If I were to try to build a robot that could walk, or roll, around a room, avoiding objects, I might start with some type of model car chassis. I would need some electric motors, probably, or just one. Then I would have to make some type of sensor system, perhaps some tactile ones: plungers hooked up to electric switches from Radio Shack, or more ambitiously, a diode or viewing system — a camera that would require a program, a computer and software, to recognize shapes and respond appropriately.
There would be a “master” program that would react to the events generated by the sensing system(s). Some kind of logic to control speed and direction — turning angles. The master program would have to “know” how to get out of a corner, or what to do when running into an object. Maybe backup, turn right 45 degrees and try again.
And how fast to go so it didn’t destroy itself.
If it was desired for this robot to be able to do anything useful, beyond reacting to things, it would be necessary to program for this, also. And perhaps attach useful machinery. For example, there already are vacuum machine robots that move around the living room carpet, cleaning as they go.
After some time the robot, if it were ever completed successfully, would break down, run out of batteries, or a part would break off, or it would fall down a staircase, or run into some horrible demise, unforeseen by its creator: thrown by a child, chewed by a dog, stepped on by a guest? And eventually it would be forgotten.
How different are living creations.
There are more examples than I can cite, but one will suffice to make a point. The Paramecium (http://en.wikipedia.org/wiki/Paramecium)
This is a microscopic, water-born, lozenge-shaped animal that motors around using cilia (hairs) attached to its elastic outer shell. The cilia act in an oar-like fashion, with a brisk forward “stroke”, and a gentle recovery backstroke to get ready for the next stroke. The numerous cilia “oars” work together in a wavelike fashion.
A Paramecium, when it runs into something, backs up, reversing the direction of its stroke. Then it retries the passage. It continues this attempt/retry until the object is passed. In the water things move around a lot, so apparently this strategy, encoded in its DNA, works well.
A Paramecium has other smaller sets of cilia which sweep bacteria food into its mouth. It has a digestive system which uses enzymes that turn the bacteria into energy to keep it alive and moving. The food waste is propelled out the anal cavity. It has a system to regulate water intake and outflow, also. Apparently, merely by eating what it eats and being eaten by its predator, Didinium, Paramecium fulfills an important role in the food chain that helps keep life rolling along.
All of this, so far, represents a light-years advance on the robot I was considering building — and all in a package of 50 to 330 micrometers in length — much smaller than I am capable of bread-boarding.
But there is more. The Paramecium can reproduce itself in two ways: either on its own, spontaneously splitting into two; or by combining with another Paramecium of a similar type.
Needless to say, our human-designed machines are not programmed to reproduce and thus create a new generation of themselves. Cars, washing-machines, smart-phones. No. Fortunately.
Let all of us humans who build things, or use things other humans build, and think we live in an enlightened age of technological wonder, just take a step back and literally apologize in all humility to the Supreme Creator of Nature, the Master Engineer.
We should continue to study life, like the protozoologists Antoni van Leeuwenhoek and Christian Huygens did in the 17th century, when they discovered the Paramecium.
We’re not so smart.