Non-science note. The more I see David Dastmalchian as he plays Murdoc, the more impressed I am. That dude is awesome. Also, this episode has a great “Midnight Run” type of feel (great movie, btw).

Now for some science stuff.

Portable Gas Chromatagraph

This part of the script is pretty nice:

Jack: “You brought something too?”

MacGyver: “It is a portable gas chromatograph. So, It takes samples from the air and it scans them for explosive particular matter.”

Jack: “So, it’s a bomb detector? Why didn’t you say that?”

MacGyver: “I thought I did.”

Perfect.

A gas chromatograph is sort of complicated. But yes, it could be used to detect chemicals. Yes, you can make them portable. That’s enough.

DIY Noise Maker

How do you get the attention of a bad guy? House about a noise maker? This is essentially the same as this mouse-trap powered car. https://www.wikihow.com/Build-a-Mousetrap-Car —but instead of a spinning wheel, it

Oh, it has a built in timer—a leaking bottle of water. Here is the shot from the show.

And here is my rough sketch.

Speaker Microphone

Oh snap. That pay phone is broken. Wait! What’s a pay phone?

MacGyver fixes the missing headset by using two speakers from the car. One speaker is used for the speaker and the other speaker is used for the microphone.

It’s actually pretty cool, but most speakers can be used a microphone. The normal speaker is basically just three parts:

• A magnet.
• A coil of wire.
• Some type of surface area to push air.

The coil of wire is connected to the speaker surface. When current is run through the wire, the coil makes a magnetic field. This magnetic field from the coil interacts with the other magnet to either push or pull the surface of the speaker. This in turn pushes the air into compressions—and it is these compressions in the air that make the sound.

For a microphone, the reverse happens. Compressions in the air push the surface. This moves the coil closer (or farther) from the magnet. This motion changes the magnetic flux (via Faraday’s Law) which induces a current in the coil. This current is then recorded as an audio signal.

Don’t believe me? You should try it. Oh, make sure you use a speaker like this:

OK, there are some weird things in these old phone head sets. I think they have to use super low resistance microphones and speakers since the power comes over the phone line. But still, this is very plausible.

Break a chain with handcuffs

Oh, and a steel rebar thing. MacGyver loops the handcuffs around the chain and then puts the rebar through the cuffs and twists.

With a longer metal bar, you can get a high torque on the chain. This should break the chain—at least as long as the hand cuffs are stronger than the chain.