There’s a summer camp going on at Waterloo’s Institute for Quantum Computing called QCSYS, the Quantum Cryptography School for Young Students. A lot of these kids are interested in physics in general, not just quantum computing, so they give them a tour of Perimeter. While they’re here, they get a talk from a local postdoc, and this year that postdoc was me.

There’s an image that Perimeter has tossed around a lot recently, All Known Physics in One Equation. This article has an example from a talk given by Neil Turok. I thought it would be fun to explain that equation in terms a (bright, recently taught about quantum mechanics) high school student could understand. To do that, I’d have to explain what the equation is made of: spinors and vectors and tensors and the like.

The last time I had to explain that kind of thing here, I used a video game metaphor. For this talk, I came up with a better metaphor: legos.

Vectors are legos. Spinors are legos. Tensors are legos. They’re legos because they can be connected up together, but only in certain ways. Their “bumps” have to line up properly. And their nature as legos determines what you can build with them.

If you’re interested, here’s my presentation. Experts be warned: there’s a handwaving warning early in this talk, and it applies to a lot of it. In particular, the discussion of gauge group indices leaves out a lot. My goal in this talk was to give a vague idea of what the Standard Model Lagrangian is “made of”, and from the questions I got I think I succeeded.

## 5 thoughts on “Physics Is about Legos”

1. ohwilleke

Love it. Way better than the video games analogy. Also, good job keeping in human by discussing the people who did it. I also like to talk about how Newton was a Unitarian theologian and alchemist.

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2. Giotis

Very good indeed.

Haven’t you forgotten something the skeleton in the closet (or in the action at this case) though?

Λ

🙂

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