What keeps a train on the tracks going round a bend?

Do you think it is the flanges on the wheels? Sorry, not right! Ok, it must be a differential. Sorry, not right again! But there must be a differential because the outside wheel travels further going round the bend. Sorry, there is no differential! What’s more the axle between the two wheels is solid. So what is going on?

Let the late Richard Feynman explain. Among the many awards he received he won the Nobel Prize for Physics in 1965. Feynman’s ability to explain something is amazing. Click here. Enjoy. Also click here for another explanation.