top of page

Brain- Dump on all my understanding of String Theory - 

Humanity's attempt to create the legendary unified field theory that pushed Einstein to the brink of destruction and eventually was left unfinished. 

Summary - the universe is not made up of a ton of point particles, but rather of a ton of tiny vibrating strings, all interconnected with each note in the strings correlating to a subatomic particle. 

I like this so much because it paints the interactions in the universe, both big and small, as a function of music. All the interactions in the world that we see are just a symphony of all those strings! 

Einstein called it "cosmic music resonating through space time" 

---------------------

There are two major theories that govern physics - general relativity and quantum theory 

But first, the foundations

Newtonian Physics - describes the theory of motion and gravitation 

These are especially noteworthy because they possess the first real explanation of symmetry, which will govern all of the physics theory from that Newton's time onward. Symmetry is this beautiful thing in physics, where equations can remain the same when we introduce the moving of variables or rotation of the entire system. 

Maxwell and Faraday work in Quantum Mechanics - The Unification of Magnetism and Electricity 

Maxwell discovered something extremely important - the duality of light. Faraday helped us understand the languages of forces and magnetic fields that govern our Earth. All the known forces of the universe are now expressed in the terms of fields that were first expressed by Faraday. 

... but there was a huge problem. Michio Kaku explains it best in his book The God Equation "Physicists at that time did not realize that the two great pillars of science, Newton's and Maxwell's equations, were actually incompatible. They contradicted each other." 

How? Well, on a moving body, higher-view level, Newtonian physics governed the world and it worked always, but Maxwell's equations would fail. But, once you take it down to a quantum level, Newtonian physics breaks down and Maxwell's equations take the stage. They are contradictory, and Einstein was about to blast that open. 

Einsteins two great theories 

(1) Theory of special relativity - Time slows down the fast you move 

The speed of light is measured using units like meters and seconds, the unit of time is meters per second squared. The speed of light, though, must be constant no matter how fast you are moving. So, if you are moving at the near speed of light, then time must slow down in order to keep the speed of light constant 

  • Side Note: You can actually try this on an airplane if you have a high-precision clock. Time will move slower on the plane than it does with the same clock on earth.

  • But, this does not apply to gravity and accelerated motions, it breaks when you get there

So, Einstein deep-dove into gravity and found that gravity does not actually pull, it pushes. The universe is warped my large masses like the sun so that the curvatures of space can pull the planets towards the sun. Gravity does not have a "centrifugal force" that pulls- space pushes. 

(2) Theory of General Relativity - Introduced gravity as the bending of space-time 

This was applied to all the bodies that were accelerating through space-time and dealt with gravity in a unified way. 

This picture does a good job of showing the warped space-time due to gravity

 

 

 

He tried tirelessly to unify these two theories of electromagnetism and gravity, but he failed. He had created two major theories of physics that were both true, but they contradicted each other. 

He went on to build up Quantum Theory, which further divided Newtonian physics from quantum physics. He was actually one of the harshest critics of it. 

String Theory is so promising because Gravity will show up at the quantum level, in a particle called the graviton, which shows up as the lowest vibrations on the strings. It combines the uncombinable into one unified theory where things no longer contradict each other. It is a beautiful form of physics. They are on a quest to find "supersymmetry" in order to make these connections possible. 

  • How can we test it you may ask? Well, we sorta need a particle accelerator that is the size of the galaxy to directly test this theory... so that's unfortunate. But many people are trying their best to prove small parts of it, and it is probably one of the greatest mysteries and excitements of modern day physcis. 

 

Spacetime_curvature.png
bottom of page