Leaving aside the obvious political humor potential
in your question, you did ask about the densest
THING, not the densest material, on Earth. That
would probably be a neutron. While many subatomic
particles are considered points, and thus could be
thought of as having an infinite density, the
neutron has a measurable size (about 10-15 m in
diameter) as well as mass (about 1.7 x 10-27 kg).
Those numbers result in a density of about 1018 kg/m3.
That value matches the estimated density of neutron stars, the densest objects known in the
Universe. (A black hole's mass is concentrated in an immeasurable singularity). A single
neutron
is a smaller (MUCH smaller!) version of a neutron
star, and the Earth is loaded with neutrons.
Answered by: Paul Walorski, B.A. Physics, Part-time Physics Instructor
'One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day.'