# MacGyver Season 4 Episode 13 Science Notes: Save + The + Dam + World

Is this the best episode title? Probably.

Sheva Power

So, there’s this machine that Tesla made (just in case you weren’t following the previous episodes) called Sheva. It was used as a type of directed EMP device to destroy electronic stuff.

Aunt Gwendolyn says that it’s not just a weapon. It’s also a renewable power source. OK. Let’s just assume that Tesla figured out something that no one else figured out. I’m fine with that.

However, you can’t get energy for free—like, never. If you want to produce some electrical energy output, SOMETHING has to decrease in energy. It is the way. Even with a nuclear power plant, there is a change in mass energy (from the $E = mc^2$ thing).

What about renewable energy? Really, this just means the original source of the energy is something we don’t care about. If you use solar panels on your house, you can get electrical energy. This comes from the Sun—which is basically a giant nuclear fusion power plant. But who cares if the Sun decreases in mass? It’s really not our problem. So, solar panels aren’t giving you “free energy”.

OK, so what about Sheva? No one knows. That’s why this is such a great weapon/tool. Maybe it gets energy from the interaction between the Earth and Sun’s magnetic fields. Perhaps it has something to do with other dimensions. Clearly, it’s not just hand-crank powered. That wouldn’t give enough energy for an EMP and it wouldn’t be renewable. The mystery is why it’s cool.

Nuclear Critical Mass

There’s a bunch of stuff here, so let’s start with the most basic part. What is nuclear fission?

OK. Suppose you have a big atom. Let’s say it’s Uranium-233 (this means it has 92 protons and 141 neutrons in the nucleus). If you throw a neutron at this atom, it becomes unstable and (usually) breaks into Xenon-137, Strontium-94 and 3 neutrons. The mass of all this stuff is less than the mass of the U-233 with the lost mass being converted to energy.

If you have just one uranium atom, you just get a small amount of energy. But if you have a whole bunch of uranium atoms, you can get a chain reaction from those neutrons. How many atoms you need for a chain reaction is the critical mass.

Sheet Metal to Protect from Missile.

A missile is inbound to hit the warehouse with MacGyver and Riley. MacGyver takes a piece of sheet metal to cover both of them inside a small inclosure. The missile hits. Boom. Explosion. Fire.

Would this work? There are three things you have to worry about with an explosion:

• Projectile debris. Stuff gets flung all over the place. If this stuff hits you, it’s like getting shot with a bullet (or worse).
• Pressure wave. The explosion creates a change in air pressure that pushes outward. This pressure wave can seriously destroy the insides of humans.
• Fire. Sometimes, there is also fire.

The sheet metal and the enclosure would surely give some protection from the projectile debris. It might also protect from fire. It wouldn’t do too much against the pressure wave. However, for an unconfined explosion the pressure wave expands in all directions and decreases in damage as it gets farther away. If they aren’t too close, they might be able to survive.

Destroying a Nuclear Bomb with a Conventional Explosion

So, there’s a nuclear device. It’s going to explode and destroy a dam. The dam will flood a volcano. The volcano explodes and covers much of the Earth’s atmosphere with volcanic ash to make things bad. That means MacGyver needs to stop the nuclear explosion.

Really, you don’t need some super secret knowledge to make a nuclear bomb. Pretty much everyone knows how to do it. However, it’s still difficult. You need the following two things for a nuclear weapon:

• Nuclear material.
• Precise engineering.

The key is to get a nuclear chain reaction started. The reaction is almost always (but not always) initiated with conventional explosives. It has to be JUST right to get the thing to go nuclear.

If you put a conventional explosive near a nuclear bomb, it can disrupt the very delicate start of the chain reaction. Of course, it’s still a bomb—so, that’s not good. Also, much of the stuff in the nuclear bomb is radioactive and you will have just spread that all around the place, that’s also bad. But it’s better than a nuclear device.

## 4 thoughts on “MacGyver Season 4 Episode 13 Science Notes: Save + The + Dam + World”

1. Michael Burns-Kaurin says:

I’ve seen movies where the hero has the nuclear bomb opened up and just has to snip one wire to keep one conventional explosive from exploding to prevent the proper compressional shock, but can’t figure it out. Kudos to MacGyver.

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