The Thought of the Week

Dramatic sunset, orange clouds.

The Universe

From Popular Science Magazine

An atom consists of protons, neutrons, electrons. But matter consists of a whole lot more than that. A little less than one-third of the universe—around 31 percent—consists of matter. Astrophysicists have long believed that something other than tangible stuff makes up the majority of our reality.

Thinkers throughout history had vague ideas that existence could be divided into basic components. But something that resembles the modern idea of the atom is generally credited to British chemist John Dalton, a Quaker. In 1808, he proposed that indivisible particles made up matter. Different base substances—the elements—arose from atoms with different sizes, masses, and properties. Today we know of 118 physical elements.

Not all matter is alike. Very little of it, in fact, forms the objects we can see or touch. The universe is replete with examples of matter that are far stranger. When we think of “matter,” we might picture the objects we see or their basic building block: the atom. But, our conception of the atom has evolved over years.

One of the hallmarks of Albert Einstein’s theory of relativity is that mass and energy are connected. All mass is concentrated energy. Einstein’s famous E=mc² equation indicates that there is a lot of energy in matter. Take, for example, a nickel which weighs 5 grams. Multiply by the speed of light, then multiply that answer by the speed of light again—that’s how many ergs of “nuclear” energy is contained in a nickel. (Don’t even worry about ergs, grin).

Since the early 20th Century, physicists have known that tinier building blocks lurk within atoms. And it’s not simple. By the middle of the century, physicists realized that protons and neutrons are actually combinations of even tinier particles, called quarks. To be precise, protons and neutrons both contain three quarks each: a configuration type that physicists call baryons.

In our everyday world, matter typically exists in one of four states: solid, liquid, gas, and plasma. However it is not simple. Under extreme conditions, it can take on a menagerie of more exotic forms. At high enough pressures, materials can become supercritical fluids, simultaneously liquid and gas. At low enough temperatures, multiple atoms coalesce together, and behave as one, acting in all sorts of odd quantum ways.

Such exotic states are not limited to the laboratory. Just look at neutron stars: Their cores aren’t quite massive enough to collapse into black holes when they become supernovas in their old age. Instead, as their cores crumple, intense forces rip apart their atomic nuclei and crush the rubble together. The result is essentially a giant ball of neutrons—and protons that absorb electrons, becoming neutrons in the process—and it’s very, very dense. A single spoonful of a neutron star would weigh a billion tons!

Physicists study neutron stars to learn about these objects—and about what happened at the beginning of the universe. The matter we see around us did not always exist; it formed in the aftermath of the big bang. Before atoms formed, protons and neutrons swam alone through the universe. Even earlier, before there were protons and neutrons, everything was a super-heated quark slurry.

Before that there was “THE WORD/AWARENESS”.