Saturday, January 23, 2021

Against Dark Skies

We do not have the same perceptions with light that we do with sound. You can close your eyes. You cannot close your ears. So, we have laws against noise. We do need a rational theory of law to address noisy light. But not all light is pollution, any more than all noise is bad. After all, most people enjoy the sound of children playing and most so-called “light pollution” is equally benign.

Moreover, you can see a lot from the city if you know where to look. I live in the city of Austin, one mile from South Park Meadows, a major shopping center. From my backyard, I can show you the Andromeda Galaxy. On hobbyist discussion boards, I have shared my views of binary stars. This is an endeavor that many hobbyists pursue, seeking out stars that look like single points to the naked eye, but which a modest telescope will reveal to be two or even four. 


We backyard astronomers know the book, Turn Left at Orion by Guy Consolmagno, SJ, Ph.D. He had a doctorate from Harvard and taught at MIT, but never knew the sky the way an amateur does until a friend showed him the stunning yellow-blue double star known as Albireo at the head of The Swan (or the Foot of the Cross). His friend did that with a small portable telescope from within the glare of New York City in Fort Lee, New Jersey. Turn Left at Orion was written for the urban or suburban hobbyist. 


Some dark skies can be found in North America

One of our local leaders is a sun-watcher. With a special telescope costing four times more than a nice hobbyist instrument and ten times more than an entry-level telescope, he views our Sun, the closest star, and a very average star. Viewing in broad daylight, he never worries about light pollution.


Astronomers also complain about “constellations” of artificial satellites, clusters and strings launched by private companies for communications, natural resource monitoring, economic research, and disaster response. When disaster strikes, we all want our cellphones to bring the responders to our exact locations by GPS. That convenience comes with a cost. 


Not so dark in China; dark skies in North Korea.

Apart from the hobby, serious astronomy has been carried out for 50 to 70 years with radio telescopes, or “dishes.” First investigated by amateurs just before World War II, radio telescopes receive wavelengths that are not blocked by light pollution (or rain). Today, radio astronomy continues to be a pursuit for some amateurs. It is a spin-off of ham radio. 


Other leading edge research in astronomy is performed from orbiting platforms such as the Hubble and Hipparcos satellites. As enthusiasts of space exploration, the backyard astronomers do not complain about the consequences of building giant rockets to carry giant telescopes into orbit. 


Dark skies in central South America.

It is true that amateur astronomers collaborate with professionals. One way is by reviewing the data in computerized “warehouses” of numbers and images. We have more data than university professors can analyze. So, they turn to amateurs. Those hobbyists work from the comfort of their homes, consuming electrical power, and other resources, that also create light pollution.


Amateurs also build their own remote-controlled observatories and monitor the views on high-definition video screens. Those installations are hundreds of miles from their homes where the amateurs enjoy the benefits of civilization. 


Even deeper into the wilderness, some impassioned hobbyists travel to the darkest skies at state and national parks for their star parties. There, many of the instruments are custom-built, huge, complex telescopes, some of which need their own trailers to be hauled to the campsite. At those events, deep sky stargazers pursue “faint fuzzies” the galaxies and nebulas at the limits of viewing. For them, the planet Jupiter is light pollution. At a dark sky site, with no other competition, our solar system’s largest planet is bright enough to cast shadows. In the large “light buckets” built to gather the faintest glows from the farthest objects, the glare of Jupiter washes out the sky. So, one astronomer’s target is another astronomer’s light pollution. The same is true of the Moon. Some hobbyists do study it. It is not a dead world. But generally speaking most suburban hobbyists consider the Moon to be light pollution. 


I am not insensitive to the problem. I believe that a correct political analysis begins with considerations of property rights. A couple of years ago, I wanted to arrange the loan of a large hobby telescope to a co-worker who recently moved into a rural area. Sadly, he declined the offer because his neighbor had just installed a security light, a mercury-vapor spotlight that illuminated her land, his, and much else. If the light waves were sound waves, she would be blasting rock ‘n’ roll at 2:00 AM. That is a problem that is easy to understand and any number of local ordinances (if not common sense and common courtesy) would put a stop to it. 


We all want clear dark skies full of beautiful bright stars. Backyard astronomers also want telescopes, which are mass-production manufactured items, mostly from China. Even custom-made hobbyist telescopes two feet in diameter costing near $10,000 are built from precision glassware made in China. Backyard astronomers here do not mind if China's skies are polluted. 

Dark skies in central Africa, but not the Nile Valley.


I admit that it was at the Austin Astronomical Society's dark sky site 80 miles away from Austin that I first saw the Milky Way from horizon to horizon. It was worth the drive. There is no shortage of dark sky for anyone willing to make an effort, invest resources, and put up with some minor inconveniences. That being so, absent the amenities of civilization, daily life 80 miles from a Level One trauma center could be precarious should you break your arm or have a heart attack. Like telescopes, modern hospitals are another product of our industrial economy. What formal logic calls the law of the excluded middle is commonly expressed as, “You cannot have your cake and eat it, too.”


Seeing in the Dark: Your Front Row Seat to the Universe

Turn Left at Orion


Anthropocene: A Bad Name for a Good Thing

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