A Quick Summary of the Universe

A short guide to physics and the mysteries of our universe, for those of you that don’t have much time.

Having an understanding of physics is good for many reasons. Not only does it inform us about our home in the Solar System and in the grander universe, but it is the foundation for something we all use: technology. It is what spurred both the industrial and electric revolutions, bringing to life modern society as we know it. It allows you to access the internet, watch your favorite shows, and have important imaging done when you’re at the hospital. In the future, technology will allow us to do so much that most of what today qualifies as science fiction — think moving objects without touching them, having invisibility, and curing aging — will become a reality. Our counterparts of the future will appear divine compared to what we can achieve today. And, because of exponential growth in technology, all of this could happen within 100 years.

Here I’ve attempted to lay a quick foundation for physics and what it can tell us about our universe.

Brief History of Physics

There are four main forces in the universe. In order from strongest to weakest, they are: strong nuclear, weak nuclear, electromagnetic, and gravity.


At the age of 23, Isaac Newton created calculus at the rate at which one learns calculus in class. He also invented the reflecting telescope which he was using to track a comet at the time. He also, of course, gave us the concept of gravity. This was our first step to unlocking the secrets of our immense and mysterious universe.

As a quick reminder, Newton’s Laws are as follows:

  1. An object in motion will stay in motion or an object at rest will stay at rest unless acted upon by an outside force.

2. Force= mass(acceleration)

3. For every action there is an equal and opposite reaction.

These first laws of science gave rise to the industrial revolution and thus, the modern age was ushered in. However, there were a couple of other important players as well.

“A staggered waterfall in motion flowing through a mossy rock mountain in Holland Park” by www.headsmartmedia.com. It is gravity which allows this water to continue flowing in beautiful curtains.


The electric revolution occurred in large part because of a man who’d never even had a formal education. Michael Faraday demonstrated properties of electricity during his public lectures. He would walk into steel cages and electrify them, showing that steel created a barrier and that, as long as you didn’t touch the barrier yourself, you would be safe from the electric currents. His law is about how voltages of electricity can be created from a magnetic environment. A moving wire in a magnetic field will create an electrical current by having its electrons pushed.

If a moving magnet creates an electric field, then the inverse is also true. A moving electric field will result in a magnetic field. They are one and the same. A single unified forced.

James Maxwell, during the Civil War, calculated the velocity for a wave which oscillated between magnetic and electric fields. A wave in which magnetic fields created electric fields which created magnetic fields which created electric fields. The velocity of this wave turned out to be the exact velocity of light. In fact, this was light itself!

Maxwell’s Equations

Strong and Weak Nuclear Forces

Both these forces work at the atomic level, if for exactly opposing reasons. Strong forces are some of the strongest in all the universe and they are what bind the component particles of the nuclei — that is, the protons and neutrons. The weak force deals with the radioactive decay of subatomic particles. It is also what kick starts the nuclear fusion that keeps the sun burning. When an element decays through the weak force, it changes into a completely different element. Carbon, with 6 protons and 8 neutrons, decays into Nitrogen, with 7 protons and 7 neutrons. In this case, the weak force has acted on a neutron and changed it into a proton.

Einstein’s Most Famous Formula

Your weight is not fixed. The faster you move, the heavier you become. Mass is energy. This is the idea behind Einstein’s most famous formula: e=mc², or, the energy of motion= mass(speed of light)².

This formula, along with our knowledge of the weak nuclear force, helped us understand what went on within the sun.

We are lucky enough that our sun is currently at a point in its life when it is incredibly stable, consistently converting hydrogen into helium. However, in a billion years this will no longer be the case. The sun will at that point become hot enough to boil our oceans and, in a few more billion years after that, it will turn into a red giant so huge that it will consume us altogether. There is a chance, however small, that Earth will escape the heat of the sun and will survive beyond the sun’s red dwarf stage. But if it does survive, it will eventually be out orbiting near the asteroid belt, now circling the new white dwarf sun.

Needless to say, the chances that our species will survive long enough to see our star’s beautiful death are incredibly small.

String Theory

This is the theory that attempts to marry Einstein’s theory of relativity to quantum mechanics. That is, it attempts to be an explantation for the smallest particles in our universe all the way up to the larger bodies, those of planets and stars. It works by assuming that particles are strings and that vibrating those strings in a different way will convert them to a different particle. Thus, it would bring together all four forces which we just spoke about.

While Einstein’s equations break down at the center of a black hole and at the time before the Big Bang, String Theory suggests that we are not only one universe, but one universe that’s part of a multiverse. And if that’s true, we might in the future be able to create wormholes to these other universes. Even creating time machines is feasible, though they would require an enormous amount of energy.

Mystery of Dark Energy and Dark Matter

While physics books in circulation today will tell you that most of the universe is made up of atoms, that’s not true. Most of the universe is dark. Dark energy makes up 68% of the universe, dark matter makes up 27% and so called “normal matter” — you and I and everything we see around us — is less than 5%.

We know dark energy and dark matter exist because we observe how they affect our universe. Dark matter, for instance, does not interact with any other basic force in the universe except for gravity. It has six times more gravity than regular matter and, without it, galaxies wouldn’t exist as matter’s gravity isn’t enough to keep stars together in galactic clusters. We know dark matter exists, too, because light will bend around it.

Photo by Alexander Andrews

Dark energy is causing the universe to expand at a rate much faster than what we would have expected. In fact, it was believed that gravity would eventually slow and stop the expansion of the universe. What we know of dark energy is only that it exists where there is empty space and that it continues to get stronger as time goes by.

There is a Nobel prize waiting for anyone who can tell us what dark matter and dark energy are, or even why we exist at all. No, really. None of this is supposed to exist. We are here only because there was an imbalance of matter to antimatter by a respective ratio of one billion and one to one billion. What caused this imbalance? Nobody knows.

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