Artificial life comes in three basic flavors.

1. 1.Soft: In ‘soft’ artificial life, the idea is to think about what constitutes life, to use software (or culture, in a pre-software age) to model and describe those processes that seem to be essential to life—reproduction, digestion, excretion, metabolism, and so on. John Conway’s game of life (see links to the left) is a classic example. Soft ‘a-life’ is a natural extension of work in artificial intelligence and game theory.
   
   

2. 2.Hard: In ‘hard’ artificial life, the goal is to reproduce and model essential features of life with hard, real-world materials such as steel, ceramic, plastic, integrated circuits and the like. Sony’s Asimo is a human-shaped example (also called an android), but the burgeoning field of robotics ranges from industrial robots to mechanical cockroaches, drone aircraft, or a child’s toy that is sitting in my basement right now, waiting to eat my whole family while I am asleep.
   
   

3. 3.Wet: In ‘wet’ artificial life, scientists attempt to reproduce life using organic compounds, and synthetic biological components (for real world examples, see “Cellular Automata”). Dr. Frankenstein decided to apply the newly-discovered electricity to pieces of corpses sewn together and miraculously discovered that he had created ‘wet’ life (previous fantasies of artificial life had always been based on a ‘hard’ simulation (marble for Pygmalion, gold and silver for Hephestus).
   
   

4. 4.A fourth category might combine some or all of the above, as in this disturbing video in which a cockroach (wet) is interfaced with a small vehicle (hard) via a computer interface (soft). Fortunately, we can control our cockroach overlords, too. When applied to humans, this combination of soft, wet and hard (insert joke here) is called ‘cyborg,’ short for ‘cybernetic organism.’ They’ve done equally creepy things with monkeys and other animals, too, but the time is coming soon when they’ll be able to do this for people who have lost legs or arms—they already do it for ears (cochlear implants) and eyes (a visual prosthesis), and other areas of the brain.