Praise then darkness, and creation unfinished

The latest meme going around is to ask someone for "3 subjects I don't think you know or care much about. Then you talk about those subjects in your journal". noachoc gave me:

• Morse Code
• Teletubbies
• Deep sea fishing

What I know about Morse code includes that it's basically a binary code, and that being able to use Morse code used to be a requirement for an amateur radio license in the United States. Free-association gets me to the fact that the Morse "SOS" emergency call was first used by the Titanic, and has now been officially discontinued, but is lurking in slang, the same way "4-1-1" is sometimes used to mean "information" by people who haven't dialed "4-1-1" on a phone in many years, possibly not since they had dial telephones. (This one connects to history, language, and communications, but I'm just free-associating here, and not looking anything up.)

I have seen a couple of episodes Teletubbies, many years ago. I was visiting bohemiancoast, when she had a child in the age group that the program is aimed at. I found it mildly amusing for a little while, but suspect that it would get old very quickly, especially if I had to watch it, rather than happening to be in the room while it was on.

Deep sea fishing is one of those dangerous things that I'm grateful other people are willing to do, because I like eating ocean fish, including tuna. Many people who don't go to sea don't realize how dangerous it is as an occupation, and it's not the only occupation that's true of. (I'm sure there are other jobs that are more, or less, dangerous than I realize.)

(I could take this topic in the direction of conservation, oceanography, the development of navigation, or the European exploration of the Americas, but none of those is exactly about fishing, despite the connection to the Portuguese fishing off the Grand Banks, and the trade in dried cod. Excuse me, I have a sudden impulse to go read about the Hanseatic League.)

If anyone would like me to give you three topics, along the same lines, ask; of course, if I don't know you very well, I may give you a subject on which you could happily talk for days.

Turtles belong to the reptilian grade of physiological organization. They are ectothermic and have relatively low metabolic rates. Being ectotherms, their body temperature remains close to the temperature of their environment, and they are entirely reliant on external sources of heat. Many turtles bask in the sun to raise their body temperature to a point where bodily functions can operate optimally. One species, the leatherback, can maintain a body temperature above that of its environment, but how this is achieved is yet to be determined. Most turtles cannot be active during very hot or very cold periods. Therefore, hibernation in winter and aestivation in summer is common for members of this group.

Turtles breathe with lungs located inside of a rigid ribcage. They therefore must use a different mechanism for breathing than most vertebrates. Muscles in the region of the leg pockets act to inflate the lungs, muscles on the surface of the lungs dorsally and ventrally deflate them. Many turtles augment gas exchange at the lungs with gas exchange in the throat or in the cloaca.

In addition to providing protection for the turtle, the shell of at least some species has an important physiological function. It acts as a "calcium bank". Calcium and other cations are taken from the carapace and plastron to buffer the blood during hibernation when metabolic acids are likely to build up. In other species, it appears that in reproductively active females, calcium is removed from the shell and incorporated into eggshells forming around follicles in the oviducts.