Classical Music Timeline: 1780s

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.

1781
Wolfgang Amadeus Mozart (1756-1791) completed Violin Sonata No. 25 in F major, K. 377 (374e)

1782
Joseph Haydn (1732-1809) completed Symphony No. 73 in D Major, Hob. I:73 “La Chasse”

1783
March 23 – Symphony No. 35 in D major, K. 385 “Haffner”, by Wolfgang Amadeus Mozart (1756-1791) was first performed in its final form in Vienna, Austria

November 4 – Symphony No. 36 in C major, K. 425 “Linz”, by Wolfgang Amadeus Mozart (1756-1791) was first performed in Linz, Austria

1785
Joseph Haydn (1732-1809) completed Symphony No. 83 in G minor, Hob. I/83 “The Hen”

March 9 – Wolfgang Amadeus Mozart (1756-1791) completed Piano Concerto No. 21 in C major, K. 467

1786
Joseph Haydn (1732-1809) completed Symphony No. 82 in C major, Hob. I/82 “The Bear”

March 2 – Wolfgang Amadeus Mozart (1756-1791) completed Piano Concerto No. 23 in A major, K. 488

May 1The Marriage of Figaro, K. 492, by Wolfgang Amadeus Mozart (1756-1791) was first performed in Vienna, Austria

1787
Joseph Haydn (1732-1809) completed Symphony No. 88 in G major, Hob. I/88

Joseph Haydn (1732-1809) completed String Quartet No. 37 in C major, op. 50, no. 2, Hob. III/45

January 19 – Symphony No. 38 in D major, K. 504 “Prague”, by Wolfgang Amadeus Mozart (1756-1791) was first performed in Prague, Czech Republic

October 29Don Giovanni, K. 527, by Wolfgang Amadeus Mozart (1756-1791) was first performed in Prague, Czech Republic

1788
Joseph Haydn (1732-1809) completed String Quartet No. 43 in G major, op. 54, no. 1, Hob. III:58

Luigi Boccherini (1743-1805) completed Sinfonia in C minor, G. 519

June 26 – Wolfgang Amadeus Mozart (1756-1791) completed Symphony No. 39 in E♭ major, K. 543

July 25 – Wolfgang Amadeus Mozart (1756-1791) completed Symphony No. 40 in G minor, K. 550

1789
Joseph Haydn (1732-1809) completed Symphony No. 92 in G major, Hob. I/92 “Oxford”

1770s

1790s→

Quotable Arthur C. Clarke

Sir Arthur Charles Clarke (1917-2008)

Clarke’s Three Laws

  1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
  2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
  3. Any sufficiently advanced technology is indistinguishable from magic.

The greatest tragedy in mankind’s entire history may be the hijacking of morality by religion.


I don’t believe in God but I’m very interested in her.


The rash assertion that “God made man in His own image” is ticking like a time bomb at the foundation of many faiths, and as the hierarchy of the universe is disclosed to us, we may have to recognize this chilling truth: if there are any gods whose chief concern is man, they cannot be very important gods.


Science can destroy religion by ignoring it as well as by disproving its tenets. No one ever demonstrated, so far as I am aware, the non-existence of Zeus or Thor—but they have few followers now.


I would defend the liberty of consenting adult creationists to practice whatever intellectual perversions they like in the privacy of their own homes; but it is also necessary to protect the young and innocent.


I would like to assure my many Buddhist, Christian, Hindu, Jewish, and Muslim friends that I am sincerely happy that the religion which Chance has given you has contributed to your peace of mind (and often, as Western medical science now reluctantly admits, to your physical well-being). Perhaps it is better to be un-sane and happy, than sane and un-happy. But it is the best of all to be sane and happy. Whether our descendants can achieve that goal will be the greatest challenge of the future. Indeed, it may well decide whether we have any future.


There is the possibility that humankind can outgrown its infantile tendencies, as I suggested in Childhood’s End. But it is amazing how childishly gullible humans are. There are, for example, so many different religions—each of them claiming to have the truth, each saying that their truths are clearly superior to the truths of others—how can someone possibly take any of them seriously? I mean, that’s insane. Though I sometimes call myself a crypto-Buddhist, Buddhism is not a religion. Of those around at the moment, Islam is the only one that has any appeal to me. But, of course, Islam has been tainted by other influences. The Muslims are behaving like Christians, I’m afraid.


Sometimes I think we’re alone in the universe, and sometimes I think we’re not. In either case the idea is quite staggering.


Perhaps, as some wit remarked, the best proof that there is Intelligent Life in Outer Space is the fact it hasn’t come here. Well, it can’t hide forever—one day we will overhear it.


The fact that we have not yet found the slightest evidence for life—much less intelligence—beyond this Earth does not surprise or disappoint me in the least. Our technology must still be laughably primitive, we may be like jungle savages listening for the throbbing of tom-toms while the ether around them carries more words per second than they could utter in a lifetime.


The moon is the first milestone on the road to the stars.


We are just tenants on this world. We have just been given a new lease, and a warning from the landlord.


Human judges can show mercy. But against the laws of nature, there is no appeal.


This is the first age that’s ever paid much attention to the future, which is a little ironic since we may not have one.


As our own species is in the process of proving, one cannot have superior science and inferior morals. The combination is unstable and self-destroying.


Our age is in many ways unique, full of events and phenomena that never occurred before and can never happen again. They distort our thinking, making us believe that what is true now will be true forever, though perhaps on a larger scale.


It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars.


New ideas pass through three periods:

  1. It can’t be done.
  2. It probably can be done, but it’s not worth doing.
  3. I knew it was a good idea all along!

Politicians should read science fiction, not westerns and detective stories.


There is hopeful symbolism in the fact that flags do not wave in a vacuum.


The Information Age offers much to mankind, and I would like to think that we will rise to the challenges it presents. But it is vital to remember that information—in the sense of raw data—is not knowledge, that knowledge is not wisdom, and that wisdom is not foresight. But information is the first essential step to all of these.


Communication technologies are necessary, but not sufficient, for us humans to get along with each other. This is why we still have many disputes and conflicts in the world. Technology tools help us to gather and disseminate information, but we also need qualities like tolerance and compassion to achieve greater understanding between peoples and nations. I have great faith in optimism as a guiding principle, if only because it offers us the opportunity of creating a self-fulfilling prophecy. So I hope we’ve learnt something from the most barbaric century in history—the 20th. I would like to see us overcome our tribal divisions and begin to think and act as if we were one family. That would be real globalisation. [December 2007]

Classical Music Timeline: 1770s

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.

1770
December 16 – Ludwig van Beethoven (1770-1827) was born in Bonn, Germany

1771
Wolfgang Amadeus Mozart (1756-1791) completed Divertimento in E flat, K. 113

1772
Giovanni Battista Sammartini (1700?-1775) almost certainly completed Symphony in F Major (J-C 36) by this year, probably much earlier

Joseph Haydn (1732-1809) completed Symphony No. 45 in F♯ minor, Hob. I:45 “Farewell”

1773
April 16 – Wolfgang Amadeus Mozart (1756-1791) completed Symphony No. 27 in G major, K. 199/161b

October 5 – Wolfgang Amadeus Mozart (1756-1791) completed Symphony No. 25 in G minor, K. 183/173dB

1775
Wolfgang Amadeus Mozart (1756-1791) completed Violin Concerto No. 5 in A major, K. 219

January 15 – Giovanni Battista Sammartini (1700?-1775) died in Milan, Italy

September 12 – Wolfgang Amadeus Mozart (1756-1791) completed Violin Concerto No. 3 in G major, K. 216

1778
Joseph Haydn (1732-1809) completed Piano Sonata in E minor, Hob. 16:34

Wolfgang Amadeus Mozart (1756-1791) completed Violin Sonata No. 21 in E minor, K. 304 (300c)

Before 1770

1780s

Infinity

George F. R. Ellis weighs in on the concept of infinity in his excellent paper, Issues in the Philosophy of Cosmology, available on astro-ph at https://arxiv.org/abs/astro-ph/0602280. He writes:

9.3.2 Existence of Infinities

The nature of existence is significantly different if there is a finite amount of matter or objects in the universe, as opposed to there being an infinite quantity in existence. Some proposals claim there may be an infinite number of universes in a multiverse and many cosmological models have spatial sections that are infinite, implying an infinite number of particles, stars, and galaxies. However, infinity is quite different from a very large number! Following David Hilbert, one can suggest these unverifiable proposals cannot be true: the word “infinity” denotes a quantity or number that can never be attained, and so will never occur in physical reality.38 He states:

Our principal result is that the infinite is nowhere to be found in reality. It neither exists in nature nor provides a legitimate basis for rational thought . . . The role that remains for the infinite to play is solely that of an idea . . . which transcends all experience and which completes the concrete as a totality . . .

This suggests “infinity” cannot be arrived at, or realized, in a concrete physical setting; on the contrary, the concept itself implies its inability to be realized!

Thesis I2: The often claimed physical existence of infinities is questionable. The claimed existence of physically realized infinities in cosmology or multiverses raises problematic issues. One can suggest they are unphysical; in any case such claims are certainly unverifiable.

This applies in principle to both small and large scales in any single universe:

The existence of a physically existing spacetime continuum represented by a real (number) manifold at the micro-level contrasts with quantum gravity claims of a discrete spacetime structure at the Planck scale, which one might suppose was a generic aspect of fully non-linear quantum gravity theories. In terms of physical reality, this promises to get rid of the uncountable infinities the real line continuum engenders in all physical variables and fields40. There is no experiment that can prove there is a physical continuum in time or space; all we can do is test space-time structure on smaller and smaller scales, but we cannot approach the Planck scale.

Infinitely large space-sections at the macro-level raise problems as indicated by Hilbert, and leads to the infinite duplication of life and all events. We may assume space extends forever in Euclidean geometry and in many cosmological models, but we can never prove that any realised 3-space in the real universe continues in this way—it is an untestable concept, and the real spatial geometry of the universe is almost certainly not Euclidean. Thus Euclidean space is an abstraction that is probably not physically real. The infinities supposed in chaotic inflationary models derive from the presumption of pre-existing infinite Euclidean space sections, and there is no reason why those should necessarily exist. In the physical universe spatial infinities can be avoided by compact spatial sections, resulting either from positive spatial curvature, or from a choice of compact topologies in universes that have zero or negative spatial curvature. Machian considerations to do with the boundary conditions for physics suggest this is highly preferable; and if one invokes string theory as a fundamental basis for physics, the “dimensional democracy” suggests the three large spatial dimensions should also be compact, since the small (“compactified”) dimensions are all taken to be so. The best current data from CBR and other observations indeed suggest k = +1, implying closed space sections for the best-fit FL model.

The existence of an eternal universe implies that an infinite time actually exists, which has its own problems: if an event happens at any time t0, one needs an explanation as to why it did not occur before that time (as there was an infinite previous time available for it to occur); and Poincaré eternal return will be possible if the universe is truly cyclic. In any case it is not possible to prove that the universe as a whole, or even the part of the universe in which we live, is past infinite; observations cannot do so, and the physics required to guarantee this would happen (if initial conditions were right) is untestable. Even attempting to prove it is future infinite is problematic (we cannot for example guarantee the properties of the vacuum into the infinite future—it might decay into a state corresponding to a negative effective cosmological constant).

It applies to the possible nature of a multiverse. Specifying the geometry of a generic universe requires an infinite amount of information because the quantities necessary to do so are fields on spacetime, in general requiring specification at each point (or equivalently, an infinite number of Fourier coefficients): they will almost always not be algorithmically compressible. All possible values of all these components in all possible combinations will have to occur in a multiverse in which “all that can happen, does happen”. There are also an infinite number of topological possibilities. This greatly aggravates all the problems regarding infinity and the ensemble. Only in highly symmetric cases, like the FL solutions, does this data reduce to a finite number of parameters, each of which would have to occur in all possible values (which themselves are usually taken to span an infinite set, namely the entire real line). Many universes in the ensemble may themselves have infinite spatial extent and contain an infinite amount of matter, with all the problems that entails. To conceive of physical creation of an infinite set of universes (most requiring an infinite amount of information for their prescription, and many of which will themselves be spatially infinite) is at least an order of magnitude more difficult than specifying an existent infinitude of finitely specifiable objects.

One should note here particularly that problems arise in the multiverse context from the continuum of values assigned by classical theories to physical quantities. Suppose for example that we identify corresponding times in the models in an ensemble and then assume that all values of the density parameter and the cosmological constant occur at each spatial point at that time. Because these values lie in the real number continuum, this is a doubly uncountably infinite set of models. Assuming genuine physical existence of such an uncountable infinitude of universes is the antithesis of Occam’s razor. But on the other hand, if the set of realised models is either finite or countably infinite, then almost all possible models are not realised. And in any case this assumption is absurdly unprovable. We can’t observationally demonstrate a single other universe exists, let alone an infinitude. The concept of infinity is used with gay abandon in some multiverse discussions, without any concern either for the philosophical problems associated with this statement, or for its completely unverifiable character. It is an extravagant claim that should be treated with extreme caution.

38An intriguing further issue is the dual question: Does the quantity zero occur in physical reality? This is related to the idea of physical existence of nothingness, as contrasted with a vacuum. A vacuum is not nothing!

40To avoid infinities entirely would require that nothing whatever is a continuum in physical reality (since any continuum interval contains an infinite number of points). Doing without that, conceptually, would mean a complete rewrite of many things. Considering how to do so in a way compatible with observation is in my view a worthwhile project.


So, given this discussion of infinities, the answer to the doubly hypothetical question, “Can God make a rock so big he can’t pick it up?” is likely a “Yes”! – D.O.

Classical Music Timeline: Before 1770

This is the first 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.

1659
September 10? – Henry Purcell (1659-1695) was born in London, England

1678
March 4 – Antonio Vivaldi (1678-1741) was born in Venice, Italy

1685
March 31 – Johann Sebastian Bach (1685-1750) was born in Eisenach, Germany

1689
Dido and Aeneas, Z. 626, by Henry Purcell (1659-1695) was first performed in London, England

1695
November 21 – Henry Purcell (1659-1695) died in London, England

1700
Giovanni Battista Sammartini (1700?-1775) was born in Milan, Italy

1715
Antonio Vivaldi (1678-1741) completed Gloria, RV 589

Johann Sebastian Bach (1685-1750) completed Puer natus in Bethlehem, for children’s chorus, cello, and organ, by this date

1717
Antonio Vivaldi (1678-1741) completed Credo, RV 591

June 18 – Johann Stamitz (1717-1757) was born in Havlíčkův Brod, Czech Republic

1721
March 24 – Johann Sebastian Bach (1685-1750) completed Brandenburg Concerto No. 1 by this date

March 24 – Johann Sebastian Bach (1685-1750) completed Brandenburg Concerto No. 2 by this date

1731
Antonio Vivaldi (1678-1741) completed Chamber Concerto for Lute and 2 Violins in D major, RV 93

Johann Sebastian Bach (1685-1750) completed Concerto for 2 Violins in D minor, BWV 1043, by this date

1732
Giovanni Battista Sammartini (1700?-1775) completed Symphony in D minor (J-C 23), perhaps earlier

March 31 – Joseph Haydn (1732-1809) was born in Rohrau, Austria

1741
July 28 – Antonio Vivaldi (1678-1741) died in Vienna, Austria

1743
February 19 – Luigi Boccherini (1743-1805) was born in Lucca, Italy

1746
Johann Stamitz (1717-1757) completed Symphony in A major, “Mannheim No. 2” and Symphony in B♭ major, “Mannheim No. 3”, perhaps earlier

1750
July 28 – Johann Sebastian Bach (1685-1750) died in Leipzig, Germany

1756
January 27 – Wolfgang Amadeus Mozart (1756-1791) was born in Salzburg, Austria

1757
Johann Stamitz (1717-1757) completed Trio in E major, op. 5, no. 3, perhaps earlier

March 27 – Johann Stamitz (1717-1757) died in Mannheim, Germany

1764
Joseph Haydn (1732-1809) completed Symphony No. 22 in E-flat Major, Hob. I:22 “The Philosopher”

1768
Wolfgang Amadeus Mozart (1756-1791) completed Bastien and Bastienne, K. 50

1770s

Nearest Stars & Planets

Here’s a table of all known star systems within 15 light years (ly) of our Solar System. I will endeavor to keep this list up to date, so please post a comment here if anything needs to be corrected or added.

There are 41 star systems1 within a volume of

V = \frac{4}{3}\pi r^{3} = \frac{4}{3}\pi (15\;ly)^{3} = 14,137\;ly^{3}

Assuming that these 41 star systems are uniformly distributed within a sphere of radius 15 ly, the average distance from any star to its nearest neighbor is given by

\bar{d} = r\left [ \frac{\pi }{3n\;\sqrt[]{2}} \right ]^{\frac{1}{3}} = (15\; ly)\left [ \frac{\pi }{3(41)\;\sqrt[]{2}} \right ]^{\frac{1}{3}} = 3.94\;ly

So, even though it seems that 41 star systems within a distance of 15 ly from our Solar System is a lot, the volume of 14,137 cubic light years is not that small, and the average distance between any star and its nearest neighbor is about 3.94 ly. Our nearest neighbor is Proxima Centauri, which at a distance of 4.24 ly is quite close to the 3.94 ly average distance derived above.

Nearest Stars (within 15 light years)

Star Distance (ly) Spectral Type Constellation Planets?
Sun 0.00 G2V zodiacal Yes
Proxima Centauri 4.24 M5.0V Centaurus Yes
Alpha Centauri A & B 4.36 G2V & K0.0V Centaurus Unknown
Barnard's Star 5.97 M3.5V Ophiuchus Unknown
Luhman 16 A & B 6.59 L8 & T1 Vela Unknown
WISE 0855-0714 7.26 Y2 Hydra Unknown
Wolf 359 7.87 M5.5V Leo Yes
Lalande 21185 8.29 M2.0V Ursa Major Yes
Sirius A & B 8.65 A1V & DA2 Canis Major Unknown
Luyten 726-8 A & B 8.79 M5.5V & M6.0V Cetus Unknown
Ross 154 9.70 M3.5V Sagittarius Unknown
Ross 248 10.29 M5.5V Andromeda Unknown
Epsilon Eridani 10.48 K2.0V Eridanus Yes
Lacaille 9352 10.72 M1.0V Piscis Austrinus Yes
Ross 128 11.01 M4.0V Virgo Yes
EZ Aquarii A, B, & C 11.27 M5.0VJ Aquarius Unknown
61 Cygni A & B 11.40 K5.0V & K7.0V Cygnus Unknown
Procyon A & B 11.44 F5IV-V & DQZ Canis Minor Unknown
Struve 2398 A & B 11.49 M3.0V & M3.5V Draco Yes
Groombridge 34 A & B 11.62 M1.5V & M3.5V Andromeda Yes
DX Cancri 11.68 M6.0V Cancer Unknown
Epsilon Indi A, B, & C 11.81 K4.0V, T1, & T6 Indus Yes
Tau Ceti 11.89 G8.5V Cetus Yes
Gliese 1061 11.98 M5.0V Horologium Yes
YZ Ceti 12.11 M4.0V Cetus Yes
Luyten's Star 12.25 M3.5V Canis Minor Yes
Teegarden's Star 12.50 M6.5V Aries Yes
Kapteyn's Star 12.83 M2.0VI Pictor Unknown
Lacaille 8760 12.95 K9.0V Microscopium Unknown
SCR 1845-6357 A & B 13.05 M8.5 & T6 Pavo Unknown
Kruger 60 A & B 13.08 M3.0V & M4.0V Cepheus Unknown
DENIS J1048-3956 13.19 M8.5V Antlia Unknown
UGPS 0722-05 13.43 T9 Monoceros Unknown
Ross 614 A & B 13.49 M4.0V & M5.5V Monoceros Unknown
Wolf 424 A & B 13.98 M5.0VJ Virgo Unknown
Wolf 1061 14.05 M3.5V Ophiuchus Yes
van Maanen 2 14.07 DZ7 Pisces Unknown
Gliese 1 14.17 M1.5V Sculptor Unknown
TZ Arietis 14.59 M4.0V Aries Yes
Gliese 674 14.84 M2.5V Ara Yes
Gliese 687 14.84 M3.0V Draco Yes
LHS 292 14.90 M6.5V Sextans Unknown

1 Here we are considering Proxima Centauri and Alpha Centauri A & B to be one star system.

References
Henry, T.J. 2020, The Nearest Stars in The Observer’s Handbook 2023, ed. J. Edgar, The Royal Astronomical Society of Canada, p. 284-288.

Blinding Headlights

I’ve lived in Tucson, Arizona for ten months now, and I have to tell you, it is no fun driving here at night. While it is a joy living in a city that for a change isn’t horribly overlit and that takes light pollution seriously (though that is starting to erode), it is often hard to see at night because of the many vehicles on the road with blinding headlights. In recent years, this has become a huge problem throughout the U.S., and the National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS) needs to act quickly and decisively to deal with this dangerous nuisance.

Not only have headlights gotten brighter and bluer (which makes glare much worse), many vehicles have multiple sets of headlights, including “fog lights” that are anything but. High-profile vehicles such as pickup trucks and SUVs are especially bad when it comes to causing blinding glare for smaller, less extravagant vehicles. Jacked-up pickup trucks are the worst, and there are a lot of them here.

When one of these headlight-offensive vehicles is heading towards you, it makes it difficult to see the road ahead. It is especially hard to see pedestrians and bicyclists. Pavement markings are also harder to see because of the glare from the oncoming vehicle, especially when those lines are badly faded and in need of re-painting (as they often are here).

Tucson has far too many busy intersections without a protected left turn, and if you find yourself in a left-turn lane being stared down by a headlight-offensive vehicle in the opposite left-turn lane, the glare blinds you so much that it is difficult to see oncoming vehicles in the through-traffic lanes.

When a headlight-offensive vehicle comes up behind you and, as they often do, practically rides your bumper because driving at or near the speed limit isn’t fast enough for them, you’re hit with their intense glare in all three rear-view mirrors. This makes it harder to see the road ahead, and you have to slow down—which tends to aggravate them more than they already are. If you’re lucky, they can pass you—though sometimes they will illegally cross a double yellow line to do it.

Because of all these intense and unregulated vehicle headlights, I now avoid driving at night whenever possible.

Sure, headlights like these helps the perpetrator see better so they can drive down the road at night exceeding the speed limit (which is seldom enforced here, by the way), but everyone else—drivers, bicyclists, and pedestrians—is blinded.

What are the specific problems with modern vehicle headlights that need to be addressed, and what are the solutions?

  • Problem: The average vehicle’s total headlight lumen output (and individual headlight luminance) has dramatically increased in recent years, causing a corresponding increase in discomfort and disability glare for everyone else.
  • Solution: Headlights would not have to be so bright if speed limits were lower at night on many city streets and thoroughfares, and if the posted speed limits were actually enforced.
  • Solution: Implement adaptive driving beam (ADB) technology that uses sensors to detect oncoming traffic and adjusts the projected beam pattern to allow plenty of light for the driver without blinding other motorists. (ADB is widely used in Europe, but is not yet legal in the United States.)
  • Problem: Light-emitting diode (LED) and High Intensity Discharge (HID) headlights emit more light at the blue end of the visible spectrum than traditional warm-white or yellowish halogen headlights do, and these bluer lights result in significantly greater visual discomfort and impairment for other drivers.
  • Solution: Limit the amount of blue light that headlights can produce.
  • Problem: Poor headlight aim leads to dangerous glare for others.
  • Solution: Require regular headlight aim inspections and adjustments. Anytime a vehicle’s suspension is lifted, require headlight aim to be adjusted downward accordingly.

Here’s a petition you might want to sign:

https://www.change.org/p/u-s-dot-ban-blinding-headlights-and-save-lives

I’d like to close this article by quoting one of the many insightful comments in the Comments section of the New York Times article listed under References below.

Like everything else, it is no longer about the collective good and the laws that protect it. Individualism now rules—individual freedom. Headlights have become a First Amendment issue—an element of free speech.

And they have become part of the conservative anti-government backlash. Laws regulating headlights are seen as government intrusion into personal freedoms. It is seen by many to be like the COVID mask issue. Too many people think personal freedom trumps everything else–even collective health and safety.

And there is a free-market aspect to this. Manufacturers are looking for ways to add features to cars that will make them more attractive to buyers. They know the lights are unsafe, yet they put them on their vehicles.

America has lost all common sense.

Michael
Evanston, IL | June 9, 2021

Mark my words, if we keep heading down this path of excessive individual freedom (read: selfishness) without significant responsibility for the common good (that means everybody, not just your tribe), it will be our undoing. The United States will become a miserable place to live for the majority of us for at least a generation. I’m not hopeful that we can turn this around in time. Too many of us are “asleep at the wheel” and too easily swayed by misinformation and propaganda.

References

Mele, Christopher. “Blinded by Brighter Headlights? It’s Not Your Imagination.” New York Times, June 5, 2021, https://www.nytimes.com/2021/06/05/business/led-hid-headlights-blinding.html.

Zodiacal Light 2023

In 2023, the best dates and times for observing the zodiacal light are listed in the calendar below. The sky must be very clear with little or no light pollution. The specific times listed are for Tucson, Arizona (32° 16′ N, 111° 03′ W).

Here’s a nicely-formatted printable PDF file of the zodiacal light calendar:

January 2023
SUN MON TUE WED THU FRI SAT
1 2 3 4 5 6 7
8
Zodiacal Light 7:02 – 7:14 p.m. West
9
Zodiacal Light 7:03 – 8:03 p.m. West
10
Zodiacal Light 7:04 – 8:04 p.m. West
11
Zodiacal Light 7:04 – 8:04 p.m. West
12
Zodiacal Light 7:05 – 8:05 p.m. West
13
Zodiacal Light 7:06 – 8:06 p.m. West
14
Zodiacal Light 7:07 – 8:07 p.m. West
15
Zodiacal Light 7:07 – 8:07 p.m. West
16
Zodiacal Light 7:08 – 8:08 p.m. West
17
Zodiacal Light 7:09 – 8:09 p.m. West
18
Zodiacal Light 7:10 – 8:10 p.m. West
19
Zodiacal Light 7:11 – 8:11 p.m. West
20
Zodiacal Light 7:11 – 8:11 p.m. West
21
Zodiacal Light 7:12 – 8:12 p.m. West
22
Zodiacal Light 7:13 – 8:13 p.m. West
23 24 25 26 27 28
29 30 31        

February 2023
SUN MON TUE WED THU FRI SAT
      1 2 3 4
5 6 7
Zodiacal Light 7:26 – 7:58 p.m. West
8
Zodiacal Light 7:27 – 8:27 p.m. West
9
Zodiacal Light 7:27 – 8:27 p.m. West
10
Zodiacal Light 7:28 – 8:28 p.m. West
11
Zodiacal Light 7:29 – 8:29 p.m. West
12
Zodiacal Light 7:30 – 8:30 p.m. West
13
Zodiacal Light 7:31 – 8:31 p.m. West
14
Zodiacal Light 7:31 – 8:31 p.m. West
15
Zodiacal Light 7:32 – 8:32 p.m. West
16
Zodiacal Light 7:33 – 8:33 p.m. West
17
Zodiacal Light 7:34 – 8:34 p.m. West
18
Zodiacal Light 7:34 – 8:34 p.m. West
19
Zodiacal Light 7:35 – 8:35 p.m. West
20
Zodiacal Light 7:36 – 8:36 p.m. West
21 22 23 24 25
26 27 28        

March 2023
SUN MON TUE WED THU FRI SAT
      1 2 3 4
5 6 7 8 9
Zodiacal Light 7:49 – 8:43 p.m. West
10
Zodiacal Light 7:49 – 8:49 p.m. West
11
Zodiacal Light 7:50 – 8:50 p.m. West
12
Zodiacal Light 7:51 – 8:51 p.m. West
13
Zodiacal Light 7:52 – 8:52 p.m. West
14
Zodiacal Light 7:52 – 8:52 p.m. West
15
Zodiacal Light 7:53 – 8:53 p.m. West
16
Zodiacal Light 7:54 – 8:54 p.m. West
17
Zodiacal Light 7:55 – 8:55 p.m. West
18
Zodiacal Light 7:55 – 8:55 p.m. West
19
Zodiacal Light 7:56 – 8:56 p.m. West
20
Zodiacal Light 7:57 – 8:57 p.m. West
21
Zodiacal Light 7:58 – 8:58 p.m. West
22 23 24 25
26 27 28 29 30 31  

April 2023
SUN MON TUE WED THU FRI SAT
            1
2 3 4 5 6 7
Zodiacal Light 8:12 – 8:37 p.m. West
8
Zodiacal Light 8:13 – 9:13 p.m. West
9
Zodiacal Light 8:14 – 9:14 p.m. West
10
Zodiacal Light 8:14 – 9:14 p.m. West
11
Zodiacal Light 8:15 – 9:15 p.m. West
12
Zodiacal Light 8:16 – 9:16 p.m. West
13
Zodiacal Light 8:17 – 9:17 p.m. West
14
Zodiacal Light 8:18 – 9:18 p.m. West
15
Zodiacal Light 8:19 – 9:19 p.m. West
16
Zodiacal Light 8:20 – 9:20 p.m. West
17
Zodiacal Light 8:21 – 9:21 p.m. West
18
Zodiacal Light 8:22 – 9:22 p.m. West
19
Zodiacal Light 8:23 – 9:23 p.m. West
20
Zodiacal Light 8:24 – 9:24 p.m. West
21 22
23 24 25 26 27 28 29
30            

May 2023
SUN MON TUE WED THU FRI SAT
  1 2 3 4 5 6
7
Zodiacal Light 8:41 – 9:41 p.m. West
8
Zodiacal Light 8:42 – 9:42 p.m. West
9
Zodiacal Light 8:43 – 9:43 p.m. West
10
Zodiacal Light 8:44 – 9:44 p.m. West
11
Zodiacal Light 8:45 – 9:45 p.m. West
12
Zodiacal Light 8:46 – 9:46 p.m. West
13
Zodiacal Light 8:47 – 9:47 p.m. West
14
Zodiacal Light 8:48 – 9:48 p.m. West
15
Zodiacal Light 8:49 – 9:49 p.m. West
16
Zodiacal Light 8:50 – 9:50 p.m. West
17
Zodiacal Light 8:51 – 9:51 p.m. West
18
Zodiacal Light 8:52 – 9:52 p.m. West
19
Zodiacal Light 8:53 – 9:53 p.m. West
20
Zodiacal Light 8:54 – 9:54 p.m. West
21 22 23 24 25 26 27
28 29 30 31      

June 2023
SUN MON TUE WED THU FRI SAT
        1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30  

July 2023
SUN MON TUE WED THU FRI SAT
            1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 31          

August 2023
SUN MON TUE WED THU FRI SAT
    1 2 3 4 5
6 7 8 9 10 11 12
13 14
Zodiacal Light 3:59 – 4:18 a.m. East
15
Zodiacal Light 3:19 – 4:19 a.m. East
16
Zodiacal Light 3:20 – 4:20 a.m. East
17
Zodiacal Light 3:21 – 4:21 a.m. East
18
Zodiacal Light 3:22 – 4:22 a.m. East
19
Zodiacal Light 3:23 – 4:23 a.m. East
20
Zodiacal Light 3:24 – 4:24 a.m. East
21
Zodiacal Light 3:24 – 4:24 a.m. East
22
Zodiacal Light 3:25 – 4:25 a.m. East
23
Zodiacal Light 3:26 – 4:26 a.m. East
24
Zodiacal Light 3:27 – 4:27 a.m. East
25
Zodiacal Light 3:28 – 4:28 a.m. East
26
Zodiacal Light 3:29 – 4:29 a.m. East
27
Zodiacal Light 3:30 – 4:30 a.m. East
28
Zodiacal Light 3:31 – 4:31 a.m. East
29
Zodiacal Light 4:03 – 4:31 a.m. East
30 31    

September 2023
SUN MON TUE WED THU FRI SAT
          1 2
3 4 5 6 7 8 9
10 11 12 13
Zodiacal Light 3:43 – 4:43 a.m. East
14
Zodiacal Light 3:44 – 4:44 a.m. East
15
Zodiacal Light 3:45 – 4:45 a.m. East
16
Zodiacal Light 3:46 – 4:46 a.m. East
17
Zodiacal Light 3:46 – 4:46 a.m. East
18
Zodiacal Light 3:47 – 4:47 a.m. East
19
Zodiacal Light 3:48 – 4:48 a.m. East
20
Zodiacal Light 3:49 – 4:49 a.m. East
21
Zodiacal Light 3:49 – 4:49 a.m. East
22
Zodiacal Light 3:50 – 4:50 a.m. East
23
Zodiacal Light 3:51 – 4:51 a.m. East
24
Zodiacal Light 3:51 – 4:51 a.m. East
25
Zodiacal Light 3:52 – 4:52 a.m. East
26
Zodiacal Light 3:53 – 4:53 a.m. East
27
Zodiacal Light 4:06 – 4:53 a.m. East
28 29 30

October 2023
SUN MON TUE WED THU FRI SAT
1 2 3 4 5 6 7
8 9 10 11 12 13
Zodiacal Light 4:04 – 5:04 a.m. East
14
Zodiacal Light 4:05 – 5:05 a.m. East
15
Zodiacal Light 4:06 – 5:06 a.m. East
16
Zodiacal Light 4:06 – 5:06 a.m. East
17
Zodiacal Light 4:07 – 5:07 a.m. East
18
Zodiacal Light 4:08 – 5:08 a.m. East
19
Zodiacal Light 4:08 – 5:08 a.m. East
20
Zodiacal Light 4:09 – 5:09 a.m. East
21
Zodiacal Light 4:10 – 5:10 a.m. East
22
Zodiacal Light 4:11 – 5:11 a.m. East
23
Zodiacal Light 4:11 – 5:11 a.m. East
24
Zodiacal Light 4:12 – 5:12 a.m. East
25
Zodiacal Light 4:13 – 5:13 a.m. East
26
Zodiacal Light 4:13 – 5:13 a.m. East
27 28
29 30 31        

November 2023
SUN MON TUE WED THU FRI SAT
      1 2 3 4
5 6 7 8 9 10 11
12
Zodiacal Light 4:26 – 5:26 a.m. East
13
Zodiacal Light 4:27 – 5:27 a.m. East
14
Zodiacal Light 4:27 – 5:27 a.m. East
15
Zodiacal Light 4:28 – 5:28 a.m. East
16
Zodiacal Light 4:29 – 5:29 a.m. East
17
Zodiacal Light 4:30 – 5:30 a.m. East
18
Zodiacal Light 4:30 – 5:30 a.m. East
19
Zodiacal Light 4:31 – 5:31 a.m. East
20
Zodiacal Light 4:32 – 5:32 a.m. East
21
Zodiacal Light 4:33 – 5:33 a.m. East
22
Zodiacal Light 4:33 – 5:33 a.m. East
23
Zodiacal Light 4:34 – 5:34 a.m. East
24
Zodiacal Light 4:35 – 5:35 a.m. East
25
Zodiacal Light 5:13 – 5:36 a.m. East
26 27 28 29 30    

December 2023
SUN MON TUE WED THU FRI SAT
          1 2
3 4 5 6 7 8 9
10 11
Zodiacal Light 4:47 – 5:47 a.m. East
12
Zodiacal Light 4:48 – 5:48 a.m. East
13
Zodiacal Light 4:48 – 5:48 a.m. East
14
Zodiacal Light 4:49 – 5:49 a.m. East
15
Zodiacal Light 4:50 – 5:50 a.m. East
16
Zodiacal Light 4:50 – 5:50 a.m. East
17
Zodiacal Light 4:51 – 5:51 a.m. East
18
Zodiacal Light 4:51 – 5:51 a.m. East
19
Zodiacal Light 4:52 – 5:52 a.m. East
20
Zodiacal Light 4:53 – 5:53 a.m. East
21
Zodiacal Light 4:53 – 5:53 a.m. East
22
Zodiacal Light 4:54 – 5:54 a.m. East
23
Zodiacal Light 4:54 – 5:54 a.m. East
24
Zodiacal Light 5:14 – 5:54 a.m. East
25 26 27 28 29 30
31            

The best nights to observe the zodiacal light at mid-northern latitudes occur when the ecliptic plane intersects the horizon at an angle of 60° or steeper. The dates above were chosen on that basis, with the Sun at least 18° below the horizon and the Moon below the horizon being used to calculate the times. An interval of time of one hour either before morning twilight or after evening twilight was chosen arbitrarily because it is the “best one hour” for observing the zodiacal light. The zodiacal light cone will be brightest and will reach highest above the horizon when the Sun is 18° below the horizon (astronomical twilight), but no less.

If you are interested in calculating the angle the ecliptic makes with your horizon for any date and time, you can use the following formula:

\cos I = \cos \varepsilon \sin \phi-\sin \varepsilon \cos \phi \sin \theta

where I is the angle between the ecliptic and the horizon, ε is  the obliquity of the ecliptic, φ is the latitude of the observer, and θ is the local sidereal time (the right ascension of objects on the observer's meridian at the time of observation).

Here’s a SAS program I wrote to do these calculations:

References
Meeus, J. Astronomical Algorithms. 2nd ed., Willmann-Bell, 1998, p. 99.

Tucson Classical Music Performances 2024

Here’s a comprehensive list of live classical music performances in Tucson for the year 2024 where the program of composers and works has been published. I will keep this Excel document regularly updated. Please post a comment if anything should be added or changed.

I’ve included a column called “Dave’s Faves” which notes the works I am already familiar with and that I highly recommend. This is subjective, of course, but I hope this will help some of you in deciding which concerts to attend.

Happy Listening!

Link below is an Excel file (.xlsx).
Last Updated: March 24, 2023

Tucson Classical Music Performances 2024

Click here for 2023 concerts.

If you live in the Tucson metro area and would like to get together each month to listen to and discuss recordings of favorite classical music pieces we love and would like to introduce to others, I hope you will consider joining:

Tucson Exploring Classical Music

Sources
Tucson Symphony Orchestra
Arizona Friends of Chamber Music
University of Arizona Fred Fox School of Music
Southern Arizona Symphony Orchestra
Civic Orchestra of Tucson
Tucson Repertory Orchestra
True Concord, Voices & Orchestra
Arizona Opera
Helios Ensemble
Tucson Masterworks Chorale

Meteor Shower Calendar 2023

Here’s our meteor shower calendar for 2023.  It is sourced from the IMO’s Working List of Visual Meteor Showers (https://www.imo.net/files/meteor-shower/cal2023.pdf, Table 5, p. 25).

Each meteor shower is identified using its three-character IAU meteor shower code.  Codes are bold on the date of maximum, and one day either side of maximum.

Some additional events have been added to the calendar from Sources of Possible or Additional Activity, Table 6a, p. 27). I used the following abbreviations for the Table 6a events that do not have a standard three-character meteor code:

BA* = 2016 BA14
46P = 46P/Wirtanen

Here’s a printable PDF file of the meteor shower calendar shown below:

Happy meteor watching!

January 2023
SUN MON TUE WED THU FRI SAT
1
QUA COM
2
QUA COM
3
QUA COM
4
QUA COM
5
QUA COM
6
QUA COM
7
QUA COM
8
QUA COM
9
QUA COM KCA
10
QUA COM GUM KCA
11
QUA COM GUM KCA
12
QUA COM GUM
13
COM GUM
14
COM GUM
15
COM GUM
16
COM GUM
17
COM GUM
18
COM GUM
19
COM GUM
20
COM GUM
21
COM GUM
22
COM GUM
23
COM
24
COM
25
COM
26
COM
27
COM
28
COM
29
COM
30
COM
31
COM ACE
       
February 2023
SUN MON TUE WED THU FRI SAT
      1
COM ACE
2
COM ACE
3
COM ACE
4
COM ACE
5
ACE
6
ACE
7
ACE
8
ACE
9
ACE
10
ACE
11
ACE
12
ACE
13
ACE
14
ACE
15
ACE
16
ACE
17
ACE
18
ACE
19
ACE
20
ACE
21 22 23 24 25
GNO
26
GNO
27
GNO
28
GNO
       
March 2023
SUN MON TUE WED THU FRI SAT
      1
GNO
2
GNO
3
GNO
4
GNO
5
GNO
6
GNO
7
GNO
8
GNO
9
GNO
10
GNO
11
GNO
12
GNO
13
GNO
14
GNO
15
GNO
16
GNO
17
GNO
18
GNO
19
GNO
20
BA* GNO
21
BA* GNO
22
BA* GNO
23
GNO
24
GNO
25
GNO
26
GNO
27
GNO
28
GNO
29 30 31  
April 2023
SUN MON TUE WED THU FRI SAT
            1
2 3 4 5 6 7 8
9 10 11 12 13 14
LYR
15
PPU LYR
16
PPU LYR
17
PPU LYR
18
PPU LYR
19
ETA PPU LYR
20
ETA PPU LYR
21
ETA PPU LYR
22
ETA PPU LYR
23
ETA PPU LYR
24
ETA PPU LYR
25
ETA PPU LYR
26
ETA PPU LYR
27
ETA PPU LYR
28
ETA PPU LYR
29
ETA LYR
30
ETA LYR
           
May 2023
SUN MON TUE WED THU FRI SAT
  1
ETA
2
ETA
3
ELY ETA
4
ELY ETA
5
ELY ETA
6
ELY ETA
7
ELY ETA
8
ELY ETA
9
ELY ETA
10
ELY ETA
11
ELY ETA
12
ELY ETA
13
ELY ETA
14
ARI ELY ETA
15
ARI ETA
16
ARI ETA
17
ARI ETA
18
ARI ETA
19
ARI ETA
20
ARI ETA
21
ARI ETA
22
ARI ETA
23
ARI ETA
24
ARI ETA
25
ARI ETA
26
ARI ETA
27
ARI ETA
28
ARI CAM ETA
29
ARI CAM
30
ARI CAM
31
ARI
     
June 2023
SUN MON TUE WED THU FRI SAT
        1
ARI
2
ARI
3
ARI
4
ARI
5
ARI
6
ARI
7
ARI
8
ARI
9
ARI
10
ARI
11
ARI
12
ARI
13
ARI
14
ARI
15
ARI
16
ARI
17
ARI
18
ARI
19
ARI
20
ARI
21
ARI
22
JBO ARI
23
JBO ARI
24
JBO ARI
25
JBO
26
JBO
27
JBO
28
JBO
29
JBO
30
JBO
 
July 2023
SUN MON TUE WED THU FRI SAT
            1
JBO
2
JBO
3
CAP
4
CAP JPE
5
CAP JPE
6
CAP JPE
7
CAP JPE
8
CAP JPE
9
CAP JPE
10
CAP JPE
11
CAP JPE
12
CAP SDA JPE
13
CAP SDA JPE
14
CAP SDA JPE
15
CAP SDA PAU
16
CAP SDA PAU
17
PER CAP SDA PAU
18
PER CAP SDA PAU
19
PER CAP SDA PAU
20
PER CAP SDA PAU
21
PER CAP SDA PAU
22
PER CAP SDA PAU
23
PER CAP SDA PAU
24
PER CAP SDA PAU
25
PER CAP SDA GDR PAU
26
PER CAP SDA GDR PAU
27
PER CAP SDA GDR PAU
28
PER CAP SDA GDR PAU
29
PER CAP SDA GDR
30
PER CAP SDA GDR PAU
31
PER ERI CAP SDA GDR PAU
         
August 2023
SUN MON TUE WED THU FRI SAT
    1
PER ERI CAP SDA PAU
2
PER ERI CAP SDA PAU
3
KCG PER ERI CAP SDA PAU
4
KCG PER ERI CAP SDA PAU
5
KCG PER ERI CAP SDA PAU
6
KCG PER ERI CAP SDA PAU
7
KCG PER ERI CAP SDA PAU
8
KCG PER ERI CAP SDA PAU
9
KCG PER ERI CAP SDA PAU
10
KCG PER ERI CAP SDA PAU
11
KCG PER ERI CAP SDA
12
KCG PER ERI CAP SDA
13
KCG PER ERI CAP SDA
14
KCG PER ERI CAP SDA
15
KCG PER ERI CAP SDA
16
KCG PER ERI SDA
17
KCG PER ERI SDA
18
KCG PER ERI SDA
19
KCG PER ERI SDA
20
KCG PER SDA
21
KCG PER SDA
22
KCG PER SDA
23
KCG PER SDA
24
KCG PER
25
KCG
26
KCG
27
KCG
28
AUR KCG
29
AUR
30
AUR
31
AUR
   
September 2023
SUN MON TUE WED THU FRI SAT
          1
AUR
2
AUR
3
AUR
4
AUR
5
SPE AUR
6
SPE
7
SPE
8
SPE
9
DSX SPE
10
DSX SPE
11
DSX SPE
12
DSX SPE
13
DSX SPE
14
DSX SPE
15
DSX SPE
16
DSX SPE
17
DSX SPE
18
DSX SPE
19
DSX SPE
20
STA DSX SPE
21
STA DSX SPE
22
STA DSX
23
STA DSX
24
STA DSX
25
STA DSX
26
STA DSX
27
STA DSX
28
STA DSX
29
STA DSX
30
STA DSX
October 2023
SUN MON TUE WED THU FRI SAT
1
STA DSX
2
STA ORI DSX
3
STA ORI DSX
4
STA ORI DSX
5
STA ORI OCT DSX
6
STA ORI DRA OCT DSX
7
STA ORI DRA OCT DSX
8
STA ORI DRA DSX
9
STA ORI DRA DSX
10
STA ORI DAU DRA
11
STA ORI DAU
12
STA ORI DAU
13
STA ORI DAU
14
STA ORI EGE DAU
15
STA ORI EGE DAU
16
STA ORI EGE DAU
17
STA ORI EGE DAU
18
STA ORI EGE DAU
19
STA LMI ORI EGE
20
NTA STA LMI ORI EGE
21
NTA STA LMI ORI EGE
22
NTA STA LMI ORI EGE
23
NTA STA LMI ORI EGE
24
NTA STA LMI ORI EGE
25
NTA STA LMI ORI EGE
26
NTA STA LMI ORI EGE
27
NTA STA LMI ORI EGE
28
NTA STA ORI
29
NTA STA ORI
30
NTA STA ORI
31
NTA STA ORI
       
November 2023
SUN MON TUE WED THU FRI SAT
      1
NTA STA ORI
2
NTA STA ORI
3
NTA STA ORI
4
NTA STA ORI
5
NTA STA ORI
6
LEO NTA STA ORI
7
LEO NTA STA ORI
8
LEO NTA STA
9
LEO NTA STA
10
LEO NTA STA
11
LEO NTA STA
12
LEO NTA STA
13
NOO LEO NTA STA
14
NOO LEO NTA STA
15
NOO AMO LEO NTA STA
16
NOO AMO LEO NTA STA
17
NOO AMO LEO NTA STA
18
NOO AMO LEO NTA STA
19
NOO AMO LEO NTA STA
20
NOO AMO LEO NTA STA
21
NOO AMO LEO NTA
22
NOO AMO LEO NTA
23
NOO AMO LEO NTA
24
NOO AMO LEO NTA
25
NOO AMO LEO NTA
26
NOO LEO NTA
27
NOO LEO NTA
28
PHO NOO LEO NTA
29
PHO NOO LEO NTA
30
PHO NOO LEO NTA
   
December 2023
SUN MON TUE WED THU FRI SAT
          1
PUP AND PHO NOO NTA
2
PUP AND PHO NOO NTA
3
HYD PUP AND PHO NOO NTA
4
GEM HYD PUP PHO NOO NTA
5
COM GEM HYD MON PUP PHO NOO NTA
6
COM GEM HYD MON PUP PHO NOO NTA
7
COM GEM HYD MON PUP PHO NTA
8
COM GEM HYD MON PUP PHO NTA
9
COM GEM HYD MON PUP PHO NTA
10
COM GEM HYD MON PUP NTA
11
COM GEM 46P HYD MON PUP
12
COM GEM 46P HYD MON PUP
13
COM GEM 46P HYD MON PUP
14
COM GEM HYD MON PUP
15
COM GEM HYD MON PUP
16
COM GEM HYD MON
17
COM URS GEM HYD MON
18
COM URS GEM HYD MON
19
COM URS GEM HYD MON
20
COM URS GEM HYD MON
21
COM URS
22
COM URS
23
COM URS
24
COM URS
25
COM URS
26
COM URS
27
COM
28
QUA COM
29
QUA COM
30
QUA COM
31
QUA COM