April 2023 – Cosmic Reflections

Classical Music Timeline: 1830s

This is one of a series of postings of important classical music dates, from the 17th century to the present. Included are the date and location of the birth and death of composers, and the premiere date and location of the first public performance of works. When the premiere date and location is unknown, the date or year of completion of the work is given. Though reasonably comprehensive, this is a subjective list, so the choice of composers and works is mine. If you find any errors, or if you can offer a premiere date and location for a work where only the completion date or year is listed, please post a comment here.

1831
Frédéric Chopin (1810-1849) completed Étude in C minor, op. 10, no. 12, “Revolutionary”

1832
Frédéric Chopin (1810-1849) completed Three Nocturnes, op. 9

Frédéric Chopin (1810-1849) completed Étude in E major, op. 10, no. 3, “Tristesse”

May 14 – Overture to The Hebrides, in B minor, op. 26, by Felix Mendelssohn (1809-1847) was first performed in London, England

1833
Frédéric Chopin (1810-1849) completed Four Mazurkas, op. 17

May 7 – Johannes Brahms (1833-1897) was born in Hamburg, Germany

November 12 – Alexander Borodin (1833-1887) was born in Saint Petersburg, Russia

1834
Frédéric Chopin (1810-1849) completed Fantasie Impromptu in C♯ minor, op. 66

November 23 – Harold in Italy, op. 16, H. 68, by Hector Berlioz (1803-1869) was first performed in Paris, France

1835
October 9 – Camille Saint-Saëns (1835-1921) was born in Paris, France

November 9 – Piano Concerto in A minor, op. 7, by Clara Schumann (1819-1896) was first performed in Leipzig, Germany

1836
Robert Schumann (1810-1856) completed Fantasie in C major, op. 17

January 30 – Octet for Strings in E♭ major, op. 20, by Felix Mendelssohn (1809-1847) was first performed in Leipzig, Germany

December 9 – A Life for the Tsar, opera, by Mikhail Glinka (1804-1857) was first performed in Saint Petersburg, Russia

1837
Frédéric Chopin (1810-1849) completed Étude in C minor, op. 25, no. 12, “Ocean”

January 2 – Mily Balakirev (1837-1910) was born in Nizhny Novgorod, Russia

June 23 – Ernest Guiraud (1837-1892) was born in New Orleans, Louisiana

1838
Frédéric Chopin (1810-1849) completed Prelude in A minor, op. 28, no. 2

Frédéric Chopin (1810-1849) completed Prelude in E minor, op. 28, no. 4

Robert Schumann (1810-1856) completed Scenes from Childhood, op. 15

January 6 – Max Bruch (1838-1920) was born in Cologne, Germany

October 25 – Georges Bizet (1838-1875) was born in Paris, France

1839
Frédéric Chopin (1810-1849) completed Prelude in D♭ major, op. 28, no. 15, “Raindrop”

Frédéric Chopin (1810-1849) completed Prelude in C minor, op. 28, no. 20

March 21 – Symphony No. 9 in C major, D. 944 “The Great” by Franz Schubert (1797-1828) was first performed in Leipzig, Germany

March 21 – Modest Mussorgsky (1839-1881) was born in Karevo, Russia

←1820s

1840s→

Non-Aggression, Floodlights, and the Aging Eye

In our ongoing journey back through the archives of the IDA Information Sheets, here are three more that are noteworthy and still relevant.

IDA Information Sheet 161 – April 2000
IDA’s Approach to People About Bad Lighting

Though this information sheet was produced in the year following my tenure as IDA Information Sheet Editor, I am sure this one was penned by David L. Crawford (1931-), co-founder of the International Dark-Sky Association.

In these hyper-polarized times, Crawford’s advice is even more important than it was in April 2000. Not only for how to talk to someone about their bad lighting, but for talking to anyone about any behavior born out of ignorance or the consumption of misinformation.

I have so many fond memories of hearing Dave Crawford, the good-lighting evangelist, speak. If I recall correctly, his father was a minister, so you can see where he began to hone his exquisite powers of persuasion and his always non-confrontational approach. He never talked down to you. Or over you. He was effective. “Avoid confrontation, even in a crisis mode. Be professional, and calm.” And, “It is critical to speak from knowledge and experience, not just emotion.” Words of wisdom. Even in the worst of circumstances.

IDA-Information-Sheet-161-April-2000 Download

IDA Information Sheet 158 – October 1999
Shielding Floodlights

Bob Crelin, inventor of the phenomenal GlareBuster (sadly, no longer available), and author of the children’s books There Once Was a Sky Full of Stars and Faces of the Moon, wrote this information sheet. What a pleasure it was working with Bob and I treasured our conversations at IDA meetings in Tucson back in the day. I wonder what he is up to these days?

IDA Information Sheet 158 – October 1999 DOWNLOAD

IDA Information Sheet 156 – August 1999
The Aging Eye – Some Basic Information

Dave Crawford wrote this information sheet, and it contains a wealth of information. Notice how he hits the major points multiple times and yet from a variety of angles. Repetition can help us to learn and internalize what we read.

From my own personal experience with “aging eyes”, I am finding it more difficult to drive at the posted speed limit at night. 5 mph less than the posted speed limit is more comfortable, and safer. I drive a low-profile vehicle with normal halogen headlights. But the many aggressive drivers now with high-profile vehicles (SUVs and pickup trucks—those with suspension lifts are the worst) and blindingly-bright headlights (the likes of which we have never seen before) are making night driving increasingly dangerous for the older driver. And there are many of us.

IDA-Information-Sheet-156-August-1999 Download

Classical Music Timeline: 1820s

1820
December – Franz Schubert (1797-1828) completed Quartettsatz (Movement for String Quartet) in C minor, D. 703

1821
October 16 – Franz Doppler (1821-1883) was born in Lviv, Ukraine

1822
December 10 – César Franck (1822-1890) was born in Liège, Belgium

1823
January 27 – Édouard Lalo (1823-1892) was born in Lille, France

1824
March 2 – Bedřich Smetana (1824-1884) was born in Litomyšl, Czech Republic

September 4 – Anton Bruckner (1824-1896) was born in Ansfelden, Austria

1825
April – Franz Schubert (1797-1828) completed Ave Maria, op. 52, no. 6

October 25 – Johann Strauss II (1825-1899) was born in Vienna, Austria

1826
August 26 – Overture to A Midsummer Night’s Dream in E major, op. 21 by Felix Mendelssohn (1809-1847) was first performed in Berlin, Germany

October – Ludwig van Beethoven (1770-1827) completed String Quartet No. 16 in F major, op. 135

1827
Franz Schubert (1797-1828) completed Four Impromptus, op. 90 (D. 899)

March 26 – Ludwig van Beethoven (1770-1827) died in Vienna, Austria

November – Franz Schubert (1797-1828) completed Piano Trio in E♭ major, D. 929

1828
March 23 – String Quartet No. 16 in F major, op. 135 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

May – Franz Schubert (1797-1828) completed Three Piano Pieces, D. 946

November 19 – Franz Schubert (1797-1828) died in Vienna, Austria

December 14 – Symphony No. 6 in C major, D. 589 by Franz Schubert (1797-1828) was first performed in Vienna, Austria

1829
Frédéric Chopin (1810-1849) completed Étude in C major, op. 10, no. 1, “Waterfall”

October 4 – Mass No. 6 in E♭ major, D. 950 by Franz Schubert (1797-1828) was first performed in Vienna, Austria

←1810s

1830s→

Light Blue Blob in a Daytime Sky

Joan Oesper photographed this anomalous light blue patch on
April 13, 2023 at 1:04 p.m. CDT (1804 UT) from Alpine, TX

See the light blue blob in the photograph above? Even though it is partly cloudy, the light blue blob is decidedly different in color from the nearby patches of blue sky. Is this some unusual atmospheric phenomenon, or was there a daytime on orbit rocket burn (such as an apogee kick motor)? If the latter, I have not been able to find any evidence online of a rocket firing around 1804 UT on 13 Apr 2023.

Joan Oesper took this photo from the campus of Sul Ross State University in Alpine, TX at 1:04 p.m. CDT (1804 UT) on Thursday, April 13, 2023. The exact coordinates where the photograph was taken are 30° 21′ 54″ N, 103° 39′ 00″ W. She was facing an azimuth of approximately 161° (SSE) and the altitude of the blue blob was approximately 15° above the horizon.

Joan writes, “The people I saw it with said they’d been watching it and that it had moved eastward during the 5-10 minutes they were watching. It seemed to be behind the clouds.”

Has anyone seen something like this in the past? Was there an on-orbit daytime rocket firing at this time?

Classical Music Timeline: 1810s

1810
Ludwig van Beethoven (1770-1827) completed Piano Sonata No. 26 in E♭ major, op. 81a, “Les Adieux”

March 1 – Frédéric Chopin (1810-1849) was born in Żelazowa Wola, Poland

June 8 – Robert Schumann (1810-1856) was born in Zwickau, Saxony, Germany

1811
January 13 – Piano Concerto No. 5 in E♭ major, op. 73 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

October 22 – Franz Liszt (1811-1886) was born in Raiding, Austria

1813
May 22 – Richard Wagner (1813-1883) was born in Leipzig, Germany

October 9 – Giuseppe Verdi (1813-1901) was born in Le Roncole, Italy

October 28 – Franz Schubert (1797-1828) completed Symphony No. 1 in D major, D. 82

December 8 – Symphony No. 7 in A major, op. 92 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

1814
February 27 – Symphony No. 8 in F major, op. 93 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

1815
July 19 – Franz Schubert (1797-1828) completed Symphony No. 3 in D major, D. 200

1819
Franz Schubert (1797-1828) completed Piano Quintet in A major, D. 667 “Trout”

September 13 – Clara Wieck [later Schumann] (1819-1896) was born in Leipzig, Germany

←1800s

1820s→

Using the Inverse Hyperbolic Sine

Image processing is both an art and a science, in equal measure, and I never cease to be amazed at the skill of the few people who are able to master it.

One tool in the ever-expanding workshop is the inverse hyperbolic sine, also known as the hyperbolic arcsine. Its use for image processing was described twenty years ago by Robert Lupton et al. (2003) in a paper entitled “Preparing Red-Green-Blue (RGB) Images from CCD Data.” In the abstract, the authors write:

We also introduce the use of an asinh stretch, which allows us to show faint objects while simultaneously preserving the structure of brighter objects in the field, such as the spiral arms of large galaxies.

Before we can know what a hyperbolic arcsine (asinh) is, we need to understand what a hyperbolic sine is. Just as a circle can be drawn out by the set of coordinates (x,y) = (cos θ, sin θ), the right half of an equilateral hyperbola (also known as a rectangular hyperbola) can be drawn using (x,y) = (cosh θ, sinh θ) where cosh is the hyperbolic cosine, and sinh is the hyperbolic sine. Just as the arcsine is the inverse sine function, i.e. if y = sin x, then x = asin y (also written as x = sin^-1 y), so, too, the hyperbolic arcsine is the inverse hyperbolic sine function, i.e. if y = sinh x, then x = asinh y (or x = sinh^-1 y).

If we consider the light intensity recorded by a pixel (say, a number between 0 and 65,536, where 0 is the darkest value and 65,536 the brightest) to be x, and then x′ to be the value of that pixel after passing through the hyperbolic arcsine function, we can map pixels using the following equation:

$x'=sinh^{-1}\left ( \frac{x}{\beta } \right )=ln \left ( \frac{x+\sqrt{x^{2}+\beta ^{2}}}{\beta } \right )$

where β is called the “softening parameter”, something you can tweak to bring out desired details.

If you play with this equation a little bit, you’ll quickly see that the smallest values of x (representing the darkest parts of your image) are pretty much left alone, but large values of x (representing the brightest parts of your image) are transformed to much smaller numbers. This then allows you to bring out the fainter details in your image without completely saturating the brighter parts of your image, since whether displayed on a monitor or the printed page, you have a limited dynamic range that can be rendered. Here is an example of an image that has benefited from a hyperbolic arcsine stretch.¹

M17 with linear display (left) and after asinh stretching (right)

¹IRIS Tutorial: Stretching levels and colors

Classical Music Timeline: 1800s

1800
March 28 – Trumpet Concerto in E-flat major, Hob. VIIe/1 by Joseph Haydn (1732-1809) was first performed in Vienna, Austria

April 2 – Symphony No. 1 in C major, op. 21 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

1801
Ludwig van Beethoven (1770-1827) completed Piano Sonata No. 14 in C♯ minor, op. 27, no. 2 “Moonlight”

Ludwig van Beethoven (1770-1827) completed Romance No. 1 in G major for violin and orchestra, op. 40

1802
February 20 – Charles Auguste de Bériot (1802-1870) was born in Leuven, Belgium

1803
Joseph Haydn (1732-1809) left uncompleted his last composition, the String Quartet No. 68 in D minor, op. 103, Hob. III:83

April 5 – Symphony No. 2 in D major, op. 36 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria
April 5 – Piano Concerto No. 3 in C minor, op. 37 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

December 11 – Hector Berlioz (1803-1869) was born in La Côte-Saint-André, France

1804
Ludwig van Beethoven (1770-1827) completed Piano Sonata No. 21 in C major, op. 53 “Waldstein”

May 31 – Louise Farrenc (1804-1875) was born in Paris, France

June 1 – Mikhail Glinka (1804-1857) was born in Novospasskoye, Russia

1805
Ludwig van Beethoven (1770-1827) completed Piano Sonata No. 23 in F minor, op. 57 “Appassionata”

April 7 – Symphony No. 3 in E♭ major, op. 55 “Eroica” by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

May 28 – Luigi Boccherini (1743-1805) died in Madrid, Spain

1806
March 29 – Leonore Overture No. 3 in C major, from the opera Fidelio, op. 72, by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

December 23 – Violin Concerto in D major, op. 61 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

1807
March – Symphony No. 4 in B♭ major, op. 60 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

1808
December 22 – Symphony No. 5 in C minor, op. 67 by Ludwig van Beethoven (1770-1827) was first performed in Vienna, Austria

1809
February 3 – Felix Mendelssohn (1809-1847) was born in Hamburg, Germany

May 31 – Joseph Haydn (1732-1809) died in Vienna, Austria

←1790s

1810s→

IDA Information Sheets

I recently received a membership renewal notice from the International Dark-Sky Association (IDA) quoting Christopher Kyba that if light pollution continues to grow at the rate it currently is, “Orion’s belt will disappear at some point.”

This made me remember that I had written an IDA Information Sheet back in March 1997 that also had addressed how light pollution could erase much of the Orion constellation. I wrote,

Orion, arguably the most prominent of the constellations, begins to look more like “Orion, the Hunted” under a magnitude +4.0 sky. Under a magnitude +3.0 sky, Orion is on his deathbed. When light pollution is so bad that we have a magnitude +2.0 sky, only blazing Betelgeuse, regal Rigel, and Bellatrix and Alnilam remain to regale us.

Speaking of the IDA Information Sheets, I was the IDA Information Sheet Editor from 1996-1999, during which time I revised and edited most of the existing information sheets, edited and added many new ones from a number of contributors, as well as contributed many new ones that I authored, though I never credited myself as the author. One of the ones that I wrote was IDA Information Sheet 120, referenced above (and shown below). I have a complete hard copy set of IDA Information Sheets 1 through 175, the last of which was published in June 2000. I also have WordPerfect Macintosh source files for IDA Information Sheets 1 through 158, the last of which was completed on October 27, 1999.

Here’s IDA Information Sheet 120:

IDA-Information-Sheet-120-March-1997 Download

It is a shame that these IDA Information Sheets are no longer available anywhere on the Internet. At the very least, they are of historical interest, and I would say that much of the content is still relevant. Presumably, the IDA still has all of these information sheets, but after the Dave Crawford era, they have decided to remove access to them.

Finally, I want to express my disappointment that the International Dark-Sky Association has recently decided to change their name to DarkSky International. They are still in the process of changing everything over, but once that transition is complete, the IDA will be no more. The break with the Dave Crawford era will be complete. I, for one, will never forget how much Dave Crawford was able to accomplish during those early years, and how proud I was to have been a part of it.

The IDA/DSI is still a great organization, and I strongly encourage you to generously support it, as I do. It remains the most effective organization in the world addressing light pollution and the loss of our night sky and the natural nighttime environment.

Classical Music Timeline: 1790s

1791
March 11 – Symphony No. 96 in D major, Hob. I/96 “Miracle” by Joseph Haydn (1732-1809) was first performed in London, England

June 23 – Ave verum corpus, motet in D major, K. 618, by Wolfgang Amadeus Mozart (1756-1791) was first performed in Baden bei Wien, Austria

December 5 – Wolfgang Amadeus Mozart (1756-1791) died in Vienna, Austria

1792
February 29 – Gioachino Rossini (1792-1868) was born in Pesaro, Italy

March 23 – Symphony No. 94 in G major, Hob. I/94 “Surprise” by Joseph Haydn (1732-1809) was first performed in London, England

1793
Joseph Haydn (1732-1809) completed Piano Sonata “Un piccolo divertimento” (Variations) in F minor, Hob XVII: 6

1795
Ludwig van Beethoven (1770-1827) wrote Rondo a Capriccio in G major, now known as “Rage Over a Lost Penny”, op. 129

February 2 – Symphony No. 102 in B♭ major, Hob. I/102 by Joseph Haydn (1732-1809) was first performed in London, England

1797
Joseph Haydn (1732-1809) completed String Quartet in G major, op. 76, no. 1, Hob. III:75

Joseph Haydn (1732-1809) completed String Quartet in C major, op. 76, no. 3, Hob. III:77 “Emperor”

Joseph Haydn (1732-1809) completed String Quartet in B♭ major, op. 76, no. 4, Hob. III:78 “Sunrise”

January 31 – Franz Schubert (1797-1828) was born in Vienna, Austria

1798
Ludwig van Beethoven (1770-1827) completed Romance No. 2 in F major for violin and orchestra, op. 50

Ludwig van Beethoven (1770-1827) completed Piano Sonata No. 8 in C minor, op. 13 “Pathétique”

←1780s

1800s→

Hidden Wonders of the Southern Sky

Here in southern Arizona, we can theoretically see 92.4% of the celestial sphere. I say “theoretically” because atmospheric extinction, light pollution, local topography, and obstructions limit the amount of the celestial sphere that we can see well. Also, far southern objects (down to δ = -58° at φ = 32° N) spend very little time above our horizon each day.

Practically speaking, then, we see somewhat less than 92% of all that there is to see from spaceship Earth.

Percent of the Celestial Sphere Visible

$\% = 50\left [ 1-sin\left ( \left|\varphi \right| -90^{\circ}\right ) \right ]$

where |φ| is the absolute value of your latitude in degrees

What are the most prominent objects we are missing, and what objects that we can see are they closest to?

Alpha Centauri

Never visible north of latitude 27° N, the nearest star system beyond our solar system is Alpha Centauri. Alpha Centauri A & B are bright stars, having a visual magnitude of 0.0 and +1.3, respectively, and in 2023 they are separated by just 8 arcseconds, about 1/4 of the angular separation between Albireo A & B. While Alpha Centauri A & B—which orbit each other once every 79.8 years—lie just 4.36 ly away, a faint red dwarf companion, Proxima Centauri (shining at magnitude +11.1), is even closer at 4.24 light years. It is not yet known whether Proxima Centauri, discovered in 1915, is gravitationally bound to Alpha Centauri A & B, or just presently passing through the neighborhood. Proxima is a full 2.2° away (over four moon-widths) from Alpha Centauri A & B.

When Arcturus (α Boo) and Zubenelgenubi (α Lib) are crossing our celestial meridian, so are Alpha & Proxima Centauri below the southern horizon.

Large Magellanic Cloud

The Large Magellanic Cloud (LMC), the largest satellite galaxy of our Milky Way galaxy and easily visible to the unaided eye, lies directly below our southern horizon when Rigel has crossed the meridian and Bellatrix is preparing to do so.

Small Magellanic Cloud

The Small Magellanic Cloud (SMC), the second-largest satellite galaxy of the mighty Milky Way lies underneath our southern horizon when M31, the Great Andromeda Galaxy, crosses the meridian near the zenith.

47 Tucanae

The 2nd brightest globular cluster in the sky (after Omega Centauri) is impressive 47 Tucanae. It is just 2.3° west and a little north of the Small Magellanic Cloud, so crosses the meridian below our horizon just as M31 is nearing the meridian.

Eta Carinae Nebula

Four times larger and brighter than the Orion Nebula, NGC 3372, the Eta Carinae Nebula, is a spectacular star-forming region containing a supermassive (130 – 180 M_☉) binary star (Eta Carinae) that may go supernova at any time. When Leo the Lion is straddling the meridian, the Eta Carinae Nebula sneaks across as well.

Any other spectacular objects I should be including that are south of declination -58°? If so, please post a comment here.