I’m a huge fan of both science and the Marvel Cinematic Universe, so it’s awesome when these two collide. That’s exactly what happened in Episode 5 of WandaVision.
Here is my super basic introduction to WandaVision for those of you that haven’t seen it. Wanda is a superhero with magical powers that allow her to do all sorts of cool stuff. But one thing that’s maybe not so cool is that she can turn the town of Westview (and all of its people) into some type of TV show. I know, it seems weird—but I’m just trying to set up the physics. In order to keep most people out of her make-believe show, Wanda creates a sort of radiation field around the town, called the Hex.
One of the people trying to figure out what’s happening with Westview is S.W.O.R.D. agent Monica Rambeau. After being ejected from the Hex, Monica wants to get back in and find out Wanda’s motivation. However, there’s a problem: The Hex does stuff to people. In WandaVision, this radiation can make you think you are in a 1970s sitcom or give you superpowers. (In the real world, radiation messes up molecular bonds, including the ones in our bodies’ cells. For humans, that’s just plain bad.)
In Monica’s case, she wisely figures that she needs some type of radiation shielding to get through—and she works out her calculations on a board. (Here you can see part of her calculations.)
So, provided that you also needed to get into Westview, how would you calculate the amount of shielding you would need? Are these equations even legit? Let’s find out.
What Is Radiation, Anyway?
First, we have to figure out what the heck “radiation” actually is. Historically, people discovered radiation before understanding exactly what was going on. At first, they classified it into three categories: alpha, beta, gamma (not very creative). Alpha and beta radiation are particles that are emitted, often due to some type of nuclear reaction. Gamma rays are not particles, but rather a short wavelength of electromagnetic radiation.
Gamma rays are a type of electromagnetic waves—just like radio waves, visible light, and ultraviolet light. Technically, you could consider all electromagnetic waves to be “radiation”—but it turns out that very small wavelengths are the ones that interact with your body’s cells at higher energy levels, which makes them more dangerous. Not only can these rays deposit energy in human tissues, but they can also damage DNA and cause mutations. (It’s very unlikely that gamma rays will turn you into the Hulk.)
All the types of radiation are actually extremely different. The alpha particle is (relatively) heavy and positively charged, but the beta particle has a lower mass and can be negative or positively charged. Gamma rays are just oscillating electric and magnetic fields. There’s also a fourth kind, neutron radiation, that doesn’t have an electric charge. It should be noted that neutrons were discovered long after the first three kinds of radiation, so this type didn’t get a cool Greek letter like the others.
How Do You Calculate Radiation Shielding?
Now we need to calculate the amount of shielding required for Monica’s mission past the hex field and into Westview. How about using a bunch of lead—doesn’t that stop radiation? At least, that’s how you stop Superman’s x-ray vision. (Yes, I know Superman is in the DC Universe and not the MCU.)
Lead does indeed stop radiation, but a shielding calculation is more complicated than just slapping up some thick lead walls. There are several important things to consider when calculating the thickness of a particular shield.