Fundamental forces at heart of everything in universe
Tim Philp, For the Expositor
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Published on: July 4, 2019 | Last Updated: July 4, 2019 12:47 PM EDT
Electromagnetic force is responsible for most things that happen in the universe, including radio. jakkapan21 / Getty Images/iStockphoto
Physicists are always trying to reduce the universe to its simplest parts. This has been an incredibly successful approach for physics – indeed, for science itself. By breaking complex problems and mechanisms into simpler pieces, we can thoroughly understand these simple parts and thus gain an understanding of the entire process.
For instance, to understand how a car works, you can look at the individual parts and see how each functions and relates to the entire vehicle. A car is relatively simple technology when it is compared to the universe. But physicists have, with great success, taken the same reductionist approach to the universe.
For example, we have learned that the matter in the universe comprises simpler components called atoms which, in turn, are composed of simpler parts called protons, neutrons, and electrons. Protons and neutrons are composed of objects called quarks. The electron, on the other hand, appears to be a fundamental particle with no internal workings at all.
In this "quantum" world, particles can behave like waves, and waves can behave like particles. They can be in one place and then appear in another because we can never know the position and momentum of a particle to more than a certain level of precision. It is a place that is more akin to The Twilight Zone than any place that makes rational sense. That does not mean we cannot understand the quantum world, but we can only understand it using statistics, not precise calculation.
The interaction of all these particles are governed by four forces that appear to be fundamental. These forces are the strong and weak nuclear forces that only act within the radius of an atom, and the electromagnetic and gravitational forces that appear to act over billions of light years.
The strong force is what holds together the atoms. The nucleus of atoms are positively charged and these protons repel each other with tremendous force. The strong force keeps the atoms from flying apart at tremendous speed. Without this force, atoms could not exist.
The weak nuclear force only acts within about one per cent of the radius of the atom. It is responsible for, among other things, radioactive decay. Without this force, the sun would not be able to transform matter into energy and all life on Earth, indeed the universe, would not exist.
The fundamental force that we are most familiar with is the electromagnetic force. It is a powerful force that is responsible for most things that happen. It is responsible for the existence of light that allows us to see. It is responsible for radio and television. Indeed, all the electronic devices that we have ever constructed rely on the electromagnetic force to operate. It is responsible for chemistry and it is also the reason why you don't fall through the floor.
The last fundamental force is gravity. While the other forces are quite powerful, gravity is the weakest of all. If you have ever fallen, gravity may appear to be a powerful force. But, when you consider that it takes the entire mass of the Earth to pull you to the ground and you can easily overcome the force of gravity with your muscles, you begin to see just how weak the force of gravity is.
Gravity can become powerful, but, only by putting enough matter together in one place, can you even notice the effects of gravity. Every object with mass attracts every other object with mass, but that attraction is so incredibly small for ordinary amounts of matter that it is almost completely undetectable. To put this into perspective, gravity is 42 orders of magnitude smaller than the electromagnetic force. That is a tremendous difference which we do not, at present, understand.
Laws of physics and fundamental forces may appear to be distant and esoteric subjects, but they are at the heart of everything we can see in the universe.
Tim Philp has enjoyed science since he was old enough to read. Having worked in technical fields all his life, he shares his love of science with readers weekly. He can be reached by e-mail at: tphilp@bfree.on.ca or via snail mail c/o The Expositor.