>>13032516You are not understanding
>>13030707The speed which the cube enters the orange portal relative to the orange portal, is equal to the speed at which the cube exits the blue portal relative to the blue portal. For every slither of cube entering one portal, and equal amount of cube must exit the other portal.
Lets say you are on earth moving at 0m/s.
The ISS is moving at 7600m/s
You pass a cube through the stationary portal on earth at 10m/s, it exits the portal on the ISS at 7610m/s, the people on the ISS see it moving at 10ms/s (7610 - 7600)
cube_speed1 - portal1_speed = cube_speed2 - portal2_speed
10 - 0 = 7610 - 7600
In the case of
>>13030707You have the cube stationary, with the portal moving at 10ms/s
The other portal is stationary with the cube emerging at 10m/s
0 - (-10) = 10 - 0
If you inverted it and had the cube moving instead of the portal it would be
10 - 0 = 10 - 0
Portal moving one way, or cube moving the other way is the same
