The other train appears to move backward because you’re on a faster train. It creates relative motion that tricks your brain. Think of it like passing a slow car – it seems to reverse.
When you’re sitting on a train, your train feels like your own little world that’s standing still. But really, your train is moving forward at a certain speed.
Now, when another train passes going the same direction, it’s also moving forward. But if your train is moving faster, the other train looks like it’s falling behind you. Your brain sees the difference in speeds and interprets this as the other train going backward, compared to you.
It’s like if you’re jogging past a walker. Even though you’re both moving forward, to you it looks like you’re leaving the walker behind.
Here’s why the illusion is so convincing:
As the other train goes by, you first see the front cars, then the middle cars, and then finally the back cars. This sequence tricks your brain because it’s exactly how something would look if it was actually moving backward!
So in reality, both trains are still traveling forward at their own speeds. The illusion comes from your perspective on the faster train. An observer on the platform would just see two trains moving forward at different speeds.
