# Improper Lorentz transformation

Gavroy
hey,

I heard about improper Lorentz transformations, but I did not really understand what they are. I just know that their determinant is -1, but what does this physically mean?

Can somebody explain this to me?

the_house
hey,

I heard about improper Lorentz transformations, but I did not really understand what they are. I just know that their determinant is -1, but what does this physically mean?

Can somebody explain this to me?

Basically, an improper Lorentz transformation involves a spatial reflection, so the determinant of the transformation matrix has determinant -1. See
http://en.wikipedia.org/wiki/Lorentz_group#Connected_components