Have you ever wondered?

There are some questions we always seem to be asking, but never answering. They aren't necessarily important queries, but ones that we do find ourselves thinking about quite often.
I have recently invented the belief that, in order to begin answering life's bigger questions, you should take care of the smaller questions, the ones you are capable of answering.
During my hours at the local library, checking in and shelving books, I have been fortunate enough to come across books that I never would have otherwise. Some of these books have held the answers to some of those very questions; antidotes to cure some of my perennial curiosity.
Lying in wait inside those pages are not only replies to my plaguing inquiries about the world in general, but pathways that lead to other discoveries and more knowledge.
I found the answers to the following questions in the book Why is Yawning Contagious? by Francesca Gould.
I recommend you read it.

So, why do onions make us cry?
When you cut an onion, sulphur compounds from inside the vegetable are released into the air. When these compounds come into contact with the water on our eyes, it reacts, and creates sulphuric acid. This acid is, as one would expect, quite irritating. Our eyes then produce tears from our lachrymal glands (tear glands) to 'flush away to irritant'. Rubbing your eyes will only make the sensation worse, as you would now have sulphur compounds on your fingers.

Why do we get goosebumps?
When we are cold tiny muscles in our skin (erector pili muscles) contract, causing our hairs to stand on end. When we were once covered in hair, this would result in a layer of warm air being trapped between the skin and the hair, keeping us warm.

What is the ''funny bone''?
Most of you will think the thing that causes your arm to tingle in the painful way when you knock your elbow is a bone. However it is actually a nerve. This nerve is known as the ulnar nerve, and it runs down the inside of the elbow and ends in the little finger, controlling the feeling in your fourth and fifth fingers, and the movement of the wrist. The nerve is connected to a bone called the humerus bone, which runs from the shoulder to the elbow. As you may have concluded, this bone is what gives the ''funny bone'' its name. The painful tingling you experience you feel when you bang your elbow against something is a result of the ulnar nerve knocking against the humerus bone.

And, just if you were wondering, the medical term for using your finger to pick mucus from your nose is rhinotillexis, and the act of eating one's ''bogies'' is known as mucophagy.