You are almost entirely empty space!

I know that sounds crazy and if you think about the details too much it tends to shake your sense of reality. The last 120 years of physics has radically changed our perception of reality many, many times.

Atom History

The study of the microscopic world took off during the early 1900’s with the introduction of Quantum Mechanics.

Atoms were thought to be fundamental and then the electron was discovered in 1897. In 1919, the nucleus was discovered to be discrete positive charges of matter. In 1932, the neutron was discovered. The current model we are familiar with consists of a proton/neutron nucleus surrounded by an electron cloud .

Protons and neutrons however are not fundamental particles. They are composed of quarks and the force holding them together called gluons. Each proton and neutron is composed of 3 quarks bound with gluons, which carry the strong nuclear force.

Atom Composition

The average atom is about 10-8 centimeters in size. This means 108 atoms or 100 billion atoms would stretch a centimeter, about the size of your fingernail. A human hair is about a million atoms across.

The nucleus is 100,000 times smaller or 10-15 centimeters. The electron is about 2,000 times smaller than the proton. The nucleus is the core and contains 99.9% of the atom’s mass with the infinitesimal electron making up the rest.

To give more perspective, if the atom nucleus were expanded to the size of a marble the atom’s edge would be a football field away. As you can see most of the atom is empty space, called the electron cloud. These microscopically tiny pieces of matter make up everything we can see.


The human body has roughly 7*1027 atoms. This is 7 followed by 27 zeros, 7,000,000,000,000,000,000,000,000,000. Even with that unfathomably high number if you removed all the empty space you would be reduced to a particle of dust. The dust particle would be very heavy though as it maintains your weight.

The entire human race could be compressed into a volume the size of a marble weighing over 730 billion pounds.

Global Population Weight

The global human weight was detailed in the BMC Public Health Journal using census figures from 2005. The researchers found a combined weight of 316 million tons. The actual number will be higher as only people over the age of 15 were counted.

iCraveScience used the following method for the infographic and article posted.

316 million tons equates to 632 billion pounds. 632 billion divided by 6.5 billion people gives you 97.23 pounds per person. This is low because the researchers did not figure in children.

In 2017 the population is about a billion higher than 2005 at 7.5 billion people. If you assume the same 97.23 pounds per person you now have a combined weight of 730 billion pounds, 365 million tons.

You Haven’t Really Touched Anything

As if that wasn’t enough to make your head spin. You have never really touched anything.

Electromagnetic force between electrons gives us the illusion of a solid surface. When you “touch” something you are actually feeling the electromagnetic force of your electrons pushing on their electrons. You never touch the “mass” of the atom.

Technically, if you’re sitting while reading this you are slightly hovering over the chair. We don’t notice any of this because we blissfully live in the macroscopic world.

Source: Jefferson Lab, Symmetry



Comments are closed.