Well, one difference between "heat conduction" and "phlogiston" is that the former carries some additional information with it - heat conduction is a well-understood mechanism by which energy is transferred from place to place. Maybe it does apply in that situation and maybe it doesn't - in the example given, it doesn't, there's no heat-conduction mechanism to transfer heat from one side to the other - but the fact that there's actually a mechanism behind the words separates it, qualitatively, from an explanation like "phlogiston." It has equations behind it which can then be written down and tested for agreement with reality.

Really, I can quite understand the students... if you say "I don't know" you have a zero percent chance of getting the explanation right. If you say "that seems impossible," then you're guaranteed to get it 100% wrong - since it DID happen, and thus it must be possible. The best course of action in the situation is to think of all the hypotheses you can, and then guess at one of them - whichever one has the highest chance of being right, given what they know about physics.

Now, I certainly hope that the students wouldn't think that by throwing around guesses they're "doing physics" - yes, doing physics would involve taking actual measurements, and I would hope that after taking some measurements of the block over time they would see "oh, this isn't actually at equilibrium like we had all assumed." (Alternatively, if a student took the words and wrote down an actual model of how the air currents or the different metals or the heat conduction could lead to the observations, that would also be "doing physics", though the only end result of it would be to yield a mathematical model which would quickly be easy to proven false by measurements or stability analysis.) But neither of those avenues is open to them when they walk into a classroom and the teacher asks them to "explain this phenomenon."

I think the students would quite happily agree that they haven't given an explanation which is good by any sane measure - it's quite likely that many of them would also agree that they don't actually believe their explanations. But I wouldn't agree that they're being irrational in stating them.

Interestingly enough, my teacher, Chris. Alexander (author of A Pattern Language), recounts his entrance test for a physics degree at Cambridge. The applicants were asked to experimentally determine the magnetic field of the earth. He performed the experiment, and came up with an answer he knew to be wrong. Wrong by too large a margin to put down to experimental error. A smart chap, he had time to repeat the key part of the experiment, and recalculate - got the same answer. He used the last part of his time to write down his hypothesis for having achieved such a result. And, alone among the students, he was right. A massive electro-magnet was being used on the floor below as part of another experiment.

I believe the advice offered to me as an 18yr old physics student encountering similar circumstances was simply to show my workings and the incorrect result, and to add that I knew this was not the 'right' answer.

"They wanted to maximise their chances of pleasing the prof., not maximise their chances of understanding the world."

I don't know that I buy this. If the students make a guess that's wrong, one would expect that to kickstart a process of the professor helping them to understand why it's wrong. (Student: "Um... because of heat conduction?" Teacher: "OK, what does heat conduction suggest should happen in this situation?"...) This seems more likely to result in learning than just sitting there and saying "I don't know". If anything, I think it's often a bigger problem from a learning perspective, when people are too afraid of being wrong to put out tentative ideas.

"I don't know" is a rational response to this situation if you are sure enough of your understanding of all the potential principles involved that you know they can't explain the phenomenon (and you don't happen to guess that the professor is messing with you). But it's fairly clear the students aren't in that situation, so starting to generate hypotheses about what's going on seems perfectly sensible. Of course, they should be actual hypotheses, and Eliezer's perfectly right that "because of heat conduction", if offered as an actual explanation, isn't an hypothesis as much as a cop out. But if it's a starting point, rather than an endpoint, then that seems perfectly reasonable.

In short, the problem isn't that they're guessing. It's if their guesses aren't actually saying anything, but they think that they are. (And I think Eliezer's admonition to just say "I don't know" conflates these two problems.)

At one of the websites I frequent the first paragraph of this article was posted.

I guessed the teacher had set up the plate and turned it around.

As a student of the theatre I am somewhat versed in the arts of "Illusion". There was one show where we set off a smoke bomb and lowered the lights at the end of the first act. We then had intermission At the beginning of the second act we set of a smoke bomb and raised the lights. It's amazing how many people wrote about how we made the prop appear out of nowhere on the stage. They edited the intermission out of their remembrance of the story.

This story quickly sprang to my mind and I realized that if you can fool someone into forgetting an intermission you can fool someone that had no idea what was done before they came into the room in the first place.

but that was entirely rational because the professor set them up to believe that.

They were rational, but not unbiased. They wanted to maximise their chances of pleasing the prof., not maximise their chances of understanding the world.

I think this teaching approach was great, and I might use something similar myself (there are mathematical equivalents of the above situation). Learning science means that you have to learn a boatload of facts, and learn the scientific method. Since the boatload of facts has to be accepted without question (for the whole of your early career), this undermines the teaching of the method (when it is taught at all). A few sessions like this (properly exploited by the instructor) would do a world of good.

AC, what you're describing here is a severe case of déformation educationnelle.

Really, I can quite understand the students... if you say "I don't know" you have a zero percent chance of getting the explanation right.

If you say "I don't know" you have a zero percent chance of getting a gold star in the idiot damned school system. But it is still the rational thing to say when, in fact, you don't know. You can easily do worse than maximum entropy if you guess at random.

Furthermore, "getting it right" by guessing the verbal phrase the teacher has in mind, even if the school system gives you a gold star for it, does not necessarily mean that you possess any anticipation-controllers. All you got right was a string of words, like guessing the passphrase to the teacher's login.

"Heat conduction" is a verbal phrase which may, for someone who knows the equations, invoke genuinely explanatory equations from memory. And for someone who knows the equations, it should be obvious that the equations do not predict the further side being warmer.

If you don't know the equations, then "heat conduction" is a verbal phrase invoking magic from the Star Trek genre. Even if the teacher says "You're right!", because there were only a limited number of phrases you learned about this semester and one of them had to be "right", you still don't know anything except an arbitrary passphrase.

If you memorized the equations but you didn't apply them, then "heat conduction" still invokes magic - it's not enough to know what symbols to scribble on the final exam, you've got to do the math or it doesn't count.

I should note that I read about this scenario in the Canonical List of Science Jokes but I have no idea whether it was a note from someone's experience. If anyone tries this, I'd love to know the result - my guess is that in real life, at least one student in the class would guess it, which is why I'd suggest having students write down their best suggestions on paper; followed by the teacher asking "How could you falsify your theory?" and writing that down as well.

Explaining things by magic has been the default state of human existence for far longer than science ever existed. Anyone using fancy words must be assumed to be invoking magic by default.

The training of a rationalist must be strict! No human can be unfair enough; you have to match swords against Nature to develop the requisite skills.

I agree with AC...you're being too hard on the students. I doubt very much they were stating anything with confidence. It's quite possible that some of them didn't really care about understanding physics and were just trying to get the right answer to please the teacher, but others were probably just thinking out loud. Thinking "maybe it's heat conduction" might just be the first step to thinking "no, it can't be heat conduction," or even to realizing "I don't really understand heat conduction," and there is nothing wrong with this train of thought. They were probably "biased" towards the idea that there was some physical principle causing the effect, but that was entirely rational because the professor set them up to believe that.

Great story, though.

A student who said it was done by magic would, of course, have been correct. Because it was done by magic.

The teacher moved the plate when the audience wasn't looking. That is one of the ways magicians perform their tricks.

If they had used words such as "supernatural," "miracle," or "paranormal," then they would not have been discussing physics.

But good magicians are the best practical physicists.

I have a bad memory for isolated facts (like names or past events), and comparatively poor ability to guess intended meaning of things people are talking about in real time. When I was younger, I would just randomly guess possible answers to patch over the gaps in my mental picture (with little chance for actual success) in situations where it was expected of me to know the answer. Generation of random explanations that have nothing to do with actually explaining the observations might sometimes be motivated by a similar psychological pressure to give some answer.

Now I say "I don't know" or "I don't understand", to the bewilderment of people who would expect better mental agility of me, but don't know me well enough.

Is there any way to set up a classroom (or an educational system) so that these students would get the right answer? Alternatively, is it even desirable?

If you teach students to think this way, you're saying "The world is governed by comprehensible scientific laws -- which is irrelevant, because people are constantly screwing with you." This experiment might be useful in a physics class for lawyers (who would probably catch on) or conspiracy theorists (who would, at least, have more entertaining hypotheses).

A compromise might be for the teacher to not just ask for an explanation, but ask for a testable explanation, and reward people for coming up with a theory they can falsify. The sad truth is that there's one more group that would figure out the answer right away: Creationists.

• We can be swayed by the context we are operating in, thinking inside-the-box
• Don’t use terms and explanations if you are not really sure about the concepts

(Response to old post)

These are students, so they don't have perfect understanding of science. Even if they understand how to calculate what some theories predict, they don't know exactly when to apply those theories or what confounding effects might occur.

So unlike someone with perfect understanding, they don't know with 100% certainty that any specific theory applies. Asking what caused X to happen is really asking "what theory, among the ones you know, has the highest probability of having caused this result".

But even if the result is wrong and no theory actually would lead to that result, the students would grant some non-zero probability that each theory produced that result (since they know they imperfectly understand the theories). There would still be a highest probability. They would then say "conduction" and they would be correct--the probability, given their limited understanding, that conduction produced this result is non-zero and greater than the probability for, say, convection.

"Because of heat conduction" is the correct answer-heat from the radiator conducts to the plate-heat from the plate conducts to the air regardless of which side is being examined. The teacher asked "Why does this happen?" not "Why is the closest side to the radiator cold and the distant side hot?"-the question which is assumed to be implied by the actual one. The answer to THAT question would be "because of magic" since the professor was performing an illusion that was prepared ahead of time. The data points necessary to divine the nature of the illusion (Mr. Wizard) would be: temp of the radiator, average air temp, temp of the cold side, temp of the warm side...that would be sufficient to demonstrate that "because of heat conduction" one side was closer to the radiator while the other was exposed to the air-despite the appearance of the opposite circumstances. Fake explanation FTW

Phew. This is just an 'ask a stupid question, get a stupid answer' situation.

Questions 'why' and 'what is' are metaphysical or semantic and have nothing whatsoever to do with science. The only reason why those are prevalent in education is that education sucks. Science is not a search for answers to "why X happens", even though it is popularized as such.

My school physics wasn't like this at all (eastern Europe here). I would have a problem to solve - how many watts of heating are required to maintain uniform temperature of 20 degrees Celsius in a 10x5x2.2m room with concrete walls of 20cm thickness and outside temperature of -20 degrees Celsius (you can look up thermal conductivity of concrete). A very reasonable question. In the end, you're good in physics not when you have some warm inner feeling of understanding, not when you can 'explain' why something happens, but when you can PREDICT what will happen and/or make things happen. Nature couldn't care less if you know or not "why" stone axe is good for killing a mammoth (or something), it doesn't care if you call it 'inertia' or something else.

Conchis, the problem is guessing passphrases instead of anticipation-controllers.

Robin, I am indeed considering it, it will depend on how much raw material I can generate.

I have seen this example before. I actually do not blame the students at all for the following reasons (some taken from other comments)

1) They are thinking out loud, so seeing that some aspects points it could be heat conduction(after all that would be the typical reason for most temperature discrepancies withing an item) then they scream "heat conduction" as an invitation for closer look which is a valid (as pointed by other commentors) method of thinking

2) They are screaming the highest probable answer they can think of. Magic and heat conduction are not the same in that case. The students know they do not know the answer for sure and they basically going for the most probable cause that exist in their mind database and isnt that how a theory is initially theorized? after initial stating it get questioned and removed or confirmed

3) This is a physics class. It is assumed you do not know the answer so guessing is a valid way to learn because imagine in a different situation when it was NOT a trick question and the answer was actually heat conduction. The student who GUESSED heat conduction will feel the joy of being right and probably will remember that lesson better for the future since he will link it to a happy specific incident in the class. I think the student aim for that feeling and it is a good thing because I believe it helps them actually learn [need memory learning references]

4) They know (assume) the teacher knows the correct answer, and thus guessing wrong answers is not bad since no one will take their word for it and instead wait for the final correct answer by the teacher. There is no harm at all to guess and try to rationale through all of your theories. Stating the topic of those theories is a valid first step since that's how we usually solve any physics problem (e.g. to calculate the speed of falling ball, you need to recognize which equation you should investigate, should it be conservation of energy or the acceleration equations. Stating the title then investigating till proven right or wrong is a correct way to address this problem. Part of solving a problem is recognizing the telltales that direct you to the right equation, this case had a lot of telltales for heat conduction)

5) While this relates less, but i do not blame the students for not figuring out the right answer because its probability is pretty low. If they never got trick questions from this teacher, it seems a pretty unreasonable thing to assume from a physics teacher during class.

6) I would guess most of the students who would say "i dont know" FAST without exploring those wrong theories will be the lazy and uninterested students. it is equivalent to giving up and shutting down your rationale.

I am pretty confident if this happened to me i will be one of the students who keep trying theories and discussing them with others. I learned a LOT of physics concepts through discussing ideas with bunch of students who none knew the right answer. Many times we were able to reach the right answer after several wrong ones. I think in this situation this what the students were doing and I approve of it [sadly my approval means nothing :D].

I heard this in the popular 'Oxbridge Interview Question' genre, a long time ago. It actually makes great sense there, as a 1960s don would have had a coal fire burning in winter, when the interviews are done, and be able to turn the plate round between interviews. And the interviewer would be expecting everyone to know all the relevant laws, and be looking for exactly the right level of bewildered confusion and hypothesis generation that you're hoping for.

The point is not to guess the right answer (that's essentially random inspiration and the ability to detect trickery is irrelevant for physics). The point is to provoke a detailed conversation about physics.

Some of these stories are clearly apocryphal, and some of them have the ring of truth. This one seems a bit dodgy since the previous interview candidate could easily spread the information about the trick (and although that's rather irrational, candidates do do this). Although if a candidate guessed straight away, the interviewer could just use another stock question.

I not so sure that when the student suggests "because of heat conduction", they are attempting to provide a full explanation.

I model their internal thinking more along the lines of "Well, I don't know for sure what's going on here, this is an obscure effect I've not come across before, but it seems plausible to me that it will be in some way connected with conduction, so I'll suggest that as a first step, and hope someone else can fill in the mathematical details for me."

It is closer to the situation when a company owner says to her managers "Production has dropped by 50% in the last quarter, what's the cause and what can we do about this?" and a manger replies "Well, I don't know for sure, but I think it might have something to do with the recent marketing campaign where we changed the product name to 'Yucko'."