There are Great Mysteries in life, questions that linger, unanswered, over the years. They come to mind for a time and then again another time, when some event triggers them.
One such question for me was, Why do rainbows curve?
I would ask people that question, and most of the time they tried to tell me about prisms and light refraction--concepts I already understood and that had absolutely nothing to do with my question. One time I had seen a triple rainbow: One complete one; underneath it (and with the colors reversed) a second complete rainbow; and to the right, curving away from the first two, was half of a third rainbow. Whatever explanation I received would have to cover all three rainbows, plus one that a co-worker described: from an airplane, he had looked down at the clouds to see a U-shaped rainbow.
I finally got my explanation in two pieces. One person asked if there was a body of water near my triple rainbow that could have reflected light upward to form the second, reversed rainbow. There was: The Yellowstone River. The second answer was given to me by Ask.com, similar to this article, but with diagrams.
Another question came from my 8th grade General Science class and the limited mini-chemistry lesson we got. It was, How can there be carbon monoxide?
We had learned, in 8th grade, about filling the outer shell of electrons, so we calculated carbon and oxygen and got carbon dioxide. But I wondered, if it took two oxygens to fill up carbon, then how could a carbon/oxygen molecule get by with only one oxygen? I never asked my teacher.
I got my answer about ten years later, on the drive to go cross-country skiing with my husband and a friend of ours. I asked the question, since both of them had been science majors. Our friend had taken Chemistry, so he explained rough concepts of single bonds and double bonds and electron-sharing between atoms. I asked a lot of questions to get it clarified just enough that I could picture how carbon monoxide could exist.
Then I started wondering, How does carbon monoxide kill you? I guessed that it bound to the O2 in the blood, rendering it incapable of being used by the body.
A few years later, we were at the beach with my sister-in-law's family, and she was studying Physiology and happened to be reading about the chemistry of the blood. So I borrowed her textbook and looked up carbon monoxide. I had guessed wrong. It binds to the hemoglobin.
Normally, hemoglobin forms an incomplete bond with the O2, so it's easy to let go of the O2 at the right time. But if carbon monoxide gets in there, it forms a complete bond with the hemoglobin and won't let go. After enough exposure, there isn't enough un-monoxided hemoglobin available to transport the O2 around the body, and your tissues die for lack of oxygen when there's plenty of oxygen in your system. It's very sad. Carbon monoxide is chemically evil. (My apologies to Chemistry majors if I butchered this description. I learned it over 20 years ago.)
That brings me to some still-outstanding Great Mysteries:
Why can't Hollywood get the end credits on movie DVDs sharp enough that you can actually read them?
Why does toothpaste say, "For best results, squeeze from bottom of tube"? Do they put all the fluoride at the bottom, and if you squeeze in the middle, you don't get any fluoride or whiteners?
What's on the other side of the end of the universe?
If you have answers, please let me know.
Better yet, tell me what Great Mysteries have been plaguing you. What is it that you want to know?