The quantum force that can make boats crash into each other

Well, sort of. The latest episode of The Quantum Around You explains the Casimir force, and its real-world impacts.

Back in the 1800s, sailors believed there was a “mysterious force” that would pull ships together if they sailed alongside each other.

It sounds superstitious, but it turns out there may have been some truth to the story - and this mystery force may have been similar to a quantum mechanical effect known as the Casimir force. 

In the latest episode of The Quantum Around You, Associate Professor Andrea Morellofrom the School of Electrical Engineering and Telecommunications at Australia's University of New South Wales (UNSW), provides one of the simplest explanations of the Casimir force we’ve seen, and shows why it’s so crucial to helping us shrink down current technology.

To use boats as an example, picture a ship sailing along a choppy ocean, being swayed by waves on either side.

Because there is an equal chance of waves hitting the boat from every side, the boat continues along its straight path.

But if there are two boats next to each other, any wave between the two will need to have a length that’s equal to or shorter than the distance between the two ships - this means that there’s less chance of the two boats being hits by waves from in between each other than from outside, where there are no limitations on wave type.

As a result, the boats will eventually end up being pushed towards each other by the force of the outside wave and will crash.

While that’s bad news for sailors, the Casimir force is also causing a lot of problems now for people who want to create minuscule metal switches that are made up of two metal plates - the kind of switches that are required to shrink down computers and other devices such as mobile phones.

Instead of ocean waves, the metal plates are being affected by electromagnetic waves, and there’s more force coming from outside the two plates than from between them.

While that might not sound like a very strong force, when you’re working on the nanoscale, it can cause small metallic objects to stick together, as Morello explains (much better than we do, trust us). So take an online quantum physics class from one of our favourite lecturers by watching his video above, and find out more about the Casimir force and how it’s impacting the miniaturisation of today’s technology.