Recent content by martyf

L1 and L2 are two generical lorents tranformation. I must demostrate that their product is also a lorentz transormation. Can I demostrate : g_\alpha_\beta x^\alpha x^\beta = g_\mu_\nu \Lambda^\mu{}_\alpha \Lambda^\nu{}_\beta x^\alpha x^\beta with \Lambda =L3= L1 L2 ?

Ah , I understood why I was confused! In the prof's notes, first there is the definition of timelike 4 vector as the vector such that c^2t^2 - x^2 - y^2 - z^2 > 0 But then he introduces the ict convention. So when I calculate the norm^2 of the 4-velocity it's =-1, so I thought it should...

Homework Statement A relativistic particle with mass at rest M0 and velocity v hits another particle with mass at rest M1. the collision is perfectly inelastic. How can I calculate the mass at rest of the new particles after the collision? Homework Equations The Attempt at a...

:) very funny, however my prof is able to find a textbook that was written after 1936. In fact I don't find a textbook that uses the ict convention!But I had to study on the prof's notes. The professors should be renovate their lessons, I should learn from them!

complex number : i^2=-1

(\frac{v_{x}}{c\sqrt{1-\beta^{2}}} , \frac{v_{y}}{c\sqrt{1-\beta^{2}}} , \frac{v_{z}}{c\sqrt{1-\beta^{2}}} , \frac{i}{\sqrt{1-\beta^{2}}} )

is it right?

I wanted to say : Definition of "timelike" 4-velocity :4-velocity of a PARTICLE THAT travels slower than light (ordinary particles). I wrote in a rush. (if you're referring to this)

Definition of "timelike" : travel slower than light WHY a 4-velocity that travel slower than light satisfies t² - x² - y² - z² = 1 ?! BTW, I'm trying to understand the meaning of time-like 4-velocity, I have not written any equation, any text of an exercise

why?

Ok, so if I have a given 4-velocity how can I show in terms of mathematics that it is time-like ?

How can I show that a 4-velocity is always time-like?

But |4-velocity|^2 = -1 . So why is it time-lke?

...if : x^{2}_{0} - r ^{2}= (\Lambda ^{0}_{\nu} x_{0})^{2} -( \Lambda ^{\mu}_{\nu} r_{\mu})^{2}

Ok, thanks!