Why is it that some people get a bit queasy when facing backwards on a train? Find out in this QotW! Plus, we ask how it's possible that someone is unable to see coloured lines on a whiteboard. Like this podcast? Please help us by <a href="https://www.thenakedscientists.com/donate">supporting the Naked Scientists</a>

Why might a person not be able to see coloured ink on a whiteboard?

Each week we set out to solve one of the world's weirdest, wackiest, funniest and funkiest scientific puzzles. And along with the answer there's a brand new question to think about for next time...