Musings on optics, physics, astronomy, technology and life

Posts tagged ‘lighting’

Jyväskylä: The “City of Light in Finland” balances lux and luxury

Here’s a nice post from the International Year of Light’s official blog. Jyväskylä (please don’t ask me how to pronounce that!) is about 300 km north of Helsinki, as far as I can tell from online maps — not far enough north to be truly Arctic, but still up there in the “long winter nights” department. I like this city’s approach to good urban lighting design, with due consideration to mitigating light pollution.

International Year of Light Blog

Jyväskylä located in Central Finland is a lively city with a growing population. Finland’s seventh largest city is home to almost 136,000 people. Jyväskylä, well known for its green surroundings and Alvar Aalto architecture, is also Finland’s City of Light.

Kuokkala bridge. Credits: Jani Salonen Kuokkala bridge. Credits: Jani Salonen

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Happy New Year!

First of all, I would like to wish my friends and readers a very Happy New Year! I wish you inner peace, good health, much happiness, and at least enough prosperity to keep the metaphorical wolf away from the door.

I also wish you much light, especially in the darkness of the Northern Hemisphere. It’s easy to feel the “winter blahs” without actually connecting them to the shortened hours of daylight and the increased time spent indoors under artificial lighting. Here’s a New Year’s resolution you may not have thought of making: Get in touch with your circadian rhythm; make sure you get some natural light into your eyeballs during daytime hours, and sleep in a nice dark room (after you’ve done some stargazing, of course!).

Some six or seven weeks ago, I wrote a short Optics & Photonics News article about a small Norwegian town that, for its entire existence, has gone without direct sunlight for six months in every year, because it is located in a deep valley. That’s right — for six months, every day feels like a cloudy day, even if the sky is clear overhead. To brighten up the town square, the town of Rjukan installed a mirror array atop one of the nearby mountains, with solar-generated electricity running a computer system to move the mirrors to track the sun.

When I did the article, I must have gotten on Rjukan’s press mailing list. Just before the winter solstice, I got this notice:

52 days of winter sun in Rjukan.
Since the unveiling of the sun mirror 30th of October this year, the sun mirror has brought light and attention to Rjukan. For the first time the sun shines on the Christmas tree at the market square.

The square has become a meeting place for both young and old residents, as well as for tourists. Several shops and cafes have increased sales. Krossobanen, the cable car that still carries people up to the sun, drove filled carriages the first weekends after the sun mirror opening. It is not usual in November.

– People have been curious about the small town between Gaustatoppen and Hardangervidda ,” says tourist manager Karin Roe. We hope the curiosity takes over and that they visit us as well. – Because we have so much to offer to visitors, especially our exciting history now nominated for UNESCO World Heritage List, she concludes.

Mayor Steinar Bergsland has been busy on other areas after the opening. In late November he presented the news that Green Mountain Data Centre establishes in Rjukan. 2 weeks later the mayor and Rjukan population mobilized against plans to close down parts of the local hospital. However, he still has the great pleasure of the sun mirror.

 – The Sun mirror has become a natural part of life. Even when the clouds are low down the mountainside we are looking up at the sun mirror as we walk past the square, says the mayor who believe that citizens have been more proud of their city and what they have managed to achieve.

Here is a photo of the sun mirror shining down on the Christmas tree in Rjukan’s town square:

Photo credit: Terje Prestaarhus

Photo credit: Terje Prestaarhus

I think that’s a beautiful image, don’t you? I hope the people of Rjukan are having their happiest winter ever.

A graphic demonstration

A couple of entries ago, I alluded to the powerful storm that knocked out electrical power to more than 1 million customers in the mid-Atlantic region. A NASA imaging satellite has captured before-and-after pictures of the region at night — and the results reveal something about light pollution, too.

NASA’s Suomi National Polar-orbiting Partnership spacecraft, a project based right here in my current community of Greenbelt, Maryland, imaged the region just before and after the storm last Friday night. Be sure to click on the “View Image Comparison” button — it takes you to a layered image with a “slider” so you can “blink” between the two photographs.

Granted, after the storm the Philadelphia, Delaware and Eastern Shore (Maryland) regions were covered with clouds. But you can definitely see the widespread outages all over the area west of the Chesapeake Bay. Not everyone lost power — you can see where the cities are, but they looked “dimmer” from outer space.

Of course, we use electrical power for lots of things besides lighting. However, we Americans tend not to be models of prudence when it comes to outdoor lighting, and we end up sending an awful lot of lumens up into the sky, especially when we live close to each other. I wonder how many people looked up at the night sky after the storm (maybe very late Friday night/early Saturday morning, or Saturday evening) and noticed a difference. Was there indeed a difference? I’m curious whether anyone made reasonably quantitative measurements. (Sorry, I didn’t.)

Courtesy of my Google Alert, here are a few more news article on The City Dark from, the International Business Times, the Pittsburgh Post-Gazette and the Chicago Sun-Times. Also, Discovery News offers tips on how to view the Milky Way — that is, if you can get far away from the murk of the cities to detect it at all.

A “point of view” you absolutely must see

As if someone at PBS headquarters was reading Optics & Photonics News (I wish!), PBS has scheduled the wonderful documentary The City Dark for its “POV” summer documentary series.

I saw The City Dark earliest this year at an environmental film in Washington, D.C. Why, yes, I just happened to be working on my OPN article at the time, but I would have appreciated the movie even if I had no plans to write about light pollution. It’s just more lyrical and expressive than I can manage. (I used to think I was pretty eloquent, but that was back in the day when electric typewriters still set the standard for individual written communication.) And it had Neil deGrasse Tyson. I’ve seen Neil deGrasse Tyson in person a couple of times, most recently (well, a couple of  years ago) at a retirement “roast” for longtime American Astronomical Society press officer Steve Maran. When it comes to communicating astronomy to the public, Neil deGrasse Tyson rocks my world.

Anyhow, you can watch the trailer for The City Dark on the PBS website and check the local listings for the film, because PBS stations often do their own thing. Supposedly, “POV” is a Thursday night feature, but here in the Washington area, WETA is airing the documentary on Saturday, July 7, at 11:15 p.m. Also check out for information where you can see it possibly on a larger screen than you have at home and/or with a bunch of like-minded people besides your own family.

Welcome again!

If you’re coming to this blog from my feature article on light pollution in the July/August issue of OPN, welcome!

I mentioned my blog at the end of the article for the simple reason that I found out way, way more information about light pollution than I could ever cram into a magazine article of a manageable length. And news is always coming out about the subject, even as I sit here and type this. So I thought I’d experiment by blogging updates to my article, at least for a month (or two, since OPN combines its July and August issues into one).

First off, if you are on Facebook and don’t already “Like” my science-writing page, please do so! On some days, it’s just easier to forward an interesting link that someone else posted than to do the writeup myself. Of course, on my Facebook page as well as on this blog, not all the posts are concerned with light pollution. However, I try to keep them reasonably focused on science topics that I find interesting or novel.

Second, the world’s premier organization fighting light pollution, the International Dark-Sky Association, also has a Facebook page. I follow it closely.

Although I wish I could write more tonight, I hate to spend too much time on a single entry right now. Thanks to this weekend’s derecho, electrical power in my region is tenuous. I had one outage from Friday night through yesterday evening, and a second blackout for about two and a half hours tonight. I’m not entirely convinced I won’t get a third before things get back to normal.

The blankness of the common thread

At many times in my past, I’ve felt a bit whipsawed as I careen from one writing and editing assignment to another: from elder affairs to school board meetings, from dying kids to budgetary minutiae, from higher mathematics to apartment fires.

In recent months, I went straight from writing about photography in the American Civil War — the pre-light-bulb era — to putting together a feature on modern-day light pollution — which has a lot to do with poorly placed electrical lighting fixtures. So what could these topics possibly have in common?

Blank skies.

The blankness is obvious in this famous Crimean War photograph by Roger Fenton (which actually predates the American Civil War) and this image of a dead Confederate soldier at Gettysburg by Alexander Gardner. Even when there’s a sharply defined shadow, as in this Mathew Brady photo, you can’t distinguish between blue sky and white clouds. (The line at the top of that photo looks like an issue with the collodion plate coating or other chemicals.)

Yet when I got my first 35-mm SLR camera as a high school graduation present and started learning about photography, I read that, in order to increase the contrast between puffy white clouds and beautiful blue skies, one should use a red filter in black-and-white photography and a polarizing filter in color photography. So, why the blank skies in the Civil War?

The answer: prior to 1873, photographic chemicals were sensitive only to blue light. So the wet photographic plates picked up the blue light coming from the sky (Rayleigh scattering and all that) and the blue component of the light reflected off the clouds and recorded them all the same. Photography studios of the era often had walls painted in a sort of robin’s-egg blue, yet they looked lighter on the resulting ambrotype or tintype than they would on modern panchromatic black-and-white film (or digital images turned monochromatic in an image-editing program).

More blank skies are readily visible in this amazing set of Western American images by Timothy O’Sullivan, one of the Civil War photographers who kept on plying his trade after the fighting ended. It makes you wonder about some of the gorgeously detailed skies in the works of some 19th-century Romantic painters — were they trying to one-up the photographers?

Meanwhile, light pollution makes today’s urban night skies look just as blank to the naked eye as the daytime Civil War skies looked to the wet-collodion plates (see top and bottom images here). Different effect, same blah outcome.

My feature article on photography in the American Civil War just came out in the June 2012 issue of Optics & Photonics News. My story on light-pollution will appear in that magazine later this year. If you are an OSA member or can get to a library that subscribes to OPN, please read my article and let me know what you think.

A couple of “not quite…” moments

First off, let me apologize for not posting interesting thoughts to this blog as soon as they pop into my mind (or as soon as I read them elsewhere on the Internet). Recently I just finished one feature-length article for Optics & Photonics News (OPN), and I have a second one due in less than two weeks.  Plus, I’m working on a shorter article and some other projects. You can always follow my Twitter feed or “Like” my Facebook page.

Anyhow, here’s what I’ve been reading….

First off, a couple of Fridays ago (March 9, to be exact), the Washington Post had a front-page story screaming, “Affordability award goes to a $50 light bulb” (or “Government-subsidized green light bulb carries costly price tag” on the Web version). Apparently, the winner of the U.S. Energy Department’s “L Prize” award for innovation in energy-efficient lighting is a lamp that costs $50 per bulb. Since practically all of us American adults have grown up in the era of ultra-cheap incandescent bulbs, that seems almost prohibitively expensive, doesn’t it? Especially since the story was accompanied by an infographic that claimed that it would be cheaper for a household to buy 30 inefficient incandescent bulbs (which generate more heat than light) over 10 years than to buy just one of the super-efficient prize-winning lamps.

As my high school chemistry teacher used to say, “Yah, but….” As it turned out, the original infographic had gotten the math wrong. As it turns out, if you stuck with incandescents for your favorite lamp, over the next decade it would cost you $228 — $30 for 30 bulbs and $198 for 1,800 kWh of electricity. However, you could spend the next decade using the $50 bulb in your lamp and expend only 300 kWh of electricity, for a grand total of $83.

Hat tip to the Media Matters for America blog for pointing out the change in the infographic, as well as straightening out the often-distorted reporting about the coming changes in our light-generating technologies. I’m really getting sick and tired of hearing politicians tag President Obama with the alleged “light-bulb ban” when his predecessor, President George W. Bush, was the guy who actually signed the relevant legislation. If it didn’t happen during the Bush administration, then how come I wrote about it back then?

However … At least the Post‘s “Fact Checker” blogger got things right when he pointed out that Republican presidential hopeful Mitt Romney attributed the “ban” on incandescent bulbs to “Obama’s regulators.” The blog gave Romney three Pinocchios (out of four), meaning “(s)ignificant factual error and/or obvious contradictions,” for that one.

Remember, folks, incandescent bulbs aren’t going to be “banned” — they’re just going to be held to a much higher energy-efficiency standard, and if they can’t cut the mustard, well, so be it. That’s “not quite” a ban.