Question: what is the strongest gravitational pull can a human withstand and does it change depending on the direction of the pull

Charles Laing answered on 17 Jun 2016:

Hi felixdacat,

This depends on a number of factors, such as if the person is lying or standing and whether or not they are squeezing the muscles in their legs. Let me explain…

A person standing up and feeling the G-force to their legs can withstand much less than someone lying down and feeling it through their chest. This is important to know and one of the reasons astronauts are in a sitting/lying position when they are launched and return to Earth.

With G-force blood pools in the legs and this take blood away from the brain. If the body cannot get blood back to the brain fast enough the person will faint.

Ways to get blood back to the brain include squeezing the legs muscles and this is why fighter pilots wear anti-G suits that do just this.

With protection humans can withstand high G-levels (up to 13G) but without they are very vulnerable. Standing up (without protection) a human can not withstand 3G for much longer than 10 minutes.

Charlie 😀🚀