[Cboldt]

-- You are just confusing Mass with Size. The first is a measure of density, the other a measure of distance. --

Mass v. density, what has more mass, a ton of feathers or a ton of lead?

Mass is emphatically not a measure of density. It is a measure of mass. Density is (usually) a measure of mass per unit volume, but can also refer to obstinate or ignorant thinkers.

[SunTzuWu]

Mass v. density, what has more mass, a ton of feathers or a ton of lead?

Mass and weight are not the same thing.

[SunTzuWu]

Just caught that you said density, not weight...