Sunday Science: Quantum Mechanics

This week, scientists reportedly brought "nonsensical" quantum physics into the real world for the first time. Is quantum physics really nonsensical? Or do we just need an Ironman Lego figure to help us truly understand it?

What is quantum mechanics?

Quantum mechanics is the science of the incredibly small. When you are trying to describe how a tiny particle will act (compared to an object you can see unaided in the real world) weird stuff starts to happen.

Time to look at a superhero example. Here's Ironman standing on my desk:

Because I live in a world governed by the rules of the classic physics, I'm pretty confident that Ironman will stay stood there until my son reclaims him.

In the quantum world, if you conduct a measurement you can’t get a single, definite answer about its outcome. 

​When I'm not looking at Ironman in the quantum world, he could be doing an infinite number of things. By observing him, I am forcing him to do the most likely of these things.

The minute I look at him, I dictate the state he's in. It's most likely that he'll still be there, in the same position on my desk. So, that's the state he returns to when I look at him.

As Einstein once put it: “Do you really think the moon isn’t there if you aren’t looking at it?”

It's confusing stuff, and here's some extra reading to help you out:

• Are the Quantum World and the Real World the Same Thing?
• What can the Quantum World teach us about reality?
• Physicists can't agree what the Quantum World looks like

Why should I care?

If quantum mechanics exists on a scale so small that we can't see it - why do we need to understand it?

Well, the principles of quantum mechanics have guided some of our most important discoveries. For example, the transistor and diode (two of the most fundamental parts on a computer chip) are based on the laws of quantum mechanics. Without quantum mechanics, I wouldn't have a computer to write this on.

Here's an excellent article highlighting 10 of the practical applications of quantum mechanics.

​There is also a range of practical uses for one of the spookiest quantum mechanical phenomenon - entanglement. Quantum entanglement states that particles on opposite sides of the universe separated by billions of light-years are intrinsically linked, and this link lets them share information instantly.

​Einstein scoffed at the premise - but it was later proven by John Stewart Bell. 

And that's the real problem with quantum mechanics - its principles and ideas are so alien to our human brains that we can struggle to visualise and understand them.

With this week's first glimpses of quantum effects happening on a scale just big enough to be seen by the human eye, a new era of understanding and discoveries in the quantum world can, hopefully, begin.

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What is Sunday Science?

Hello. I'm the freelance writer who gets tech. I have two degrees in Physics and, during my studies, I became increasingly frustrated with the complicated language used to describe some outstanding scientific principles. Language should aid our understanding - in science, it often feels like a barrier.

So, I want to simplify these science sayings and this blog series "Sunday Science" gives a quick, no-nonsense definition of the complex-sounding scientific terms you often hear, but may not completely understand. 

If there's a scientific term or topic you'd like me to tackle in my next post, fire an email to  [email protected] or leave a comment below. If you want to sign up to our weekly newsletter, pop your email in the form below - thanks!