The Seed Vault is real

It’s basically a giant insurance policy. Suppose something terrible happens and a bunch of crops are wiped out. What then? How do you start over? Yes, you go to the seed bank and withdraw your seeds.

https://www.croptrust.org/our-work/svalbard-global-seed-vault/

Feather to detect air currents

MacGyver pulls a feather out of his jacket and uses this to detect air currents. This should work since the feather will move due to super tiny air motion that would be too small for a human to feel.

This reminds me of a job I once had. The job was to go to people’s swimming pools and find leaks. I would take a small squeeze bottle with red dye and let out tiny amounts into the water to see what would happen. If the red dye got sucked into the wall—there’s your leak. Oh, this was done with scuba gear so that I could stay underwater for long periods of time. It was extremely boring.

Finding position from a smartphone accelerometer

Your phone has an accelerometer (probably). At the very least, this accelerometer is used to determine the orientation of the phone so that it knows if you are taking a normal video or a vertical video (don’t do vertical videos).

This accelerometer is essentially a tiny mass on a spring (but not an actual spring). When the phone accelerates, the spring gets compressed by an amount that is proportional to the acceleration. That’s how you get the acceleration. Once you have the acceleration, you can integrate twice to the get the change in position of the phone (assuming the phone started from rest). If you keep doing this every tenth of a second (or whatever time frame you want), you can track the location of the phone. True.

In fact, if you use the augmented reality (AR) on your phone then you have to use the accelerometer. Your phone figures looks at a surface from different viewpoints to figure out how far away it is. The different viewpoints are determined by the motion of the phone and the accelerometer.

Just because it’s cool—here is my short explanation of AR on the phone.

Toxic Pea

Can you actually make a toxin from a pea seed? Yup. That’s possible. In fact, there are a bunch of things out there in the real world that have some pretty deadly stuff in them. Here are some options.

• Fruit seeds. Many fruit seeds have cyanide in them. Not much, but it’s there.
• Some peas have abrin. Toxic stuff.
• Here are 10 deadly plants. Including the caster bean.

Directional satellite dish

If you have a normal wifi antenna on your computer (and you probably do), it basically just transmits radio waves in all directions. It’s not a completely uniform signal strength in all directions, but let’s just assume it is.

Imagine these radio waves expanding out and forming a sphere. Since the area of the this radio wave sphere is proportional to the square of the radius, the signal power decreases with distance. That’s just how it works.

But wait! What if you redirect these waves into one direction? That would increase the radio power along that direction and give you a better signal. However, you now have to aim this thing.

There are several methods to make a directional antenna. The two common methods are to use a parabolic dish (like a satellite dish) or a wave guide. The wave guide uses a tube with an antenna located at a certain point. Waves go down the tube and then reflect to constructively interfere and make the signal stronger in that direction.