deletions | additions       diff --git a/4-Dimensions.tex b/4-Dimensions.tex  index bf31ef0..3e24c7d 100644  --- a/4-Dimensions.tex  +++ b/4-Dimensions.tex 
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But this shows that \begin{equation}  \textbf{E}={_t\textbf{r}_1} \times {_t\textbf{r}_2} \\  \textbf{B}=\bigg(  \begin{vmatrix} t_1 & x_1 \\ t_2 & x_2 \end{vmatrix}  ,  \begin{vmatrix} t_1 & y_1 \\ t_2 & y_2 \end{vmatrix}  ,  \begin{vmatrix} t_1 & z_1 \\ t_2 & z_2 \end{vmatrix}  \bigg)  \end{equation}  That is the electric field corresponds to the corss cross  product of the spatial comonents of the four vectors. vectors, and that the magnetic field is the determinants of spatial components with time.