Question

What is the physics behind balancing these forks?
https://www.youtube.com/watch?v=dTKQAMkGXPI

Answer 1

It just all about the " Center Of Mass" .

Answer 2

for instance, consider the basketball. the way you rotate it on fingers- you first find the exact point where you can rotate it. and you try to balance the ball at that point. that point is call center of mass- where the whole body mass is concentrated.
So in our Fork problem, we first find the Center of mass- which is near the intersection of the two fork.
then at this point, it can be rotated. so its simple science.