Wednesday, November 25, 2020

Assign a Number to it, said Lord Kelvin

“When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and  unsatisfactory kind:  it may be the beginning of knowledge, but you have scarcely in your thoughts, advanced to the stage of science, whatever the matter may be.” – Sir William Thomson, FRS, FRAS, etc., “Electrical Units of Measurement,” May 3, 1883 in Popular Lectures and Addresses, MacMillan, London, 1893.

Oddly enough, for all of the numbers in the hobby of astronomy, we observers report very few of our own. We have the Bortle scale of relative darkness. And of course, stellar magnitudes are commonly referred to, mostly in the context of what is the dimmest you can see tonight? We know that for eta Cassiopeiae, the main star is +3.44 (apparent) and +3.45 absolute and that the companion is +7.51 because that is what is in the references, the same as their classes: G0 for eta Cass A and K7 for eta Cass B. But we do not measure them and report those facts ourselves. Someone might take a picture of them. No one subjects them to a spectroscopic investigation. I, too, am remiss: I only have noted visual impressions and subjective evaluations.

PREVIOUSLY ON NECESSARY FACTS 


Sunday, November 22, 2020

Viewing epsilon Lyrae

I do not remember where I read of epsilon Lyrae as a viewing target, but I have it in my notebook between 12 and 14 November as a possible goal along with eta Cassiopiae and gamma Delphinus. (I identified Delphinus on 01 November, above Jupiter.) I found eta Cass, but have not pursued gamma Delph. Capturing all four stars associated with epsilon Lyr took some work and encouragement from peers.


My first problem was finding a graphical guide. I read that the separation between e1 and e2 is 208 arc seconds (3 mins 28 secs). I also knew that the separation at eta Cass was 5 secs in 1890 and is predicted to be 16 secs in 2150. I figured that it is about 10” or 11” now. And I saw that double star on 15 November (easily) and again on 18 Nov 2034 hrs at 77.5x and 165x. So, I expected the separation of e1 e2 Lyr to be 2o times that. 

 


I posted my sketches to The Sky Searchers under Observing Reports. (I also figured out a way to make drawings more-or-less to scale by keeping both eyes open and holding a ruler at arm’s length in the image.) 

 


Username Bigzmey replied that with my ES-102 and a 6 mm ocular with 2x Barlow, I ought to be able to split the two stars e1 and e2 into four. I went back and did more reading and found my mistake.  

 


I posted my sketches of 20 November 1851 hours along with my thanks.

[A note on the scientific illiteracy of our era: On this blog you can find excoriations of Neil deGrasse Tyson's Spacetime Travesty and errors in the Sky & Telescope desk calendar. In this article, you will have caught the fact that the Greek letters are written out. I write my drafts in Word. Characters created with the MS-Word Symbol font do not always import. It depends on the versions of this and that. Google Blog has Lots of New Cool Fonts, (including Cherry Cream Soda) none of them supporting a technical set. Even the s0-called Cambria Math is sadly deficient. 


Georgia - a b c d e f g h i  j k l m n  o p q r s t u v w x y z 

Cambria Math - a b c d e f g h i  j k l m n  o p q r s t u v w x y z 

Cambria Math - å ı Ç Î ´ Ï © Ó ˆ Ô ˚ Ò Â ˜ Ø ∏ Œ ® Í † ¨ √ ∑ ≈ Á Ω 

A-hat and O-hat are OK for unit vectors, or would be if they were lowercase. Such do not exist. 

The right-hand alt opt key give the line shown above.

The left-hand alt opt yields these: å ∫ ç ∂ ´ ƒ © ˙ ˆ ∆ ˚ ¬ µ ˜ ø π œ ® ß † ¨ √ ∑ ≈ ¥ Ω 

... because mathematicians and other technical workers so often call on the archaic copyright © and registering ® their trademarks to protect their incomes in Japanese ¥ yen when citing the words of James Madison on the advantages of a fœderal constitution.]

 

PREVIOUSLY ON NECESSARY FACTS

The Andromeda Galaxy 

Beehive Cluster First Sighting 

Space is the Place: Come to the High Frontier 

Of Watches and Beaches and Atheists 


Saturday, November 21, 2020

Viewing Mars

On October 13, 2020, at 23:00 UTC (6 PM CDT), Earth passed directly between the Sun and Mars. And given the eccentricity in the two orbits, this was a close opposition. Even into November, the viewing has been good. My new telescope arrived on October 24, but I did go out earlier with my National Geographic 70 mm and view. “You can observe a lot just by watching,” said Yogi Berra.

I had seen and described Mars earlier, on 17 June 2017, at 21:21 CDT, and made my first sketch on 17 August 2018 at 23:15 hours, but forgot about those until I reviewed my notebook. 

 

00:15 HRS CDT 12 October 2020
National Geograph 70 mm f/10


Technically, Venus is the planet closest to Earth most of the time, but at opposition, especially when Venus is at inferior conjunction (on the other side of the Sun), Mars is closer still.  That fact has been with me since I first saw Invaders from Mars (1953) on TV about 1960 or 61. 


Posted to Cloudy Nights “Mars – November/December 2020” 

in “Observing/Solar System Observing” 

on 17 November 2020 at 0954AM

Received reply:

“Good sketch, Mike.  You saw Syrtis Major and Mare Tyrrhenum”

SpecialEd 17 November 2020 at 02:38 PM


Unlike Venus which is covered in clouds, Mars has long enticed us with its changing surface features. I even have a Warner Brothers Marvin the Martian t-shirt and another with the Martian fleet from Mars Attacks (1996). My first narrative view of a Martian was in Assignment in Space by Blake Savage (a re-issue of Rip Foster Rides the Grey Planet, 1953). 

 

PREVIOUSLY ON NECESSARY FACTS

Rescuing Aristotle and the Church

Science versus Common Sense

Teaching Science with Science Fiction

Still Riding the Gray Planet 


Tuesday, November 17, 2020

New Cat: Sunny

We knew that Désirée had feline leukemia when we adopted her four years ago. After she passed away, we waited a few months to take in a family member. Sunny is also a rescue. PTSD is the easiest diagnosis. 

Laurel got her from a rescue lady with a clouder of her own. Sunny's kittens had been taken away from her and she spent her time with her nose in the corner of a closet. We got her here and put her in a closet. It took about two weeks for her to settle in under the bed. She was good about the litter box and always cleaned her food dish so like you just put it back in the cupboard. But she was tragically aloof. She still does not like to be petted. But now she does come out to play with us, chasing balls. 

She watched me hide the ball under the rug.

She comes into the living room and watches TV fairly intently. We moved her food from the bathroom to the bedroom and now into the living room. She still does not like to spend too much time in the kitchen, but does explore. She found the back door and sniffed at it and her back went up. She likes attention from a distance. And she like to play ball. Not only does she chase them, of course, but she bats them back and has a backhand move. Last night, she slept on the bed and did not spring off and go under when one of us shifted. Recovery is a process.

PREVIOUSLY ON NECESSARY FACTS

Only a Cat 

Désirée (Miss Kitty) 

Fossils and Behaviors 

Plenty of Time When We Get Home   


Tuesday, November 10, 2020

Redshift: Six Years with Astronomy

My wife and daughter bought me a telescope for my birthday in 2014. Today, I reviewed by notebook. It was disappointing. Overall, I made very little progress in observation, even though encouraging entries do exist. I first saw Mars on 17 June 2016. I sketched it two years later on 17 August. I spotted the Andromeda Galaxy 1 December that year. I attended some good star parties and a lecture by Dr. Steven Weinberg. This past June, I became an assistant editor with the History of Astronomy Division of the American Astronomical Society. In six years (2162 days), I have 195 pages with ten colored flags for wins. Flags aside, the latest entries since April are more informative. 

Community Outreach is important to the mission
 of the Austin Astronomical Society.
Several factors contributed the present plateau of success. 

  • Practice helps. I did not view the stars for an hour a day for six years, but an hour (or more) for one night a month (or less). It took a while to build some experience. 
  • Sketching and drawing improved with trial-and-error. 
  • I found helpful websites and online discussion boards. 
  • Instrumentation helps. I borrowed two Meade LX 200 Classic Schmidt-Cassegrain catadioptric instruments from the Austin Astronomical Society, an 8-inch and 10-inch. I did not need to fight the instrument and the work was rewarding. The German fork mounts were easy to use. The finder scopes were 8x with crosshairs. So, just targeting Jupiter, I could see its moons. The images in the telescopes were large and bright. Even the setting circles were large enough to be practicable and practical. I noted the actual positions of stars and planets.

I may unpack the Celestron EQ-130 (5-inch reflector) and use it again, but it is not my favorite. 

The Celestron telescope came with a lot of trade-offs.
The Celestron Lens  & Filter Kit is popular with many amateurs
and has served me well with all of my telescopes.

In many ways the abused National Geographic 70mm (2-3/4 inch) refractor that I bought served me better. It has a longer focal length and a higher f/stop ratio. And it is a simple altitude-azimuth XY mount.
  
Top: What their uncle gave them for Christmas.
Bottom: In July I repaired it well enough for myself.

My time in the Austin Astronomical Society has been a ledger of gains and losses. Laurel gave us a family membership with my telescope in November 2014. When the club had the Canyon of the Eagles dark sky site and observatory, I completed a certificate in telescope operations with their classic 12.5-inch Newtonian and 16-inch Cassegrain instruments on March 15, 2015. 

Five months later to date, at a COE members-only star party, when he was serving as the Outreach director, Jim Spigelmire spent an hour with me getting me oriented to more stars than I had seen in my life at one time and place. 

When she was serving as the newsletter editor, Joyce Lynch assigned me to interview the club’s stalwarts for a series of articles in 2016. I learned a lot. I interviewed Terry Philips (now serving as the president), on May 27; and thanks to him, on June 17 I first viewed Mars with my EQ 130. I interviewed astrophotographer Mike Shaffer and learned that a telescope is composite of different assemblies: an objective lens system in an optic tube, oculars (“eyepieces”), a mount, and a tripod. When you buy them all as a package, you buy someone else’s trade-offs in price and performance. As a mechanical engineer, he preferred to write his own requisitions. 

After one club meeting on the University of Texas campus, we held a star party on a walkway over MLK Boulevard and one of my colleagues lined up Albireo for me in his telescope. 

The downsides reflect the fact that we prefer to be alone in the dark focused on objects very far away. Everyone is on the autism spectrum, often with obsessions, compulsions, and other disorders. One of the affiliated social clubs is “Astronomy on Tap” and I served on a committee with a mean drunk. 

After a star party, I put the telescope back in its shipping cartons for five months, devoted more attention to my military service, and let my membership lapse. I re-enrolled in 2019 and volunteered as a member-at-large on the executive committee. This past June I ran unopposed for vice president. 
My newest is an Explore Scientific 102-mm
 f/6.47 refractor "First Light" series.
Typically a beginner scope, it is easy to use.

For those of us who do not work and play well with others, online discussion boards can substitute for warm body interactions. I subscribe to Cloudy Nights and The Sky Searchers, writing and reading more with the latter. 

I also subscribed to Sky & Telescope and Astronomy. I leaf through them, but they don't speak to me. Purchased from their bankrupt holding company Sky & Tel is now published by the American Astronomical Society. Astronomy maintains a database of past articles that was not as  helpful for research as I had hoped. I bought their CDs of past issues, but unfortunately, the disks are no longer compatible with Mac OSX. So I sent them back and told them to keep the $129 because it was not as important to me as knowing never to buy from them again. Then, Astronomy caught me with an automatic renewal this year, so that was fifty bucks out the door, but I was able to cancel it for the next time around. 

 

I like to go out at night, observe the universe, and satisfy myself that it is pretty much as described. The heavens are orderly and predictable, made of the same stuff as I am, yet made astonishingly different from mundane, secular experience. The stars are pretty at any magnification. Viewing them bigger and brighter only reveals their surfaces. As pleasurable as observing is, my greater passions are for the history, the theory, and the history of the theory. 

Ultimately, for myself, astronomy is about the mathematics and science and the people who discovered them by creating methods and instruments. The invention and improvement of the telescope, the discovery of the spectrum, the application of radio to astronomy, and then launching those telescopes and radios into outer space are all very grand. That it can be expressed as a small set of symbols that I can understand is at once humbling and ennobling. 

 

PREVIOUSLY ON NECESSARY FACTS

Austin Under the Stars 

Measuring Your Universe: Alan Weinberg's Astronomy Activity Manual

The Drunken Astronomers 

Physics for Astronomers: the Works of Steven Weinberg

Burnham’s Celestial Handbook 

Turn Left at Orion

 

Thursday, October 29, 2020

Clear Nights, Full Moon

The full Moon on the 31st is a problem, but the nights are clear and cold. So, I took out my Explore Scientific First Light 102-mm refractor. I also brought my old and overused National Geographic 70-mm refractor. I viewed Jupiter, Saturn, Mars, the Moon, and unsuccessfully chased what appeared to be open clusters near the zenith. I do not know what the atmospheric effect is--and it may be my early cataracts--but I see patches of faint, cloudy light in the open sky. The telescopes do reveal stars there, only not tight groups. 

With the ES-102, the Red Planet was green around white with all oculars. 

Encouraged by a how-to on The Sky Searchers, I tried all of the smaller eyepiece combinations, 17-mm, 13-mm, 8-mm, and 6 alone and with the 2x Barlow lens. The 8-mm alone is the limit and the best views are with the teens through the Barlow. One advantage to the 8-mm over the 17-plus-Barlow is that the 8 alone is just a little clearer because it is just a little less glass for the light to work its way through, but that could just be the result of my expectation.

The Moon was great. I used their 25-mm (with my red filter 15% passage) and my Celestron 32-mm (with Moon filter 14% passage). Almost like being there...

We just had a week of rain and by 11:00 PM stuff was getting wet from condensation. So, I brought everything in. I slept through until 4:30. Tonight I will set an alarm and get up at 01:00 to try the Pleiades.

PREVIOUSLY ON NECESSARY FACTS

New Telescope: ES 102 

The Perfect Machine

Seeing in the Dark

Saturday, October 24, 2020

New Telescope: Explore First Light 102 mm Refractor

The problem with consumer goods is that at the designers are not you. Everything is always a matter of trade-offs. The decisions that other people make for you might not be the ones you would make for yourself. 

I bought a new telescope to use in the backyard. As vice president of the Austin Astronomical Society, I invited Scott Roberts, the CEO of Explore Scientific, and Stuart Parkerson, publisher of Astronomy Technology Today, to be our guests for a panel discussion. Ahead of that, I shopped at Explore for my next backyard instrument. They answered three emails and then asked me to call them on the phone before I was a customer. And they talked me out of buying extra oculars until I used the telescope often enough to judge better what would suit my needs. I was impressed. 


The Explore Scientific First Light 102-mm refractor ($279) is a good instrument. Placing aside my cognitive dissonance, I made some minor modifications. 

 

Because the objective lens is so large and heavy, the telescope does not balance in the center of the dove-tail receptacle. It balances almost full-forward in the grip so that the ocular has more moment arm, like a child on a see-saw balancing a grown-up. 



The objective still has a tendency to dip into the tripod, so I attached two strips of foam under the front. 

The XYZ control is a single lever that I found too short. So, I added 6 inches of plastic tube to bring the control closer to the focus draw adjustment wheels. 


29 October: I removed the extension. It was too much leverage. It is easier to control the alignment by holding the frame. The action is still very tight: won't go--won't go--won't go--too far! I now know that I personally prefer gear-driven tracking. 



The only other payment for the price is that the very artistic mount has the elastic stability of a thin plate. Fortunately, it damps out quickly. 

 


The optics are good. The 102-mm (4-inch) objective brings in Jupiter, Saturn, and Mars well enough. The 660-mm focal length works best with my 17, 13, and 8 mm oculars. When the weather clears, I will use the Moon to try my 32-mm and the new 25-mm eyepieces. The final test will be the Pleiades, over my neighbor’s treetop after midnight and on the zenith before 03:00. 

 

I was never satisfied that I had properly collimated my Celestron 130 EQ reflector. After a final round of stargazing and finding Albireo on my own, I put it all back in its shipping cartons and stored it in the garage along with the Meade 10-inch Schmidt-Cassegrain telescope (SCT) that I have on loan from the Austin Astronomical Society. (I took that one out just once; and at 65 lbs to my 68 kg, I found it inconvenient.) I bought a used 8-inch Meade LX Classic SCT from the club. The circa-1995 on-board computer did not work, after being repaired twice. They asked $250 and I countered with $325. It was a nice scope, but the right ascension (XY-left right) locked up and I did not want to take it apart. So, I gave it to the Goodwill. They will fix it, pass it along, and make some money. 

 

My go-to scope has often been a 70 mm National Geographic refractor that I bought used from some kids down the street. They got it for Christmas and by July had lost the eyepieces, the cellphone adapter, the center plate, and the control rod for altitude (Z-up down). And the dew shield was jammed on backwards. (For all of that, they had never used it outdoors.) But it was a National Geographic brand; and I tested it on the street, and the objective seemed OK. It takes the standard 1.25-inch oculars. And it is an f/10 with a 700 mm focal length, which works well for higher magnifications: 13-mm ocular with 2x Barlow for 108x. So, for what it is, it has served me well in the backyard. But after three years, it is held together with rubber bands. So, I went shopping for a new go-to 'scope. The best thing about the Explore First Light 102 is the word “light.” All together I can carry it with one hand.

 

PREVIOUSLY ON NECESSARY FACTS

Problems with Pop Sci from Sky & Telescope 

Physics for Astronomers: the Works of Steven Weinberg 

The Asteroid Hunters by Carrie Nugent 

Backyard Astronomy (2) 

Backyard Astronomy (1) 

 

Thursday, October 22, 2020

Galileo and Saturn: Epistemology not Optics

It is commonly claimed that Galileo did not perceive the rings of Saturn because the telescope he was using was not capable of magnifying the image. That is not true. After Galileo, astronomers needed another 50 years to think about the problem and re-imagine it. They needed to ask the right questions. Christiaan Huygens was the first to perceive the structure as a ring. However, it was another 200 years before the ring was understood as a system of particles, rather than a rigid body. The problem was epistemology, not optics.

Galileo’s Images of Saturn 1610 and 1616
https://attic.gsfc.nasa.gov/huygensgcms/Shistory.htm

    “Galileo Galilei was the first to observe Saturn with a telescope in 1610. Because of the crudeness of his telescope, he couldn't determine what the rings were. He incorrectly guessed that there were two large moons on either side of Saturn. Two years later when he viewed Saturn again, the "moons" had disappeared. We know now this is because Galileo was viewing the rings edge-on so that they were invisible, but at the time it was very confusing to Galileo. After another two years, Galileo viewed Saturn again and found that the "moons" had returned. He concluded that the rings were “arms” of some sort.

            “Many years later, in 1659, a Dutch astronomer named Christiaan Huygens solved the mystery of Saturn's "arms." Because of improved telescope optics, he correctly deduced that the "arms" were actually a ring system. Huygens also discovered Saturn's moon, Titan, and for this reason, the probe exploring Titan is named after him.” 

From NASA’s Cassini-Huygens Mission website (no longer current) here https://attic.gsfc.nasa.gov/huygensgcms/Shistory.htm

Galileo’s Sketch of Saturn” 
from Galileo and the Scientific Revolution 
by Laura Fermi and Gilberto Bernardini,
Basic Books, 1961.

“When he turned his telescope on the planet Saturn, he found that this did not always look like a round body but seemed of strangely variable shape. He thought it to be “three-bodied; that is it … was an aggregate of three stars arranged in a straight line parallel to the ecliptic, the central star being much larger than the others.” His telescope was not sufficiently powerful to let him to distinguish the three, possibly four, rings we now know are around Saturn. It was the Dutch astronomer Christian Huygens (1625-1695) who discovered Saturn’s rings.” -- Galileo and the Scientific Revolution by Laura Fermi and Gilberto Bernardini, Basic Books, 1961.

 

“Galileo continued his telescopic observations from his new home in Florence. Here he discovered that Saturn sports a pair of curious appendages, but his telescope was not powerful enough to reveal their true nature. (They were Saturn’s rings.)” Parallax: the Race to Measure the Cosmsos by Alan Hirshfeld, W. H. Freeman and Company, 2001. 

 

“1610 - Galileo Galilei becomes the first to observe Saturn's rings with his 20-power telescope. He thought the rings were “handles” or large moons on either side of the planet. He said “I have observed the highest planet [Saturn] to be tripled-bodied. This is to say that to my very great amazement Saturn was seen to me to be not a single star, but three together, which almost touch each other”. 

“1612 - Galileo was astounded when he found that the rings he first observed a couple of years earlier had now disappeared. He wrote "I do not know what to say in a case so surprising, so unlooked for and so novel". The rings were, in fact, edge-on from Earth's perspective. Galileo inadvertently became the first person to observe a Saturn ring plane crossing. 

“1616 - Galileo now observes the rings as two half ellipses. He wrote “The two companions are no longer two small perfectly round globes ... but are present much larger and no longer round ... that is, two half ellipses with two little dark triangles in the middle of the figure and contiguous to the middle globe of Saturn, which is seen, as always, perfectly round.”

 From Views of the Solar System Copyright © 1995-2015 by Calvin J. Hamilton. https://solarviews.com/eng/saturnbg.htm

 

Museo Galileo, Florence
https://catalogue.museogalileo.it/indepth/SaturnsRings.html

“In some observations conducted in 1610, Galileo (1564-1642) saw Saturn as tricorporeo [three-bodied], i.e.,composed of a central body and two lateral bulges, which he mistakenly thought to be satellites. In 1655, Christiaan Huygens (1629-1695), thanks to a more powerful telescope, observed Saturn's rings for the first time. He described them accurately in Systema Saturni (The Hague, 1659). The Accademia del Cimento was concurrently investigating the nature of the rings. Between 1671 and 1684, Giovanni Domenico Cassini (1625-1712) discovered four satellites of Saturn, in addition to the one previously found by Huygens. Cassini also observed and studied the divisions between the rings. Recently, the Voyager space probes have revealed that the many concentric rings are thin bands consisting of countless rock and ice fragments that orbit the planet and reflect sunlight.”

© 2018 - 2020 Museo Galileo - Istituto e Museo di Storia della Scienza 

https://catalogue.museogalileo.it/indepth/SaturnsRings.html

 

https://www.bibliovault.org/thumbs
/978-0-8165-0829-7-frontcover.jp
g

“Telescopic studies of Saturn, its ring system, and its satellites from 1610 to about 1900 are surveyed. Early observations of the Saturn system and changing beliefs about the constitution of the rings are covered, showing that what an observer sees in the heavens depends not only on the quality of his instruments, but also on what he expects to see. The first observations of the Saturn system by Galileo, the development of the ring theory by Huygens, and the replacement of Herschel's and Laplace's solid ring theories by Maxwell's particle ring theory are recounted.” 

Saturn Gehrels, Tom; Matthews, Mildred Shapley (Editors). Tucson, University of Arizona Press, 1984, p. 23-43.

 

Introduction to Objectivist Epistemology
by Ayn Rand (2nd. edition)


In Introduction to Objectivist Epistemology, Ayn Rand asserted that a sensation must be identified to become a percept. A set of percepts, identified and integrated by common attribute becomes a perception. A set of perceptions integrated by their common characteristics are given a name and thereby made into a concept. Concepts are further abstracted by their essential distinguishing characteristics, according to objective context, into wider (and more powerful) ideas. Without identification, a sensation alone is meaningless. Not knowing what to expect, Galileo could not perceive the rings of Saturn correctly.


Just as it took time for the nature of Saturn’s rings to be teased out from the observations, so, too, did someone 400 years after Galileo finally put 2 and 2 together. In 2005, the science of epistemology informed astronomy.


“Saturn was first seen through the telescope by Galileo in the summer of 1610. In the ensuing half century, Saturn's strange appearances became a celebrated puzzle. The problem was often not the poor quality of telescopes: a number of observers drew images that we would interpret as showing a ring around the planet. It was also a problem of concepts because for several decades observers had the wrong model in mind when they observed the planet. Thus we could say that their telescopes could show them the ring, but their preconceptions did not allow them to see it. The manner in which Christiaan Huygens arrived at the solution, in the winter of 1655-56, shows that more than good telescopes were necessary, although for rhetorical reasons Huygens maintained the opposite. And Huygens's ring-theory, [elegant] as it was, had several shortcomings that were slowly fixed--often by others.” --  “Saturn through the Telescope: The First Century” by Albert Van Helden. American Astronomical Society, DPS meeting #37, Bulletin of the American Astronomical Society, Vol. 37, p.620. Pub Date: August 2005

 

Explore Scientific First Light 102
660 mm focal length


Last night, I went out with my telescope to see what Galileo could or could not have perceived, had he held the identifying concept. Admittedly, the 102 mm objective of my Explore Scientific refractor has 16 times the area of his. However, I am inside a city, a mile from a major shopping center. He was in Florence, a city with smoke, perhaps, but no arc vapor street lights. 


I tested three magnifications: 20.8x (32 mm), 26.4x (25 mm) and 38x (17 mm). At 21 power, it was a strong “maybe” given Galileo's patience. At 26.4 power the rings were discernable without question, and at 38x, they were undeniable. Although his 20x telescope was his primary instrument, it was not his only telescope. He had made a 30-power at the same time, but gave it to Cosimo Medici. I believe that Galileo’s instruments were good enough, but understanding of the taxonomy of the solar system required a conceptual leap that would have to wait for later astronomers.


PREVIOULSY ON NECESSARY FACTS

 

The Scientific Method 

Feynman's Rainbow 

Harriman's Logical Leap

Cosmos: a Spacetime Travesty 


Sunday, September 27, 2020

Celestial Mechanics

I first got interested in celestial mechanics in 1978. I enrolled in three independent study classes at two schools, New Mexico State University, then at Lansing Community College (1981, 1982). In 1981, I met an astronomer from Michigan State University who encouraged me to get this book on algorithms for calculators. He wanted it for himself and I was working for a publisher. So I ordered two. I used the routines as outlines for some BASIC programs but never went much further with it. 

[An earlier version of this essay was posted to The Sky Searchers discussion board in the Astrophysics forum.] 

Book cover Mathematical Astronomy with a Pocket Calculator by Aubrey Jones
John Wiley and Sons.
(c) Aubrey Jones 1978

My wife and daughter bought me a telescope for my birthday in 2014. In the past six years, I have enjoyed going out in the backyard (often) and to star parties (a few times) and verifying for myself that the universe is pretty much as described in the books. But what’s next?

I am not facile with mechanical tasks. Things come apart a lot easier than they go back together. That can be useful for documenting physical systems, but it suggests that photography and spectroscopy are not likely to be rewarding as hobbies complementing observational astronomy.  
 

On the one hand, in order to pursue celestial mechanics you really need to love mathematics. As much as I enjoy it, I took Calculus-1 twice to get a C+. I learned integration (usually Calculus-2) by taking a computer programming class and coding up the Midpoint Rule, Simpson’s Rule, and the Trapezoid Rule. The advantage to me is that it is easier to erase a mistake than it is to drive to Home Depot to buy another part (which I have to do to finish work on the backyard gate). 


McCuskey, Addison-Wesley, 1963
In the 18th and early 19th centuries, orbit plotting was the focus of astronomy. Following Sir Isaac Newton’s 
Principia, and the parallel work of Gottfried Wilhelm Leibniz, Pierre-Simon Laplace developed what we recognize today as the calculus of celestial mechanics. It allowed astronomers to establish the orbits of the planets and their newly discovered moons and the two new planets, Uranus and Neptune, and their moons. It also allowed astronomers to determine the physical arrangements of binary stars. With the advent of photography and spectroscopy, orbit plotting fell out of favor with researchers as those tools revealed deep and starling new truths. However, even as radio astronomy came to the fore in the 1950s, celestial mechanics regained some importance with the space age. 

 

But if you are not the person launching a satellite to Saturn, why grind through transcendental equations? My reply is the same as for any amateur pursuit, any hobby, or sport: You do it for yourself because it is at once rewarding and edifying. And unlike most other hobbies, astronomy is a study where amateurs and professionals collaborate. 

 

How fast does the Moon go around the Earth?

How fast does the Sun go around the Earth?

How fast do the stars go around the Earth?

And when will that comet come back?

 

If you have lived any arbitrarily long time, you know that our easy estimates – the Moon travelling through 360 degrees in 28 days; the Sun circling the Earth 360 days each year (plus 5 days for a long holiday "off the books"); the fixed stars moving westward one degree per night through the year -- have errors that accumulate. Can I make more accurate predictions?

 

Not only has the hard mathematics been done already, reducing the problems to the application of formulae, but I now have a computer and a spreadsheet. All I have to do is take the measurements and reduce the data.

 

(More later.)

 

PREVIOUSLY ON NECESSARY FACTS

Newton and Leibniz

Astrophotography is a Lot like Love 

Measuring Your Universe: Alan Hirshfeld’s Activity and Laboratory Manual

In Support of the Entry-Level Telescope 

John Kemeny Knew: We Shall Have Computed 

 

 

Thursday, September 17, 2020

Hail to the Spartan Victors?

I do not remember where I was driving when I saw this banner. The incongruity prompted me to stop and take a picture. I found it again in my archives but it had been edited and the date was too current now. 

We mostly lived in Michigan for about 30 years off and on from 1977 to 2011, almost 20 years continuously from 1979 to 1999. The hometown rivalries are between the Michigan State University Spartans (green and white) and the University of Michigan Wolverines (blue and maize). 


Never much for team sports and certainly not college football, the fact is that we lived in and around Lansing until 1999. My daughter and I made good use of the MSU campus. I had a community library card. We skated the grounds, rented canoes, and explored buildings when classes were out. 


But Laurel’s freshman year was at the U of M before we met. She returned to work at the University and take a graduate class when we were living in Ann Arbor and attending Eastern Michigan University 2005-2010. So, our loyalties are somewhat conflicted.

 


But, as I said, I don’t follow sports. So, there was one time I was working for a software firm in Lansing and some of the programmers were MSU graduates; everyone else was an MSU fan. I caught a cold the week of Thanksgiving and missed a day of work that Wednesday and spent the weekend in bed recuperating. The Michigan-Michigan State game was televised (oddly) and I caught snatches of the last quarter as I surfed the channels. When the game was over, the Green and White band came out and played “Hail to the Victors.” 


 The next Monday, they were talking about the game, and going to school, and learning the MSU fight song at orientation. And I said, “Hail to the Victors” and they said, “WHAT?!?!” And I explained that I caught the end of the game and the Spartan band played “Hail to the Victors.” And they said, “That’s because we lost. The band salutes the winner by playing their song.” Oh…


PREVIOUSLY ON NECESSARY FACTS

Hook ‘em Horns! 

Good-Bye Redskins 

Why a Level Playing Field? 

Big Bang Theory: More Friends than Seinfeld 

 


Tuesday, September 8, 2020

Pencil Notes: Reflections on Henry Petroski’s "The Pencil"

“Yet, perhaps in part because specialization was no doubt as common in ancient times as it is today, the written history of engineering is sparse. Even the most able and articulate of ancient engineers, whether they were known as artisans, craftsmen, architects, or master builders, might have had no more time or inclination or reason to articulate what it is they did and how they did it than do some of the most able of today’s engineers.” – page 17

That is why they hire technical writers. To me, it is a right-brain/left-brain situation. Engineers tend to be right brain thinkers. Technical writers bring that with them, also, the ability to read, edit, and create drawings, whether architectural plans or software flowcharts. Ultimately, though, the images get verbal explanations. That may explain why so many technical writers are women: the left and right hemispheres of the brain are connected by the corpus collosum, which tends to be more highly developed in females than in males.

 


It is difficult to be certain how this or that better design for a brush, plow, house, or sword evolved from its predecessors, for the process was at best sketched metaphorically in pencil and seldom if ever copied in pen. It is because of this that the ideas and artifacts of technology—the processes and products of engineering—are so very different from the creations and theories of literature, philosophy, and science. … The classics, even if superseded in factual or theoretical sophistication are considered models of thinking from which one can today still benefit by emulation, or at least inspiration. […] Curators of technological artifacts, industrial archaeologists, and historians of technology represent rather new careers…” – pages 20-21

  1. First, that is why we have industrial archaeology now, to recover and understand those earlier activities and artifacts. 
  2. Second, we have lost some mathematics. Richard P. Feynman wanted to demonstrate to his class how Newton proved Kepler’s laws, and he wanted to do it in Newton’s own language. He could not. Feynman could not recreate the geometry that was fundamental to the Principia. We have become so dependent on algebra and calculus that we have forgotten the admittedly more cumbersome tools of earlier mathematics.
  3. We also lost the machinery of the Antikythera Mechanism. It would be almost 1500 years before clocks were again so complicated, accurate, and precise.
  4. Fourth, and to Petroski’s point, antiquarians do inform the present. Though we had advanced past the hand-hammered methods of coinage, it is famous that President Theodore Roosevelt commissioned Augustus Saint-Gaudens to give America coinage as compelling as that of the ancient Greeks. 

Professional Coin Grading Service "Coin Facts" website
TOP: Half Dollar of Charles Barber imitating the work
of Oscar Roty for France. BOTTOM: Something better. 


“[Sir Isaac Newton’s] seashore metaphor allows that one shell (theory) may be prettier (more elegant) than another, and perhaps the searcher becomes less fond of the old shells as prettier ones are found, but the implication is still that the truths are whole in the ocean and it is just a matter of time before they are found thrown up on the shore.

“While pencils may be helpful in formulating abstract theories of motion and gravitation, abstract theories do not make pencils.” – page 74.

 

The history of modern physics may refute that. The mathematics describing atomic and nuclear processes energy became the design specifications. We did not tinker our way to nuclear power.

 

Of all the revelations and insights here, I was captivated by the story of Henry David Thoreau (Chapter 9: An American Pencil-Making Family). We recently watched the most recent remake of Little Women (Greta Gerwig director). We see Jo March’s ink-stained fingers and we watch her on the floor, scribbling in pen. But we all also know that the family was connected with the Transcendentalists, among them Henry David Thoreau. But who knew that his family made pencils? In his list of supplies taken to Walden Pond, mostly likely written with the pencil he carried, Thoreau omitted the pencil. Thoreau also billed himself as a surveyor and civil engineer, two professions that even in 1840 depended on good, reliable graphite pencils. 

 

I wrote here last week about the passage on pages 223-225 describing how engineers often were trained to draw by copying architectural treatments. It is, of course, how architects learned to draw. That opened up a new vista on an early passage in The Fountainhead. That being as it may, it is nonetheless true that to learn science, we recreate the important experiments of the past. We just do not slavishly recreate them with archaic beakers, wires, and flyball governors. I believe that it is a valid criticism of physics in particular, stated in Thomas Kuhn’s Structure of Scientific Revolutions, that we are handed science as a completed artifact and do not trouble ourselves much with discarded paradigms—or why we discarded them. (My review for this blog is here.)

 

“One desirable quality is often gained at the expense of another, for how the properties of complicated materials will change with changing ingredients and methods of preparation, whether they be pencil leads or concrete, is not always easily predictable. While a new mixture might give a stronger material, it might also give a more brittle one that will be greatly weakened by a small crack.”—page 236

 

“The stories of the Munroes and the Thoreaus and their pencils illustrate in microcosm the often conflicting objectives of real-world engineering and business: making pencils as fine as possible as an end in itself; making pencils better in quality or price than other pencil makers; making pencils secretly in order to have an advantage over the competition; making pencils overtly to conceal a more profitable business; making pencils for the social and cultural good of artists, engineers, and writers of all kinds. There is no such thing as pure engineering, whether in the artifact or in the abstract—for that would be nothing but irresponsibility or a mere hobby. Engineering, far from being applied science is scientific business.” – page 276-277.

It reminded me of the discussions among Austrian economists over what entrepreneurship essentially is. (See NecessaryFacts here.) Being rationalists  they seek one or a few axioms from which all of the remainder can be derived by pure reason. Do entrepreneurs bring new inventions to market? Do they arbitrage risk? Do they carry goods from where they have lower value to where they are valued more? Do they drive each other out of business by any means possible? Do they find cooperation where others find conflict? Do they take advantage of the unwary or do they profit from intelligent decisions? Mises pointed out at some length that the entrepreneur can be so self-centered that they invest all of their resources in a lost cause when a rational person would just get any good-paying job and keep it. There is no such thing as pure entrepreneurship unless it is a hobby. 

 

In 1933 [the Lead Pencil Institute] has ten members who together manufactured 90 percent of all American pencils. Thus the institute effectively represented the entire industry, which at that time included thirteen firms. They were roughly in order of size: Eagle Pencil Company, New York, N.Y.

Eberhard Faber Pencil Company, Brooklyn, N.Y.

American Lead Pencil Company, Hoboken, N.J.

Joseph Dixon Crucible Company, Jersey City, N.J.

Wallace Pencil Company. Brentwood, Mo.

General Pencil Company, Jersey City, N.J.

Musgrave Pencil Company, Shelbyville, Tenn.

Red Cedar Pencil Company. Lewisburg, Tenn.

Mohican Pencil Company, Philadelphia, Pa.

Blaisdell Pencil Company, Philadelphia, Pa.

Richard Best Pencil Company, Irvington, N.J.

Empire Pencil Company, New York, N.Y.

National Pencil Company, Shelbyville, Tenn.

(Page 293)

 

I found it disappointing that Petroski quoted John Middleton Murray at length on the poetry of being a pencil, but never mentions “I Pencil” by Leonard E. Reed.

 

The old meets the new. These pencil extenders are built
from STL files provided to 3-D printers

“Who today but a frugal draftsman would use a pencil down to such a stub? But our pencils, unlike many of those of the Victorians, have lead from end to end, and some engineers and draftsmen, when a good pencil’s stub is too small to hold even in a pencil extender, have been known to cut away the last of the wood case and use the left in their compasses.” – page 354

 

Previously on NecessaryFacts

Imaginary Numbers are Real but Pegasus is not 

Forbidden Planet 

Spoken American Grammar 

The Map that Changed the World