Right ok I've had a lot of thoughts about this so here we go: While my plane question might meet the definition of a trick question I really don't think it fits the spirit of one. I dislike the term because it shifts the responsibility for getting the wrong answer from the answerer to the question. It's just a poor way of appreciating the point of asking the question.

: a deceptive question that is intended to make one give an answer that is not correct or that causes difficulty

a question that makes you believe you should answer it in a particular way, when the real question is hidden or there is no right answer

If someone asks you a trick question, they ask you a question which is very difficult to answer, for example because there is a hidden difficulty or because the answer that seems obvious is not the correct one.

The question was not inherently deceptive, the deception lies in the beholder. At it's most simple and primitive form the question as it might be asked down the pub to your friend next to you as you idly ponder is; "can a plane on a conveyor belt take off?". You can break it down and augment it with all kinds of clarifications but then it becomes a not very interesting question so what would the point of asking it be?

There's perhaps no way of asking and phrasing the question in such a way that people can't trick themselves with it, that doesn't just give it away to you by doing the work you would need to do yourself to answer the question as typically asked. Notice there is the implication that the plane moves forward in my question -

Imagine a plane standing on a giant conveyor belt runway, the conveyor is programmed to move backwards at exactly the same speed as the plane moves forward relative to the ground on the sides of the conveyor. Can the plane take off?

Just think of it as an engineering experiment, as the plane starts to move forward the conveyor moves backwards at the same rate of acceleration the plane would have were it on solid stationary ground.

Yet people assumed that it was somehow being held stationary. They didn't read the question properly.

Let me demonstrate by asking a series of different questions about the same scenario:

1) Do plane engines drive the wheels?
2) Can planes travel faster than their take-off speed?
3) Considering your answers to 1) and 2), if a plane is on a conveyor belt moving in the opposite direction, can it still reach take off speed?

I think everyone here can answer those questions, and the questions don’t push them towards visualising a static plane the way your / the ‘Mythbusters’ question does.

So firstly I think there would still be people that get it wrong due to not reading the question statements properly, and they'd probably also feel hard done by. And the thing is with the question as you have laid it out is that it has pretty much done the 'hard work' of breaking apart the various forces and mechanisms of the plane for the reader, it more easily leads them to the right answer but defeats the point of asking it.

The point of me asking it was to shine a light on how your intuition and assumptions will fail you, I did this as best I could without deception, assuming you had a very basic understanding of what a plane is and roughly how it worked you had all the information you needed to come to the correct conclusion.

By the way here is the original myth as read out by Adam Savage at the start of that episode -

Normally a plane sits on a runway, spins up it's engine, moves forward, gets enough air over the wings and takes off. But in this case the plane is sitting not on a runway but a huge conveyor belt that is matching the plane's forward speed in reverse. And the grand question is, can the plane take off? The myth is, it can't..

I started off like everyone thinking about it and being fairly sure that it couldn't take off, it was only right at the final experiment that I realised I had got it wrong. Initially there was a bit of sheepishness and shame but that quickly subsided as I realised that it was my intuition and knowledge about planes and lift that had led me down the wrong path.

That was a 'holy shit' moment because it made me think about how easy it is for us to trick ourselves this way, and there must be many things that we assume to be true that we might be completely wrong about. It's liberating. I didn't feel deceived or misled in any way, it was I that got it wrong, not the question.

DrewMerson wrote:

Any question which leads people to misunderstand the real question being asked is a trick question, or just a badly worded one.

Once again; the question did not lead you to misunderstand, you did that to yourself.

Yossarian wrote:

I think it fits the definition of a trick question based on those definitions above. The trick for me, if we were to take the question as posed in the Mythbusters version is in the words “a huge conveyor belt that is matching the plane's forward speed in reverse” because the conveyor belt isn’t able to do that, the plane can always move faster. By implying that this is possible within the question, it sends you down the wrong path.

The conveyor belt can match the forward speed in reverse, that is entirely possible. If the plane moves faster then so does the belt. The whole point is that the conveyor belt is essentially irrelevant to the plane due to the free spinning wheels. It's counterintuitive and therefore interesting.

Like I said it might fit the definition of a trick question, but not the spirit. And the term is a shit one because it gives a person who gets it wrong an excuse that is was an unfair question rather than their flawed thought process. And if it's not clear I'm not having a go or mocking anyone who gets it wrong, it's a good thing to be proved wrong, "failure is always an option".

Yeah, it spins the wheels faster but that doesn’t impact the plane’s speed.

Imagine the plane is on ice skates on a massive frozen lake. It’s essentially the same thing. Once the wheels are spinning they’re essentially just supports to stop the plane skidding on the ground, so it doesn’t matter how much they spin.

I like the question, gets you thinking.

Matching speed is not an impossibility, you may be confusing this version with the one where the conveyor matches the rotation of the wheels, I think in that one you get a feedback loop to infinity when you factor in the thrust from the plane as the wheels will always move faster than the belt. However I think that even if you tried this as a real experiment the plane could probably still take off and the belt would obviously hit some limit. But theoretically that version of the question is paradoxical.

If it makes you feel better you can call this a trick question. As I've said though, I wasn't trying to trick you, it's a simple physics/engineering question.

To be fair i read it as treadmill not conveyor belt initially so obvs i didn't read it properly!

Nope.

It took off even after the rug had been pulled out from under our wheels!

Let's sweep it under the conveyor belt

1. No, it's a simple question that just happens to be one that almost everyone trips up on. There's probably a cognitive bias or two that lines up with this, and I'm reading through the big list of them atm to see what it could be. I think it's quite an interesting phenomenon.

I believe it to be a tricky question, not a 'trick question', there is a difference.

2. As I have previously thought aloud about, it seems like the more knowledgeable you are about aviation and physics, the more likely you are to get stuck on the 'not moving forward = no lift' part. Just because many very smart people can get a thing wrong absolutely does not make it a trick question. See the Monty Hall problem once again. This is do with one or more cognitive biases that lead us to answer incorrectly.

Yes.

Minute hand
360/60 = 6
6x12 = 72
72 degrees

Hour hand
360/12 = 30
30x3 = 90

30/60=0.5
0.5x12 = 6

96 degrees

Distance between the hands is 24 degrees. Unless bullshit or my head maths has failed me.

You’ll probably also have people “well acthully”-ing the phrasing as well, no?

They’ll go from the hour to the minute, not the minute to the hour. So they’ll go around the clock. Then you’ll have people doing an Uno reverso and saying that there’s no need to calculate degrees clockwise and so it doesn’t matter, and then...

Basically it's a bullshit question.

It’s not a trick question but it might be a bad question. If it was in a maths exam and you wanted to test whether or not kids could do the correct calculations then it should be specified to also incorporate the movement of the hour hand. It might occur to someone to do it, but then they think they’re being too clever and just work out the minute hand movement.
If it’s a test of reasoning, then it shouldn’t.