what is string theory in simple language?
Answers
String theory in simple words? Here you go, my man-
Note: I tried to break it down to a first-grade level, but it turned out to be a bit long but bear with me :)
Let's look at some history first, okay?
Once upon a time, we thought that an atom was the smallest, indivisible and most fundamental particle in nature, but boy were we wrong! It turned that an atom is further divided into protons, electrons and neutrons. Later, we realised that there are further smaller particles still, and we called them as "quarks" (interesting fact: there are 6 types of quarks in nature!)
So now we ask ourselves, what is smaller than a quark? In other words, what are quarks made up of? The answer is, NO ONE KNOWS! But, many people came up with many interesting theories, and the most popular, enticing and yet the most controversial amongst them was the "String Theory"!
String Theory suggests that it does get smaller. The tiniest, most fundamental building blocks of matter and the universe are "tiny strings" or "little filaments of energy that vibrate and dance around" (roughly speaking).
But what makes ST so elegant, you ask? Well according to it, every fundamental sub atomic particle is made by the vibrating strings. To sum it in one line: ST described many different elementary particles as different modes of vibrations of the string. In simple words, if a string vibrates this way, then an electron is made. If it vibrates another way, then a quark is made. If it vibrates in another way, then a neutrino pops out... so on and so on. Hope it makes sense till now xD
Now, I hope you know that there are 4 dimensions- 3 dimensions and 1 temporal dimension (AKA time).
It turns out that the math behind String Theory tells us that our Universe has 10 dimensions instead of just the 4 that we know!
To also add one more thing that is very important-
The thing scientists are most interested about concerning ST is less of anything I mentioned above but instead something called "Quantum Gravity"
Einstein's Theory of General Relativity is extremely accurate and has been one of the most useful tools for understanding the universe around us. But it only answers problems for all the large scale things in the universe: Gravity, Black Holes, Time, Light etc...
The other side of the coin is Quantum Mechanics, which deals with all of the smallest things in the universe: Atoms, subatomic particles, a whole bunch of other behaviors and phenomena at very tiny scales, etc...
Relativity and Quantum Mechanics are the two most accurate and all-encompassing branches of science known to Man. However, they don't work together. Quantum Mechanics doesn't work with large scale stuff and Relativity doesn't work at Quantum levels. So you might think that one of them obviously has to be wrong then. But they aren't. Again, there is no problem scientists have ever thrown at these two fields that doesn't get solved, except when you try to marry the two together. Bringing the two together successfully is something called "Quantum Gravity".
If we can figure out Quantum Gravity, that will probably be the biggest discovery ever made in history. It would help us solve everything!!
It just so happens that if String Theory is true and we can figure it out, it would solve for this Quantum Gravity problem. String Theory is also known as "The Theory of Everything" for obvious reasons :D
A'ight, I hope this helps you!
Ciao ✌️