# Q: If we find a “Theory of Everything” will we be done?

Physicist: Not even close.

One could even make the argument that finding the theory of everything (often called “unified field theory”) is just the start of the real science.  The theory of everything (TOE) will finally tie together all of the fundamental forces, describe the behavior of every type of particle, and explain in fine detail how space and time behave in all cases.

We’ve seen unifying theories before (not the unifying theory) and they don’t generally answer questions on their own, but merely provide tools to explain things later on down the line.  For example; in several strokes of the quill Newton unified the “make apples fall” force with the “swing planets around” force under the umbrella of “universal gravitation”.

With universal gravitation (which says that gravitational force is: $F=\frac{GMm}{R^2}$, where M and m are the different masses involved) you can quickly explain why the Moon goes around the Earth, why all orbits are elliptical, and even why planets, Stars, Moons, and the Earth are round.

What you can’t explain, without buckets of math (and often as not: computer power), are things like phase lock, Lagrange points, and why many galaxies have spiral arms.  Even worse, you can’t actually solve problems involving 3 or more objects.  You can exactly write down how two objects will orbit each other, but as soon as there are three, the best you can do is approximation.  This is called the “three body problem”, and it’s likely to remain unsolvable forever.

The Trojan Asteroids float around in two of Jupiter's Lagrange points. This is completely described by the Law of Universal Gravitation, but it still took a lot of work to figure out what was going on. Image stolen from: http://www.dtm.ciw.edu/users/sheppard/satellites/trojan.html

So, a theory of everything, while it would be able to describe the details of how all forces and particles interact on all levels, would still only be a set of equations.  And having the equations is pretty different from having the solutions to those equations, and really different from understanding the implications of those solutions.

The equations required to describe the motion of a particle according to Quantum Electro Dynamics (an extremely accurate theory). Solving these equations is left as an exercise for the reader.

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### 3 Responses to Q: If we find a “Theory of Everything” will we be done?

1. Jason says:

Could you explain the Three Body Problem and more specifically why it is likely to be unsolved?

2. bigyan says:

personally i think theory of everything will not give an end to science because the other parts such as thermodynamics are left……

3. Normand Menard says:

Do you really want to find the theory of everything? Probably, but you want to find it under your own terms. You go around stating the impossible because you don’t understand a concept. Oh look, light is both a particle and a wave. Oh look, particles of matter come in and out of existence in the quantum world. Oh look, superfluids defy gravity. The universe is a very logical place. I have found the theory of everything and nobody wants to listens. Why? Because I am not one of you. Swallow your pride and try every once in a while to hear the rest of us. You may be surprised at what you hear. In the mean time I will try with all of my powers to publish my manuscript. Maybe someone out there is listening.