Physics and Intuition

Nicholas Covington over at SkepticBlogs has a post that relates to the borderlands of science and philosophy, intuition and its utility. His observations are done in light of some of the blog posts by Luke Muehlhauser (who more recently went to work at the Singularity Institute and the website Less Wrong).

Philosophers have long worked with what ideas we have in our heads, the primitive notions of things such as the reliability of the senses, our reasoning abilities, that other people have minds, etc. However, there is a continuing body of growing research that shows the limitations of our intuitions and our mental faculties (some I mentioned on my appearance on the Magic Sandwich Show). Nonetheless, Nick is correct that we ought not to go all-out against intuitions having epistemic value. Though we ought to be aware of its limitations (Nick mentions the Monty Hall Problem which drives first-year statistics students and normal people nuts.) Moreover, intuitions should not be beliefs that some have called properly basic, as they can and should be subject to scrutiny. Nick concludes that we have inductive reason to take them as probably true since they seem to work rather often.

But this leaves the question of when are our intuitions untrustworthy? Should be consider evolutionary history? Richard Dawkins had commented that perhaps because we evolved at the macroscopic level we did rather than nanoscopic (extremely small) or megascopic (extremely large) we may not have the mental faculties to understand modern physics like quantum mechanics and special relativity. This implies that we would be better adapted as Newtonian thinkers, since that is the world we live in; Newton's laws and principles correctly explain most everything material in our day-to-day world, the world our ancestors would have inhabited. So this implies a potential limitation on what we can understand and what we do understand.

Unfortunately, my own research in physics education shows that college students are not Newtonian thinkers, and this has been the conclusion of PER since at least the 1980s. For example, there are the interviews done by McCloskey et al. as summarized in Scientific American back in 1983. They noted that often students seem to have something like the medieval impetus view of motion.

For example, they asked the question of you walking at constant speed in a straight line while holding a ball out and shoulder level. If you continued on an the same speed and on the same path, and you dropped the ball, would you expect to see it fall behind you, in front of you, or at your feet? Before reading the conclusion, think about what the answer is to yourself.

Don't scroll down unless you have an answer.

Have a guess now?

Really?

OK, go ahead and read on.

Well, most of the people asked said the ball would fall behind them. 49% said it would fall over the exact spot the ball was let go, and a small percentage (6%) said it would actually travel backward. Only 45% accounted for the forward velocity of the ball when it was let go. And this was asked of college students, which means students with more education than the average in the US, let alone the world.

What is going on here? Some have noted the students had a general model for how things move. One of the things most people have in their minds is that without a force things don't move. There is also the notion of a force in the direction which tends to weaken with time (like the impetus dissipating as the object traveled). More recent research argues against most people having a complete model in their minds of how things work, and Andrea diSessa's idea of p-prims tries to account for what is going on with a collection of primitive ideas about physics (physics primitive ==> p-prims). What the correct model is, I cannot say.

However, the question of where these intuitions come from is one that currently needs more research, and I am glad to be working on that currently. I shan't say too much of what I have done until publication, but what I can say I did at the AAPT meeting last month. And what I did reveal is that students claim to actually feel the sorts of forces that may account for these anomalies from reality, but those forces simply are not real. At the intuitive level, we seem to believe we are pushed around in ways that simply are not true and at variance to Newtonian (let alone modern physical ) mechanics.

This indicates that Dawkins is wrong about our adaptability to understanding the Newtonian world--we don't even get that right. Perhaps that should be no surprise since it took near 2000 years of science to come up with Newton's physics (starting with Aristotle, and then on from there). Physics teachers also have come to learn that the correct ideas are hard to get into their students, and they tend to revert to incorrect views. On the other hand, we tend not to have strong convictions about things at the extremely small level or at super-fast speeds, so perhaps the theories of special relativity and quantum mechanics are easier to learn, if not necessarily understand, since we don't experience this realm and cannot fall back onto our beliefs of what happened last time.

All this would also imply that we should be very cautious using the intuitions we build up at the level we live and project them into realms we have no experience. If our experience will betray us about moving in a circle, why think they are unquestionable with things beyond our current comprehension, such as the state of the universe before the Big Bang?

I see science as progressing by testing our intuitions and seeing that they fail, and in the process building up new intuitions via the scientific method, thus creating a coherent, tested theory. It has at least been working pretty well.

So when are intuitions trustworthy? Perhaps the best rule of thumb (which is all an intuition can be) is that intuitions are useful in situations you have had significant experience. You don't need to bring out a piece of paper and a calculator to see if a train is about to hit you based its distance and speed; you can tell you need to move, else you won't be there to analyze your intuitions!

However, this would be extremely limiting to thought experiments that philosophers use all the time. How to deal with this? That is another avenue of research that needs exploration, and I know there are people on the case. In the mean time, I have a gut feeling that this won't convince everyone to give up their gut beliefs about how the world works, from politics to morality. Oh, so much work ahead.

Recent Appearance on the Magic Sandwich Show

I had the chance to check out and participate in the BlogTV broadcast of the Magic Sandwich Show, named after a food concoctions "invented" to cure just about anything but really to mock an argument against non-belief. The major topic of the show was a look at sophisticated theology, in particular mentioning the famous and respected philosopher of religion Alvin Plantinga.

Plantinga has come out with an argument that suggests there is a inconsistency between naturalism/materialism and the theory of evolution. Basically, if evolution made our brains and sense organs (and this is something Plantinga has doubted at least in the past), it may not have made them such that they will give us correct beliefs. Thus naturalism cannot account for our ability to reason and perceive correctly. He then suggests that God/supernaturalism can provide the reason we can trust our cognitive faculties. The Wikipedia page on the Evolutionary Argument Against Naturalism (EAAN) summarizes it well.

I got to participate a bit on that subject as seen in this bit of the video (jump to time 33:14):



I'll summarize my point here. One of the major premises of Plantinga's argument is the idea that our reasoning and sensory faculties are reliable. However, they often do fail us. We know there are many different cognitive biases, and we do tend to see and hear things that aren't there, even if we aren't chronic hallucinators or on drugs. We see patterns where none are, and even more-so when we are stressed. There is a lack of correlation between vividness of a memory and its accuracy, and we do mis-remember things. I also gave the example of the Stroop effect (or test) where we misread color words when the color is different than the word itself. Some of this stuff about our non-so-great minds and senses are discussed in books such as Michael Shermer's The Believing Brain and V. S. Ramachandran's The Tell-Tale Brain. These points also seem to be made by William Ramsey is his essay about EAAN.

So we know that our faculties are not completely reliable. And more interestingly, the sorts of issues our brains have can be explained by our evolutionary history. For example, making false-positives with patterns had an evolutionary advantage as opposed to the opposite error: mistake that there is a tiger and run, no harm done; mistake that there isn't a tiger, and you're dead. Thus we have a selective pressure to make us more likely to see what isn't there. But according to Plantinga, God ensures the proper functioning of our minds.

That leads to two possibilities: the supernatural hypothesis has this evidence against it, or a faulty mind is consistent with the supernatural. The first one obviously isn't good for the case against naturalism, and it means that in fact the argument is for naturalism. So perhaps the God hypothesis can be compatible with faulty thinking faculties. However, this is made initially unlikely because we expected otherwise (Plantinga certainly did). But let's just be favorable and say supernaturalism is 50/50 on whether we would have reliable cognitive faculties. Nonetheless, on naturalism with evolution we expect to have some limitations in the reliability of our ability to perceive and reason, so the probability here is greater than 50%, and closer to 100% (if not exactly 100%). That means on either of the possibilities, the probability of naturalism goes up and supernaturalism down (using a Bayesian inference method).

So that means Plantinga's argument goes against his beliefs. That he uses the argument for his position is the definition of delusional: held with conviction, not significantly changing with counter-evidence (even after years of philosophers showing him errors), and implausible (i.e. the reliability of our faculties; supernatural beings and powers).

And considering how Plantinga is considered (rightly) as one of the best in philosophy of religion yet his arguments have such scientific flaws and similar to bad street preachers (as pointed out by the hosts of the Magic Sandwich Show), it really should indicate how bad the arguments for the supernatural are, at least using armchair philosophy. It's why I'd rather talk about evidence.

The other topic that unfortunately I didn't get to delve into enough was that theology has a huge amount of intellectual capital to use for its cause. Astrology and other pseudo-science and history doesn't have anywhere near the resources of intellectuals to defend them. Astrology used to be that way with support from scientists and church figures, but not so anymore, and their arguments are thus very bad. Religion, on the other hand, has an industry of defending the faith or finding new interpretations. So I am impugning both liberal and conservative religious folk with this; both camps have a lot of power to either defend their dogma with endless apologetics, and liberals have a significant "phase space" of what to focus on in their beliefs or holy books to come up with some more rational position without having to admit their belief or book is no more worthy of being called sacred or inspired than any other of the same type. Again, astrology and astrologers don't have the same luxury of ways to interpret their practices or defend them that stand up to much critical scrutiny; very few have a science or philosophy background in this day and age.

Then again, being a philosopher doesn't mean you won't get the science wrong and think there are no transitional fossils or that irreducible complexity is evidence against evolution.