I’m a firm believer in the power of riddles. I love riddles and enjoy the challenge of solving them. They force me to think in unconventional, abnormal ways – to approach the entire space differently. I enjoy finding and seeing the patterns that emerge in the datasets, and working the various iterations through my imagination. I love my job.

But to the point of this post, I propose that riddles provide excellent critical thinking exercises, and that anyone who proposes to study anything, should desire to hone their critical thinking skills.

A good friend of mine James Babbington and I had a number of conversations around riddles back in the day. He is an excellent thinker, problem solver, and riddler. One of the things I would repeatedly hear him remark on is the elegance of the appropriate solution. Ask him about it sometime and he will wax philosophic on the topic. He is correct as well, one of the most beautiful pieces of answering a riddle or logic problem is the pure elegance of the answer. Once you have it, you know you have it because of the quality of the excellence of the answer, you will not need anyone else to confirm it.

Your hermeneutic is very important in both solving problems and in studying anything. Most folk don’t even know what a hermeneutic is, of the ones that do, most do not know how to suspend or avoid their own nor adopt another. Excellent problem solvers do this regularly, even if they themselves do not formally know the definition of the word. In the most general sense, I intend to use the word hermeneutic as a particular method or strand of interpretation.

By default, your entire life, the sum of all your knowledge, is the window through which you interpret, that is your hermeneutic and you likely do not realize the power that it has over you. I regularly use riddles to determine how well another can solve problems, and even to what degree they suspend their own hermeneutic. One of my favorite riddles for watching hermeneutics at play in the wild is the Airplane vs. Conveyor Belt. It goes like this:

We are familiar with the treadmill? A man gets on, begins walking/jogging/running and a belt moves under his feet to allow him to simulate forward motion at whatever speed without actually moving.

Image we take a runway and replace it with a massive conveyor belt contraption. We then have an airplane rigged to wirelessly transmit it’s speed to the belt controller and program it such that the conveyor belt will always move under the plan, in the reverse direction of the plane, at the same speed of the plane.

You can imagine an ultralight or 747, and an appropriately sized runway rigged as an airplane treadmill, but for the sake of the argument, all parts and equipment are of such quality that the experiment will not negatively impact them beyond normal usage.

In attempting to take off, will the plane succeed in liftoff?

You can go Google airplane vs treadmill and read the myriad of response on the internet to see a good dataset of answers. When I ask people this question, I get a handful of categorically traditional responses.

• Most Common Answer – No. Because without moving forward there isn’t any air pressure around wings and thus no lift.
• Less Common Answer – Yes. Because the plane really doesn’t care what the runway does in this regard.
• That Guy – There isn’t enough data to deduce an answer or; I am so clever I can imagine a way to break the scenario so that the answer can be no.

 The answer is rather straightforward physics, yes the plane will take off.

The most common answer is hindered by hermeneutic. Life experience tells us that motor vehicles are propelled by the wheels.  For many, they daily go get in a car and their experience is one that says, If I put this car on the same contraption with the same rules, it would stay stationary. (As a side note, that isn’t a true statement, it’s just another way people interpret.) So it stand to reason, for them, that the plane must stay stationary as well. So we explain to them that the conveyor belt has a negligible friction affect on the plane that in no way prevents it from lifting off.

The undercarriage (or landing gear) of a plane is primarily the structure that supports an aircraft while it is not in the air, allowing the plane to taxi, takeoff, and land. Typically wheels are used, but skids, skis, floats, or a combination of these and other elements can be deployed, depending on the surface.

Our problem begs for wheels to be deployed. If you imagined skids, skis, or floats, you are likely that one that will be excited to tell us how you broke the problem. Wheels are elegant in this scenario, they are also the single most common deployment that everyone will be familiar seeing.  A wheeled undercarriage is also most often deployed as a simple tire, connected to an axle, with a braking mechanism (for landing). If your imagination insisted on having the brakes stuck in the scenario to prevent takeoff, or you Google’d up one of the exceeding few plane designs in existence that actually relies on propelled tires to assist in takeoff, you are probably that guy.

This question is so divisive because it is a trick question playing upon folks mind in interpreting the relative speed of the plane in respect to the earth, then convolutes the issue with the conveyor belt which, in most folk’s minds, acts like an invisible chain of friction/traction that binds the plane horizontally. They confuse speed with force. The treadmill can move with an opposing speed to the plane, but it does not apply an equal and opposing force, because wheel bearings transmit only a very small rolling friction. The question nowhere states that the treadmill counters the plane’s thrust or keeps it stationary; only that it moves in the opposite direction at the same speed.

Those in the Less Common category nod their heads at this point, go get some popcorn, and proceed to watch the fun. What happens next is nothing less than astonishing.

Most folk refuse to accept the answer. Utterly and completely, just flat out refuse. Their answer is no, and thus the answer is no. There will be a few who will look at the truth and go “Oh. Duh. I see that.” There be some more who will struggle with the anxiety, anger, and embarrassment that being wrong causes them, and will ultimately accept the answer. But the rest, the majority, they are fun to watch.

Folk will rage, they will argue, they will campaign, they will band together with people they might have never known before to convince the world that the the invisible chain of friction exists. Well, they won’t put it that way, but that becomes the logical conclusion of their arguments. Then, some of them will start gathering around that guy, you know, the one who is so clever he imagined a way to break the scenario? They would prefer to go down the street with that guy, who is typically very full of himself, than to grapple with and grasp the truth. The saddest part is this, that guy knows the truth, he gets it. His ego is so full of having people follow and group around him, he isn’t interested in explaining to them the truth, he wants to be glorified in pointing out exceptions.

What can we learn about humans from Google’n airplane vs treadmill and reading all the responses?

1. Few people have the ability to look past their hermeneutic and see the truth, regardless of how elegant it is.
2. A small number of people can easily see the truth when it is concisely presented to them.
3. A few more will struggle with truth that is presented, and eventually embrace it.
4. Many will choose to follow a (some will be the) self absorbed “teacher” who will tell them what they want to hear, that the answer can be no and it is ok for them to believe that.
5. Most will simply maintain that they are correct, effectively sticking their fingers in their ears and singing “neener neener neener” to avoid the truth.