Having a bad day? Hel­mut Smits suggests a simple yet ingenious solution to brighten your drive.

If you suddenly decided to see a rainbow it would be really problematic – not only you’d have to wait for the rain to come, but there should also be a sun shining through the falling raindrops. Luckily, now there is this cool rainbow creating book! It’s a flip-book, but rather than seeing animation, it creates a 3D rainbow in your hand. Just be sure not to flip it too much, as others might think you are sending some kind of secret rainbow signals to them.