Disable a Motorcycle
Some dudes are trying to escape with a motorcycle. MacGyver uses a strap with a hook and launches at the motorcycle. The hook grabs onto the chain and then Mac pulls so that the chain pops off the gear.
Oh, sure — this would be pretty hard to accomplish, but it’s at least plausible. Normally these motorcycle chains are fairly difficult to remove, but it’s possible it was loose to begin with.
Henna Oxidation Test
So, there is a henna smudge on a murder victim. As part of the wedding festivities, many people were getting henna on their hands (henna is a type of temporary body art — it’s pretty cool). MacGyver comes up with an idea to use all the social media posts to match the henna smudge with an actual person.
When henna is applied, it interacts with the oxygen in the air (pretty much everything does this) which causes it to change color. This is an oxidation reaction. MacGyver just needs a relationship between the color of the henna and the time it takes to get to that color. Then he can find the time the henna was applied and look for someone that posted an image to identify the killer.
Instead of waiting for a long time — MacGyver builds a little oxidation oven to speed things up.
MacGyver first notices stains on Sumita’s fingers. He then smells ammonia nitrate (honestly, you probably wouldn’t still be able to smell it — but it’s possible). Of course ammonia nitrate can be used to make bombs.
Now, for a bomb detector — from a fish tank. So, you have to monitor the nitrate levels in a fish tank to make sure the levels are right. Here is a very cool (and real) nitrate monitor.
He starts off with a carbon monoxide detector and adds cadmium (from an old cordless drill ni-cad battery) so that it can react with the nitrates.
You would really need to get the air moving over this thing fairly fast — but like many hacks, it’s at least based on real science stuff.
Just like MacGyver says, there are two things that explosives do — they shoot shrapnel and stuff everywhere and they make a pressure blast wave. Both of these are bad for humans.
MacGyver takes two large planting pots and stuffs the bomb in one of them. He then turns them upside down. When the blast goes off, these will provide some level of protection (it wasn’t a huge bomb anyway).
Actually, a fairly common physics demo (but dangerous) is to put a trash can over a liquid nitrogen bomb. This is what that looks like.