Help me 'see' the threat of light pollution.

Will enlightenists rise in the Y2K’s and outshine environmentalists? Air, water, and even noise pollution are relevant in my world but the number of stars visible to my very naked eye seem inconsequential.

However I seem to recall a simple and inexpensive device which directs the multitude of street lights in a terrestrial direction, eliminating the glaring illumination of humanity. Is this a legitimate device? Do any non-astronomers care?

Satellite Images of light pollution.

An articleabout light pollution

I sit on the fence, somebody push me off.


Well, it’s not something where little children cough up their lungs, or babies are born without eyelids, if that’s what you mean. It’s an esthetic point. That said, dumping lots of light energy all over the place may represent waste. The waste is of fuel of course, not of energy, since energy is neither created nor destroyed, but it may be a symptom of ways of doing things which result in more pollution of a less ethereal nature–stuff that does make little kids cough up their lungs, or stuff that maybe messes with the climate. For those more pressing reasons, we may need to move to a society which uses its resources a little more wisely.

A streetlamp that doesn’t direct light upward can give ample illumination with half the wattage of the old fixtures.
Calgary, Alberta expects to save $1.4 million a year by switching to from old 200 watt street lamps that muck up the sky to more efficient 100 watt units.

Here in Tucson, astronomy and optics are a major part of the economy. The city has some pretty strict laws regarding light pollution, and as a result, the night sky is pretty good even downtown, and just outside the city it’s spectacular.

Besides which, it really does help contribute to our local economy; several observatories, a massive lens manufacturing establishment, research grants, and tons of optics companies have made their homes here, much to the delight of the Chamber of Commerce.

I grew up in the suburbs of Montreal. Stars were rarely visible, not very noticeable, as the sky (even when clear) was a red wash emanating from the downtown core 40 kilometres away.

Then I moved to Vancouver, which has a much smaller population, and said “Wow”. Checking out stars at night is spectacular. I can’t help but notice them-- and I finally get constellations. I’d hate to give that up.

Here in Columbus Ohio it always looks like the sun is rising…

There are three separate, but related, issues when discussing light pollution.

The first, as others have noted, is the impact on the astronomy industry and related industries. Light pollution makes it very difficult to conduct optical astronomy. Observatories must be located in increasingly isolated (and therefore expensive to build at) sites to achieve any sort of clear-sky view. Plus, many astronomical areas of study (variable stars, for example) rely on amateur data, and amateurs have a more and more difficult time finding non-polluted sites from which to observe.

Second, the sky is (or can be) considered a natural resource just like land, air and water. Much like we dedicate efforts to preserve National Parks and other areas for their resources and their aesthetic value, we should make efforts to preserve views of the sky.

Finally, as MEBuckner noted, it’s inefficient. The whole idea of outdoor lighting is to light the ground – for cars, for pedestrians, etc. Light that is shining on the sky is wasted. Money is being wasted on it, fuel is being wasted generating it, and it isn’t lighting anything that anyone needs to see. By using shielded, directional lighting, municipalities can light the ground more efficiently at lower wattage.

An excellent resource for pursuing local dark-sky initiatives is the International Dark Sky Association.

How do the ‘retro’ Bishop’s-Crook style streetlights that seem to be mandatory for all recent downtown renewal projects stack up? - they seem like they would be a source of upward light leakage.

A disclaimer: I wouldn’t want to live anywhere where I could see the stars. (Even though I am getting tired of Chicago cabbies trying to run me down)

What ever happened to the project to send a satellite in orbit with a giant mirror that would reflect light to, say, New York City and thereby eliminate the need for street lights. It would turn New York into a dim version of day at night.

I say we solve the air pollution problem and invent some inexpensive way to turn sea water into fresh water before spending any money on light pollution.

Eliminating wasteful lighting is a no-brainer. It’s all
benefits, and no draw-backs.

Some seem to fear that anti-light-pollution crusaders want to plunge our cities into darkness so that The Streets Will Not Be Safe. Far from it. Downward-directed lighting provides better illumination than wasteful lights. It puts the light where it is needed, rather wasting it to space.

There isn’t a significant difference in initial outlay for downward-directed lighting. Also, more efficient lighting can pay for the cost of replacement because it saves on power bills into the future.

Cities and property-owners do not have to rip up all their lighting and replace it right now. Most dark-sky advocates simply recommend that as new lights are installed older fixtures are replaced, we should use better, non-polluting, efficient lights.

Something else that no one has yet mentioned is that light pollution can have negative effects on nocturnal animals. I understand that only a few studies have been done in this area, so no one is quite sure how big of a problem this might be. We don’t yet know which animals are most affected. We don’t know how strongly they are affected. But some of the preliminary studies have shown that some animals are to a degree adversely affected. As the light pollution from metropolitan areas affects areas up to 100 miles away (depending on local conditions) there are increasingly few areas that are unaffected.

The Great Gazoo wrote:

<Darth Vader voice>
If you only knew the power of the dark side!

Along the lines of bartman’s comment, in my part of the world (NE Florida), there is definitive evidence that light pollution affects animal life. But in this case, it’s not light going UP, but ‘horizontal’ light. Sea Turtles lay eggs in the sand along the shore, the eggs hatch (usually at night), and hundreds of little turtles head for the sea. Since over the millennia, it has always been brighter over the ocean than over the land, the little guys are programmed to head for the lightest part of the sky. If that is Buffy and Clive’s decorative landscape lighting on their beach-front home, or the gazillion candlepower lights at the minimart across the street, well, that’s where the baby turtles head. Here, the light pollution battle DOES involve ‘safety and security’ lights. There are ways to shield them to minimize the effect on the turtles, but many folks resist, either out of fear of the bad guys, or rejection of any ideas from tree-hugging pinko environmentalists.

I think that a diminished night sky contributes to the psychological poverty of city-dwellers.

If I were a bible-banger I might cite Mad John’s vision of the apocalypse:

“And the fourth angel sounded, and the third part of the sun was smitten, and the third part of the moon, and the third part of the stars; so as the third part of them was darkened…”

One major point is that better lighting already exists; therefore no money need be spent to research the problem. It may cost more initially, but saves money in the medium and long run in energy savings. Once local politicians figure this out, it’s easier to get them to buy the better lights.

[nitpick]Yeah, it can’t be created or destroyed, but only so much of it is useful. It is perfectly valid to say that something is a “waste of energy.” Just in a different sense (Gibbs free energy, for example)[/nitpick]

Also, light pollution just annoys me.

(1) Many people, including non-astronomers do like to see a starry sky.
(2) It is beneficial for people to have a better understanding of the world/universe around them than not. Being able to see more, helps further understanding.
(3) Sky glow is ugly compared to a starry sky.
(4) Glare from poorly aimed/overly bright outdoor lights is a driving hazard. This is particularly true for older people who have more difficulty with night vision.
(5) Light trespass is a nuisance factor (e.g., that annoying neon sign from the business across the street).
(6) Light pollution can be harmful to wildlife. E.G., after hatching, baby sea turtles have been known to head toward a lit roadway rather than the ocean. Many birds are attracted to/confused by and die from collisions with lit towers (or guy wires to those towers). Some trees/vegetation may not grow as well without a night time “rest cycle”.
(7) Light pollution reduces the efficiency and/or increases the expense of scientific studies (astronomy).
(8) There is no evidence that more lighting reduces crime. (outdoor flood lights are often used based on the assumption that they reduce crime)
(9) Over-lighting can create driving hazards. For example, a driver leaving a bright gas station onto a darker street would not have dark-adapted vision and may not see that pedestrian crossing the road.

…and most significantly to those who do not care about seeing stars…

(10) Light pollution wastes money. Light is energy and energy costs money. If you are just trying to light a parking lot, then why pay money to light the neighbor’s yard and the underside of airplanes? If lights are applied to just the targeted area, then less energy-intensive bulbs can be used to achieve the same effect that a larger wattage bulb does which lights a larger area. If this not of concern for your electric bill, then it can still be of concern for your tax bill paid to your town. Towns spend huge amounts of money on street lighting alone.

…corrolaries to this would be…(these are simple matters of efficiency)…

(11) Light pollution wastes energy (hello, California crisis?)
(12) More energy spent for lighting means more pollution from power plants.

This was a Russian program. There was a test flight that failed. They don’t have the money to try again right now.

Thing is, reducing light pollution saves money in the long-run by reducing electric bills. More money would be available to address other problems. You might not notice the difference in your own bank account but municipal budgets would notice the difference.

People wouldn’t even need to waste time re-doing everything. Most state light pollution laws seem to “grandfather” all existing lights and just require that any new/replacement lights be set up a certain way.