Those of you that read this irregular series know that I am from Hackett, Arkansas, just a mile of so from the Oklahoma border, and just about 10 miles south of the Arkansas River. It was a redneck sort of place, and just zoom onto my previous posts to understand a bit about it.
I never write about living people except with their express permission, so this installment is about a long dead denizen of Hackett. This time it is about a teacher of mine, Elwood Brockman.
Mr. Brockman taught high school maths, and was also the grade school principal. Since the entire school system from grades 1 to 12 (no K at the time), double duty was the norm.
For a firearm to operate, there must be an energy source to impart kinetic energy to the projectile being fired. This is is true in general, but our discussion shall be limited to small arms with only a couple of exceptions. These materials are called propellants, and the name is quite apt.
The first propellant used was blackpowder, the exact origin of which is lost in antiquity. For centuries, actually up to very late in the 19th century, blackpowder was the only propellant available.
In the late 1880s what is now called smokeless powder was developed, and has replaced blackpowder in almost all applications except for what I refer to as “boutique” ones. A substitute for blackpowder, Pyrodex(R) was developed , along with some other substitutes for reasons that will become apparent later.
Hydraulic fracturing, also called hydrofracture or just fracking, is a commonly used method to increase the yield of fluid raw materials, usually petroleum or natural gas, from formations that are not “easy” extraction targets. Easy targets are ones that the fluids dispersed in sands or very porous rock formation.
Let us dispel a common myth right now: oil and gas is almost NEVER found as big pools of those materials in large holes in the rock. Almost without exception, and perhaps quite without exception, these materials are dispersed in some more or less porous rock or sand. When you see pictures of underground reservoirs of gas or oil, you are really looking at the fluid as it is dispersed in the native matrix.
Sand and very “rotten” sandstone are easy matrices from which to extract the fluids. Shale and hard sandstone are much more difficult matrices, and hydraulic fracturing is used to increase yields from such formations.
Anterior poliomyelitis, mainly called polio (the old name was infantile paralysis) was a scourge for centuries, but was not recognized as a specific disease until comparatively recently. This piece is in honor of the huge immunization program that was begun 56 years ago last week in the United States, that fact kindly pointed out by our good friend ek hornbeck at TheStarsHollowGazette.com a couple of days ago.
Most people do not know anyone who was infected with the paralytic form of this disease these days, partly because they either died or got better, but mostly because of the most successful vaccination program against an infectious disease ever attempted. I have first hand experience with two cases, and will turn 54 on this coming Wednesday. Few people younger than about my age will have known anyone who had it.
Everyone is familiar with phase transitions even it they are not familiar with the term. Amongst the most familiar is the melting of ice and the boiling of water to form steam. Technically, these transitions are called fusion and vaporization, respectively. There are more and we shall discuss some of them later.
All phase transitions are accompanied by changes in the free energy of the substance undergoing the transition, and this free energy has two components, the enthalpy of the transition and the entropy of the transition. Unless very careful work is being done, the entropy change is often ignored because it, in many cases, is the lesser contributor. However, it is never zero (except at absolute zero) and sometimes is the dominant factor.
I was astonished at the response for the first installment for this series, and so decided that instead of just a couple of survey pieces, reader interest justifies a bit longer treatment, getting more into the weeds. Thus, I have come up with a bit more structured series.
Unlike rifled firearms like pistols and rifles, shotguns are smoothbore weapons. That is, they have no rifling to impart spin to stabilize the projectile, in the case of shotguns usually multiple projectiles. Shotguns are a relatively recent development in their current form, but the concept of firing more than one projectile at a time goes back a very long time.
Modern shotguns are designed to fire a relatively large diameter cartridge as opposed to rifles and pistols. In addition, a different system is used to state the diameter of the cartridge in most cases.
Happy New Year to everyone! I hope that 2011 will find you well and prosperous. Last week we began to examine the so called Rare Earth Elements, which turn out to have lots of uses, many of them to do, oddly, with optics in diverse ways. This week we shall finish up the series about them.
I reluctantly admit that I did not take as much time as necessary for the piece last week, mostly because even I did not understand just how important these elements are, both from a modern technological standpoint and also from an historical one for chemistry becoming a modern, “hard”, science. First we shall look into some history, then finish up the elements themselves.
The first total lunar eclipse in nearly three years will be visible this
Monday/Tuesday over North and South America beginning at midnight on the
21st of December, 2010.
The Moon’s orbit is slightly canted with respect to
the plane of the ecliptic (the plane in which the Earth orbits the Sun)
and therefore crosses that plane twice a month.
At the points where the full Moon crosses the ecliptic
a lunar eclipse can occur. Like solar eclipses there may be between 2 and
5 lunar eclipses per year.
There are three types of lunar eclipses. Penumbral, partial, and
selenelion (selenehelion).
A penumbral eclipse occurs when the Moon passes through the Earth’s
penumbra. The penumbra causes a subtle darkening of the Moon’s surface. A
special type of penumbral eclipse is a total penumbral eclipse, during
which the Moon lies exclusively within the Earth’s penumbra. Total
penumbral eclipses are rare, and when these occur, that portion of the
Moon which is closest to the umbra can appear somewhat darker than the
rest of the Moon.
A partial lunar eclipse occurs when only a portion of the Moon
enters the umbra. When the Moon travels completely into the Earth’s umbra,
one observes a total lunar eclipse. The Moon’s speed through the shadow is
about one kilometer per second (2,300 mph), and totality may last up to
nearly 107 minutes. Nevertheless, the total time between the Moon’s first
and last contact with the shadow is much longer, and could last up to 3.8
hours.wiki: [1] The relative distance of the Moon from the
Earth at the time of an eclipse can affect the eclipse’s duration. In
particular, when the Moon is near its apogee, the farthest point from the
Earth in its orbit, its orbital speed is the slowest. The diameter of the
umbra does not decrease much with distance. Thus, a totally eclipsed Moon
occurring near apogee will lengthen the duration of totality.
A selenelion or selenehelion occurs when both the Sun and
the eclipsed Moon can be observed at the same time. This can only happen
just before sunset or just after sunrise, and both bodies will appear just
above the horizon at nearly opposite points in the sky. This arrangement
has led to the phenomenon being referred to as a horizontal eclipse. It
happens during every lunar eclipse at all those places on the Earth where
it is sunrise or sunset at the time. Indeed, the reddened light that
reaches the Moon comes from all the simultaneous sunrises and sunsets on
the Earth. Although the Moon is in the Earth’s geometrical shadow, the Sun
and the eclipsed Moon can appear in the sky at the same time because the
refraction of light through the Earth’s atmosphere causes objects near the
horizon to appear higher in the sky than their true geometric position.wiki:
[2]Wikipedia
Unfortunately, the weather seems to be taking a Republican bent and will
not cooperate over the 20th/21st.
Again thanks for your time. I look forward to your comments and critiques
below.
If you’ve ever visited the Daily Kos you may have noticed my nightly comments where I post a video from the series called Sixty Symbols on the Overnight News Digest. I thought you might enjoy these videos with some additional explication and exploration. There are a whole passel of them so getting through them all will take some time. I wonder, as I begin this random walk, where it will take me and what exciting and cool things I might learn and share.
No? OK, but apparently four engineers from prestigious universities using integral calculus, high speed photography and borrowed equipment from the International Space Station, curious about how cats drink figured out just how our feline companions and their larger counterparts in the wild lap it up. It isn’t what you would think, after all, cats are not dogs.
Cats lap water so fast that the human eye cannot follow what is happening, which is why the trick had apparently escaped attention until now. With the use of high-speed photography, the neatness of the feline solution has been captured.
Writing in the Thursday issue of Science, the four engineers report that the cat’s lapping method depends on its instinctive ability to calculate the point at which gravitational force would overcome inertia and cause the water to fall.
What happens is that the cat darts its tongue, curving the upper side downward so that the tip lightly touches the surface of the water.
The tongue is then pulled upward at high speed, drawing a column of water behind it.
Just at the moment that gravity finally overcomes the rush of the water and starts to pull the column down – snap! The cat’s jaws have closed over the jet of water and swallowed it.
The cat laps four times a second – too fast for the human eye to see anything but a blur – and its tongue moves at a speed of one meter per second. . . .
At first, Dr. Stocker and his colleagues assumed that the raspy hairs on a cat’s tongue, so useful for grooming, must also be involved in drawing water into its mouth. But the tip of the tongue, which is smooth, turned out to be all that was needed.
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