2
$\begingroup$

This is probably a newbie question (but I guess is what I am right now) but I can't understand de difference between Galilean Boost and Galilean Translation.

I thought a boost was something like an S' frame of reference with constant velocity in relation to an S frame of reference. Mathematically:

$$ x' = x - vt; y' = y; z' = z; t' = t$$

so a boost would be an uniform motion between these to frame of reference and a translation would be an S'' frame of reference "fixed" but the origins dislocated in relation with S.

The thing is: I found in pdf files (and wikipedia) that these equations of a galilean transformation is actually a translation. Is that right?

Improve this question
$\endgroup$

1 Answer 1

Reset to default
4
$\begingroup$

A boost refers to a coordinate transformation associated with a change in velocity and is mathematically equivalent to a translation of the coordinates by $vt$ where $v$ is the velocity and $t$ is time. This type of translation is not constant in time. On the other hand, a translation is a constant shift in coordinates.

Improve this answer
$\endgroup$
4
  • $\begingroup$ So the exemple I made is a boost while something like x' = x - cst; .... t' = t - cst2 is a trasnlation? $\endgroup$
    – evmiz
    Commented May 23, 2020 at 20:21
  • $\begingroup$ Are $cst$ and $cst2$ constants? $\endgroup$
    – Feynman's Cat
    Commented May 24, 2020 at 17:57
  • $\begingroup$ Yes they are!!! $\endgroup$
    – evmiz
    Commented May 25, 2020 at 21:07
  • $\begingroup$ In that case yes, the case in you comment above is a translation. $\endgroup$
    – Feynman's Cat
    Commented May 26, 2020 at 1:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.