Have you ever wondered why do ballpoint pens have a little hole on the side? It turns out, there is a good reason for it.
For example, if you’re travelling on a plane and the air pressure changes, without this little hole your pen could ruin your trip by leaking in the pocket of your favorite jacket or literally exploding.
Even a common pen has a couple of secrets. So, here are 10 everyday things with unexpected functions.
Often we don’t realize how thoroughly thought through are the technologies behind some objects that we use on an every day basis.Do you ever wonder about the stranger, smaller things in life? Like how many ways you can really tie a tie, or which genius first thought to combine chocolate and milk?