What? Really? This is a fact and not just an illusion. Astronauts have been known to gain over 2 inches of height in space which returns back to normal once they are back to earth. You know why? All because of zero gravity.

We all know that our height is determined by our vertebrae (or spine). Now this vertebrae is in the form of a coiled spring.
The gravity on Earth pulls this spring downwards. Have you ever tried pushing down on the spring with your finger? The spring is compressed, but when the force is released, the spring stretches out. The same thing happens to the spine, it elongates by up to three percent while humans travel in space. There is lesser gravity pushing down on the vertebrae in space than Earth, so they can stretch out – up to 3 inches. Keeping this fact in mind astronaut suits are designed to be longer.

A similar thing happens when your are sleeping at night.  All of us look taller while lying down because the force of gravity is not pushing us down.

Hmm! So when someone asks for your height which one should you tell? On Earth or the one in space. Think about it.