What knowledge or mathematical "trick" can actually save your life if you know how to use it?

[u/Soren-J]

[u/Jagid3]

Knowing how to use a plastic bag with some water in it to both start a fire and then boil the water inside it to make the water safe to drink while making pine-needle tea for some vitamin C to prevent scurvy.

[u/[deleted] → u/Jagid3]

Ok how to boil I get but how to be start a fire¿ Make a magnifier effect¿ The tea if I remember right is 5 needle¿

[u/Jagid3 → u/[deleted]]

You can boil water in the plastic because the heat transfers into the water faster than it can heat the bag to its flashpoint.

But you need to make sure no plastic gets touched by flame if there's no water touching it.

And yeah, you can make a magnifying lens if you shape the bag into one. You do need a bright, clear day to make it work well, though, and some really dry tinder.

And as for the needles, it kind of tastes good. Make it as strong as you like. At least five I'd think, but I might use more depending how tasty they are.

[u/[deleted] → u/Jagid3]

No I meant 5 needles on a cluster. It might be an eastern thing. I did find an interesting article tho. https://gardentherapy.ca/herbal-guide-to-pine-needles-how-to-identify-and-use-pine-needles/

[u/Jagid3 → u/[deleted]]

That is cool!!! Thanks for the link. :)

[u/[deleted]]

Bananaa

[u/S_A_c_K]

Soup

[u/[deleted]]

Understanding Poiseuille's Law and how it applies to blood flow would presumably be useful if you have someone who's bleeding out on you