This screen saver is based on John Horton Conway's fascinating game of Life in which a pattern of cells "evolves" from generation to generation based on a few simple rules of life.
In the field of mathematical research, Life is considered to be an example of "cellular automation."
To learn more about Life, here are a couple of good websites:
Notice that a square on a chess board (such as the white cell below) has 8 neighboring squares touching it:
| 1 | 2 | 3 | ||
| 4 | 5 | |||
| 6 | 7 | 8 | ||
In the game of Life, each cell (each square on an infinite chess board) is either alive or dead. A white cell is alive, and an empty cell is dead.
You start by entering an initial pattern of live cells, such as this one:
Then the program scans every cell in order to find out how many living neighbors it has. The numbers below indicate how many living neighbors each cell has:
| 0 | 0 | 0 | 0 | 0 |
| 1 | 2 | 3 | 2 | 1 |
| 1 | 1 | 2 | 1 | 1 |
| 1 | 2 | 3 | 2 | 1 |
| 0 | 0 | 0 | 0 | 0 |
In the next "generation," some of the living (white) cells will be dead, and other living (white) cells will still be alive, and some of the dead (empty) cells will become alive (i.e. be born) based on the following rules:
So if any cell has 3 live neighbors, or if a cell is alive and has 2 live neighbors, then it will be alive (white) in the next generation, else it will be dead (empty).
Based on these rules, here's how the cells in the above pattern will be affected. Some cells will be Born, and some cells will Die, and some cells will Stay alive:
| B | ||||
| D | S | D | ||
| B | ||||
So the initial pattern of cells will evolve into this pattern in the second generation:
In the third generation, the pattern will evolve so that it looks like the initial pattern again (can you see why?):
Since this pattern flip-flops back and forth in succeeding generations, it is called a "blinker."
For lots of fascinating patterns which have been discovered in the game of life, see the websites in the Overview section (above).
As the screen saver (Life.scr) is running, press 'a' at any time. This will permanently turn off the screen saver and allow you to enter patterns to see what they do. You are now in ADD mode.
In ADD mode, the following keys are active (CapsLock must be off):
I: moves the blue cursor up.
K: moves the blue cursor down.
J: moves the blue cursor left.
L: moves the blue cursor right.
U: turns a cell on (white).
O: turns a cell off (empty).
R: runs Life (press A to return to ADD mode).
Consider visiting some of my other websites!
You'll find a Christian ministry with dozens and dozens of articles and answers to many questions that I have received over the years (please feel free to send me your questions and prayer requests!); plus a collection of some of the best self-working card tricks around (no sleight-of-hand required!); plus instructions and pictures which show you how to tie dozens of the most useful rope knots; plus a bunch of amazing/funny/fascinating/interesting videos from around the Web which are all clean and family-friendly; plus lots of reviews of numerous fun and educational (and free!) computer games that you can download; plus a huge collection of cool science tricks and other fun stuff to try (using things around the house), and more!
For a complete list, go to http://www.Layhands.com/DavesWebsites.htm.
Dave Root
Send e-mail to: dave@Layhands.com