Liam.lah

First post here, Hi all. I had thought about this some years ago, but visiting here, this seemed like the place to posit it. Many of you will be familiar, in relativity with the thought experiment of the light bulb in the moving train carriage. The light bulb is in the centre of the carriage, and when turned on, depending on the observer, the light may reach the back of the carriage before the first, or both at the same time, whether you are looking in from an embankment, or sitting inside the carriage respectively. Say we were to take this further... Inside the carriage, on either side are small light sensitive switches, both of which are connected to a board with two LEDs on it, if the light sensor at the back of the carriage is hit first, the red light will come on, if it hits the front light sensor, or both at the same time, the green LED will flash on. If we work through this again, the man sitting on the embankment will observe the light hitting the sensor at the back first, and should therefore expect to see a red LED turn on. The man inside the carriage should see both light sensor activated simultaneously and should expect to see the green LED turn on. This doesn't seem possible at all in the real world. Have I missed some important part of this thought experiment?