String Theory For Noobs!
Even though it still has much to prove, String Theory is one of the most interesting fields in modern theoretical physics. Not only does it try to establish what the entire world is made up of and give a fundamental structure of the entire universe, it also claims that there are many extra dimensions out there that we are unable to see with our bare eyes. It does sound pretty crazy, but here is a beginners look at some of the main aspects of the so-called “Theory of Everything”.
For a long time, scientists thought that atoms were the smallest building blocks in the universe, but it turned out we could go much deeper. Electrons, neutrons and protons together form atoms, but the nucleus (neutrons and protons) can be divided into smaller components called quarks. We get a little perspective of how small these quarks really are, when we know that the size ratio between a quark and an atom is the same as an apple to the earth. String theorists go even further, and claim that these quarks consist of smaller components called strings, and that these strings are what all particles and therefore the entire universe is made of. The size ratio of a string to a quark is like that of an atom to the earth. These strings are the essence of the theory, that tries to unify quantum mechanics (particles) and general relativity (space and time) to explain our existence. Pretty mind-boggling stuff to put it mildly.
Instead of the typical point image of a particle, supporters of string theory envision oscillating 1-dimensional strings. Just like a guitar string vibrates to make different sounds, these strings vibrate to create the different mass and energy in elementary particles. We further categorize these strings into open and closed, but also membranes (often called branes) that allow open strings to attach themselves on them. These branes are vital in understanding the relationship between gravity and quantum mechanics, and they have also thought us a lot about black holes.
String Theory predicts there are more ways to see space than just 3 dimensions
Instead of just the 3 dimensions that we humans can easily see (back-forth, up-down, left-right) plus the time dimension, the only way for string theory to mathematically work is if there are several extra dimensions (10 + the time dimension). These dimensions are present in everyday life, but too small for us to see. Some claim that these extra dimensions don’t necessarily have to be small, and that one membrane could make up an entire universe. That could mean that the Big Bang was caused when a membrane (universe) collided with another membrane (parallel universe) and later expanded. I know, pretty trippy!
There is a lot of criticism against string theory because of the vague answers it gives us and since it is almost impossible to prove. It is a very new theory though, which is constantly being changed and improved. There are some “footprints” of string theory in tests we could do now, but as our technology improves, it will be very interesting to see what answers places like the Large Hadron Collider in Geneva, Switzerland can give us. Some scientists like Stephen Hawking and Michio Kaku see M-theory, which is based on string theory, as a possible new and improved “Theory of Everything”, even though Hawking has later implied that he thinks we will never get to the bottom of the universe’s mysteries. It’s not many years ago since we thought atoms were the smallest possible units in the universe, and it is possible that we haven’t even scratched the surface when it comes to theoretical physics. However it turns out, wrong or right, string theory is very fascinating and it will help us on the way to find out more about the mysteries of the universe!
It is easy to get confused while reading about it, but if you want to learn a little more about bosonic strings, black holes, supersymmetry, the Big Bang and the rest of the things that will make your brain hurt, then superstringtheory.com is a great place to start. Enjoy!
The Large Hadron Collider in Switzerland may give us some interesting answers in the future