It’s a little known fact (outside of the scientific community) that radio waves travel faster than sound waves. Which sounds illogical and frankly unbelievable.

However, there’s a simple way of proving this theory. Simple, that is, if you live in London, or plan to visit London anytime soon.

Big Ben, the giant clock tower attached to the Houses of Parliament, chimes every hour, and the BBC has a microphone hooked up close to the bell. This is played out on radio twice a day.

So, as this video shows, if you stand within earshot of Big Ben with a radio held up to your ear, you’ll find out whether radio waves or sound waves travel faster.