DIY Stethescope

MacGyver takes a bucket and places it up against the wall in order to get a better way to hear what’s going on. This is essentially the same trick as holding up a glass to the wall to hear what’s on the other side.

Sound is an oscillation—usually in the air. When you talk, your vocal cords push on the air to make compression waves. These air compression waves travel out such that your ear can detect them—that’s hearing.

But sound can also travel through solids. Actually, sound travels better through solids than through gases—mostly because the atoms in solids are closer together than atoms in gases. And that is exactly what’s going on here. The sound from the humans travels through the air and hits the wall. This vibrates the wall and the wall vibrates the bucket. Finally, MacGyver can hear the bucket.

Artificial Sunlight

In order to convince the Merchant that he’s in a prison, they need to make artificial light. So, what’s the difference between sunlight and light from an LED? Well, it’s possible to produce a light source with similar colors as sunlight, but how do you reproduce the atmosphere?

When sunlight passes through the atmosphere, the violet and blue wavelengths tend to scatter off the air. This is called Rayleigh scattering. You don’t need to remember that term, but it IS going to be on the test at the end of the semester. Oh, this Rayleigh scattering is why the sky looks blue and the sun looks more red-ish when it’s closer to the horizon.

Well, guess what? There is an idea for artificial sunlight. Instead of passing light through the atmosphere, this system uses nanoparticles. Check it out.

https://www.smithsonianmag.com/smart-news/led-skylights-perfectly-mimic-natural-sunlight-180954348/

Lock pick gun

The basic idea of lock picking is to push the lock pins in the lock cylinder upwards so that they get stuck. Since all the pins have different lengths, the normal way to open the lock is to use a specially shaped metal object that pushes each pin the proper amount. We call this metal object a “key”.

Here is a nice video showing how this works.

But what about a lock pick gun? It’s just like using a rake to go over the pins and push them up, but it does so very quickly with a quick hit. This can push all the pins while twisting the cylinder in hopes of getting them all up at the same time.

For this hack, MacGyver uses the gas cylinder from a taser to power the pick. Seems like it could work.

Grenade protection

Oh! It’s a grenade! MacGyver uses a kevlar vest and a trash can to cover it up. There are two bad things that come from grenades. The first is explosive debris. When it blows up, it sends tiny fragments everywhere—these fragments are like bullets. Bullets are bad. The kevlar vest and the trash can should do a nice job stopping these.

The other bad grenade thing is the pressure wave. The explosion pushes the air into a high pressure wave. When this wave passes over people, bad things happen. The trash can might cut this pressure wave down a bit—but what would really help is distance. The farther you get from the explosion, the greater the decrease in pressure.