Why Does Ink Not Spill Out Of A Ballpoint Pen?

19 December 2017, 16:24

Picture: N/A

Mystery Hour Question

When you’re writing using a ballpoint pen, why doesn’t the ink leak onto the paper?

Angela, Epping

Answer ** Definitive **

Name: Dean, Wigan

Qualification: A-level physics

Answer: It’s to do with atmospheric pressure. There is pressure pushing into the pen which keeps the ink in place. Because it is completely airtight at the top, there’s no pressure form the other side to push it out.