Streetlighting Concerns

I submitted the following letter to the editor to the Dodgeville Chronicle this evening:

Dear Editor:

Have you noticed the gradual transformation of our streetlights in Dodgeville, Mineral Point, and other communities in SW Wisconsin?  The light source in our streetlights is changing.  High Pressure Sodium (HPS), which has been in use for decades and produces a orangish-white light, is being replaced by light emitting diodes (LEDs), producing a whiter light.

What’s not to like?  LED’s many advantages include: efficiency, longevity, instant-on and instant-off, and dimmability, to name a few.  But Alliant Energy is installing new streetlights that produce white light that is too blue, and the illumination levels are about 2.6 times as bright as the high pressure sodium streetlights they are replacing.

Lighting specialists use a term called “correlated color temperature” or CCT (in Kelvin) that allows us to compare the relative “warmness” (redder) or “coolness” (bluer) of  various light sources.   The illumination provided by candlelight has a CCT around 1500 K, HPS around 2000 K, an incandescent light bulb around 2800 K, sunrise/sunset around 3200 K, moonlight around 4700 K, and sunny noon daylight around 5500 K.  The higher the color temperature, the bluer the light.

Higher color temperature illumination is acceptable in workplace environments during the daylight hours, but lower color temperature lighting should be used during the evening and at night.  Blue-rich light at night interferes with our circadian rhythm by suppressing melatonin production, thus reducing sleep quality, and several medical studies have shown that blue light at night increases the risk of developing cancer, most notably breast cancer.  Even low levels of blue-rich light at night can cause harm.  While it is true that something as natural as moonlight is quite blue (4700K), even the light of a full moon provides an illumination level of just 0.01 foot-candle, far dimmer than street lighting, parking lot lighting, and indoor lighting we use at night.

LED streetlights are available in 2700K, 3000K, 4000K, and 5000K.  I believe that Alliant is installing 4000K streetlights in our area—I certainly hope they are not installing any 5000K.  What they should be installing is 2700K or 3000K.  These warmer color temperature lights are no more expensive than their blue-white counterparts, and the slightly higher efficiency of the blue-white LEDs is entirely nullified by over-illumination.

Even considering a modest lowering of light level with age (lumen and dirt depreciation), these new LED streetlights are considerably brighter than the HPS lights they are replacing.  Just take a look around town.  What is the justification for higher light levels in our residential areas, and when was there an opportunity for public input?  In comparison to older streetlights, the new LED streetlights direct more of their light toward the ground and less sideways or directly up into the night sky, and that is a good thing.  But now the illumination level is too high and needs to be reduced a little.

If you share my concerns about blue-rich lighting and illumination levels that are often higher than they need to be, I encourage you to contact me at oesper at mac dot com.  I operated an outdoor lighting sales & consulting business out of my home (Outdoor Lighting Associates, Inc.) from 1994-2005, and wrote the first draft of the Ames, Iowa Outdoor Lighting Code which was unanimously adopted by the city council in 1999, so I am eager to work with others in the Dodgeville area who are also interested in environmentally-friendly outdoor lighting.

David Oesper
Dodgeville

Dodgeville Streetlights

Has anyone else noticed how Alliant Energy is gradually replacing our orangish-white-light streetlights with bluish-white-light ones? The orangish-white-light streetlights are high-pressure sodium (HPS) with a correlated color temperature (CCT) of 1900K, whereas the bluish-white-light streetlights that are replacing them are LED with a CCT of 4000K, and, most notably, they are two and a half times as bright.

Even though I have written to both Alliant Energy and the City of Dodgeville, nothing has changed.

My questions, which are still unanswered:

What is the justification for increasing the streetlighting illumination level by two and a half times over what it has been for decades?

Why are we going from 1900K to 4000K (cold white), when 2700K or 3000K (warm white) is readily available and being used in many communities in the U.S. and Canada?

This same transformation is happening in Mineral Point, and probably many other communities in SW Wisconsin as well.

Is anyone else noticing how this is profoundly changing the rural character of our nighttime environment? Is anyone else concerned about this? The increase in glare and light trespass onto neighboring properties from these new LED lights is quite noticeable to me, even though they are nominally full-cutoff. Why? They are too bright, and too blue.

If anyone locally is reading Cosmic Reflections (and sometimes I wonder if anyone is…), and if you have noticed and are alarmed by these streetlighting changes, please contact me on blog or off blog (oesper at mac.com) and let’s meet and discuss a plan of action. Something needs to be done before it is too late and we are stuck with this very negative change to our nighttime environment.

Dark-Sky Communities

Back in 2006, I started a Yahoo! Group called DarkSkyCommunities. My goal was to provide a forum for astronomy enthusiasts and other like-minded individuals to discuss living where you’d have a star-filled night sky and never have to worry about streetlights or neighbor’s lights. Everyone else in the community would value the night sky and a natural nighttime environment as you do.

My approach with DarkSkyCommunities was not to be a heavy-handed moderator. I approved new members but after that, members were free to post (within reason) anything they wanted to. In that sense, it worked pretty well and there were very few postings I ever had to take down.

Unfortunately, astronomers know next to nothing about intentional community and intentional communitarians know next to nothing about astronomy, so the group drifted far from my original intent to a general discussion about light pollution, with “what’s wrong with the IDA” being a surprisingly popular topic for discussion. Eventually, though, a small number of individuals with a chip on their shoulder or an axe to grind became the most frequent posters, and that sort of poisoned the group.

So, I’d like to introduce to you DarkSkyCommunities 2.0: a Google group called Dark-Sky Communities. Here’s the description on the landing page:

Dark-Sky Communities is a discussion group for the development and nurturing of intentional communities where the night sky and the nighttime environment are valued and protected. The emphasis is on affordable, sustainable dark-sky communities where those of modest financial means can live, work, and retire. This group is moderated to keep the focus on intentional communities that are astronomy-friendly.

This time around I am going to approve (or disapprove) the messages posted to the group so that we stay on the topic of astronomy-friendly intentional communities. If you have an interest in this topic, please join!

Light pollution, despite our best efforts, is getting worse almost everywhere. LED lighting which had (and still has) so much promise is generally resulting in more lights, brighter lights, and bluer lights—not the direction we want to head.

Someday, I would like to live in a place where I can walk a few feet beyond my door, set down a lawn chair, and watch a meteor shower without being assaulted by streetlights, insecurity lights, glare, and skyglow. Is that too much to ask?

Would you like to live in a place like that, too? Let’s make it happen!

A Shroud of Satellites

The first five Iridium satellites were launched on May 5, 1997, and by 2002 there were 66 operational satellites, providing consistent global satellite phone coverage. These satellites have the interesting property that their antenna panels sometimes reflect sunlight down to the Earth’s surface, causing what came to be known as “Iridium flares”, delighting terrestrial observers—myself included. During an Iridium flare event, the satellite suddenly appears and gradually brightens and then dims to invisibility as it moves slowly across a section of sky over several seconds. Many of these events reach negative magnitude, with some getting as bright as magnitude -9.5.

The next generation of Iridium satellites began launching in 2017, but these satellites are constructed in such a way that they do not produce flares. Gradually, the original Iridium satellites are de-orbiting (or being de-orbited), so eventually there will be no more Iridium flares.

The Iridium flares haven’t been much of a nuisance to astronomers because the number of events per night for a given observer have been in the single digits.

But now we’re facing too much of a good thing. The first volley of 60 Starlink satellites was launched on May 24, with 12,000 expected to be in orbit by 2028. These satellites will provide broadband internet service to the entire planet. Though the Starlink satellites aren’t expected to produce spectacular flares like the first generation of the Iridium satellites, they do reflect sunlight as any satellite does, and the sheer number of them in relatively low Earth orbit is sure to cause a lot of headaches for astronomers and stargazers throughout the world.

I estimate that about 468 of the 12,000 satellites will be above your horizon at any given moment, but how many of them will be visible will depend on their altitude (both in terms of distance above the Earth’s surface and degrees above the horizon), and where they are relative to the Earth’s shadow cone (they have to be illuminated by sunlight to be seen).

And Starlink will not be the only swarm of global broadband internet satellites, as other companies and countries plan to fly their own satellite constellations.

This situation illustrates yet another reason why we need a binding set of international laws that apply to all nations and are enforced by a global authority. The sooner we have this the better, as our survival may depend upon it. How else can we effectively confront anthropogenic climate change and the precipitous decline in biodiversity?

As for these swarms of satellites, two requirements are needed now to minimize their impact on astronomy:

  1. Build the satellites with minimally reflective materials and finishes
  2. Fly one internationally-managed robust constellation of global broadband internet satellites, and require competing companies and nations to utilize them, similar to the co-location often required for terrestrial communication towers

I’d like to close this piece with a few questions. Will future “stargazers” go out to watch all the satellites and generally ignore the real stars and constellations because they are too “boring”? Will professional astronomers increasingly have to move their operations off the Earth’s surface to the far side of the Moon and beyond? Will we continue to devalue the natural world and immerse ourselves ever more deeply into our human-invented virtual environments?

Milutin Milanković

Serbian engineer, mathematician, and scientist Milutin Milanković was born 140 years ago on this date in 1879, in the village of Dalj on the border between Croatia and Serbia—then part of the empire of Austria-Hungary. He died in 1958 in Beograd (Belgrade), then in Yugoslavia and today in Serbia, at the age of 79.

Milanković is perhaps most famous for developing a mathematical theory of climate based on changes in the Earth’s orbit and axial orientation. There are three basic parameters that change with time—now known as the Milankovitch cycles—that affect the amount of solar energy the Earth receives and how it is distributed upon the Earth.

I. Orbital eccentricity of the Earth changes with time

The eccentricity (e) tells you how elliptical an orbit is. An eccentricity of 0.000 means the orbit is perfectly circular. A typical comet’s orbit, on the other hand, is very elongated, with an eccentricity of 0.999 not at all uncommon. Right now, the Earth’s orbital eccentricity is 0.017, which means that it is 1.7% closer to the Sun at perihelion than its semimajor axis distance (a), and 1.7% further from the Sun at aphelion than its semimajor axis distance.

The greater the eccentricity the greater the variation in the amount of solar radiation the Earth receives throughout the year. Over a period of roughly 100,000 years, the Earth’s orbital eccentricity changes from close to circular (e = 0.000055) to about e = 0.0679 and back to circular again. At present, the Earth’s orbital eccentricity is 0.017 and decreasing. We now know the Earth’s orbital eccentricity changes with periods of 413,000, 95,000, and 125,000 years, making for a slightly more complicated variation than a simple sinusoid, as shown below.

II. Tilt of the Earth’s axis changes with time

The tilt of the Earth’s polar axis with respect to the plane of the Earth’s orbit around the Sun—called the obliquity to the ecliptic—changes with time. The Earth’s current axial tilt is 23.4°, but it ranges between about 22.1° and 24.5° over a period of about 41,000 years. Greater axial tilt means winter and summer become more extreme. Presently, the axial tilt is decreasing, and will reach a minimum around 11,800 A.D.

III. Orientation of the Earth’s axis changes with time

The Earth’s axis precesses or “wobbles” with a period of around 26,000 years about the north and south ecliptic poles. This changes what latitude of the Earth is most directly facing the Sun when the Earth is closest to the Sun each year. Currently, the southern hemisphere has summer when the Earth is at perihelion.

Milanković used these three cycles to predict climate change. His ideas were largely ignored until 1976, when a paper by James Hays, John Imbrie, and Nicholas Shackleton in the journal Science showed that Milanković’s mathematical model of climate change was able to predict major changes in climate that have occurred during the past 450,000 years.

These Milankovitch cycles are important to our understanding of climate change over much longer periods than the climate change currently being induced by human activity. Note the extremely rapid increase of greenhouse gas concentrations (CO2, CH4, and N2O) in our atmosphere over the past few decades in the graphs below.

The world population has increased by 93% since 1975. In 1975, it was about 4 billion and by 2020 it is expected to be 7.8 billion.

Stevens Point

I visited Stevens Point, Wisconsin for the first time over the Memorial Day weekend and, I have to say, this community of 26,000 is impressive. A great place to stay while you’re there is the Baymont Inn & Suites at 247 Division St. N. It is a short and pleasant walk to the University of Wisconsin – Stevens Point campus, the Schmeeckle Reserve (wow!), and the Green Circle Trail. Michele’s Restaurant is only a few blocks down the street. Great food!

I miss living in a college town. It is energizing to interact on a daily basis with well educated, intellectually curious, and cosmopolitan people who are passionate about their work. I lived in Ames, Iowa—where Iowa State University is located—for nearly 30 years, and I feel more at home in Stevens Point, a smaller community, than I do now in Ames. I think Stevens Point is the nicest community I have visited since leaving Ames in 2005. Definitely would be willing to live there someday. UW-Stevens Point even has a physics & astronomy department, an observatory, and a planetarium. Perhaps I could help out in retirement.

Some towns have a lot going for them even without a college or university—around here, Mineral Point and Spring Green come to mind. Some towns are at somewhat of a disadvantage because they have a name that is not particularly attractive. For example, Dodgeville, where I currently live and work, has a moniker that isn’t all that inviting. But there is no place so nice to live as a college town—for people like me, at least.

My primary civic interests are in gradually developing a well planned network of paved, off-road bike paths, walking trails through natural areas, a center for continuing education, a community astronomical observatory, and a comprehensive and well-enforced outdoor lighting ordinance to restore, preserve, and protect our nighttime environment and view of the night sky. Living in a community like Dodgeville, I don’t get the sense that there is enough interest or political will to make any of these things happen. I can’t do it alone.

Infrasound and Meteors

Humans typically can hear sound waves in the range 20 Hz to 20,000 Hz. Frequencies below 20 Hz are called infrasound and frequences above 20 kHz are called ultrasound. The speed of sound in dry air at a temperature of 20˚ C (68˚ F) and an atmospheric pressure of 1 bar (slightly less than the average air pressure at sea level) is 343 m/s. Dividing the speed of sound by the frequency (in Hz) gives us the wavelength of the sound waves: 17 m (56 ft.) at 20 Hz, and 17 mm (0.67 in.) at 20 kHz.

Meteoroids enter the Earth’s atmosphere (thus becoming meteors) at hypersonic velocities, 35 to 270 times the local speed of sound (Mach 35 to Mach 270). Only a small portion of the total energy of the incoming meteoroid is transformed into visible light: most of the energy dissipated goes into acoustic shock waves. If the meteoroid is on the order of a centimeter (0.4 inches) or larger, infrasound waves are generated that can be detected on the ground, albeit after a delay of many seconds to minutes.

Infrasound waves can travel long distances, but higher frequencies are attenuated due to spreading losses and absorption over much shorter distances. There are many natural and man-made sources of infrasound waves, so identifying an incoming meteoroid as the source of the infrasound requires that we also “see” and record the meteoroid optically (the “meteor”), through radar, or VLF radio emissions from the meteoroid’s ionization trail in the Earth’s atmosphere. Ideally, all of these methods should be used at each observing station to best characterize the size and kinetic energy of each incoming meteoroid.

Infrasound detectors are not yet an off-the-shelf commodity. Chapparal Physics (http://chaparralphysics.com/) is one good source, but seeing as they do not list any prices you know the equipment will be expensive.

An infrasound detector is basically an extremely sensitive microphone that can detect tiny changes in air pressure. A peak sensitivity around 1 Hz is probably a good place to start for detecting meteors. Meteors large and/or energetic enough to be detected on the ground are rare, not even one a day for a given station, so automated recording will be necessary.

Finally, it is important to know that louder sounds that we cannot hear (infrasound and even ultrasound) can sometimes have adverse physical and psychological effects on humans. The cause can be as simple as a malfunctioning piece of mechanical or electrical equipment, or as nefarious as a sonic weapon. It would be advantageous to have a readily available and affordable infrasound and ultrasound detector to detect problem emissions.

For example, you might want an

  • Infrasound detector that maps 0.02 Hz – 20 Hz to the 20 Hz – 20 kHz audible range
  • Ultrasound detector that maps 20 kHz – 20 MHz to the 20 Hz – 20 kHz audible range

References
Silber, Elizabeth A. (2018). Infrasound observations of bright meteors: the fundamentals. WGN, Journal of the International Meteor Organization, 46:2.


Tax Choice

Wouldn’t it be nice if you got to choose where some of your income tax money goes? Where you the taxpayer have some say in how your hard-earned tax dollars are allocated?

Here in the dis-United States, about 50% of us want lower taxes, and 50% of us would be receptive to higher taxes provided that it pays for things we believe in like universal health care and low-cost or no-cost education.

Short of amicably splitting up our country (a civil separation), changing our tax policy may help alleviate some of the frustration many of us have that half of the country is keeping us from building the kind of country we want for ourselves and for our children.

Federal income tax, and state and local income tax (where in effect) would be divided into a non-discretionary portion (100% currently) and a discretionary portion.

When you fill out your tax return each year, you would designate the government agencies and programs where you want the discretionary portion of your taxes to go.

Going one step further, I would like to see taxpayers given the option to choose either the standard or a supplemental tax tier. Those who opt to pay higher taxes by choosing the supplemental tax tier would pay a fixed percentage more, regardless of income (like a true flat tax).

To be fair, those paying in at the higher supplemental tax rate should receive additional benefits compared to those paying in at the standard rate. This could mean lower medical costs, lower education costs, or increased social security payments during retirement, for example.

Would this be easier to implement than partitioning the U.S.? Perhaps. Would it be the more effective solution to satisfy those with very different viewpoints about the proper role of government? Perhaps not.

In my view, society is far too reliant on volunteers. If a job is worth doing, and if it is a benefit to society, then, more often than not, it needs to be a paid position. There is so much work of a humanitarian, educational, and environmental nature that needs to be done that cannot and will not be done by any capitalistic enterprise. As members of society, we all have an obligation to help fund these activities through strong government and non-sectarian non-profit partnerships.

I dream of a day when paying for our medical care is no longer tied to having health insurance through an employer, when each of us will have the freedom to work in a variety of capacities, for both profit and non-profit organizations, throughout our careers, and to receive adequate training and pay for those efforts.


A Warm Day on Pluto

The coldest weather I’ve ever experienced occurred January 30-31, 2019. Here in Dodgeville, Wisconsin, I measured a low temperature the morning of Wednesday, January 30, 2019 of -31.0° F and a high that day of -14.4° F. It was even colder the following night. On Thursday, January 31, 2019 the low temperature was -31.9° F.

Thanks to the National Weather Service, we had advance notice of the arrival of the Arctic polar vortex that was to bring the coldest weather to Wisconsin in a generation. Concerned about the effect this would have on my observatory electronics, I started running my warming room electric heater continuously from 8:30 p.m. CST Monday, January 28 until 9:45 a.m. CST Friday, February 1. Of course, I left the warming room door open to the telescope room to ensure that some of the heat would reach the telescope and its associated electronics.

During this time, I made a number of temperature measurements from an Oregon Scientific weather station inside the house, connected by 433 MHz radio frequency signals to temperature sensors inside the observatory and on the north side of my house.

Here are those observations:

And here is graph plotting both temperatures at each time:

Air (north side of house) and Observatory (inside the observatory) temperatures January 28-February 1, 2019.

And here is a plot of the temperature difference vs. the outside Air temperature:

Temperature difference vs. Air temperature with a linear regression line

There seems to be a general trend that the colder it was outside the observatory, the bigger was the temperature difference between inside the observatory and outside the observatory. Why is that? The electric heater is presumably putting out a constant amount of heat, so you might think that the temperature difference would remain more or less constant as the temperature goes up and down outside. It doesn’t.

There are a number of factors influencing the temperature inside the observatory. First, there is the thermal mass of the observatory itself, and some heating of the inside of the observatory should occur when the sun is shining on it. There is the wind speed and direction to consider. There may be some heating through the concrete slab from the ground below. It seems to me that thermodynamics should be able to explain the general downward trend in ΔT as the outside air temperature increases. Can you help by posting a comment here?

You’ll notice three outliers in the graph above where ΔT is quite a bit lower than the regression line. The points (-22.0,16.6) and (-10.5,10.1) were consecutive measurements just 76 minutes apart (8:32 a.m. and 9:48 a.m.), the first readings I made after the lowest overnight temperature of -31.9° F on 1/31. The point (8.2,7.6) was my first reading on 1/28 at 8:42 p.m., soon after turning the space heater in the observatory on. The points (-16.4,25.2), (-17.9,26.0), (-19.5,26.3), (-25.1,27.2), and (-26.9,27.4) all are above the regression line and are consecutive readings between 8:29 p.m. on 1/29 and 3:20 a.m. on 1/30 before the -31.0° F low on the first really cold night.

My weather station keeps track of the daily high and low temperatures, but not the time at which those temperatures occur. On 1/30 when the outside low temperature of -31.0° F was recorded, the low inside the observatory was -4.0° F (though not necessarily at the same time). ΔT = 27.0°. The high temperature that day was -14.4° F and 6.4° F inside the observatory (ΔT = 20.8°). The next night, 1/31, the low temperature was -31.9° F and -6.2° F inside the observatory (ΔT = 25.7°).

So, despite the many factors which influence the temperature differential between outside and inside the observatory, the clear trend of smaller ΔT at warmer outside temperature begs for an explanation. Can you help?

Pet Peeves

Here is a list of 10 irritations, in no particular order, that make me feel like an alien on my own planet.

  1. High color temperature headlights – Traditional automotive headlights have a yellowish-white color temperature of 3200K. Xenon headlights emit a bluish-white light around 4500K. LED lights are even bluer at around 6000K. These new “blue” headlights make me want to give up night driving altogether. They are too glary and too bright for oncoming traffic. Add in the same for so-called “fog” lights, and the result is often blinding for other drivers.
  2. High color temperature LED lights – While we’re on the topic of lighting, most indoor and outdoor LED lighting should have a color temperature between 2700K and 3000K. This provides a soothing yellow-white light instead of the garish and glary blue-white LED lights in common use today with a color temperature of 4000K or even higher.
  3. Dusk-to-dawn lighting – With the availability of modern light sources, control, and dimming technologies, most outdoor lighting does not need be on or running at full brightness all night long.
  4. Television advertisements – I don’t know how anyone can stand to watch television because there are so many advertisements. I’ve given up watching anything that has advertisement propaganda embedded within the program.
  5. Dystopian movies and television programs – Why would anyone find a dystopian portrayal of the future entertaining or even desirable? I find it utterly horrifying and we should do everything possible to make sure such a future never occurs. Furthermore, I find the amount of violence and aggression in movies and television appalling. This is entertainment? No thanks, I’ve got better things to do with my time.
  6. TV Screens in Restaurants – When I’m dining at a restaurant, just about the last thing I want to see is the distraction of one or more television screens. I’m there to enjoy the food and the company I’m with and screens of any kind are intrusive.
  7. Overuse of smartphones – So many people seem addicted to their smartphones. I don’t generally use one and get along just fine. As much as I use computers in my everyday life, I don’t want one with me everywhere I go. I am really thankful I grew up before personal computers and smartphones existed. Gives one a different perspective.
  8. Sports – I have absolutely no interest in sports. Physical fitness and healthful living, yes, but sports seems like a big waste of time. I don’t see how so many folks can get so excited about something that does absolutely nothing to make the world a better place.
  9. Hunting – I don’t see how anyone can derive pleasure out of depriving another animal of its life. It’s just sick. It is one thing to kill an animal if it is necessary for survival, or self-defense, but for sport it is disgusting. For necessary animal population control, why not use high-tech science-based birth control methods instead?
  10. Pets – I love seeing animals in nature, but have no interest in owning or taking care of a domesticated animal. I much prefer solitude or the company of people. I’m too busy to have any time for a pet, anyway. Don’t like it when you visit someone and their dog or cat jumps on you or licks you. Yuck.