I'm currently reading DF Lawden's book Introduction to Tensor

[jbowers9]

I'm currently reading DF Lawden's book Introduction to Tensor Calculus, Relativity and Cosmology. He coverss the idea of translation of inertial frames in the beginning and by using Minkowski's device for the time coordinate, x4 = ict, shows that inertial frames moving at velocity u = -ictan(alpha) in a Lorentz transformation are offset by -ictan(alpha). Doesn't this imply that there are singularities at certain points, ie tan90? thank you.

 

[dextercioby]

What's the definition of <alpha> ?

 

[jbowers9]

An imaginary angle length according to Lawden.

 

[dgOnPhys]

I'm currently reading DF Lawden's book Introduction to Tensor Calculus, Relativity and Cosmology. He coverss the idea of translation of inertial frames in the beginning and by using Minkowski's device for the time coordinate, x4 = ict, shows that inertial frames moving at velocity u = -ictan(alpha) in a Lorentz transformation are offset by -ictan(alpha). Doesn't this imply that there are singularities at certain points, ie tan90? thank you.

alpha is the so called rapidity (e.g. see http://en.wikipedia.org/wiki/Lorentz_transformation" )
The singularities are for v=c