Sunday Science: String Theory

​So, how confident are you that the universe we live in is made up of teeny, tiny particles?
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Pretty confident?

Sorry, you’re wrong. Under String Theory, the fundamental constituents of our universe are not particles — they’re strings.

The particles we perceive are actually vibrations in the loops of a string. These strings could be a closed loop or an open loop, like a skipping rope. Each particle has its own shape and frequency.
One of my favourite descriptions of String Theory says: “the different elementary particles we see — the electron, the photon, the quarks, and so on — may all be the same entity: an elementary string, just singing different notes.”

But these strings are so small that our best instruments cannot tell that they aren’t point-like particles.

Point-like particles are easy to visualise. They’re the veritable Lego building blocks that make up our world.

Under String Theory, here’s what the same “particles” may look like. They’re strings looped and vibrating in different ways.

​So, what’s wrong with particles?

Nothing. You were probably taught that protons, neutrons, electrons and other subatomic particles create all the matter in the universe. Scientists have come up with theories such as general relativity, special relativity and quantum mechanics using such particles as a baseline.

The problem is that when you try to describe how these particles move and interact with each other — there are a number of conflicts.
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Originally, String Theory was trying to resolve these conflicts. But it has developed into something much more ambitious.

​What’s that?

String Theory could describe the nature of the universe at the most fundamental level.

That’s a pretty big topic to cover in one post, but two major implications are around forces and the beginning of the universe.

There are four forces in the universe binding everything together: the strong and weak (keeping things together in a nucleus), electromagnetic (essentially the “opposites attract” force for electricity and magnetism) and gravity.

The Theory of Everything would describe all four forces in one unified theory.

Previous attempts at writing a Theory of Everything failed when trying to incorporate gravity.
String Theory embraces gravity.
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String Theory might also be able to explain why the early universe expanding in the way it did.
BUT (and it’s a big but) String Theory requires up to seven extra dimensions to work. It also led to the concept of “super-symmetry” — and that would double the number of elementary particles in the universe.

​So, String Theory doesn’t work?

It does work because it’s a theory. It has also spawned a lot of other theories that give us new approaches to understanding our universe.

But we need experimental proof for String Theory.

And this is the crux of the problem for String Theory. It’s so difficult to test experimentally that some scientists claim it is essentially useless.

Yet, it’s given us a heap of other theories that could explain our universe at it’s most fundamental level.

​Watch this (potentially ten-dimensional) space.

Extra reading

If you want to find out more about how String Theory could lead to a “Theory of Everything”, this article from Futurism is great. The Perimeter Institute also gives a more in-depth explanation of String Theory and its implications.
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​And, if you’ve got 20 minutes to spare, this TED Talk covering String Theory is fantastic:

​​What is Sunday Science?

Hello. I’m the freelance writer who gets tech. I have two degrees in Physics and, during my studies, I became increasingly frustrated with the complicated language used to describe some outstanding scientific principles. Language should aid our understanding — in science, it often feels like a barrier.
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So, I want to simplify these science sayings and this blog series “Sunday Science” gives a quick, no-nonsense definition of the complex-sounding scientific terms you often hear, but may not completely understand. 

If there’s a scientific term or topic you’d like me to tackle in my next post, fire an email to [email protected] or leave a comment below. If you want to sign up to our weekly newsletter, click here.