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2016 December 31 (Extra)
Two thoughts about thinking and learning
(1) Making a simple thing complicated is a misuse of intelligence. We should be
making complicated things simple.
But not simpler than they actually are, of course.
People sometimes ask me to make something simpler than it can possibly be.
(Like "Explain how a car works, but don't mention gasoline.")
The most I can do for such a person is show them where to grab the complicated whole —
that is, which parts are most important and need to be understood first.
(2) If you can't explain something simply, you don't understand it yourself.
That principle is credited to the great physicist Richard Feynman.
When you memorize and reproduce complicated sentences, words, or formulas without clearly
understanding them yourself, you're not learning. You may think you are, but actually
you are like the schoolchildren (described by Dewey, I think) who can recite "The sun rises
in the east and sets in the west" but can't point to where the sun will set
(and don't ask an intelligent question such as "Which way is west?").
To them, "east" and "west" are empty words. They think they know something, when all
they're doing is reciting words they don't understand.
How many people's understanding of algebra, or science, or even bookkeeping
is on this level? I have had an engineering student try to tell me, in all seriousness,
that Ohm's Law doesn't describe how anything works, it's just a formula "that you can't understand."
Sure, sure. To that kind of mind, "the sun sets in the west" is also just a formula you can't understand.
Still from the December 24 optics-testing session, here is an image of the Flame Nebula
(to the left of the star Zeta Orionis) and, dimly, the Horsehead below it.
This was taken from my driveway under somewhat hazy skies.
It does help show which parts of the nebulosity are the brightest.
It's a stack of ten 1-minute exposures, AT65EDQ, Nikon D5300 at ISO 400.
For a much more generous exposure of the same field,
click here.
Why I don't use Amazon Echo, Siri, or voice-recognizing toys
I don't think anyone has given enough thought to the security hazard
of having a computer, always turned on, that is listening to your voice and is
connected to the Internet.
Very simply, a bit of malicious programming could make it record everything
it hears and send it to someone far away who might be up to no good.
Right now, there's a dispute about evidence in a murder case that may have been
recorded by an Amazon Echo. Frankly, I trust the police more than I trust Amazon.
We may be entering a bizarre world in which private companies claim the right
to spy on us.
I distrust the "Internet of Things" as a whole (even though I have the
technical skills and ought to be busy building it!). The Internet is inherently
not very secure. Some parts of it, such as online banking, have been made secure
by great effort. But cheap devices that are never updated are always going
to be the least secure part.
I don't want my thermostat, car, etc., connected to the world-wide Internet so that
someone might spy on them or even tamper with them from far away.
Cheap children's toys that recognize voices, and use Wi-Fi, might be the
biggest hazard.
For the Internet of Things to succeed, it's going to have to establish security
standards and enforce them — and also not let manufacturers disclaim
responsibility for what goes wrong.
That may make an Internet thermostat cost $500 instead of $50.
But it's what is really costs.
It may also make us rethink what we want from networking.
The idea of the Internet is to put all the computers in the world on one network.
That's great for mass communication, but not for privacy.
Maybe the network within my house shouldn't have unrestricted access to and from
the outside world.
Non-routable protocols such as Coraid's ATAoE
might have a role; these are data packets that can travel on the network within
one building but can't get through a router, and so can't escape into the outside world.
Combine non-routable packets with one or two heavily secured computers that serve
as gateways to the outer Internet, and you might have something.
This strange year, 2016, is going to last one second longer than a normal calendar
year; there will be a leap second added to the end of it.
How I'll spend the extra second, I don't know.
Be ready for minor computer problems on computers that are scheduled to do something
at midnight GMT (7 p.m. EST) and might do it twice.
On a more serious note, this year has been a wild mix of good and bad things.
On the national level, we have elected an unusually
inexperienced and controversial president,
and during the campaign, some very ugly aspects of American politics were on display.
But we have a strengthening economy.
And much has been made of the flurry of celebrity deaths (most recently
Carrie Fisher and Debbie Reynolds). I think that what is actually happening is that
1960s and 1970s technology suddenly made it much easier to become very famous
than before, and now we have a huge cohort of people who achieved fame then and
are approaching the end of their lives now.
(Also, we have very high-quality films and recordings of them, so they don't seem
like people from the past; their movies and CDs don't look any older
than recently-made ones.)
From here on, celebrity deaths are
going to be common because celebrities are a larger part of the aging population.
The media are also starting to point out
that this generation of celebrities commonly lived much less healthy lifestyles than
the general public, largely because of drug abuse, and that's why they're
dying younger than their non-famous contemporaries.
On the evening of December 24 (yes, 24; remember, Christmas came for our family on the 18th),
I took a few pictures to try out the newly repaired refractor. This is one.
Stack of seven 1-minute exposures, AT65EDQ (6.5-cm f/6.5), Nikon D5300, ISO 400.
What you see is the reflection nebula M78 in Orion and another nebula north of it.
The sky wasn't perfectly transparent, but it was unseasonably warm (55 F).
We had a hot Christmas (74 F in mid-afternoon on the 25th).
A while back I noticed that my
Astronomics AT65EDQ refractor
(equivalent to Teleskop-Service TS65 (TS-APO65Q))
had an optical problem: the star images were crescent-
or D-shaped. High magnification was needed to reveal the
problem, which showed up most in the light spreading out around
highly overexposed bright stars.
Curiously, the optical problem had gotten worse in the last few months. That's a strange
thing for a defective lens to do! Here are "before" and "after" pictures, showing the
problem on the left:
The problem turned out to be pinched optics, a common problem with this
type of telescope. One of the retaining rings was too tight, and repeated thermal
expansion and contraction made it get even tighter. It was compressing the lens.
The lens mount is not as precisely shaped as the lens itself, and we don't want
the lens to bend to follow slight irregularities in its metal mount. But it was doing so.
I loosened both retaining rings (having found the front one very tight) and
left them only finger-tight. The procedure is described in
this video.
In brief:
Grasp the black part of the movable dewcap (sunshade) and unscrew the
white part of it. Set that aside.
Now you can reach the front lens cell. Unscrew the ring with writing on it,
revealing the retaining ring underneath.
You can loosen and gently retighten that retaining ring without further
disassembly. You do not have to unscrew the front lens cell from the tube,
but you can if you wish.
To get to the retaining ring for the rear element (field flattener), first
unscrew the focuser from the (black) rear lens cell. Then unscrew the
rear lens cell from the tube. The retaining ring to loosen and retighten
is on the forward end of that cell.
Bear in mind that the optical test shown above is very sensitive because
it was taken with a Nikon D5300, which has 3.9-micron pixels and no optical
low-pass filter. You can see atmospheric irregularities and small imperfections
in both images. But I think I made a difference!
For those with questions about astronomy and the Star of Bethlehem,
I refer you to what I wrote
in 2004
with updates
in 2007.
Read those links before proceeding. Then,
here are a few additional notes.
There are problems identifying, from historical records,
the census that sent the Holy Family to Bethlehem in
the first place. But as my friend Doug Downing and many others
have pointed out, if the original text actually hadn't made sense,
it would have been changed in ancient times by people who knew
about the censuses in detail. This is true regardless of whether
you believe in divine inspiration or even think the whole Gospel of Luke is fiction.
So the confusion caused by the
lack of surviving historical records is not a real problem.
[Note added 2017:] The solution to the difficulty of
identifying the census may be as follows. The word ἡγεμονεύοντος did not necessarily mean
"being governor" — it could refer to other offices, such as Imperial Legate,
which Quirinius was in 6-7 B.C., and we don't know much about what he did then.
The imperial census of Quirinius twelve years
later is not the one referred to. In any case, I stand by my main point, which is that
if the description had not made sense to the original audience, it would have
been changed.
[Note added 2022:] It may be simpler than that.
Luke 2:2 says αὕτη ἀπογραφὴ πρώτη ἐγένετο, "this first census took place" when
Quirinius was in charge. If that's the correct translation, the placement of πρώτη
is odd (adjectives don't follow nouns in Greek).
It could also mean "this census took place ahead of" (before) the much
better-known census under Quirinius (taking genitive-case ἡγεμονεύοντος as modifying
"first" rather than "took place"). In that case, there is no problem, and all
records agree. It is one of many local censuses done to implement an order from
Caesar some time earlier. See Wayne Brindle, article in
Journal of the Evangelical Theological Society, 27:43-52 (1984).
Reliable sources tell me that exploratory trips by Persian sages (Magi) were common,
so it was not unheard of for "wise men" to come to town and look around or ask questions.
Admittedly they did not normally come looking for a new king!
Herod must have thought that, whether they realized it or not, the Magi had
discovered a plot to overthrow him.
We shouldn't think of Mary and Joseph in a barn behind an inn or of a possibly
hostile innkeeper. The Gospel only says "lodging," which could be a public inn or
a private home's guest room. No innkeeper is mentioned. In the architecture of
the time, farm animals were kept in a room adjoining the house, not in a barn out back,
which is why it would not be hard to get hold of a manger in or next to the house.
[Note added 2018:] Regardless of how houses were normally built at
the time, let's remember that there is
substantial ancient testimony
(before 165 A.D.)
that the actual site of the Nativity was a cave that had been used
to shelter animals.
(Not a barn; we don't know if it was close or attached to a house.)
And don't run with the idea that Jesus must have been born in a family gathering.
Joseph was probably relying on relatives for lodging, but they may have been distant
relatives, and in any case, the thing that's clear from the Bible is that the expected
lodging wasn't available.
Let me wish you all a blessed Feast of the Nativity (Christmas), as well
as giving you my best wishes for Hanukkah, the Winter Solstice, Sir Isaac Newton's birthday,
New Year's Day, or whatever else you celebrate!
Melody came through the operation fine, but because they implanted a temporary antibiotic-filled spacer
rather than a regular hip implant, she has limited mobility and isn't ready to come home.
She will strengthen and probably be able to join us at home before the next hip operation,
but in the meantime, she will move from St. Mary's Hospital (shown below)
to The Oaks, the same convalescent facility as two years ago.
We want to thank at least 150 people (that we know of) for their prayers and best wishes.
We're having a quiet Christmas, but that's not a problem; Sharon and I are enjoying having a
bit of time to ourselves. I've been so busy that I haven't gotten into my workshop or
darkroom in a long time, and maybe I'll get to do so. And I have consulting work to do;
I always do; as you might imagine, this month I got a bit behind schedule.
Melody's hip surgery, scheduled for December 21, has just been rescheduled
for tomorrow (December 19). So we are eating dinner and are about to have
family prayers, then celebrate Christmas hastily around a potted rosemary bush
doing service as a tiny Christmas tree, then scramble to get ready
to go to the hospital. (We will go around midday tomorrow but have a long
list of things to do first, including two special baths.)
Recent events in our national life have turned friend against friend and
brother against brother almost as if there had been a civil war.
Many among us have become accustomed to feeling contempt for each other.
For the fourth Sunday in Advent I want to share with you this prayer,
which Melody composed, for people with hardened hearts, including,
to the appropriate extent, ourselves.
Our Heavenly Father,
We pray for those with hardened hearts,
who no longer hear words of truth,
who live with unfocused anger,
and sometimes raise their hands in violence
against their fellow man.
Grant that their hearts may be softened,
theirs ears opened to reason,
and their minds unclouded from hatred.
Teach them to love again,
and hold all your children in loving esteem,
seeing no difference in the color of their skin,
or the language they speak,
or the country they came from,
or whether their bodies are broken.
Guide them with your boundless love,
to love others as they love themselves.
Grant that those with hardened hearts
find themselves convicted of their sins,
repent of those sins,
and be brought ever closer to you.
Let those with hardened hearts be stricken by your Holy Spirit,
to become as our Lord Jesus Christ,
giving of themselves when there is a need,
caring for those without necessities,
speaking as Christ's wisdom guides us,
always speaking gently and kindly to others.
We praise your Holy Name. Honor and Glory Forever!
Amen.
In just one day I've graduated from Microsoft 3D Designer to
Autodesk 123D,
which is free for noncommercial use and cheap (by subscription)
for commercial use.
It produces solid models, not just mesh models; allows rotation about the center of
any face of any object, making it easy for me to simulate the movements of a telescope mount;
and will do orthographic projection (infinite-distance perspective).
Also, it has a "screen shot" function that outputs a 2D bitmap image of what is on the
screen, without the grid.
I recently learned about a mistaken impression that some of my friends, relatives,
and neighbors must have had during much of my career.
Some people think that when a professor gets a research grant, the money goes
to the professor. So if I bring in a few million dollars for research,
I'm rich.
To quote the old lady in the TV commercial, "That's not how any of this works!"
Grant money goes into the university's budget. About a third of it goes for
overhead (buildings, offices, secretarial support); the rest goes mostly for graduate
assistantships (that's how we pay for people to go to graduate school) and
for special equipment and travel. In some sciences, of course, equipment is the major cost.
The only way a grant can help me financially is (1) by keeping me employed in the first place
(some research jobs depend on bringing in grant money), and (2) by allowing me to be
employed 12 months out of the year instead of the normal 9 or 10.
There is a rule that grants cannot be used to fund pay raises.
I've made my first foray into 3-dimensional drafting.
Although the main reason people do this is to make things with 3D printers,
my need was completely different.
I need to make some accurate line drawings of a telescope on an equatorial
mount aimed in various directions, and I wanted the computer to figure out
the perspective for me.
In the picture, there's no tripod beneath the telescope.
That's intentional.
I want to dispel the myth that "you have to level the tripod."
False. As long as the polar axis (the orange part) points in the right
direction, it doesn't care what's under it.
The tripod is just to hold it up.
The only reason the tripod has a bubble level on it is to help you set it
up in the same position as the previous night.
I tried Microsoft 3D Builder (free with Windows 10), Sketchup, and Blender and
settled on the first one. It's freeware and very easy to use.
Sketchup is relatively easy to use but not free for commercial use, and they probably
consider my use commercial. Blender is elaborate, powerful, and mystifying to the beginner.
The best thing about the Microsoft 3D Builder user interface is that it
makes easy things easy. That is much more important than
making hard things easy. If the simplest operations are not quick and obvious,
the software will always be tedious. This one got it right.
Because it's not mechanical engineering software, 3D Builder does not let me
rotate any part around an arbitrary axis, so it took some thought to get everything
rotated all the ways I wanted, without disrupting anything else.
But I did it. I can capture 2D images as PDF and then either edge-find them with Photoshop
or trace them in Illustrator.
Here you see a CEREC
numerically controlled milling machine making a crown for my tooth,
the one that underwent a root canal 30 days ago.
During the installation of the crown, to add dignity to the occasion,
we listened to Händel's Coronation Anthems.
Observations:
I had been harboring an abscessed tooth for about 4 months, with minimal symptoms.
It was wearing down my overall health just a bit.
A root canal doesn't hurt. What hurts is needing one and not having it.
Crowning a tooth that has had a root canal did not require any anesthesia
and did not cause any pain.
With CEREC, the whole procedure was about 2.5 hours
from beginning to end. There were two intermissions (when the crown was being
made and when it was being baked), and I caught up on e-mail.
Hoax (?) the day: Do they have to say ze at Oxford?
[Revised.]
The strange news story today is that some substantial part of Oxford University
has ordered people to say ze as a gender-neutral pronoun in
place of he or she.
Major newspapers seem to have been taken in, but it defies confirmation.
See this.
At the very least, if a pamphlet was given out, someone should be able to find a copy of it.
This may be an inaccurate report of something real but misunderstood, or it may be a prank.
Melody's next hip operation (to deal with an infection in the same artificial
joint that got infected in 2014) is December 21, so Christmas will come early for us,
on December 20, and will be low-key.
Refrigiwear is highly recommended.
I am in the process of getting a cold-weather coverall for astronomy.
Their products are well made and are much warmer than hunting coveralls.
I tried one on and am sending it back for a different size; I may end up with a
custom-altered one (which they offer).
They say to allow an additional 20 to 25 F for sedentary work (astronomy) compared
to ordinary outdoor labor. So I'm ordering a suit rated for -50 to +20 F,
expecting to use it to about +45 F during our southern winters. A hunting coverall
is comfortable at +50 F but not much lower.
Part of this is that I'm cold-natured, and part of it is that I like to wear the
coverall over regular clothes, without adding more layers, so I can get in and out
of it quickly. That's just me; I don't like to make getting dressed into an
elaborate ritual.
If I contribute anything to the world's stock of Christmas music, it will be the
following, which can be sung as an additional verse of
"Child in the Manger" either before or after the
existing verses, or substituted for the first verse. (The tune is "Morning Has Broken.")
God above Heaven,
born of a virgin,
God beyond space, now
sheltered on Earth:
This day is holy!
Sing to the Saviour;
shepherds and angels
herald His birth.
This is my translation of the opening of the Nativity canticle of St. Romanos Melodos,
"Today the Virgin gives birth to the one above all existence (epiousion)..."
For several years I thought about trying to translate more of the canticle to make more
verses, but I got stuck. I think this one works well substituted or appended into the
existing song.
To all my readers: Feel free to sing this. If you publish it or record it commercially, I would
like to hear from you. Like all of the Daily Notebook, it is covered by copyright,
so you are using it with my permission.
Safely connecting pro audio equipment to a computer sound card
In yesterday's exciting episode (see below) we learned that
professional audio equipment can damage a computer sound card
because pro "line level" goes as high as 4 V rms, but the most a sound card
can handle without damage may be as little as 2.8 V rms.
I've encountered a case where this seems to have happened.
Of course, you can use a professional sound card designed to interface to
professional equipment — or you can do what I did.
I built this gadget, hiding the resistors inside the inline phone jack.
It accomplishes two things: it cuts the voltage to an acceptable level, and
it ensures that the ring (R) on the sound card is not connected to anything,
since computer microphones use R for power, not for signal.
For more about sound card input levels, scroll down.
What are the correct audio signal levels (in volts or millivolts) for
a computer sound card?
That information is very hard to come by; a long web search found me
little beyond vague statements.
So I decided to make my own measurements.
Surprise #1: Line and Mic may refer to the same levels!
In the normal audio world, Line is about 0.5 V rms (in consumer equipment)
or about 3 V rms (in pro equipment), and microphones output about 2 mV rms.
Not in the world of sound cards! Computer microphones have small preamplifiers
built in. In fact, sound card inputs, both mic and line, are in between
the mic and line levels used by other equipment. The most generally suitable
signal level, at either type of input, is about 0.2 V rms, but the gain controls
span a wide range.
Surprise #2: Pro audio equipment can damage a computer sound card!
That's right — pro audio "line level" can deliver as much as 10 volts peak-to-peak,
3 or 4 volts rms, and that exceeds the maximum ratings for the chips in sound cards.
I consulted an older Cmedia CM108 data sheet and found and absolute maximum rating
of 2.8 V peak-to-peak, equivalent to 1 V rms at the mic or line input.
Go much beyond that, and the chip can be harmed. Go beyond 5 V peak-to-peak,
and it certainly will.
Surprise #3: The lowest gain settings are essentially not meant to be used.
Aim to have the gain controls somewhere around 50 to 75 on a scale of 100.
To get a full-scale signal at a gain of 10 (on a scale of 100), I would have to apply
voltages higher than the electrical specifications allow.
Recall that the difference between mic and line inputs is largely wiring,
though the mic input may also have a wider range of gain or an optional 20-dB boost.
The mic input is monophonic and uses the ring of the connector for a 5-volt power
supply through a 4700-ohm resistor (or thereabouts).
The line input is stereo.
Now for the actual measurements. These are the level of a 1-kHz sine wave that
produces a level shown as 7 out of 8 bars in Windows Control Panel with various
settings of the level control. These are rms voltages; peak-to-peak voltages are
2.8 times as much.
This, too, was meant just as an autoguider test (on December 1), but it came out
fairly good for a picture taken in town.
This is the emission and reflection nebula IC 405 around the star AE Aurigae,
which appears to have been violently ejected from the Orion Nebula many, many years ago.
The nebula that presently surrounds it is unrelated; the star is just passing through.
Stack of four 5-minute exposures, AT65EDQ, Nikon D5300.
The screen of my iPhone 5 was deteriorating, and through their insurance program
AT&T gave me a very cheap upgrade to an iPhone SE, which is a more modern phone
built into the same case. New, but nothing different, and that's how I like it.
After five years of heavy use, my
Casio WV-58A wristwatch
(which sets itself automatically
from longwave radio time signals) was deteriorating too, and I got a new watch just
like it (well, with a darker-toned enclosure) from Amazon for under $25.
I then transplanted the watch band onto it (the band may be worth more than the watch).
Again, new, but nothing different. It does look spiffier, though!
Strong rants are being circulated on Facebook making the claim that if our elementary
schools stop teaching cursive handwriting, civilization will collapse, or something
equally dire will happen.
But Palmer Method Cursive is not the right way to do it.
Palmer Cursive has had a stranglehold on American education for about a century,
and it's time for it to go.
Cursive handwriting was designed for 18th-century dip pens that shouldn't be lifted
off the paper. Modern pens don't have that quirk.
My objections to Palmer Cursive and its derivatives (Zaner-Bloser, etc.) are:
It makes the children learn two alphabets. Some of the letters look quite
different in cursive than in print.
It's hard to read. Palmer's system, especially, makes different letters look
too much alike. Even the best cursive is hard to read. Done sloppily, it's impossible
to read, as all of us know.
It takes way too much time for people to learn it and build skill, time that
could be spend on other things (including learning to handwrite more clearly with a
different system!).
I'm not against handwriting. I think everyone needs to learn to print clearly and
to write quickly and legibly in a flowing way, but that doesn't mean cursive.
I prefer Fairbank italic,
which is what I normally use (a bit sped up
and simplified). My italic is as fast as anyone's cursive,
can be written with any kind of pen (although an italic pen makes it look prettier),
and is much easier to read.
I also think the D'Nealian system,
now popular in elementary schools, was a step in the right direction.
It is based on the notion that children should not
have to learn two alphabets — that there is a smooth transition from the separate
to the connected way of writing.
But its goal is to end up with something that looks too much like Palmer Cursive for my taste.
What I want to do now is answer some of the arguments I hear for cursive, some of
which are sillier than others.
(1) "Printing (writing separate letters) is too slow and too tiring."
Granted, it is if you're not doing it right.
It's important to have a fixed, smoothly flowing set of muscle movements
associated with each letter.
It's also important not to use a ballpoint pen that requires ten pounds of pressure!
To keep from getting tired, write with a rollerball or fountain pen.
(2) "Cursive is traditional and everybody needs to know how to read it."
Yes, but you can learn to read cursive in a few hours in art class in fifth grade, rather than
taking countless classroom hours for several years.
They started teaching me cursive in second grade and didn't stop until seventh!
(3) "People need to know cursive so they can read the Declaration of Independence."
See previous point, to which I would add two more:
(a) Can you tell me the rules for using the long and short lowercase S in the cursive
writing of 1776? If not, maybe you don't know enough cursive for the Declaration
of Independence either.
(b) Why stop at the Declaration of Independence? Can you read the Magna Carta?
It's in Latin and in a kind of cursive that even you would find daunting.
(4) "How will people sign checks?"
Again, learning to sign your own name is not something that will take years;
in today's society it's more an art project that part of your literacy.
And the real answer is that people don't sign checks much any more.
They use computer authentication of various kinds.
(5) "It fills up the time and gives the less intelligent students something to be good at."
This is being offered as a serious argument.
Basically, it's a way to take up time and offer less education and
less intellectual challenge. Are you sure that's what you want to ask for?
And if you do need some easy material to fill up the time, could it be something more
useful than penmanship?
Like teaching them to type?
They're not going to go work as scriveners for Ebenezer Scrooge and "copy out the
letters in a big round hand." Since the 1930s, office workers have had typewriters.
Today it's computers.
Afterthought: If the schools in the 1960s had been up to date, they would have
taught us to type in fourth grade. Instead, they drilled us on Palmer Cursive for years
as if we were going to be office workers in 1890.
(6) "I had to do it, and I want things to be just like my own childhood."
Well, things are not going to be like your own childhood.
Your children are never going to live in a world without computers, smartphones, and electronic
funds transfers. You can't go back. Don't ask children to be prepared for life in 1950 or 1890.
That's not where they're going to live.
This is a stack of three 5-minute exposures of the Orion Nebula region,
taken with an AT65EDQ (65-mm f/6.5) and Nikon D5300 on an AVX mount,
testing a 60-mm guidescope,
which passed the test with flying colors.
I shall name this guidescope Goldilocks because it is not too big and not
too small. My previous 80-mm guidescope is somewhat prone to flexure because
of its great size and because its focuser wasn't specifically designed for
guiding. My tiny homemade 35-mm guidescope is rigid but has poor optical quality,
possibly a collimation problem that I can improve.
I want to call your attention to the smaller nebula at the top of the picture,
NGC 1973-1975-1977. In front of it is a dark nebula that looks like a man running
very fast. It is called the Running Man Nebula.
The nebula has three NGC numbers because it was discovered visually, with telescopes,
and was seen as disconnected bright spots; the connection between them was not visible.
And they are an auspicious set of NGC
numbers; I entered the University of Georgia in 1973, met Melody in 1975, and
graduated in 1977. Next I need to look for NGC 1982, our wedding date!
[Addendum:] It turns out NGC 1982 is in the picture too. It is the upper part of
the nebula in the middle; a dark rift separates it from the main part.
NGC 1982 is better known as M43.
"Fallacies are more easily nipped in the flower than in the bud."
Thus said Augustus de Morgan in his book about crackpots, A Budget of Paradoxes.
What he meant is that a mistake often needs to be taken to its logical conclusion
so that people can see that it's a mistake.
UPS falsely reports defective batteries after a power failure
APS XS-1200 uninterruptible power supply (but this probably applies to many, many others too).
Symptom: After running down its batteries during a power failure,
the UPS tries to recharge its batteries, and fails,
so that a day or two later, it reports defective batteries.
(This particular one was so foolish as to actually shut down, turning off
the computer and router, even though normal AC power was coming in.)
In many cases, of course, an aging lead-acid battery does die when completely
discharged.
But that wasn't what happened to mine. I took the two batteries out and experimented
with charging them. It was quickly evident that they would take a charge normally.
So I charged them (using a lab power supply, but a trickle charger would be better)
for several hours, then put them back in the UPS (with no computer attached), plugged
it into the AC line, and turned it on.
The batteries charged all the way back up to full charge in another two days, and
then they passed the self-test.
Windows won't let you rename a folder on another computer
Symptom: You've just created a folder (as "New Folder") within a folder shared
by another computer. You try to rename it, and Windows seems to hang.
After a very long time, the renaming succeeds.
Explanation: The Windows Search service has grabbed the new folder and is trying
to index it. While the Windows Search service holds it open, no one else can
rename or delete it.
Cure: The simplest is to disable the Windows Search service on the computer that
holds the files. Control Panel, Administrative Tools, Services, find the Windows Search
service, stop it, and set it to Disabled.
Alternatively, it may be sufficient to disable indexing on one folder through its Properties
window. I haven't tried this.
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