Well, we could test it. Put lead into a funnel, suspend the funnel above a beaker, and wait for a drop. Assuming the scale is linear, you should only have to wa

Well, we could test it. Put lead into a funnel, suspend the funnel above a beaker, and wait for a drop. Assuming the scale is linear, you should only have to wait around 80 to 130 years based on pitch experiments: http://en.wikipedia.org/wiki/Pitch_drop_experiment http://en.wikipedia.org/wiki/Pitch_drop_experiment More seriously, there's possibly a viscosity at which gravity is no longer enough acceleration to overcome whatever mechanisms are holding the atoms together. If we assume that metallic lead does not exhibit any flow on Earth, then we can estimate this as being between 10^10 and 10^11P at g.