how can time slow down at the speed of light
Time dilation
v ( t ) = g t + v 0 γ 0 1 + ( g t + v 0 γ 0 ) 2 c 2 . ( \ displaystyle v ( t ) = ( \ frac ( gt + v_ ( 0 ) \ gamma _ ( 0 ) ) ( \ sqrt ( 1 + ( \ frac ( \ left ( gt + v_ ( 0 ) \ gamma _ ( 0 ) \ right ) ^ ( 2 ) ) ( c ^ ( 2 ) ) ) ) ) ) . )
v ( t ) = g t + v 0 γ 0 1 + ( g t + v 0 γ 0 ) 2 c 2 . ( \ displaystyle v ( t ) = ( \ frac ( gt + v_ ( 0 ) \ gamma _ ( 0 ) ) ( \ sqrt ( 1 + ( \ frac ( \ left ( gt + v_ ( 0 ) \ gamma _ ( 0 ) \ right ) ^ ( 2 ) ) ( c ^ ( 2 ) ) ) ) ) ) . )