You are here:

# Physics/Density

Question
I can't pin down the meaning of "density." Scientifically, density is a mass per unit volume of a substance. In plain English, density is heaviness or a thickness of a substance, relative to its size. Does mean that density is the measure of the viscosity of fluid and weight of solid? Could you please explain DENSITY in layman's term?

Density is not the same as viscosity.  Density is the amount of mass per unit volume.  That's it, nothing more.  If I have 1.2 kg in a cubic meter (air), that is its density.  If I have 1000 kg in a cubic meter (water), that is the density of that substance.  Its state of matter (solid, liquid, gas) doesn't matter, just the amount of mass in a specific volume.

Physics

Volunteer

#### Dr. Stephen O. Nelson

##### Expertise

I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.

##### Experience

I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Education/Credentials
Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.