- #1
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The terms "length contraction" and "time dilation"
Is there a particular reason why we say length contraction but time dilation? A Lorentz transformation [tex]\Lambda=\gamma\begin{pmatrix}1 & -v\\ -v & 1\end{pmatrix}[/tex] takes [tex]\begin{pmatrix}1\\ 0\end{pmatrix}[/tex] to [tex]\gamma\begin{pmatrix}1\\ -v\end{pmatrix}[/tex], which dilates the time coordinate by a factor of [itex]\gamma[/itex], but the same [itex]\Lambda[/itex] also takes [tex]\begin{pmatrix}0\\ 1\end{pmatrix}[/tex] to [tex]\gamma\begin{pmatrix}-v\\ 1\end{pmatrix}[/tex], which dilates, not contracts, the position coordinate by a factor of [itex]\gamma[/itex]. Of course a dilation by k is a contraction by 1/k, but the terminology still sounds weird to me.
(The upper component of the 2x1 matrices is the time coordinate).
Is there a particular reason why we say length contraction but time dilation? A Lorentz transformation [tex]\Lambda=\gamma\begin{pmatrix}1 & -v\\ -v & 1\end{pmatrix}[/tex] takes [tex]\begin{pmatrix}1\\ 0\end{pmatrix}[/tex] to [tex]\gamma\begin{pmatrix}1\\ -v\end{pmatrix}[/tex], which dilates the time coordinate by a factor of [itex]\gamma[/itex], but the same [itex]\Lambda[/itex] also takes [tex]\begin{pmatrix}0\\ 1\end{pmatrix}[/tex] to [tex]\gamma\begin{pmatrix}-v\\ 1\end{pmatrix}[/tex], which dilates, not contracts, the position coordinate by a factor of [itex]\gamma[/itex]. Of course a dilation by k is a contraction by 1/k, but the terminology still sounds weird to me.
(The upper component of the 2x1 matrices is the time coordinate).