MacGyver Notes Season 3 Episode 9: PAPR + Outbreak

What the heck is PAPR?  It’s an acronym.  It stands for Powered Air Purifying Respirator.  It’s a thing people wear when the are around bad stuff—like a deadly virus.  OK.  Let’s get to it.

Glycerol Lock Hack

Technically, not a “MacHack” since MacGyver didn’t do it.  I’ll proceed anyway.  So, the bad person replaces the mouse lock with a piece of solid glycerol.  Glycerol has a melting point just below room temperature (18 C).  So, in this room it would take a little time to melt.

When the glycerol melts, there is no longer a “pin” holding the door closed and the mice escape.

What other substance could the guy use?  What about something like chocolate?

Positive Pressure

Again, not technically a hack.  If you want a hazmat suit, you want it to be at positive pressure.  Positive pressure means that the interior of the suit is at a higher pressure than outside the suit.  The nice thing about positive pressure is that if the suit gets a hole, the positive pressure pushes the air in the suit out of the suit.  This makes it very difficult for an external virus to get in the suit even if it has a hole.

Sometimes, it’s better to have negative pressure.  In chemistry labs, they use things called “hoods”.  These are essentially enclosed areas that vent to the outside of the building.  They allow a chemist to run an experiment and reduce the risk from fumes.

A hood is at negative pressure.  This means that when the hood door is open, there is air going INTO the hood from the room. That prevents the chemicals inside the hood from getting out.

Oh, here is a video showing the difference between positive and negative pressure.

Detecting Hydrogen Peroxide

The bad guy (again, really he just makes bad decisions—maybe he is not bad, but who am I to judge) uses hydrogen peroxide to dye his hair blonde and to elude the team.

MacGyver then needs to make something to detect this hydrogen peroxide from his hair as the baddie sat in different taxi cabs (OK, the guy has to be bad—who still uses a taxi?).

OK, there is indeed a method to detect hydrogen peroxide and one method does indeed involve a compound from horse radish (yes, that’s weird).  I don’t think it would just turn red, but there would be an interaction between the chemical and the peroxide that could lead to a detection.  It would probably involve illuminating it with a UV light and seeing it change colors.

Battery hooked to a door handle

Again, this isn’t directly MacGyver’s hack.  Instead, Riley sets up a trap—but she said she learned it from MacGyver, so I guess it still counts.

In order to slow down a baddie (different bad guy) she takes a car battery and connects one terminal (I think she uses the positive) to the door handle.  In order for this to work, she has to also connect the negative battery terminal to ground (or something like that).

When the baddie grabs the door handle, he gets shocked.  The key here is that there must be a complete circuit formed when the dude grabs the handle.  That means the negative terminal of the battery would have to also connect to the guy somewhere so that there is a path for the current to flow and shock him.

One way to get this to work would be to have another small wire near the bottom of the door that is connected to the battery.  When the baddie grabs the handle, he also hits the wire—thus making a complete circuit.

Another option would be to use a puddle of water under the door with the negative terminal connected to the puddle. Of course, the dude would need to get wet—so normal shoes might prevent this.  Personally, I like the small wire sticking out option.

Air Wedge

Yes, air wedges are real.  You take this flat bag and stick it in a door—they are usually used for car doors.  When the wedge inflates, the car door is pulled back a little bit—enough to get a stick through the opening to open the lock.

Would this work with a normal door?  Why not.



MacGyver Notes Season 3 Episode 8: “Revenge + Catacombs + Le Fantome”

SQUID Device

This stands for Safe Quick Undercarriage Immobilization Device (SQUiD).  How long did it take someone to come up with that acronym?  Awesome job.  MacGyver’s version consists of a chain type thingy.  When a car passes over it, the chain hooks on to the axle and wraps up.  This would stop the car.

OK, it would’t flip the car over.  It would stop the front wheels and the car would skid to a stop.  But doesn’t the flip look cool?

Actually, that’s a great physics question.  How fast would a car have to travel such that a sudden stop would flip it over? That’s your homework.

Methanol fire

Yes. Methanol burns—and you can’t really see it.

Carbon Dioxide Putting Out Fire

Fire needs three things: fuel, heat (to start), and oxygen.  If you take away the oxygen, you take away the fire.  If you replace the air (which has 21 percent oxygen) with carbon dioxide, the fire goes out.

So, in this hack MacGyver uses some CO2 tanks to fight the methanol fire.  Yes, an exploding tank would put this fire out.  Oh, but it would also make it hard for a human to breathe.  Better hold your breath.

Pick a lock with a knife

This is theoretically possible.  If you stick something in the lock and use enough torque, it’s possible that the pins in the lock could break.  But otherwise, you need to jiggle the pins.

Comeback Can.

Real.  You can build one yourself.  You should.  Do it.

Chemical Detector

MacGyver puts a chemical detector on the comeback can.  When it rolls down the hallway and back, he can check if it contacted explosive chemicals.  This is very plausible—there are several ways you could make chemical detection paper.

Tarp Bomb Lift

MacGyver uses a tarp under a bomb with a rope over a rafter in the ceiling to lift a bomb.  A couple of notes.

  • If the rope just goes over a rafter (no pulley), you would need as much weight pulling down as the weight of the bomb.  Since two people are pulling, this is at least plausible.
  • A pulley would be better.  A full explanation.
  • Actually, there is a cool physics problem here.  If Riley and Bozer pull at an angle, how much can they lift without sliding towards the bomb?  Don’t do this as a homework problem, I’m going to do it.