Graduate Computing the Thomas Precession: Help from PFers Needed!

Click For Summary
The discussion focuses on deriving the expression for Thomas precession from the textbook "Classical Mechanics" by Goldstein/Poole/Safko. The user has successfully computed the matrix L'' but encounters an issue when approximating it, resulting in γ^2 instead of γ in the calculations. A suggestion is made that, to first order in β, γ^2 can be approximated as γ, which is considered a valid but informal approach. The user seeks clarification on this approximation and any potential mistakes in their derivation. The conversation emphasizes the nuances of mathematical approximations in classical mechanics.
Coelum
Messages
97
Reaction score
32
TL;DR
While computing the transformation matrix associated to Thomas precession - as described by Goldstein (7.3) - I cannot reproduce a step in the derivation.
Dear PFer's,
I am reproducing the steps to derive the expression for the Thomas precession, as described in Goldstein/Poole/Safko "Classical Mechanics". Hereafter an excerpt from the book describing the step I am currently working on.
Screenshot from 2022-08-29 17-35-19.png

I have been able to compute the matrix L'' (eqn. 7.18). However, computing its approximation as described above (eqn 7.19 and γ' = 1), I get a different result:

Screenshot from 2022-08-29 17-38-37.png
.
As you can see, I get γ^2 rather than γ in the third row. I cannot find my mistake and I cannot see how γ can approximate γ^2. Any hint?
Thanks a lot in advance,

Francesco
 
Physics news on Phys.org
Just an idea: to first order in β, γ^2 ≈ γ since γ is quadratic in β. Sort of dirty trick, but formally correct?
 
MOVING CLOCKS In this section, we show that clocks moving at high speeds run slowly. We construct a clock, called a light clock, using a stick of proper lenght ##L_0##, and two mirrors. The two mirrors face each other, and a pulse of light bounces back and forth betweem them. Each time the light pulse strikes one of the mirrors, say the lower mirror, the clock is said to tick. Between successive ticks the light pulse travels a distance ##2L_0## in the proper reference of frame of the clock...

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 9 ·
Replies
9
Views
4K