It was, I admit, far from the worst falsehood in Donald Trump’s inauguration speech:
And whether a child is born in the urban sprawl of Detroit or the wind-swept plains of Nebraska, they look up at the same night sky, they will [fill?] their heart with the same dreams, and they are infused with the breath of life by the same almighty creator.
This is roughly what the child in Detroit sees on a clear moonless night. The photo was taken in suburban southern California, which surely has less light pollution.
Credit Wikimedia
At a plausible inner city star visibility cutoff of magnitude 2, about 70 stars are visible from anywhere on the Earth, or at most 35 stars from a given point.
This is what the same night sky looks like from unpolluted and bone dry Death Valley:
Credit Grant Kaye (a fine professional photographer but I couldn’t find copyright info – I’ll replace if he objects)
At the limit for the naked eye on magnitude 6.5, the Yale Observatory has catalogued 9,096 stars visible from the globe, or a maximum of 4,500 from a single point. That is roughly what you get in Death Valley. Of course there is a reason nobody lives there. But a habitable deep rural site like Crater Lake still shows a very large number:
It is simply untrue that the child in inner-city Detroit (Bortle scale 8/9) and Nebraska (Bortle scale 3) see the same night sky. The country girl sees up to a hundred times more stars. QED.
Why did Trump and his speechwriter, believed to be Bannon, make make this simple mistake of fact? First, they don’t care and just put in a rhetorical flourish that sounds good. Second, it’s possible that as city slickers they have never really seen a sky full of stars. That would be odd, as Trump owns rural golf courses. But then, they would have had to look up not ahead or over their shoulders. Either way, the phrase is just more lying pixie dust.
Does this matter, independently of the Trumpery? Yes.
First, as a textbook externality. It works better for teaching than a critical issue like climate change, where deniers fear the loss of their liberty to drive a car and live in a suburban McMansion and realists fear for the lives of their children and think about “Second Amendment remediesâ€. Light pollution is not an existential threat. But everybody agrees that a full starlit night sky is beautiful, and its loss by city dwellers is a pity. It also illustrates the policy problem. A Coasian solution via property rights is infeasible, especially as much of the pollution comes from the provision of competing public goods like safe streets. A purely technical fix seems out of reach: LED street lights are even worse than sodium, and their cheapness will encourage proliferation.
As with other externalities, a balance has to be struck through GOVERNMENT REGULATION hiss hiss. It is possible to require lighting downwards, for streets and building façades. Much more security lighting could be triggered by sensors. Indeed, modern digital cameras are so sensitive that they can operate without night lighting – that costs more, but you save on the lighting.
Light pollution is also a complementary externality of outdoor (mainly urban) air pollution, whose main harm is in causing illness and death on a massive scale: at least 3 million premature deaths a year worldwide according to the WHO. Vehicle exhausts and the chimneys of factories, offices and homes spew out chemicals that form aerosols, responsible for much of the light reflection back to earth. I haven’t been able to find an estimate of the percentage of the responsibility, as water droplets also scatter light, but in dry cities like Los Angeles it must be high.
At first sight, a strategy to cut light pollution seems to have three elements.
- Recognize the problem and the harm. It’s not gigantic, but it’s real.
- Cut unnecessary upward lighting through regulations requiring downward and sensor-driven lighting where possible. This should not cost much if anything net.
- Replace ICEVs (starting with diesels) with electric vehicles in the city, through purchases of electric buses and other public-service vehicles, and progressively tighter low-emission central zones. This will need real money and political effort, and is mainly justified by very large public health and climate change costs and benefits.
Why bother?
Trump or Bannon got one thing right. We look up to the stars in awe. Their apparently unchanging majesty reminds us of our smallness in the universe, and raises theological and scientific questions. At first sight, the starfield is random. Early efforts to see patterns resulted in the rather specious constellations, which may just have been a way for our distant ancestors to orient themselves in the night sky and track the seasons. We can’t see the beautiful and ordered spiral arms of the Milky Way galaxy because we are in one, and so it took till the late 18th century for humans to realize that we live in a galaxy like millions of others. (BTW, the evil tyrant George III of American revolutionary propaganda also paid a salary to early galaxy-hunter Caroline Herschel, the sister of the Astronomer Royal, and possibly the first woman in the modern era to have earned a wage as a recognized scientist.)
From above, our Milky Way galaxy looks like this.
Hubble image of the Pinwheel Galaxy (M101), credit: NASA/ESA/Wikipedia, and galaxy hunter Pierre Méchain, 1781. Distance from Sol 21m ly; the image corresponds roughly to a naked-eye view from 2/3 diameters, or 350,000/500,000 ly
We now have another reason to look up at the night sky. That’s where we come from. Of the atoms in our bodies, 10% are hydrogen and are ± 13.7 billion years old, all born simultaneously in the Big Bang. All the rest - the 10 other elements in macroscopic quantities, oxygen, carbon, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium, about a dozen more trace elements in tiny quantities, and unwanted passengers like lead, uranium and aluminium – were created later in the fusion fires of giant stars just before they went supernova and blew their ashes violently into space. Gravity, assisted by shock waves from other supernovae, compressed these huge dust clouds into the accretion disk from which our sun and the planets formed.
As Genesis says, man is born of dust, and returns to it. But it is the dust of stars. Give children back the sight of their home.
Light pollution may not be an existential threat to humans, but it is a health issue https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627… as well as an existential threat to astronomy…
Striking, thanks. An elevated risk of breast cancer is not to be brushed aside but investigated further. Professional astronomers can make the trek to deserts in Chile and mountain-tops in Hawaii, but the small army of amateurs cannot. They not only provide the civic support needed by an expensive and "useless" science but make a contribution to it observing short-lived burst events.
Just wanted to say thanks for a particularly nice (not to mention thought-provoking) post, James.
Emigrants from North Korea report that the air is clean, clear and you can see a lot of stars at night.
They also no doubt have low rates of obesity, diabetes, traffic deaths, cocaine abuse, and senile dementia. The problems of prosperity are still real ones.
I live in a semi-rural place at 5500' elevation in the arid West, and the usually prominent Milky Way is a banal sight, on account of familiarity. Still capable of inspiration upon focused contemplation, to be sure.
My neighborhood is probably >80% Trump voters. The modest houses which I know for certain are Trump voters are uniformly distinguished at night by total darkness, always including drawn shades. Sort of a London WWII blackout effect. Without exception the adult occupants of these nightly blacked out houses are notably unsociable. (Not their small children though, they are mostly adorable.) By convention, there are two extended periods for acting rebellious: Halloween and Christmas. Then it is considered de rigueur to install garish flashing plastic facsimiles of whatever, along with the mandatory haphazardly strung and bizarrely colored lights. Lately gigantic pulsating electric air pumped inflatables are all the rage. Sort of an old-thyme tawdry Las Vegas effect.
We, on the other hand, possibly in part due to our incorrigible INTJ personalities, keep our front door alight all night 365 days per year, with a cheerfully prominent "Velkommen Kleven Carter" rosemåling sign front and center. We make sure the shades to the very active kitchen and dining rooms remain open as well. Otherwise the house remains unadorned by plastic effigies or extraneous lighting. Needless to say, most of the year our house is usually quite the standout, at night. It's definitely a scandal, were one to accept the opinion of the vast majority of our neighbors.
I like to think of our actions in part as a tribute to Paris.
So I am sorry, but for as long as the forces of darkness strengthen around us, I won't personally be joining the campaign against light in the night.
It would need an expert to give an informed view, but I'd be surprised if largely horizontal light from house windows and porches makes a significant contribution to skyglow light pollution. I wouldn't want to live in a WWII British blackout either.
We're 500' feet up on top of a ridge with line of sight views to Humphreys Peak, >60 miles away. At the foot of the mountain is https://lowell.edu/, the Lowell Observatory. I have had occasional twitches of guilt over the years whenever the dark skies advocates cross my fields but have noticed that big box stores and athletic fields seem to have much larger effects on upward directed night time light. One only has to to approach either on a cloudy but otherwise clear night when the location itself is topographically obscured and observe the illuminated clouds above.
"I wouldn't want to live in a WWII British blackout either."
It's an odd thing, psychologically, IMHO. A world lit only by fire? The sensibility seems congruent but the technology is not… apt. Perhaps closer might be Pynchon's tubeglow? Only… kids these days would have no idea what that means.
Nice post, thanks. I was an amateur astronomer back when my mother was alive and she had a summer place down on a relatively unpopulated peninsula on Buzzards Bay. I read the "Celestial Events" column at the back of every Natural History edition from about ages 8 to 40. It even got me laid a few times….betting a woman that we'd see a shooting star before we finished our cigarettes on the deck of a bar, or asking a Match date to drive with me out to Walden Pond to see Hale-Bopp or Kohoutek.
One point worth making is that if you enjoy the night sky, you really needn't venture too far from a city. For example, 15 or 20 minutes south of Playa del Carmen, the sky seems twice as bright. I live 8500 feet up in La Sierra Gorda, in Queretaro, a city of 1.7 million or so, and you only need to get around the bend of a few hills before the skies explode.
So I don't disagree with your larger point on light pollution, but if you want to take your kids or a date out to stargaze, you needn't go to Death Valley or Crater Lake….just to an undeveloped area near your urban apartment or suburban sprawl split-level.
Agreed that you don't need to go to exotic locations. But there are very densely urbanised areas in NW Europe, NE USA, the Ganges river plain, the Pearl River, etc., home to billions, where skyglow is pervasive and the trip to see the Milky Way far longer than 20 minutes. Via Wikipedia, a skyglow map of Europe.
Heh heh, okay, I haven't gotten a really good Milky Way look-see on Cape Cod during the summer season in 25 or 30 years. Falmouth had 7000 permanent residents and 25,000 summer residents when I was a kid, now it's about 40,000/95,000 respectively.
Great post, although the Death Valley and probably the Crater Lake photos look like long-exposure and not what you'd see with the naked eye, which is still impressive.
I'll just push for LED street lights, which in addition to being low-energy can be programmed to be dimmer late at night, say 2 a.m. when traffic doesn't need as much lighting, and give people and animals a break from the light for at least part of the night.