Occam's Razor

Occam's Razor seems to be one of the most misused and misapplied concepts I have noticed to be used by otherwise intelligent people. I notice it being evoked frequently in many of the forums I regularly read. And in Science Fiction.

The general idea of Occam's razor, what people most often mean when they refer to it is: "the simplest explanation is most likely the correct one" (this is somewhat different than the original concept of Occam's Razor, but this is what I believe most people mean when they evoke Occam's razor) Occam's razor is not a bad idea at all, and can often be a helpful guide in choosing between competing ideas. But many people seem to take it too far. They seem to feel as if Occam's razor is some sort of scientific law that all matter must obey, rather than a useful way of to approach explanations. I have frequently experienced people assuming that any time there are competing theories to explain an idea the simpler one will always be correct. People will even go so far as to try and prove their idea true simply by invoking Occam's razor. Aside from there being many theories which are true yet more complex than other seeming possibilities, the idea of what makes one explanation more simple than another can be highly subjective? The idea how 'simple' an idea is, is often based on our previous experience and expectations. Newton's ideas of gravity and motion seem more simple to us, because they describe the world as we typically interact with it. However if we had evolved so that we regularly moved extremely fast, making the effects of relativity a common experience for us, then Einstein's Ideas of gravity and motion would strike us as being more simple.

Also, it seems unlikely that any phenomenon could be entirely and accurately explained by two different theories (though there may be such a thing, and it would interesting to know what an example would be). Once all the facts are known about a phenomenon, all but one theory will fall short of explaining every possible aspect of it. Whatever theory ends up entirely explaining a phenomenon, regardless of how complicated it may be, will by necessity be the 'simplest', because it will be the only one. While Einstein's theories feel less simple than Newton's theories, Newton's theories can't explain such things as light bending around a star, so using it explain that occurrence would not be the most simple because it would not be possible.
What would be more simple explanation, that there is one universe or two? Or twenty? What makes one universe more simple than two? What is more simple, there being one human to have ever existed on earth or many billion? (how would only one human come to be?) If we were able to discover that there were two universes, than the 'two universe theory' would be a more simple explanation of what we observe than the 'one universe theory' because the 'one universe', while seemingly more simple, doesn't explain the existence of the 2nd universe.


In most of our everyday experiences, using Occam's Razor can be a useful rule of thumb, but it is often misused and can lead people astray when it is seen as something more than a useful rule of thumb. Determining what makes an explanation simple can be subjective and misleading. It would be strange to think that operations of the universe would be restricted to following human notions simplicity.