# what is reality?

I had a discussion on #linux yesterday about what my own beliefs about physics, the universe, and reality are. This post will hopefully clarify it.

In short, I said that I believe that the sum total of all things is zero – that, in effect, the universe is not “real”.

While that sounds implausible (after all, you are “real”, as is everything you see and touch), I’d urge that you continue reading.

One of the most basic laws this universe seems to obey is that “symmetry rules” – there is the law of Conservation Of Energy, the law of Conservation Of Angular Momentum, and Newton’s classic “every action has an equal but opposite reaction”.

In other words, it is impossible to change the sum state of the universe – you can change the order of it, but you will never add new energy, or destroy it.

Taking that a little further, you can extrapolate that the sum energy of the universe at its beginning must be exactly the same at its end.

But how can that be? We obviously exist, so there must be a sum greater than 0, right?

Well… no.

If you were to take the mathematical sum “**x** + **-x** = 0″, you can easily see that it is possible for two objects to exist (**x** and **-x**) even though the sum total of the equations is zero.

I explained this to someone, who then half-jokingly suggested that every piece of matter must be balanced by anti-matter, and every piece of positive energy must be balanced by an equal amount of negative energy.

This summoned up images of whole anti-worlds, where anti-Kaes lived their lives backwards. Preposterous…

The sum “**x** + **-x** = 0″ can also be written as “**x** + **y** + **z** = 0″, where one or more of those variables has a negative value. The balance must be maintained, but the symmetry does not need to be blatant.

I think that’s an over-simplification of it, though. I think the truth is more fundamental than thinking about energy or matter.

How can matter or energy pop into existance?

Here’s the bit that sounds like science fiction, but I think actually fits quite well with modern physics. The idea of virtual particles is that it is possible for a particle and an anti-particle to pop into existance without needing external energy to cause it. In fact, this happens all the time.

Usually, though, the particles exist for only a very short time before they annihilate each other. This is remarkably similar to the maths analogy. In the formula “**x** + **-x** = 0″, the “particles” **x** and **-x** can be considered to be real, as they are distinct. The analogy is continued when you consider that bringing the two particles close enough to each other will cancel them out, allowing the formula “0 = 0”.

So, the difference between existance and non-existance, is just a matter of distance between particles and their opposite values.

I won’t pretend to understand what can possibly cause the two opposites to drift apart enough that they are considered “real”, but this tiny idea is a solution to the puzzle of how something can possibly come out of nothing.