I'm currently going through my courses notes for relativity. We looked at Einsteins two postulates and then said that time must therefore dilate due to constant speed of light. That I understand, however I'm still confused about the Lorentz's transformations. My notes start with a basic form of the transformations and then goes on to calculate the constants. However the basic forms they setup I don't understand where they come from. It first sets up x'=γ(x-ut). Why does distance HAVE to change? I understand why either one of distance or time has to change to compensate for constant speed of light being constant, but why both? Furthermore why is it of that form? My notes just say that these transformations can be calculated solely from Einsteins two postulates, so how does it get this form. It also says that time must therefore be t'=a*x+b*t. Where did this form come from, and why does it depend upon both x and t? If I go really far away from someone, will we have difference in time?(adsbygoogle = window.adsbygoogle || []).push({});

I'm just confused as to where these basic forms come from, its implied straight from Einsteins two postulates but doesn't state explicitly why. I've been looking at this all day using alot of different text books. I keep flashing between understanding it and not but I ultimately have no idea how the above two forms could be found so simply it doesn't have to be stated. If you think you might help then please do, thanks :)

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Lorentz transformations derivation

**Physics Forums | Science Articles, Homework Help, Discussion**