[central_va]

I heard a prof say to me if you could hold the earth in your hand it would feel smoother than a que ball. I assuming he meant earth sans water.

[TXnMA]

The diameter of the Earth is 7,918 miles, and the maximum relief (top of Mt. Everest to the bottom of the deepest ocean) is 12.3 miles.

on a 2" cue ball that would be a total surface roughness of 3 mils (.003") -- or about the diameter of a human hair or the thickness of a sheet of paper.

Since Everest and the Challenger deep near Guam are widely separated, your fingers probably would not be able to detect the surface roughness at all.

So -- I agree with your prof:

"The earth's surface IS almost as smooth as a cue ball!"

(To make it visible on maps, Google Earth, the above APOD image, etc, we use relief exaggeration and strong shadowing -- otherwise,the relief would, essentially, be invisible at computer screen scale.

[LibWhacker]

I assuming he meant earth sans water.

You should've told him, "Correction, professor, it would feel like a wet cue ball. With gravity. And an atmosphere. It'd feel weird!" :-)