Why does holding the TV aerial improve the picture?

Why is it that, when your mum asks you to move the TV aerial to a better position, the signal improves while you move it about and then degrades as soon as you let go? We find out what it is that makes the signal improve when you're holding a TV aerial. Plus, we ask how many offspring a sperm donor is likely to generate... Like this podcast? Please help us by supporting the Naked Scientists