Take a look at this website’s banner. Do you see a background of two digits: 0 and 1? They’re the foundation (called a binary system) for all computer digital circuits that have just two states: Off (0) and On (1). Computers perform their functions by reading patterns of bits — the 0s and 1s.
Working with just 4 bits, we can represent the numbers 0 to 15. The 0s and 1s are read from right to left, and with each move to the left, the value of bits increases by a factor of 2. Let me show you what I mean:
Numeric value of bit: 8 4 2 1
Number represented: 0 0 0 0 = Zero (0+0+0+0=0)
0 0 0 1 = One (1+0+0+0=1)
0 0 1 0 = Two (0+2+0+0=2)
0 0 1 1 = Three (1+2+0+0=3)
0 1 0 0 = Four (0+0+4+0=4)
0 1 0 1 = Five (1+0+4 +0= 5)
0 1 1 0 = Six (0+2+4+0=6)
0 1 1 1 = Seven (1+2+4+0=7)
1 0 0 0 = Eight (0+0+0+8=8)
1 0 0 1 = Nine (1+0+0+8=9)
1 0 1 0 = Ten (0+2+0+8=10)
You can add and subtract with the binary system, too. (It’s different from the base 10, or decimal, mathematics we were all taught.) For example:
1100 (12 decimal) 0111 (7 decimal)
– 0111 (7 decimal) + 0101 (5 decimal)
0101 (5 decimal) 1100 (12 decimal)
Some recent supercomputer designs are experimenting with using light instead of electronic circuits. Since light can have many discreet intensities, a single light channel can represent many different numbers.
Plus, light does not generate as much heat as digital circuits so light-based computers could run much cooler that current designs. Some laboratories are also experimenting with chemical-based designs.
(Come on…admit it. This is fun stuff to learn!)