Fact Check - Occam's Razor

Kiteretsunu Today I'll talk about an interesting philosophical statement which is used universally in many fields of human knowledge. We call it Occam's Razor.

This theory is named after William of Ockham, a philosopher of the mediaval period who first popularised this philosophical statement.

Occam's Razor is stated as follows - "Whenever there are two or more theories, competing with each other to explain a phenomenon, the one that requires the minimum number of assumptions is generally correct."

Thus we "shave off" the theory which requires unwanted assumptions, and then look for the more simpler model of explanation.

So what's basically is Occam's Razor? The theory states that "out of competing theories explaining a phenomenon, the one that takes least number of assumptions, is the one that probably gonna be correct." To explain this statement, we take two famous theories, that astronomers used, to explain the working of solar system. The first one is called the Geo-centric model, the model where the earth is considered the centre of solar system and possibly the universe. The second one is called the Helio-centric model, where the sun is considered the centre of solar system. To explain the planetary movements around the earth in night sky, the geo-centric model required many assumptions. First of all , it wasn't compatible with Newton's law of motion. Second, the motion of planets seemed to be whacky if geo-centric model was put in place. The planets seemed to appear in random times, and the peculiar thing was while the sun made regular periodic motion around the earth, it was not the same for the other planets. But when the Helio-centric model was given a shot, the three rules of Kepler's laws explained all the planetary movement, and thus required the least number of assumptions. As this theory was much simpler than the Geo-centric one, Occam's razor predicts that the Helio-centric model is the correct one here, which it is.

Occam's razor can be applied in many fields of physical sciences. In any two competing theories, explainig the same phenomenon, the one which requires the least assumptions is generally accepted. To maintain the constant speed of light and uphold newtonian rules of mechanics at the same time, a hypothetical medium "ether" was introduced for vaccum space. Many other assumptions were introduced too. But when Einstein introduced his special theory of relativity, he said we don't need those assumptions like that of ether. His theory of special theory of relativity required only one assumption, and that, time does not flow at the same rate for everyone. It was shown in the future that this special theory of relativity was actually the correct one (over newton's laws of motion).

When we have a problem in our hands, and we are looking for some answers, what sort of answer we generally choose out of these. The one which is a lot simpler and requires the least number of assumptions. It's the same way nature works.

When we leave a car at a parking space, and return to find it missing, we automatically assume that it must have been stolen 'cause the only assumption we have to make is that their are theives in our locality(which is true). We don't think that it was vaporised by a Sun God because of our misdeeds we did while baking some cookies at a faulty oven (which requires the assumptions - First, that there is actually a Sun God. Second, the deeds you did while cooking was actually evil. And third, your car was actually vaporised).

But there are some places where Occam's Razor aren't necessarily applied, like morality, medicine and psychology. 'Coz there are some things which aren't meant to be over-simplified, even if it seems correct.


Very interesting blog, K. I'll certainly be waiting for more. - PositronWildhawk

This is really cool, I'll be waiting for the next one as well. Well children, I just learned something new today! - NerdyPweeps

I find it interesting how Solomonoff's theory of inductive inference is just a mathematical formalization of Occam's Razor. Basically, Solomonoff's theory details similar to William Ockham's ideas, in the sense that instead you can actually detail a pattern or prediction, but in the sense that the environment follows a computable probability distribution that details all living things. Interesting stuff, I highly recommend you read on it. This part was always fun in my Junior Year, it's a shame that they never taught it again to me in college. - visitor