Quantum Conundrum: How Do We Describe Our Universe?

The world as a whole has become more interested in particle physics since the development of the Large Hadron Collider and the recent discovery of the Higgs Boson (the particle that allows matter to have mass). Have you ever wondered how it all works?

source: nasa.gov

The Hadron Collider: basis for physics jokes everywhere.

Well, so have scientists. We have Newtonian Physics to explain the world around us (why the apples drops, why the moon orbits the Earth), but it does not explain how everything works at the subatomic level. Scientists are racing to find the ‘one theory to rule them all’ that will explain all physics – from the subatomic to the super-sized – in one fell swoop.

Dr Darren Grasso of the University of Western Australia is specialised in one particular theory called ‘Supersymmetry’. He has been fascinated by physics from a young age, since stumbling across an article in a Reader’s Digest about Einstein’s Theory of Relativity. In order to understand the complexities of Supersymmetric Theory, Dr. Grasso provides some background knowledge.

“So far we (humans) have discovered that, at the fundamental level, there are only four forces in nature. All the forces and interactions that we observe around us can be categorised as one of these four.”

These forces are; gravity, electromagnetism, strong nuclear force and weak nuclear force: Gravity holds us on the Earth and keeps our planet in orbit: Electromagnetism is the flow of electrons (negatively charged particles) which allow us to have electricity and magnetism: Strong nuclear force holds atoms together, while weak nuclear force is responsible for nuclear power. Though all these forces can be described accurately by different mathematical methods, when you try to bring them together the maths is inconsistent.

Each of these forces is mediated by particles called bosons. For example, the photon is the boson for electromagnetism; the mythical and as yet unobserved graviton is the boson for gravity. Matter particles (such as protons and neutrons) are called fermions.

The problem with the dominant theory that deals with quantum physics is that it can’t mathematically relate these two different kinds of particles. Supersymmetry seeks to describe them under the one theory. Basically, this theory gives every boson a fermion partner that is heavier (more massive) than normal, and every fermion a more massive boson partner. This creates a form of mathematical symmetry which, according to Dr. Grasso, allows the fermions and bosons to be treated “together in one neat mathematical package”. By ‘neat’, Dr. Grasso still means a horrifically complex and high level of mathematics that would turn most people’s brains to jelly; but I digress.

source:http://home.fnal.gov/~dhooper/supersymmetry.html

Here’s a visual explanation of something that is not at all visual. Enjoy.

The problem is; though the maths works nicely, this symmetry has yet to be found. “We go seeking these so-called ‘superpartners'”, says Dr Grasso, “these missing particles that should be present if supersymmetry is to be correct, and we can’t find them.”

So will evidence be found to support the theory of Supersymmetry? Not even the most intelligent physicist could tell you that. We look to organisations such as CERN to provide the answers and great minds to come up with more theories. Until then, we’ll just have to accept that the universe is a large and complicated place and that we’re lucky to be a part of it.

 

This is based upon an old assignment for my Science Communications major at the University of Western Australia.

A big thanks to Dr. Darren Grasso for helping me with the original article and allowing me to publish it here.

Image sourced from National Geographic.

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