String Theory: A Quick Summary
Atoms. Protons. Electrons. Quarks. And now strings?
Yeah. It’s weird, but weird is what’s solved our biggest conundrums in physics. From special relativity to the probabilistic nature of matter, they were all ideas which defied all logic and reason, and received massive backlash as they went against all scientific norms. And like these theories, string theory could also be another stroke of weird genius which solves the biggest problems in physics today.
Why General Relativity is Wrong
Despite the scientific revolution Einstein started with his theories, even the world’s most renowned scientist can be wrong at times. You see, whilst general relativity provided an excellent model for how gravity works at large scales, it remains as exactly that. Just a model, a toy, a specifically curated diagram which only explains gravity at large scales. Zoom in, and you’ll find that general relativity predicts gravity to create black holes on the Planck scale.
So general relativity says that we’re all made of black holes. That’s already an absurd claim, but there’s more places where gravity breaks down.
Whilst quantum mechanics is able to describe three of the fundamental forces, it just can’t do the same with gravity. For example, classical electromagnetism is quantised into quantum electrodynamics, where the new quantum field rests on the smooth, flat field of spacetime. Quantise gravitational fields though, and you end up with a disaster. Gravitational fields are spacetime, they don’t lie on top of it like how electron fields do. So quantising gravity means you have to quantise spacetime itself, leaving us with no undisturbed, clean coordinate system upon which we can ground our theory.
So where does string theory come in?
Right here. String theory adds a new fundamental material to our system, it claims that quarks themselves are made of vibrating strings (open or closed) that are 10^-33 metres small. The modes and frequency of these open or closed strings is what gives us both force transmitters, and particles.
The introduction of strings, rather than point like particles means that energy in gravitational interactions is smeared over the area of the string, instead of being concentrated on an infinitely small point, meaning no more black holes. Not only does it naturally explain quantum gravity though, it also promises to include quantum theory. This is why string theory has garnered so much attention; it predicts theories that took physicists decades of confusion to solve.
So … why hasn’t there been a string theory revolution yet?
Unfortunately, the apparent simplicity and promise of string theory seems to be a fallacy. In order to make the maths work, one needs 9 spatial dimensions (which are apparently coiled up very small, which is why we can’t see them), one temporal dimension (we have that at least), and ‘one extra dimension for M-theory’, whatever that means. Basically, to actually do the maths of string theory, we need to have a very specific set of parameters such as extra dimensions, which makes the whole process complicated. The maths starts to turn ugly when you actually try to apply it, meaning that we don’t even have a single equation for string theory yet.
Was string theory just a distraction then? Maybe, maybe not, we’ll only know when we’re able to carry out actual experimental evidence. Up until then, it does show promise to solve our biggest problems, but that doesn’t have to mean it’s true. After all, it is quite complicated for a ‘fundamental theory’.
