No matter how smart we think we are, there is always a concept out there ready to laugh in the face of our logic. We sit back, smug with knowledge, chuckling as Hermione attends two classes at once. Yet the unsettling truth is that the child who believes in these stories is unwittingly closer to the reality of the universe than we are.

Starting with primary school, we are conditioned to order our thoughts in neat progressions. Everything has a cause and effect, time moves linearly, and the world functions according to understandable, predictable rules.

What if I told you this was all nonsense?

Don’t worry, this isn’t some big philosophical revelation, just quantum physics throwing a brick at our entire belief system. Following the laws of the quantum world:

Hamlet can’t ponder whether “to be” or “not to be” because he is simultaneously dead and alive

Physicists refer to this concept as “quantum superposition”. A famous example you may already be aware of is Schrödinger’s cat (but let’s keep the Hamlet analogy because it’s more fun). Let’s put Hamlet in a box. You would think he is either dead or alive in that box. The weird thing is, Hamlet is BOTH dead and alive, up until you open the box, which is when he obtains a definitive state. This is not due to our uncertainty. In other words, we are not assuming that he is both dead and alive simply because we don’t know the answer. In the quantum world there actually is no answer. He is literally dead and alive at the same time until we observe him.

Ballerinas are having a collective meltdown because spinning clockwise in Cambridge means you can only spin counter-clockwise in New York

The ballerinas are victims of “quantum entanglement”. Two quantum ballerinas called Sara and Maya have been best friends for years. They both studied at Cambridge, but now live at opposite ends of the world. The weird thing is, if Sara pirouettes clockwise in Cambridge, Maya instantly whirls counter-clockwise in New York! This is not a telepathic connection, but what physicists call quantum entanglement.

“Einstein referred to this phenomenon as “spooky action at a distance”.”

But here’s an even dizzier thought; Sara and Maya seem to be spinning both ways at once (much like how Hamlet was both dead and alive at once). It is only when an outsider observes Sara dancing, that she “chooses” a specific spin direction. Let’s say Sara chose clockwise. At that exact moment, Maya will find herself spinning counter-clockwise regardless of how far away she is from Sara. This seemingly telepathic connection can occur between entangled quantum particles at apparently infinite distances. Einstein referred to this phenomenon as “spooky action at a distance”.

Catapulted stones from the Trojan War suddenly transform into a tsunami

This refers to arguably the most famous concept in quantum physics known as wave-particle duality. Greek catapults launch stones at Troy’s walls, stones that are about to make Houdini proud. One second they’re determined projectiles but the next they morph into a fluid collective wave; a tsunami crashing over the defences. (Until they are observed, then they suddenly transform back into stones, of course).

But stones lack the panache for such quantum shenanigans. This is reserved for electrons (pfft, show-offs). Quantum particles like electrons have been shown to act as both waves and particles, and this is the property responsible for the remarkable resolution we see in electron microscopes today!

Newton is over at the Physics department, distraught, because his apple has rudely vanished into the floor

The audacity! Poor Isaac, left to grapple with the insolence of a fruit that dared to defy the very law he established. Well, that’s just how it works in the quantum world; barriers are merely suggestions. We commoners would call this teleportation, but physicists know that this is a very real phenomenon called “quantum tunnelling”. It’s a bit like losing your car, and finding it parked on your roof. It doesn’t make sense. Luckily quantum particles couldn’t care less about our logic, they’re just doing their thing.

“It seems the only certainty is the uncertainty of it all.”

The secret is related to their wave-particle duality. Think of how sound can travel through a wall because of its nature as a wave. It’s kind of like that, but not quite. Trust me, delving deeper would only further muddy the waters.

So, in the quantum world, where apples do as they please and particles purposefully confuse us, it seems the only certainty is the uncertainty of it all.

So why does this weird stuff not occur at a macroscopic scale?

Why don’t we see ballerinas spinning clockwise and counter-clockwise simultaneously? How come Hamlet can either be or not be? How come you can’t just teleport to the other side of the door in the middle of an awful date?

The answer all lies in observation.

In all previous examples, when a quantum particle was “observed” it was forced to choose one particular state. Clockwise or counter-clockwise, particle or wave… But only when it was being observed.

At a macro scale, everything is being observed all the time!

Of course, not observation in the literal sense. For example:

A speck of dust hits a wall due to random motion. Although nobody witnessed this collision, the wall’s texture, the initial speed and spin of the speck, and the angle of impact all influence how the collision unfolds. The collision itself is an act of observation! The collision compels the speck and the wall to assume specific states.

Our macroscopic world is teeming with trillions of particles and objects constantly interacting, which means that observation is an ever-present phenomenon. Due to constant observation, there is no chance of any quantum weirdness arising at our scale.

In the quantum world, a particle such as an electron is surrounded by vast nothingness. So much emptiness relatively surrounds the electron, to an extent our brains cannot even comprehend. There is very little chance that it could be accidentally “observed”, which is why quantum weirdness can exist in the world of the tiny.