Plausibility is Always a Part of it, but it May not be so Obvious

Being a person who likes neat mental hierarchies, Hume's Problem of Induction and the implications of Gödel's Incompleteness Theorems (particularly the unprovability and unfalsifiability [in a logical sense] of certain parts of axiomatic systems–namely mathematics and Aristotelian logic) have emotionally nagged at me ever since I learned about them. In a recent episode of "Rationally Speaking", a podcast which I enjoy immensely, I was reminded of Quine's Web of Belief, which involves various belief strands with various thicknesses, but wherein the snapping of one strand does not necessarily lead to the collapse of the whole web. This is like an analogy I've heard, wherein all empirical claims are accompanied by a permanent asterisk, which is essentially saying "There is no ultimate basis for this." Even despite my desire for a rigid hierarchical system of bases, this answer is still somewhat satiating. This is especially the case, since the concept of an ultimate basis may be incoherent in any case, and this answer essentially says, "We don't have it and we also don't need it." All of this is to say that even on deep levels, the best probable view of the universe will be Bayesian in some sense. This means that plausibility is unavoidable when reasoning about the world.

What I'm saying is not that logicians should arrive at their conclusions through Bayesian reasoning, merely that there's always some level that involves plausibility. That doesn't mean that there aren't epistemic levels where same-level plausibility shouldn't be considered, however.

An example that pops to mind is that of the court and criminal justice systems. In the United States and many other parts of the Western world, a very important aspect of the criminal justice system is "innocent until proven guilty", or Presumption of Innocence. I will say that while I don't think that this is particularly epistemically sound, I agree wholeheartedly that this is how the actual execution of law should be carried out. I think that the empirical position that should be taken in a situation devoid of evidence is one of agnosticism, or a lack of knowledge; however, this should be treated as the equivalent of innocence under the law, and that is, I think, the intent behind the law. This is a perfect situation where the plausibility of guilt should not really be considered on the level of criminal justice. There should be hard and conclusive evidence demonstrating guilt before that ruling is administered, and that evidence should be conclusive from the starting point of neutrality, no matter how high the prior statistical plausibility is (consider, say, a case involving an individual belonging to an of the ethnic minorities that commit much more of a type of crime on average). The plausibility comes into play with the epistemic problems of evidence-gathering in the first place, but it is used only extremely sparingly when considering guilt on the actual level of criminal justice.

Similarly, I actually think that this should be the goal in social reasoning as well. By this, I mean the assumption of guilt on a social level, or that equivalent. In this case, I don't think that it should actually be illegal to consider plausibility in the Bayesian sense, but I do think that it should be a societal goal to eliminate at least the extremes in this case. I care much more about avoiding the creation of a social pariah from an "innocent" person than the missing of a "guilty" person.

In some senses, these are anti-utilitarian arguments, and I understand that various strains of utilitarianism can be very valuable even in social settings. I wouldn't, for example, want to seriously risk ruining a million lives just because I didn't feel that my evidence for guilt wasn't absolute and thus didn't justify treating a hypothetical person as being guilty. I don't think it's as simple as a calculation, however. There are values other than sheer maximization of intelligent happiness and minimization of intelligent suffering that must be weighed. I guess I'll have to go with the better-feeling, yet vaguer "flourishing" versus "suffering".

For this very reason, discussions about social justice on individual and even lager scales can be very difficult to have. Part of the problem will inevitably come from conflicting values. Unfortunately, morals and ethical axioms aren't objective, no matter how hard some people try to claim that they are. Even putting generally unreasonably moral systems like religions aside, some people will simply disagree that we should value the freedom of the innocent more than the imprisonment of the guilty. I find that this opinion often comes from a somewhat immature (in my opinion!) reciprocal justice view of the world, but that's not necessarily the case. There are many perfectly valid, naturalistic ethical views that conflict. That doesn't mean that progress can't be made, however. I think it should behoove us (as intelligent, sentient beings) to engage in critical discourse and to come to the best consensus that we can.

Dark Matter Spotting (and further confirmation)

In a recent press release from Fermilab, a recent survey of dark matter was announced. This survey was performed by the Dark Energy Survey using the Dark Energy Camera. To be clear, the main purpose of the Survey and the Camera is to observe and document dark energy, which makes up close to 70% of the observable universe and is "causing" the universe's accelerating expansion, but the nature of this specific survey was of dark matter, which is close to 25% of the observable universe and is responsible for the much larger amount of gravity present in galaxies than would be there if only due to conventional matter. The Camera for the Survey is extremely sensitive and looks at millions of galaxies to document their accelerated expansion over time, but the resolution is good enough to look at their specific structures, and so the dark matter forms within them as well.

Dark matter itself is mysterious and difficult to detect, since it interacts with other matter only weakly through gravity and doesn't obstruct or reflect light; however, its gravitational effects can be detected through gravitational lensing, an effect predicted by Einstein's General Relativity. This allows not only for the total amount of dark matter to be detected by subtracting the gravity of conventional matter from the gravity seen, but it also allows for the general shape of the dark matter formation to be detected.

As it turns out in this case, the shapes of dark matter formations match the predictions made based on where galaxies had formed. Normal matter was found to cluster around where the dark matter was clustered, and space between galaxies and there clusters were found to be relatively empty of both. At first, I questioned why the assumption being gone with was that conventional matter clustered around where the dark matter already was instead of other possibilities, but then I remembered that dark matter was present in the early universe and formed structures before conventional matter did. This makes it reasonable to abduce that dark matter formations attracted conventional matter, especially since the combined gravity of dark matter is so much greater and we have no reason to think that conventional matter produced it.

Although unnecessary, this review is also a nice additional confirmation of dark matter. Dark matter has been confirmed many times already, such as the Bullet Cluster analysis in 2006, and a recenter review of similar collisions; however, this is yet another level of confirmation through the analysis matching conventional theories. One would also not expect conventional matter to follow gravitational strands with models like MOND (modified Newtonian dynamics), but rather for the conventional matter and gravity to match perfectly, since the gravity is being produced by the conventional matter in the first place.

This is only the beginning of the analysis that the Dark Energy Survey will perform, and I am excited to see how the rest of it goes. The ultimate, and lofty goal of the endeavor is to document dark energy and (hopefully) determine its role and/or cause. Dark matter and especially dark energy are two of the most exciting cosmological mysteries we are confronted with today, and I would positively love to learn more about them!