Dave Morris asked:
Hello naked scientists, I love your show. My name is David, I'm from Vancouver Canada
What does escape velocity refer to exactly. It seems that if I have a tall enough ladder, i could climb up at any velocity and escape earths gravitation field, kind of like the space elevator concept. I would never need to reach that escape velocity. please clarify.
thanks naked scientists, keep up the great work
We put this question to Andrew Pontzen...
Escape velocity is the velocity which must be given to an object at the Earth's surface to enable it to make a free flight trajectory that would escape from the Earth's gravitational field. If you are continually applying more force, as with fuel burn on a rocket or muscular contraction on a stepladder, it is quite possible to escape from Earth's gravity without ever getting to a velocity anywhere near that.