# The universe, planck time and the game of life

1. Sep 3, 2011

### thedragonbook

Is the universe similar to Conways game of life? Let me elaborate. For us, a second is the unit of time and its a pretty short unit of time. But then at the atomic scale, a second is a pretty big unit of time. Everything we do is in the order of seconds or maybe milliseconds. But so much happens in that time at the atomic scale. It got me thinking about the smallest unit of time. If there is a such thing as the smallest unit of time then the universe works at that level. So such a unit of time does exist and its called the Planck time (http://en.wikipedia.org/wiki/Planck_time). If no unit smaller than that exists, then nothing happens in the universe in a time shorter than the Planck time. Does that mean the universe moves from one state to another in that unit of time? In other words, time as we know it actually results from the universe moving from one state to another? The game of life when simulated also moves from one state to another. There are rules governing these movements. Is the universe also something similar? Although far more complicated.

2. Sep 3, 2011

### rbj

i dunno the answer for you, but the generic term for "Game of Life" is "cellular automa". one notion that i had (and i would bet many other people have had) but it doesn't seem to get any physicists excited is this:

if you modify the definitions of Planck units just slightly so that:

$$c = 1$$
$$\hbar = 1$$
$$4 \pi G = 1$$
$$\epsilon_0 = 1$$

then the simplest and most basic differential equations of interaction in free space lose their scaling coefficients (the coefficients become 1). when these differential equations are discretized in the most simplest way possible, that is using Euler's forward method, then the interaction between cells (that are roughly cubes with this modified Planck length on the side) will be expressed with simple algebraic equations with no scaling coefficients. there is no notion of Nature pulling some scaling constant out of her butt to scale something like flux density to turn it into field strength. so flux density would be the very same thing as field strength.

there is or was a USENET newsgroup called sci.physics.discrete where they discuss such things.

3. Sep 3, 2011

Staff Emeritus
There is no evidence that the Planck time is "the smallest unit of time" and no evidence that the universe is a cellular automaton.

4. Sep 3, 2011

### Fyzix

I think you will find Gerard 't Hooft's (Nobel prize winner of 1999) work very interesting.
It deals with exactly what you are talking about.

While what Vanadium 50 says about there eing no evidence for the universe being a cellular automaton, there is neither anything ruling it out at all.
And the current problems we face in physics force us to consider it as a very serious possibility.

5. Sep 4, 2011

### granpa

cellular automa + entanglement

6. Sep 5, 2011

### jewbinson

There are articles on the web (search on google) about discrete spacetime.

It is a very interesting theory of physics, and some of the consequences (theoretically) on quantum mechanics are quite nice. I like the idea