Plutarch wrote:... is that what falsifiable means? Just because something makes sense, and the math works, and it fits together, does that mean it's not falsifiable? I thought falsifiable meant that something was capable of being tested scientifically, or mathematically. So even something that is regarded as absolutely true, like 2 + 2 = 4, is still falsifiable, because it can be tested? I thought that only things like religion were non-falsifiable, because they can't be scientifically tested. But I am prepared to be completely wrong about this.
Here is an example of something which is not falsifiable. I say, the gostak disdims the doshes. You point to something and say "That gostak there did not disdim any doshes.". I reply, no, that is not a gostak.
You point to something else and say "Those doshes there have not been disdimmed by any gostak.". I reply, either no, those are not in fact doshes or else Ah, but they have been disdimmed by a gostak.
If I get to decide what a gostak is, then I get to decide whether it's disdimmed any doshes or not. You can't falsify it.
Here is a different kind of example, Newton's first law. A body remains at rest, or travels in the same direction with the same velocity, unless an outside force acts on it or they all cancel. This cannot be falsified. If you observe a body traveling in constant direction with constant velocity, there are no outside forces acting on it. If you observe a body get accelerated in any direction, there must be an outside force. Physicists have observed only a few kinds of outside forces, and have no explanation for any of them. For example, like electric charges repel each other, and opposite charges attract. Nobody knows why. It's a force. There is a separate force that keeps protons inside atomic nuclei. Protons must repel each other because they have the same charge, but they are observed not to repel. Therefore there is another force which cancels the repulsion.
If you were to discover an accelerated body that was not being affected by any of the known forces, that would not violate Newton's law. Physicists would find a name for a new force and it would go on the list of forces, and somebody (probably not you, and probably not the first physicist who worked it out) would get a Nobel prize. Newton's law is not falsifiable. It is not a hypothesis, it is a way to structure your thinking.
Similarly with conservation of mass/energy. We say it is always conserved. Any time mass/energy disappears, or appears out of nowhere, we will hypothesize an undetectable particle that carries it from the place it disappears to the place it reappears. Conservation of mass/energy is not falsifiable. It is a way to structure your thinking, and not a hypothesis.
Similarly with evolution. If a population has no variability it will not evolve, and that does not falsify evolution. If a variable population has a shift in gene frequencies, we can calculate the probability that this shift happened by random chance, and if that probability is very small then we assume natural selection has occurred. Shifts in gene frequency do happen far more often than random chance would predict. Whatever causes the shift is natural selection, this is a definition and is not falsifiable. On this level evolution is not a hypothesis, it is a way to think about whatever happens.
The Law of Fives is true. I see it everywhere I look for it.