/podcasts/) and am enjoying them immensely.  I have a couple of questions for you.
 
Question 1:  Is it true that we get faster as we get older?
 
Consider that, in the Special Theory of Relativity, as objects move faster, their length decreases in proportion to the Lorentz Factor.  Also, the relativistic mass of a moving object is increased over the rest mass by the same factor.  Now I have observed that, as I get older, I am getting shorter and heavier.  I conclude therefore that I must be getting faster.  :)
 
 
Now for a legitimate question:  Given the invariant speed of light and the Lorentz length contraction, would a reader who has 20-20 vision at rest need reading glasses when riding the TGV at relativistic speeds, due to Lorentz contraction of the eyeball?
 
I look forward to hearing your answer on a future podcast (http://www.thenakedscientists.com/HTML/podcasts/) (during a slow science week, no doubt)
 

Best Regards,
 
R. Steve Colby, PhD
Raleigh, North Carolina, USA

What do you think?

Title: Does eyesight change at speed due to Lorentz contraction of the eyeball?
Post by: Bored chemist on 10/09/2009 19:41:48

If the reader needed glasses when they were moving fast then they could use this fact to tell if they were moving fast, or stationary. But reletivity says that's impossible so the answer is no.
Their eyes only shrink from the point of view of someone else (who isn't moving).

Title: Does eyesight change at speed due to Lorentz contraction of the eyeball?
Post by: LeeE on 11/09/2009 16:02:24

Just a small point perhaps, but the TGV doesn't travel at relativistic speeds  [;)]

Title: Does eyesight change at speed due to Lorentz contraction of the eyeball?
Post by: Kupac on 14/09/2009 04:14:39

@Bored chemist
Would he then need reading glasses from the point of view of the "stationary" observer? :)