Sunday, September 29, 2013


Do flergamarms exist?

Well, what do you mean by "flergamarms"? Or to put it more precisely, what empirical observations would you be able to make that would be different if flergamarms did exist than if they did not?

Flergamarms are invisible, intangible, and in fact, cannot be observed in any way. They have no observable effects, nor are they a logical consequence of something observable. As such, there is no such observation that would be different depending on the existence of flergamarms. So, do they exist?

Well, I wouldn't say they exist, but I'm also wouldn't say that they don't exist. Rather, I'd say that the question is meaningless. I would say that something can only have meaning if it's in some way connected to reality, and to be connected to reality, it has to be observable, or the logical consequence of something observable.

I'm not completely certain about that. Maybe there is some sense in which the term "flergamarm" is meaningful. I can't think of anything that could be though. And even if there is, there's still not much point in discussing such entities.

Sunday, September 22, 2013

The Autumnal Equinox

We live on the surface of a giant spinning ball. From our perspective, everything else appears to move around us as we spin. The sun, the moon, the planets, the stars. As we spin to face the sun, it appears to rise the sky. As we spin to face away is appears to set. It is no coincidence that we spin around exactly once each day. It is our spinning that determines the length of the day.

But we don't just spin in place. As we spin, we move in a circle around the sun. But the way we spin is tilted compared to the way we move around the sun. And the direction we're tilted doesn't change as we move around the sun, which means that sometimes we're tilted toward the sun, and sometimes we're tilted away from it. When you're tilted away from the sun, the days are shorter and the nights are longer, which makes it colder. The winter solstice is the day when you're tilted exactly away from the sun. When you're tilted toward the sun, the days are longer and the nights are shorter, which makes it hotter. The summer solstice is the day when you're tilted exactly toward the sun. It is no coincidence we move around the sun exactly once each year. It is our moving around the sun that determines the length of the year.
Not to scale. Credit: NOAA
Keep in mind that when the northern hemisphere is tilted toward the sun, the southern hemisphere is tilted away, and vice versa. The summer solstice in the northern hemisphere is the winter solstice in southern hemisphere, and the winter solstice in the northern hemisphere is the summer solstice in the southern hemisphere.

But today, we aren't tilted toward the sun, or away from it. Today, we are tilted perpendicular to the sun. Today is the autumnal equinox, the day when the day is equal to the night.

The equinox is a time of change. It marks the midpoint in the transition from the summer solstice to the winter solstice. Beyond that, it is also an inflection point. After the summer solstice, the days get shorter. At first, only a little bit. One day will be only a few seconds shorter than the day before it. But over time, the change increases, until one day will be minutes shorter than the day before it. The solstice is the time of the fastest change. After the solstice, the days will continue to get shorter, but the speed of the change will slow down again.

Wednesday, September 11, 2013

Free Will

If a tree falls in the forest, and no one is around to hear it, does it make a sound? Alice says yes, because it would produce a pressure wave through the air. Bob says no, because it wouldn't be perceived by anyone.

Alice and Bob aren't disagreeing about what happens when a tree falls down, they're disagreeing about the meaning of the word "sound".

Do we have free will?

Well, what do you mean by "free will"?

One notion of free will is that it is the ability to make decisions that are neither deterministically caused, nor random. This concept is called libertarian free will (unrelated to the political party), and it doesn't make much sense to me. To start off with, what's the middle ground there? How can something be neither determined, nor random?

Further, a non-determined decision wouldn't resemble a decision at all. Consider this scenario: you're in a building when a fire alarm goes off. So, you make a decision to evacuate the building. The only reason to evacuate the building was because the alarm went off. If the alarm hadn't played a role in determining your decision, then you wouldn't have made it.

So, that means we don't have free will, right? Well, it certainly means we don't have libertarian free will. But when you say things like "Free will doesn't exist.", people tend to react by saying things like "That means we can't make decisions!".

Which isn't true. Things that are completely physically determined can still make decisions. Consider a simple thermostat. If the temperature is below 18°C turn the heater on, otherwise, turn the heater off. Admittedly, that's in the fuzzy area between "decision" and "reaction", but I don't think it's fundamentally different than an undeniable decision, just simpler. (Which leads to another question of definition. What exactly is a decision?)

The fact that people tend to react that way implies that the libertarian notion of free will isn't the concept most people mean by the term "free will". So, we should find another definition that more closely matches people's free will. Here's my suggestion - Free will is the ability to make very complicated decisions that are determined by a very large number of factors and is very difficult to predict in advance.

Under this definition, we obviously do have free will. This doesn't resolve the issue. I'm still not certain exactly what a decision is. But I think it's a good step forward that helps avoid common misconceptions.