The other day I was driving home when I noticed a few people gathered around a toppled tree. They were having a lively discussion so I thought I’d see what was going on. The tree appeared to have fallen harmlessly in the yard and didn’t hit anything or anyone. I thought I was about to enter into a discussion on the best way to cut the tree up, should it go for firewood or lumber, where to find a chipper for the branches or something like that. As often happens in my life, boy was I mistaken.
As soon as I got out of the car they all said “Finally, someone who can settle this”. Of course, I had to ask “Settle what?”. It seems they were arguing over why the tree had fallen (I was afraid to question if it made a noise). One person thought that recent storms had weakened the ground, exposing the roots and then a strong wind brought it down. Another thought that beavers were moving into the area and that they had eaten the base and let it fall. And yet another was adamant that the government was testing satellite-based laser weaponry by targeting ground structures and they hit this tree. More arguing ensued.
I knew I had a job on my hands. First, I had to get them all to calm down so we could converse amicably. Then I asked them if they’d heard of Occam’s Razor. “Like the scooter?” one asked. No, I said, not like that. Another yelled “See, I told you, space weapons!”. Again, I said, no, it’s razor, not laser. I explained that Occam’s Razor is a philosophical concept to determine which out of multiple explanations is the most likely. Sometimes you see this stated as ‘the simplest explanation is the best’, but what it really means is that the one which requires the fewest (not the least! – link to old article here) assumptions is most accurate.
The first explanation requires that there had been recent rain storms, soil erosion and high winds – all things that did happen in the area. The second requires that there are beavers – which then requires that there are nearby waterways and that this type of tree is on their diet and that there are telltale signs of beaver damage. A few more assumptions now, especially needing a waterway and there isn’t one, so this is less likely. The last explanation requires that we have a government program building space-based laser weaponry which then requires that we have the technology and capability to create, launch and control these and that something this complex has been a secret. This one requires a lot of assumptions and is not likely correct. We can feel safe thinking it was storm damage and not an orbiting death ray, or even beavers.
Occam’s Razor is very useful when faced with conspiracy theories. Conspiracies often rely on a great number of things being true for them to exist. You may hear many variations about large corporations secretly doing things to control their consumers – this is a common theme. Let’s unpack this a bit. A corporation is composed of people (a lot of them) and some of them are involved in the nefarious deeds yet none talk. They will require support and yet no one else talks and funds are never found missing. Gossip spreads fast in a large company and yet no one has heard of anything. You’d think that someone who left the company disgruntled would scream about the conspiracy, but they don’t. You might hear the company threatened their life, but now you have a new set of assumptions: the company is willing to take on the legal risk of death threats, they actively employ assassins, etc. You can see how each time a new reason is given, it comes with a new set of assumptions.
Scientists will regularly use Occam’s Razor when reviewing results. A current example is about a device called the EmDrive. It is an engine that appears to produce thrust without propellant and it seems to defy the laws of physics – specifically “for every action there is an opposite and equal reaction”. This is especially interesting because many people are replicating the experiment and seeing some kind of result. However, since it does seem to defy well established theories, they want to see if there is another explanation, perhaps not simpler but which does not require the assumption that Newton’s Second Law of Motion is wrong. We may only have one assumption here, but it’s a big one. They may have a case where measurement error is creeping in, some other effect is causing the thrust or something else not found yet.
You can apply Occam’s Razor in everyday life as a useful tool. We’re often presented with explanations that we can’t tell are accurate or not. Use this to unpack the explanation. Ask yourself what assumptions must be true for the explanation to work. You may even see cases where the assumptions then spawn their own assumptions and that should definitely set off the warning alarm. You don’t even need to compare two explanations, you can use it to see if just one is likely. You could spend all day just testing explanations in politics on the news, but you may find that neither partys’ was any good! Now, I have to go check on a strange hole that was burned through my roof to see if it was beavers.