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
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
'Science knows no country, because knowledge belongs to humanity, and is the torch which illuminates the world. '