A Subversive Take on a Physics Mystery

Alejandra Miranda
6 min readApr 14, 2022


Throughout my life, I have always been the kind of person that would ask many questions. Some for genuine interest’s sake and some others for the sake of boggling the minds of adults. What can I say? I’m also quite the jester.

However, this article is not going to expressly speak about said mannerisms. Instead, we will tackle my first sentence, given that it is here that I introduce an important concept: curiosity.

And “why is curiosity important to the matter at hand?” you may ask yourself.

Well, to give you a bit of context, said curiosity is what initially made me pursue a further understanding of the one thing that seemed to appease it: philosophy.

Now, it is easy to see why that would be the case, as philosophers LOVE to analyse difficult questions. And yes, admittedly the fact that I was an angsty teenager at the time might have ignited the pursuit of such a topic, but, hey, let’s not get too meticulous, shall we?

So here I was, a youngling and all, asking the “big picture questions”. You know, the ones that go like:

Why do we exist?

What is our purpose?

Why is it that baba ghanoush is so delicious whilst looking like vomit?

And to these questions, philosophy was only able to provide Absurdist answers (except maybe for the fact that baba ghanoush is exquisite because that sincerely makes no rational sense whatsoever). And that made me needy. Needy for more. And when a person needs more, they often seek greener and better pastures.

And that’s exactly what I did.


Now, an interesting thing to note here is that my desire to study physics didn’t surge as an immediate response to the lack of answers I got from philosophy. Instead, it formed itself as a ‘gradient’. One which, I am afraid, started with a rather vague notion of ‘scientific thought’.

But it was thanks to that explicit interest in ‘scientific thought’ (and, by extension, science) that I began digging up ‘scientific matters’.

Naturally, I started my quest for knowledge with the easiest (and most boring) of sciences: biology (no hate intended to biologists), only to move on to chemistry (because exploding things is way cooler than vivisecting amphibians), which enabled me to finally land on physics.

But, boy, oh boy, what a mistake that was…

Now, don’t get me wrong with that statement. I LOVE physics. Like A LOT. After all, I wouldn’t be pursuing a degree in this subject if I hated it.

So, what is the heart behind my lament?

Well, a simple fact that is easily overlooked:

Physics is a subject for MAD people.

Just look at me! I went from being an individual who innocently wondered about the reasons behind our existence to becoming a person who questions whether we are creditors of the means to affirm that, in reality, we exist.

And such a becoming worried me a lot. At least during the initial minutes of commotion, given that after a while I simply moved on, accepting that I was now part of this “quantum realm of weird people and odd things”.

But it was this messy, curious weirdness that brought about a brand-new series of ponderings within my head that, up to this day, I can’t seem to fully comprehend or rationalise. Be it the black hole information paradox, the definition of time, the reason why space is so dark despite being full of stars, and even the reason why there is a Universe if this, in theory, should not exist!

Nevertheless, none of these “yet to be answered” questions provoked as profound an impact upon me as the one I am about to expose. Because trust me, the fact that we don’t know how any of it works is VERY important.

Yes, folks, I am speaking about the physics of cycling. Or, to be specific, the physics of bikes.

Now, I know what you are thinking: “But, Ari, how can a machine as obtuse as a bike be an object of your fancy?

Well, first I must say that I applaud your use of the word obtuse in said question, and second I must let you know that bikes are anything but obtuse in the realm of Physics.

But why is this the case?

Introduced in 19th century Europe, bicycles (bikes, for short) are human-powered (or motor-powered), pedal-driven, single-track vehicles that have two wheels attached to a frame and whose propulsion is generated through a driving force.

A pretty simple thing, right?

In theory, yes. In practice, not so much.

Allow me to explain.

As we all know, riding a bike is a REALLY fun thing. In fact, it’s one of the best things ever if you find yourself around a park that has many trees during the fall season. However, have you ever asked yourself how is it that riding a bike works?

I mean, it must be pretty simple, right? After all, a bike is just a mix of simple machines that operate together when put into motion by an external force. In most cases, you, a human being capable of riding it (or at least attempting to).

But what happens when we take “you” out of the equation? Or, to put it in “physical terms”, what happens when there is no cyclist on the bike? Can it stay up and keep on moving?

And the answer, believe it or not, is yes! Here’s a gif proving it:

Therefore, at this point, the question at the centre of our current dilemma arises: how do bikes remain upright?

However, before we fully address this highly relevant matter, I must first clarify one thing:

In order for a bike to remain upright, it MUST be set in motion at a sufficient speed.

That is to say that SOMETHING should cause the bicycle to move. In the case of the gif above, a human through a push.

So no, a bike doesn’t just get a “magical ghost rider” atop its mount every time we leave them alone. Let’s remind ourselves not to forsake the physics of motion in this equation to give rise to pseudo-scientific schemes.

But setting that aside, let’s consider the physics that we know in regards to this whole affair:

  • We know that bikes don’t stay up due to the conservation of angular momentum. This is a common mistake given the spinning of a bike’s wheels. If we assume that when a bike tips itself to a side, there will be some “magical” countering force from the wheels that keeps the bike up. This is clearly not the case if you lock the handlebars in place.
  • We also know that bikes don’t stay up due to forward momentum. A bike can indeed change its momentum when a force outside of it (such as yourself) exerts a minor push, but that doesn’t affect its upward position.
  • We also know that bikes don’t stay up due to the gyroscopic effect on their wheels. This helps the bike steer, which in turn provides stability to the bike. However, this isn’t always the case, as bikes lacking this effect are perfectly capable of maintaining an upward position.

So, if what we know is actually what we don’t know, what do we really know?

The simple answer: nothing.

And that, fellow human, is how this apparently simple fact turns itself into a mystery.

Nevertheless, I must note that I missed answering a question I left from the beginning: why is this particular mystery so “important”?

Well, for starters and following what has already been stipulated, we have covered a couple of basic concepts (which you probably learnt in school or, at the very least, have a vague idea about) concerning the physics of movement.

However, when we consider the bigger picture, the fact that none of these simple and seemingly “understood” concepts has the ability to adequately explain the real physics behind the movement of a driver-less bicycle basically means that there is something “not quite right” in our current understanding of movement and, by extension, of physics.

That is to say that: our physics is broken.

Okay, fine. That statement is a bit of a stretch, but one thing is definitely crystal clear in all of this:

Bike physics is alien stuff.

At least for now.

Thanks for reading. (:

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Alejandra Miranda

Spreading words with a sprinkle of fairy dust and, arguably, some science.