Lorentz transformation for an approaching observer

[sukmeov]

Homework Statement

Let O and O' be observers both moving along the x-axis at constant velocity. Assume O and O' meet at the origin. Suppose also that O' moves towards O with relative velocity v. O reference frame has coordinates (x,t) and O' reference frame has coordinates (x',t') What is the Lorentz transformation for the two coordinate frames. ( I only care about the relationship between the time coordinates)

Relevant Equations

Lorentz transform for positive velocity: t' = Lorentz factor * (1-v/c)t

I think this should be t'= Lorentz factor* (1+v/c)t, but that doesn't make sense to me.

 

[etotheipi]

Hello Mr inappropriate nickname,

Does this help: https://en.wikipedia.org/wiki/Lorentz_transformation

 

[sukmeov]

Many thanks. So there is no sign change in the formula, even if v is negative? Also it's not a nickname it's my surname.

 

[etotheipi]

Many thanks. So there is no sign change in the formula, even if v is negative?

You're right that $v$ can indeed be positive or negative; that constitutes the sign change. There was actually a thread about this a short while ago: https://www.physicsforums.com/threads/lorentz-boost-speed-or-velocity.988183/

Also it's not a nickname it's my surname.

I don't know what to say... goodbye PF it's been nice knowing you all

 

[sukmeov]

Very helpful. Thank you.

Ukan Sukmeov.

 

[etotheipi]

I KNEW it!