My wife used to complain about my snoring. I used to be chronically tired which led to a sleep study, which gave me a diagnosis of mild sleep apnea aggravated by my excess weight. The medical professions solution was a $1000 CPAP (Constant Positive Airway Pressure) fan-in-a-box machine (paid for by medical insurance). It is annoying, cumbersome and awkward, but it works. Chronic exhaustion is a thing of the past. Now I only suffer from ordinary tired from not getting enough sleep.
At some point I discovered that if I slept curled up on my side in my recliner (you need a wide seat to accommodate thigh bones going crosswise across the seat), I slept as well as I did with the CPAP machine. None of the doctors I have talked to about this believe me. According to the AMA, CPAP and CPAP alone can treat this problem. So it's nice to get a little validation, even if it's from an annoying YouTube video ad. Plus we have a woman snoring. Bonus!
1832 Steam Engine - Jay Leno's Garage. The comments at the end of video about Britain and steam power provide an important history lesson.
Posthip Scott got me started on steamships this morning. In 1926 the Matson Line placed three steamships in the "in the Australian trade". Can you imagine? Taking a steamship from Los Angeles to Sydney? Books, cards, booze and conversation would be your entertainment for three weeks, at least. If your companions were dull, let's hope the books weren't. So you could take a steamship to Australia in the 20's. That seems reasonable. How far back do steamships go? We had the Monitor and the Merrimac during the American Civil War, so 1860. Anything older? How about 1819?
Steamship Savannah, 1819
The first crossing of the Atlantic by a steamship was made by the Savannah is 1819. It wasn't much of a steamship, it was a sailing ship that had a steam engine added. The steam engine drove a pair of side-mounted paddle wheels. The smokestack had a swivel to direct sparks away from the sails. The engine only ran for 80 hours on its first trip across the Atlantic. It made a big impression in Europe and it managed to return to Georgia, but that was about it.
So I got to wondering just what a steam engine from the early 1800's looked like, which led me to Jay's Garage, which is where the video at the top comes from.
I like the tune and the video, even though there doesn't appear to be any direct connection between the two, other than perhaps the jilted lover syndrome. The video is reminiscent of Memento in that it happens in reverse order. The tune is just life, there's no violence in it.
How do you get a delta symbol out of Alt-J? By using a Mac. There might be a way do it on a Chromebook besides using cut and paste but I have yet to figure it out.
The Celestial Equator (Earth's Equator projected on the firmament, Light Blue) Versus The Plane of the Ecliptic (the plane all the good planets use for their orbits around the Sun, Red) They are fixed relative to each other. The line of intersection is marked by the yellow ray, which is pointing at the Autumnal Equinox.
Stu corrected my estimation of the gravity on Cere, so I start checking into it and right off I run into
"Earth's rotation period relative to the precessing or moving mean vernal equinox, misnamed its sidereal day, is 86164.090 530 832 88 seconds of mean solar time...'
The 'misnamed' sidereal day? What? Why would you put an incorrect name in an encyclopedic definition? Jerks. Well, now I've got to look up sidereal day, which is okay, because what I am after is sidereal rotation period. I mean, I've been hearing this word sidereal for like forever, and I know it's got something to do with time because the Earth rotates relative to the sun and that's what determines our normal everyday kind of time, but the Earth also rotates around the sun, so like a planetary gear we've got one extra rotation every year.
The sun gear is red and is fixed when we start this video clip. The planet gears roll around it. The ring gear is traveling in the same direction as the planets but because this is a video, much of the time it appears to be going backwards, much like the wheels on the stagecoaches in Western movies.
The direction the Earth spins is the same as if it were rolling around the surface of the sun, which maybe why the central gear in a planetary gear system is called the sun gear, and the gears that roll around it are called planet gears. Anyway, back to sidereal.
Basically, my assumption about the sidereal day was correct. Because the earth goes around the sun, in absolute terms it makes one extra rotation a year, so you divide 24 hours by 365 days and you get (24*60/365) about 4 minutes a day. That's not exact, but it's close enough for this diatribe. A sidereal day is 4 minutes shorter than a regular old day. You can see the same star in the sky with your telescope every night, without moving the scope, if you just look 4 minutes earlier every night. Eventually it will be daylight when you look and that's because now the Earth is on the opposite side of the sun and you will have to wait 6 months to be able to see it at the same position again.
The problem with the so-called "sidereal day" is because it is measured relative to the Vernal equinox, indicated by the yellow line in the picture at the top, and Vernal equinox is not fixed relative to the firmament. It is also moving, albeit very slowly, one degree every 72 years, which is not enough to make a difference to backyard astronomers, but for people who make a living out of looking at stuff in the sky, well "one degree every 72 years" is not nearly accurate enough.
So there are regular 'solar' days, sidereal days, and stellar days. The difference between a sidereal day and a stellar day is about 8 milliseconds and only matter to people who care about things like precession of the poles.
P.S. You will excuse the extraneous jaunt in gear land, but I just love this stuff. I was just going to put up a still image of a planetary gear set, but then I found a really cool animated gif, but it held the ring gear stationary, so while it was very cool, it didn't convey the correct message. So then I started looking for one that held the sun gear stationary and this video is the only one I found that did that. Keep watching and it will show you several modes.
Posthip Scott sent me a story about Solar Power, which piqued my interest enough to look up some of these places on Google Maps. Until you get up close, most of them don't look like much, they are almost indistinguishable from the background. Most of the ones I looked up are in California's Mojave Desert, which is full of nothing, and big as some of these installations are, they shrink to insignificance when viewed from 100 miles up.
We've got the picture because the bright spots to either side of Jasmine are caused by dust in the path of concentrated sunlight from the old Solar One plant. Solar One and Solar Twoused mirrors to concentrate sunlight to generate steam to drive a turbine, much like a conventional coal fired power plant does. Photovoltaic (solar cells) are getting most of the press these days, and most of the installations, but a new steam generator called Ivanpah just came online near Las Vegas.
The music is the key to whether I can watch aircraft videos. This one uses Derezzed by Daft Punk & The Glitch Mob. I don't much care for the tune by itself, but put together the video and the tune make for an enjoyable couple of minutes. There are a couple of interesting bits in the video: the clouds of condensed vapor forming over the wings at the 1:20 mark, flashing the marker lights at 3:04, followed immediately by a night landing on a carrier. At least I think that's what it is. All you can see are the marker lights. I have no idea what they mean by a "Shack".
Kind of odd that some of the coolest machines in the world are designed and built to kill people. Fortunately for the pilots, it requires constant practice to maintain proficiency, so they get to fly whether there is anyone to kill or not.
