time dilation
https://gyazo.com/138a7ef4246a3488b9b7f0089055dfeb
boostの向きは関係ないので、βは出てこなくて、γ(中身にβ^2がある)だけ出てくる
lorentz contraction
discussing time intervals for pairs of events
without paying attention to the spatial separation is simply bad reasoning in
problems where Special Relativistic effects are important.
ΔxとΔtをplotすると、物事がとても分かりやすくなるな
xもtも変化していく