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Daily Notebook

Popular topics on this page:
Believe something without thinking it best?
How not to take a flat field
M102 = NGC 5866, not M101
No messages from God in Aramaic in junk DNA
Astrometry.net: "What's this a picture of?"
Superpixel mode in DeepSkyStacker
Some management maxims
100000th anniversary
More management maxims
Down with 50 Shades of Grey
Viewing M102 (NGC 5866)
An odd guiding problem
The Dan Cooper hijacking
M13 with dust lanes
Cat's Paw Nebula (NGC 6334)
Nu Scorpii Nebula (IC 4592)
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Chilly summer?

I'm in Georgia, in three hours it will be August, and the outside temperature is 69 F. Will wonders never cease?

Our state climatologist said the other day that the cool spell will continue for a few more days or weeks. Will I get to enjoy autumnal clear skies with the August stars in the sky?

Are we plunging into poverty?

You may have heard that median American household net worth, inflation-adjusted, fell by a third in roughly the past ten years.

Before you panic, note that it's net worth, not income. It was mostly loss of home equity value.


The Dan Cooper airplane hijacking, 1971

The next time airport security annoys you, think back to the time when we didn't have any. There was quite a flurry of hijackings around 1971, done by increasingly naive hijackers.

Now that xkcd has turned everyone's attention to the Dan Cooper (D. B. Cooper) hijacking, I might as well pass along some opinions that I formed while reading up on it a while back. Based on the information summarized in Wikipedia, I think the following are very likely to be true:

  • The hijacker, with his load of ransom money, did not survive the jump.
  • Because no body was found, he presumably landed in a lake.
  • The small parcel of money that was found later was separated from the rest before the jump, probably deliberately dropped to leave a false trail.
  • The hijacker was probably not American and may not have been Canadian either.

Also, I am surprised that he was not shot dead (with a long-range rifle) during the negotiations on the ground. It should have been easy to do, and it was justifiable since he was constantly threatening to set off a bomb.

(By the way, was the bomb real? If so, he must have gotten it out of the plane without exploding it, somehow, maybe by dropping it into water.)

Read about it and form your own opinions...


The Cat's Paw Nebula (NGC 6334)

Here's the better of the two astrophotos that I took at Deerlick on the evening of July 26. This is a stack of seven 3-minute exposures with a Canon 60Da and Canon 300-mm f/4 lens on a Celestron AVX mount, processed with DeepSkyStacker in superpixel mode, corrected with darks, flats, and flat darks, and postprocessed with PixInsight. The first picture is reduced; the second is a section of the image at full size.

This kind of nebula is red because it consists of hydrogen gas, very thin, glowing because of ultraviolet light emitted by nearby stars.

The Nu Scorpii reflection nebula (IC 4592)

Taken with the same equipment and technique as the one above, this picture shows the reflection nebula (dust cloud) illuminated by the star Nu Scorpii. This is a stack of five exposures rather than seven. The nebula is very faint, and I hope to take a better picture of it in the future.

An odd guiding problem

I must confess that I wasn't paying a lot of attention to the autoguider while taking the Nu Scorpii picture; I was making my visual observation of M102 at the time. Apparently, though, the guider had a bit of a problem with oscillation; most of the exposures had double images of just the brightest stars, like this:

[Corrected; picture was upside down.]

Although it tracked the stars well, the mount seems to have made momentary excursions to a position about 30 arc-seconds to the west, just long enough for the brightest stars to acquire as ghost images. I'm not at all sure what caused this. Maybe a balance problem? Maybe vibration from the camera shutter? It is not an optical problem because one of the images does not have it (and none of the images of other objects have it). Since the German equatorial mount was "flipped" across the meridian relative to when I photographed the Cat's Paw, I'm betting it was a balance problem. You can't see it on my picture of the Nu Scorpii Nebula because I downsampled (reduced) the image to hide the problem.



Your guide to viewing M102

As I mentioned recently, American star atlases usually list M102 as a duplicate observation of M101 (which is what its discoverer, Pierre Méchain, thought at one time), but Europeans (and I) are gradually becoming convinced that Méchain actually saw the galaxy NGC 5866, then made a mistake interpreting his observations.

Last night (July 26), at Deerlick, I took a look at it with my vintage 1980 Celestron 5. This was one of the two telescopes that I used to view all the Messier objects (recognized by Americans) from 1980 to 1985. I kept a log of them in my copy of Mallas and Kreimer's Messier Album. Although I didn't get around to applying for the Messier Club certificate, these observations meet its requirements — all the objects were found from maps, without aid from a computerized telescope mount.

So this list needed one more entry, and I made it. Although I had already seen M102 briefly with my computerized C8 EdgeHD, I wanted to do it the old way.

I succeeded; in fact, M102 is quite prominent at a dark site and is framed by a triangle of stars. It has the core brightness of an eighth-magnitude galaxy, not ninth or tenth, although its total brightness may be low.

Finding it, however, was not easy, since I had only the Pocket Sky Atlas with me. I ended up turning the telescope mount around so that it wasn't polar-aligned and I could move around more easily near the pole (an old trick that I also used in the 1980s).

For the benefit of others who want to undertake this quest, I made some charts with Stellarium. First, here's the overall position of M102 relative to the Big Dipper (and M101, which Méchain mixed it up with). It is best seen in the spring, but in July it's still in our sky.

Next, here's a chart that will enable you to "star-hop" to it. Note the 5th-magnitude star HIP 73909, which helps you find it. This may be the "6th-magnitude star" that Méchain said was "close" to the galaxy, or he may have been talking about the 7th-magnitude star that is very close indeed.

Lines are 1 degree apart in declination, 10 minutes apart in R.A.

Finally, here's a computer simulation of how it looked in a telescope at 50× with a diagonal (that is, mirror-imaged). What I actually saw was rotated quite a bit relative to this picture because of the odd angle at which I had positioned the telescope. Note that the galaxy is framed by three stars and has a star very close to it.

And here's how it went into the log:

I no longer have the felt-tip pen I was using in 1985.

For an extra treat, while you're viewing M102, go to Iota Draconis and slew about 1.5 degrees north and a fraction of a degree west. You'll see a striking, wide triple star with 8th- and 9th-magnitude components including HIP 75037. It is an optical alignment, not a true system.


Down with 50 Shades of Grey


The forthcoming movie 50 Shades of Grey is being denounced and condemned by a remarkably wide range of people. I haven't seen the movie (which isn't out yet) nor read the book; I'm going by what I hear from third parties of many different sorts. And today I don't have time to insert hyperlinks, so you'll have to do your own Googling. But Dave Barry's humorous review of 50 Shades is not to be missed.

Remember The Bridges of Madison County? Its message was, "You need some adultery to spice up your marriage." A whole generation of women (and maybe a few men) went gaga over how "romantic" it was, and I don't know how many people it induced to do ruinous things.

Well, the message of 50 Shades is, as best I can make out, "You need to be abused or threatened with abuse by a sadist — it's romantic."


Based on what I've been able to find out, 50 Shades of Grey raises three big concerns.

(1) Playing fast and loose with the notion of "consent." Apparently, 50 Shades tosses around something that is called "consent" but is not the real thing, and people who are caught up in the confusion can get into real danger. "You keep using that word 'consent.' I do not think it means what you think it means."

Curiously, even organized sadomasochists are complaining. They say that if you take the book as a model, you will underestimate both the physical and the legal dangers.

(2) The "mommy porn" phenomenon. Plenty of people are suddenly willing to read a book or watch a movie that they would have considered degrading, just because they're told it's OK and fashionable people do it now. Anyone who makes moral judgments this way is wandering in a wilderness. You have a mind of your own; use it.

(3) Amorality. At what point do we stop saying "To each their own" and start saying "This is wrong"? Even with "consent," isn't it bad to derive sexual pleasure from harming or threatening to harm another human being? What about from killing an animal? Killing a human being? (Some would "consent" — it has happened.) Is there no limit? Or does "consent" make everything licit?

Notice that I'm not talking about the limits of the legal system; I'm talking about what we, with our own time and money, choose to support.

One more management maxim

I left out one more management maxim, which is fairly self-explanatory:

It's not any less work if you put it off.

'Nuff said. I've got to get to work now.


More management maxims

As a sequel to what I wrote the other day, I want to address a couple of points about time and space management.

Time management:

A short time scale does not make things urgent.
Beware the "urgent unimportant."

If you are guided only by deadlines, not judgment, you'll be in a frenzy doing unimportant things that supposedly need to be done soon and never working on long-term plans.

Advertisers try to exploit this. "Come to the 49th-anniversary sale this weekend or miss it forever!"

E-mail and social media give you a constant stream of urgent requests for undeserved attention.

Some people can't finish graduate school because they can't do a long-term project — they can only pay attention to things with short time scales.

Now for space management:

Put back.
Don't pile.
Don't keep trash.

These sound like exhortations for kindergarteners, and they could be, but they also deserve some attention from the adult mind. Quite a bit of intelligence is needed to keep a work area reasonably neat. (Think about how you'd program a robot to do it.) These three maxims, slightly expanded, are:

Put things back when you're finished using them.
Don't pile things where they are unstable or in the way.
Don't keep things that should be discarded or given away.

The first one is easy. The second is is something of an intelligence test; I've encountered otherwise normal adults who have remarkably little awareness of drawers and cabinet doors and blithely put things down to block them. The third is also a challenge; as I once summed it up (to the amusement of our Chinese graduate students),

The storage room is like Vietnam:
Nothing should go into it without a plan for getting out.

If you cannot foresee the conditions under which something will be taken out and used again, you shouldn't be storing it.

But don't be fanatical about clutter.

Remember that the purpose of a work area is to get work done, not to look neat. An aspiring business-school student once told me that our laboratory "doesn't look corporate; it looks like a lab." To which I replied, "That's what it is."

And don't be the kind of person who uses decluttering as an excuse for cutting ties with the past. Some people can't keep any possessions because, it seems, they don't want to remember their own past. They preach "decluttering" to the rest of us. In real life, a healthy person does keep some things as mementoes, not just for active use.


100000th anniversary

Today is Melody's and my 100000th wedding anniversary.

Here 100000 is a binary number; it means 32. It looks more impressive in binary, though!

Everything I said on our 25th anniversary still applies. Here's to 100000 more!


Some management maxims

I can't claim to be an expert on management, but over the years, teaching and supervising a wide range of people, I have learned a few things about how to get things done and how to lead people. Here, in no particular order, are some of the rules I've lived by.

The trains run on time.

This is a time-management principle that I live by. I do everything at the planned, scheduled time unless there is a good reason. I won't waste everyone's time by habitually delaying meetings for latecomers. In fact, if you come to one of my meetings fifteen minutes late, you may miss the entire meeting.

Work is done between meetings, not during them.

My meetings are short and to the point. I do my best thinking when I'm by myself; then I come to meetings to report the results. Some people seem to think their work is done during long, tedious meetings. In my experience, that is not the case.

Nothing has happened unless you've made sure it has happened.

It's not enough to hope or assume something has happened — I double- or triple-check. I learned this principle the hard way, early in my career, supervising someone whose job was to make tape backups. He knew they would rarely be needed and somehow got the idea he need not actually make any. Then the disk crashed, we needed one, and found out that none existed. He had never told me, in a staff meeting, that he hadn't made or couldn't make backups.

Corollary for subordinates: If told to do something, then either do it and say you've done it, or report back why it wasn't done.

Paraphrasing what Thomas Jefferson may have said, eternal vigilance is the price of success.

People hear with their eyes.

Simple but true — If you don't have eye contact, people aren't hearing your words. Sound may be omnidirectional, but attention isn't.

Time is not fungible.

I've written about this before. Unlike money or water, equal quantities of time are not substitutable for each other unless you are doing something far below the limits of your capabilities. For an assembly-line worker, every hour may be equivalent to any other hour; for an artist or engineer, definitely not. Sometimes we get vastly more done than at other times. We have to observe this fact, live with it, and try to find ways to maximize the quality of time.

In particular, interruptions can be fatal. If you interrupt a computer programmer every 5 minutes, he absolutely cannot program. The same goes for writing, designing, and planning of all types. It takes about 15 minutes to settle into the task. People differ, but I, at least, am good for 30 to 60 minutes of sustained effort, after which I "come up for air," check-email and telephone messages, and the like.

"While" is a deadly word. "Multitasking" means not working.

You can't do one thing "while" you do another thing unless both are far below the limits of your capabilities. You might be able to answer the door and answer phone calls concurrently — because neither one is a challenge at all. You cannot plan a project, design a computer program, or do homework while watching TV. In particular, I tell students to lose the word "while" and simply do things, not do things "while". It's amazing how much faster you work when not attempting to multitask.

There was a vogue for "multitasking" a few years ago. I think it came from weak managers who (1) thought it was a way of getting more for their money, (2) couldn't concentrate, and (3) thought nobody else could concentrate either.

Now it makes perfect sense to alternate between different brief tasks, and thus to have more than one responsibility. That is not the same as trying to do several separate things at the same moment.


Astrometry.net: "What's this a picture of?"

Astrometry is the science of measuring positions of stars. This usually means measuring the relationship between a photograph and the actual sky, so that coordinates can be read off it.

Astrometry.net is the handiest web site for astrophotographers I've come across in a long time. You send it a picture of any star field, and it tells you what you photographed. I sent it this picture of M17:

and here's what I got back:

test image

Impressive! I have just two quibbles. First, it reports the picture orientation upside down (this may have something to do with JPEG file format). In this picture, up is 5 degrees west of north, not 175 degrees east of north. Second, there's a missing star, apparently due to an error in the star catalogue that Astrometry.net uses. HD 168701 and HD 168702 are, as far as I can tell, a duplication in the HD star catalogue, and in the online version that I used, they have the same position. Why Astrometry.net looked for them in different positions here, I can't guess.

This is going to be a very handy tool; maybe in the future I can use it to catalogue all my astrophotos, so that regardless of how I labeled them, I'll know what is where in the sky.

Superpixel mode in DeepSkyStacker

It was recently brought to my attention that DeepSkyStacker has a "superpixel" mode that makes one pixel out of every four, reducing noise.

This is not just "binning" (combining of adjacent pixels). Rather, it is a way to avoid interpolation (guesswork) when decoding a color image. DeepSkyStacker takes every quartet of pixels — arranged as


on the sensor — and makes it into one pixel, whose red value is R, whose blue value is B, and whose green value is the mean of the two G's.

This gives you only 1/4 as many pixels as before, but with an 18-megapixel camera, that's quite fine with me — the resulting 4.5 megapixels are plenty for a full-page print. (We easily lose track of this fact: You may never have seen a picture with more than 3 megapixels visible in it. Even one megapixel will equal a typical 8-by-10-inch photographic print.)

Here's M17, the same picture as before, processed a bit differently, using superpixel mode. As I did the processing, the lack of color noise was surprising.

Note: Superpixel mode is not what made the picture brighter; that was me. I adjusted the contrast differently.

You are looking at actual (super)pixels here; the picture was cropped, not downsampled. Contrast adjustment and noise reduction have been performed.


Swan Nebula (Omega Nebula, M17)

On Wednesday night (July 16) our weather was tantalizingly clear — for a while. As thin high clouds rolled in, I managed to grab six 30-second exposures of M17, which you see, combined, here. This was a "dress rehearsal" for trips to Deerlick with the same equipment, so I took a full set of flats, flat darks, and darks for calibration and did the processing with DeepSkyStacker and PixInsight. Canon 60Da camera, Canon 300/4 lens at f/5.6, and autoguider on the AVX mount with no telescope. This is just the center of a much wider field. As you can see, the autoguider served me well.



From Cathy's lotus pond, which she planted a few years ago.


There are no messages from God in Aramaic in junk DNA

I don't normally waste space in the Daily Notebook by refuting hoaxes, but this is one that I keep getting questions about, since I am professionally trained in ancient languages and also keep up with biomedical research. (And, more to the point, I am regularly in touch with real experts on both.)

You may have heard that someone found secret messages from God, written in Biblical Aramaic, in "junk DNA" (unused portions of cellular DNA sequences).

This is, as best I can determine, a complete hoax. Never happened. If you hear a version of it that refers to real institutions or scholars, assume that they are not really involved.

If it were real, we'd definitely be hearing about it from mainstream, reliable scholarly sources. (Don't pay attention to anyone who says, "They don't want you to know" — in the world of gossip, that means "This is false.") Not everyone would believe it was miraculous, but everyone would acknowledge that something unusual had been found.

I'm not going to get tangled up in figuring out how this one got started. All I know is that I haven't heard any shred of it from any reliable source.

Don't believe a third party that tells you it's from a reliable source. Hoaxes always claim to be from reliable sources — falsely! See if you can see it, with your own eyes, in a scholarly journal or a (genuine) university web site.

It doesn't even make sense. How could a message in Aramaic be expressed in DNA? That is at least as strange as if you said that the arrangement of the stars in the Big Dipper contains a message in Swedish.

I'm guessing that somebody wants to make Christians look gullible by getting them to pass along nonsense.

A much earlier hoax of the same kind — which I first heard in the 1960s — was that NASA had used to computers to prove that the sun stood still for Joshua. (Details here.) Again, it never happened, and it doesn't even make sense. A computer can't tell you if the actual sky, on some ancient date, was different from what its calculations predict.

In that case, apparently the psychology of the hoax was more complicated. The man who did the most to promote it seems to have believed it sincerely, although it's not clear where he got it other than his own imagination. In those days people didn't have Google or Snopes, and many people who heard the story had no idea it was disputed.

Sadly, some people, even popular preachers and religious writers, would rather tell an entertaining story than a true one. At least this one doesn't accuse individuals of wrongdoing, as so much gossip does.


M102 = NGC 5866, not M101

Astronomers refer to many star clusters, nebulae, and galaxies using "M" numbers from the catalogue compiled by Charles Messier in the late 1700s. Objects M101, M102, and M103 were contributed to this catalogue by Messier's colleague Pierre Méchain. M101 and M103 are easy to identify, but M102 is disputed.

American editions of the Messier catalogue usually say that M102 is a duplicate observation of M101, as Méchain himself said shortly after it was published. European editions identify M102 as the galaxy NGC 5866, and I think they are right.

I've just had a paper accepted for publication in which I work out how all this happened. The gist of it is that Méchain misread the right ascension of M102 on a map and came up with coordinates that were suspiciously close to M101. That is, he didn't mistake one object for two when observing; rather, he mistook two objects for one later on, when he was figuring out their coordinates.

Last night I had a look at M101 and NGC 5866 through a telescope larger than Méchain's (my 8-inch) under worse conditions (haze and moonlight). Here's the clincher: although supposedly fainter, NGC 5866 is actually easier to see than M101, and it has a star right next to it, just as Méchain's description of M102 says. His description of M101 doesn't mention a star.

So, Mr. Méchain, when you thought you had made a mistake, you were mistaken.



We had a remarkable display of sunspots this week, and this may be my sharpest-ever sunspot picture. It's a stack of 7 still pictures taken on July 8 through my vintage orange-tube Celestron 5 with a Thousand Oaks full-aperture filter and a Canon 60Da. The image was sharpened with RegiStax.

Here's part of it, enlarged:

And here's a video image of a large sunspot group, made by using the camera to record over 1800 frames of video, then stacking and combining the best frames using AutoStakkert and RegiStax:

Not bad for a hot summer's day.

An audio rant

The most important classical composer to whom I have not yet paid adequate attention is Joseph Haydn, and I've been looking for CDs of his works.

That brought me to the grand opening of the new Best Buy store off Epps Bridge Parkway in Oconee County. They moved there (downsizing the store) just a few days ago. Their old location, on Atlanta Highway, had been their home for more than 20 years — I remember getting OS/2 3.0 there — and stood on the site of a strip mall containing the original ComputerLand store, the very first place I ever bought software (IBM PC Asynchronous Communication Support, 1982).

Anyhow, the new store has audio CDs by the hundreds, but no classical music (as far as I could tell). Did their demographic analysis of Oconee County tell them it wouldn't sell? Or are they phasing out CDs altogether?

I mentioned this on Facebook and was told that I should be buying MP3s by download; the audio CD is a dying medium.

So — you're telling me that instead of buying uncompressed audio files that are already on a disk that I can listen to in my car, I should buy compressed files (of lower quality), download them, and burn them to a disk myself? Why is this supposed to be more convenient?

Or maybe I'm supposed to keep them in my iPhone and plug the iPhone into the car's audio system every time I get in the car. An extra step.

The point about the lower quality of MP3 files was news to several people. I'm beginning to wonder: Is my generation the only generation that really cares about audio quality? In the 1970s, stereo systems got a lot better, and we noticed. In those days we judged a system's quality by how well it reproduced music, not explosions in movies.

People who came of age before the 1970s were accustomed to lower audio quality. And some of those who came later have strange tastes. Several years ago, at a gymnasium where we all exercised, I noticed that the music system sounded awful and offered to fix it. The amplifier volume was all the way up and the speaker pad was all the way down. The music sounded like it had been filtered through a kazoo. I set the controls normally and made it sound like music again. But the staff soon set it back the old way. They wanted a scratchy, "techno" sound.

Back to the old

I've just gone back to the past in a couple of ways.

First, I set aside the excellent Pelikan italic fountain pen to which I had never quite gotten accustomed, and resumed using the Sheaffer pen I got in Oxford in 1976. Schreibvergnügen! It's nowhere near worn out. The barrel and cap were, but they've been replaced. If I do wear it out, I can get another. And I will be selling the Pelikan pen to some lucky purchaser.

Second, after trying for six months to get used to a new pair of glasses, I went back to the previous pair and am glad to be able to see at a greater variety of distances. The older glasses are now a perfect fit, although for a while back in the winter, they had seemed not to be. I wonder if there is a seasonal fluctuation in my eyes, or if the eye doctor caught me on a bad day (when my fluid balance was wrong or my eyes were unusually tired), or both. I'll keep both pairs of glasses in regular use, of course. And the difference between prescriptions is not big enough to raise concerns about eye disease; the difference may be more in the way the lenses were manufactured (Zeiss vs. Shamir; Zeiss suits me better).

My eye doctor has retired, so I couldn't ask him for a do-over. If I hadn't gotten such good results by just switching glasses, I would have hastened to the new eye doctor; I'm not due for an exam for some time yet.

The moral? Keep your old glasses unless you absolutely can't see through them. It appears that over the past 20 years or so, my eyeglass prescription has fluctuated or wandered around rather than changing steadily in any particular direction. It's not uncommon for to match what it has been at some time in the past.


A small point of logic

"You have a right to your own beliefs," said someone to me on Facebook, "but you have no right to say they're better than anyone else's beliefs."

Pardon me... that does not make sense.

I cannot think of any way to "believe" anything without also believing that its denial is false. If I believe that the earth is round, I also believe that it is not flat.

Further, if I thought your belief was better than mine, I'd adopt it.

I don't claim to be better than people whose beliefs are different from my own. But I cannot figure out any way to hold a belief without thinking it better than the alternatives. What else could "believe" mean?

Actually, I do have some inkling what was meant. We were talking about religious beliefs, and my interlocutor apparently thought they should not really be — well — believed, in the sense of held to be true, but it's OK to keep them in a little mental museum as objects of tribal loyalty, allowing different people to claim loyalty to different ones.

That is not how I run my mind. To me, religious beliefs are claims of fact about God, the universe, and humanity.

[Addendum:] He wrote to me again to explain that his position was not quite what I thought. Rather, his position is that religious beliefs are always so conjectural and untestable that it is wrong to present them as truth; they should only be presented as conjectures. I do not agree, but I see what he means.

The view that I caricatured as "a little mental museum" is, however, something I have occasionally heard from others.

How not to take a flat field

When I do serious astrophotography, I also take "flat fields," images of the featureless daytime sky through a handkerchief, using the same optical system as the astrophotos. In image processing, these can be used to counteract the effects of edge darkening (which all lenses suffer to some extent), unevenness in the sensor, and dust in the optical system.

Well, two nights ago, I did this, and when I got them into the computer, the flat fields didn't look quite flat. Here's what one of them looked like:

Do you see what it is? If not, look at this one, which is the same picture with the contrast increased:

That's right — I somehow aimed the lens, not at the featureless northern sky, but at the treeline.




In the back yard yesterday afternoon...

Lens on equatorial mount, without telescope

Here's an astrophotography setup I've been experimenting with. This is my Celestron Advanced VX equatorial mount without the telescope. Instead, it has a 14-inch dovetail bar with my Canon 300-mm lens and camera attached to one end and, upside down at the front, the autoguider camera (SBIG STV body with homemade guidescope resembling the SBIG E-Finder but a bit bigger).

The counterweight is for an iOptron iEQ30, since Celestron doesn't make a counterweight that is light enough for this small load.

I'm enjoying the versatility of a mount that is separate from the telescope.


Fourth of July thoughts, 1:

On this fourth of July, I'd like to ask my fellow Americans to think for a moment about one thing: Freedom. One of our first questions about any proposed government action, new law, or court decision should be: "Does it increase or reduce our freedom? If it reduces it, is there sufficient reason?"

Freedom is not the only thing we want from government, but it is an important thing. It is easy to get caught up wanting to make something happen by compelling people to do one thing or another. There may be benefits, but the cost in freedom should always be weighed.

There is still plenty of room for disagreement about what kinds of freedom are most important — which hazards we most need to be protected from, at the cost of what other sacrifices. I note in passing that freedom is not a trade-off against safety; freedom is safety (from compulsion), and danger is lack of freedom.

Further, I contend (and I think Aristotle did) that maximum freedom comes from the right amount of regulation, not the absence of it. Anarchy is not the opposite of tyranny; both anarchy and tyranny are situations in which ordinary people have little freedom.

Fourth of July thoughts, 2:
False memory of a past golden age

We often hear that our republic, or civilization as a whole, is about to collapse — that we had freedom, justice, and righteousness in the past, but we're on the verge of losing it.

People who say that are half right. We're on the verge of losing it. We are always on the verge of losing our freedom and our civilization — and, I contend, we always have been.

The notion that the past was secure, and the future is calamitous, has a couple of sources.

(1) We remember what was good about the past, and we forget (or never knew) what was bad. Does anyone really want to bring back slavery, racism, or even secondhand smoke? There was certainly nobility in the 1860s, 1960s, and 1990s, respectively, but there were also those three bad things — and others.

And we easily imagine that past eras had higher moral standards because we remember the moral leaders of the past, and we forget (or never could have heard about) the decadence of ordinary people. Do you think there was no child abuse or sexual irresponsibility 75 years ago just because it was rarely talked about?

(2) We compare the real past with the imaginary future. Lots of terrible things are on the verge of happening. Most of them will not actually happen; they will be prevented, or predictions of them will turn out to have been incorrect. Do you remember that in 1970 we were about to be blown up in a nuclear war, and in 1980 we were about to starve in an ecological catastrophe? It didn't happen.

Look at a newspaper from several decades ago, and you'll see that terrible things have always been about to happen, and have been narrowly headed off. That's what civilization does — it heads off disasters one by one.

So don't imagine that the past was a golden age, or that all your nightmares are sure to come true.

But I also want to caution against chronological snobbery, the notion that the present is in all ways superior to the past, and that people in the past were all fools without consciences. Learning a bit of history will dispel that; chronological snobs are generally ignorant of history. They talk about the triumph of "science" over "superstition" as if it had all happened in their own lifetimes and none of it remained for the future.


M13 with dust lanes

This picture gives a particularly good view of a Y-shaped set of dark lanes (presumably streaks of interstellar dust) in, or in front of, front of the globular cluster M13. This feature is nicknamed "the propeller" and is easier to see with the eye than on photographs, where it is usually overexposed. Stack of sixteen 30-second exposures through the 8-inch EdgeHD. A larger version was published in the B.A.A. Deep-Sky Section Newsletter.

Public policy notes

This isn't just an astronomy blog; I occasionally comment on other matters. Here goes...

About the Supreme Court's Hobby Lobby decision, I'll say just two things.

(1) The decision is much narrower in scope than most people realize. It applies only to a special situation where everybody would get the same coverage, regardless, and the dispute was only about who should be reckoned (on paper) as having paid for it.

(2) The real problem is compelling employers to pay for health care in the first place. Why should employers be in the health-care supply chain at all? They don't provide car insurance or fire insurance, so they're not embroiled in disputes about it. The biggest problem that Obamacare didn't fix is that, for historical reasons, health insurance is tied to employment in this country. It shouldn't be. Then people wouldn't lose their health insurance when they change jobs.

On a brighter note, Georgia's newest traffic law has come into effect. On a multi-lane highway, you can't drive in the passing lane if someone is coming up behind you and needs to pass, unless you have to be in that lane to make a turn or take an exit, or traffic conditions don't allow you to move right.

I hope this will end the Georgia custom of cars traveling in tight bunches side by side, as if they were afraid of wide open spaces. But I think we also need a law against passing on the wrong side. Often, the reason I can't move right is that people are whipping around me on the right at 80 mph!

If what you are looking for is not here, please look at previous months.