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Can you write darksky with those lights?

Don't forget: TV-Turnoff week and even more important: Lights-turnoff week!

If ClearChannel is going to insist pushing these digital billboards with "time of day" related messages, then I hope they will turn down the brightness of their billboards at night as well.

Also, LEDs are becoming very usefull light sources in torches, automotive (brake)lights, traffic signals etc. etc.

Unfortunately this could start to become a problem for thouse of us trying to do something about light pollution also. Especially if and when LED's can be used for street and security lighting.

However as with most forms of light pollution it will depend on how they are applied. Plastering them all over the side of a building = bad. Directing/shielding them so that no light can spill above the horizon = good.

Cheers,
~Al
--
Deputy Chairperson, Irish Light pollution Awareness Campaign
www.irishastronomy.org/ilpac www.darksky.org

With a little more specificity, if this object is m=24, then it's about (24-7)=17 magnitudes fainter than the *best* that the human eye can do. To put that into perspective, given that five magnitudes of difference is about 100x difference in actual brightness (~2.5^5), a difference of 17 magnitudes is *roughly* 5.8E6 (2.5^17) times fainter than the human eye is capable seeing in optimal, dark-sky conditions.

Also, see: International Dark-Sky Association

The article doesn't give much information about the specific technique which is probably what matters in the case of patents, although it does at least say the following:

He said the satellites would be visible in the night sky by employing sunlight reflectors, with multiple satellites linked together to create a message large enough to be seen.

There are some clear similarities, at least, in the form of ideas and business intentions, from over a decade ago. If nowhere else, it's documented in a couple of International Dark Sky Association Information Sheets that are campaigning against a former company's ideas to put giant billboards into orbit in association with, among other things, the 1996 Atlanta Olympics. See Space Billboards Threaten Night Sky and Grass Root Opposition to Space Billboards.

Neither article is dated on the site, although references in the text of them dates back to some time around 1993. The IDA would likely have records of the original publication date and the events in question.

As a side note, the idea of putting advertising in Earth orbit like this tends to sicken me. I really hope that nobody goes for it.

The article doesn't give much information about the specific technique which is probably what matters in the case of patents, although it does at least say the following:

He said the satellites would be visible in the night sky by employing sunlight reflectors, with multiple satellites linked together to create a message large enough to be seen.

There are some clear similarities, at least, in the form of ideas and business intentions, from over a decade ago. If nowhere else, it's documented in a couple of International Dark Sky Association Information Sheets that are campaigning against a former company's ideas to put giant billboards into orbit in association with, among other things, the 1996 Atlanta Olympics. See Space Billboards Threaten Night Sky and Grass Root Opposition to Space Billboards.

Neither article is dated on the site, although references in the text of them dates back to some time around 1993. The IDA would likely have records of the original publication date and the events in question.

As a side note, the idea of putting advertising in Earth orbit like this tends to sicken me. I really hope that nobody goes for it.

Yeah, and all astronoms will hate you for this idea...

I grew up in Colombia and remember fondly countless nights spent in awe looking up at the stars; imagining, wondering.

There are people out there working hard making sure that lawmakers, corporationes, etc, are made aware that for the most part, economic development and dark skies, don't neccessarily have to be at odds; that with a few careful measures, a significant amount of light pollution can be avoided.

For more info, a useful site is

DarkSky.org

Still, despite the obvious comical aspects, I'd hate to see this sort of thing come into being, and I expect these people to agree with me on that.

--
(with thanks to subgeek)

Might I suggest this?

the second one sure looks much less light polluted.

My mother, who is an essayist for National Public Radio, wrote an essay ("Turn Off The Lights") on this topic some years ago. To her surprise, there turned out to be a whole organization dedicated to the problem of our over-lit world, The International Dark Sky Organization. Shortly after her essay was broadcast, they seized her like some kind of a messiah; I imagine that they were pleased to have a non-astronomer care. She spoke at one of their meetings, IIRC, and we (my family) still follow the organization and now do our best to speak on behalf of them, having low-key conversations with neighbors, business owners, and municipal officials, extolling the values of darkness. I think, maybe, it's catching on.

-Waldo Jaquith

Begin civil twilight 7:19 a.m.
Sunrise 7:55 a.m.
Sunset 4:20 p.m.
End civil twilight 4:56 p.m.

All times PST.

There is no way its dark at 9am. The sun has been up for an hour and twilight (when you can see although the sun isnt visible) started 1:41. Yea its dark at 5pm. Thats what you have headlights for. Its safer for you to use your headlights that great big lights blasting down causing glare and mixing light and shadow areas. In fact without all the lights the stars and moon provide enough light to see by on clear nights. I do it all the time on the way to the observatory. My biggest problem with the headlights off? The light coming off my digital odometer and radio shining in my eyes blinding me. No I can't drive safely at 70mph with no lights and the headlights off. But one or the other will suffice we don't need both.

Why does work have to go on in the daylight? Are you a farmer that plows by hand still? What does it matter if its dark or light for the 8 hours your in the cubucle with no windows?

Most of us astronomers, who don't fall into your burn the cities down category dont want all the lights turned off. Just built correctly. Properly shielded so they aim down not up. Put on timers or sensors so they are on only when needed (ever drive by a car dealership at 3am? Does it need to look like daylight?) Sensible rational lighting aimed where it needs to be is much better, safer and cheaper than football stadium like lighting blasting all over the place.

See The Dark Sky institute for more information on good lighting. Shawn

I'm from the countryside and I didn't really noticed how beautiful my night sky was. I began missing darkness and silence after moving to the city. You can't see any stars at all, and often the sky is purple with orange clouds. This just doesn't look real to me; I feel like if I'm inside a weird videogame.

By the way, if you want to help our children to see all those beautiful stars, take a look at darksky.org!

I haven't seen this mentioned yet. I would urge everyone concerned with this issue to become members of the International Dark Sky Association. They have wonderful information on the issue and are very active in trying to get light pollution laws enforced.

Whoa guys! I think we could find a happy medium between no light zones and the current levels of light pollution. For example, most outdoor lighting needlessly sends photons up into the sky instead of down towards the ground where they are most useful. Sensibly designed lights are less wasteful, cheaper and let the sky stay dark.

Light pollution control is a topic nobody every considers, but it really makes a lot of sense when you do. Please educate yourself by going to the DarkSkys site.

The International Dark Sky Association is an organization that has been looking at these issues for some time, if you want to get involved. They have some interesting information and data about night-time lighting and its relationship to crime, as well as other things.

Then, given how important astronomy has been and still is to the development of science and technology, on the fundamental level, I hope /.ers see that cutting off astronomy from the most important sources of radiation is a Bad Thing[tm], and that alltough deregulating the spectrum may be a good thing, astronomers should be heard.

Also, for more about the dark sky problem, check out the International Dark Sky Association.

Check out the international dark-sky association if you're really interested in doing something about this.

For all of the armature astronomers out there with a passing interest in this stuff, here are some helpful links for this years storm:

Where to find a dark place to view from: DarkSky.org

The storm forecast by city (US/World) from NASA: NASA

Astronomy Links In General:

NASA's J-Pass Satellite Passes: Near earth objects(Java,Email)

NASA's SkyWatch 1.4: Excellent for finding events (Java)

Satellite Related Software: For UNIX, Mac, Windows, Palm & more

SpaceWeather.com: Plan to see the auroras

SlashDot.org: Leonid's Last Year

Weather.com: Don't forget to check before you leave

By MichaelCrawford: This /.r makes telescopes

Tips: viewing and what I bring with me.

And better yet, join IDA, even if you can't be active, your membership helps.

Urge your local leaders to use full cut off, non-glaring outdoor lighting. Local action is VERY effective with dealing with light pollution.

Futhermore, when you put a sheild on a light and direct the light downwards, you can use a less powerful lamp and save both energy and money.

Oh, and by the way, that means less emmissions. Which means YOU can have an effect - and make MUCH more of a difference then just writing your Congress critter.

Finally, if you really want to see aurora, get outside more often. You won't see them from in front of your CRT. They sometimes only last a few minutes, so don't depend on Email to alert you.

Finding a dark sky near you.

It looks like I-35 is roughly the dividing line between a much lighter East and generally darker West. Luckily, I live just west of said road, and can head further west to watch from the top of a big bald rock.

Dark skies are a prerequisite to any optics based astronomy. Why are we using so much money to shine light up into the sky? If half the light is going up instead of down, then we're losing half your lighting money for nothing and lowering the standard of living.

Check them out.

It's a serious problem for anyone that wants to see stars without leaving all of civilisation. Check out the difference:

The night sky from a Dark site

The night sky from a city.

Check them out.

It's a serious problem for anyone that wants to see stars without leaving all of civilisation. Check out the difference:

The night sky from a Dark site

The night sky from a city.

Check them out.

It's a serious problem for anyone that wants to see stars without leaving all of civilisation. Check out the difference:

The night sky from a Dark site

The night sky from a city.

The point the society is trying to make is that 50%-70% of the light from outdoor lighting is wasted (points to the sky, not the ground). This causes light pollution and doubles electricity bills. Their solution has been to design alternate lighting fixtures that fit ordinary light poles.

What stars???

usa at night

There are already groups for keeping the night dark.

The light pollution you see in those images is from misused wide area lighting.

I doubt that all the WLEDs ever created, used in task lighting the way this article mentions, would show up on one of those pictures.

Read the article, and think about it...

This was also featured on Talk of the Nation on NPR last week. It is worth a listen.

• Poor weather (especially in the North East) means that you can't observer frequently enough to have good odds of being the first one to see something because you will be clouded out far too often. Truly serious comet hunters move to Arizona to have enought clear skys to have good odds.
• Today most comets are found by professional searches such as linear with bigger scopes. That doesn't leave much left for amateurs
• Equipement maybe affordable for SillyValley stock holders but not for the masses out there. Min. req. these days for comet hunting is about a 20" or 22" obsession scope. That's the trend in recent amateur discovery such as comet Petriew
• to find stuff that faint you need to be several hours out of town to get a dark enough sky becuase you work in a big town to affoard all the equipement. Avoiding light pollution is essential to see stuff that faint so you can't do it often enough

So SOHO is actually a playing field leveler in that sense and makes comet discovery more accessible than before. Sure the is less glory that doing it the old fashion way. It's free, always good weather, timely data. It's also the only legitimate way to get your name in the heavens instead of buying stars which is nothing more than a scam IMHO. So, sure, it's sure a much bigger kick to find one at the eyepiece but a SOHO one still counts in my book.

Here in Western Mass I counted 605 in 50 minutes (from my front yard too). My somewhat rural area is rated at a limiting magnitude of 5.4 according to darksky.org. So, I can imagine how many I would've seen had I driven up to an even more secluded spot. It's cold out, but that was worth it!

If you want to find a dark spot near where you live, the International Dark Sky Association has a page of tools that estimate the brightness of the night sky. You need to know your latitude and longitude for the Java applet.

If you want to find a dark spot near where you live, the International Dark Sky Association has a page of tools that estimate the brightness of the night sky. You need to know your latitude and longitude for the Java applet.

here

From Long Island, looks like I either have to buy a boat to go into the ocean or drive 120 miles.

See you near Monticello, NY Sunday morning!

The International Dark-Sky Association has a cool Dark Sky Finder on their website. Sorry Australia, it's just for the U.S.

You can click on a spot on the map, and it will find the darkest locations within 60 miles. They used census data to estimate the amount of light pollution in a given area based on population, so it might be a good idea to do a sanity check before heading out somewhere in the middle of the night.

Happy viewing!

The International Dark-Sky Association has a cool Dark Sky Finder on their website. Sorry Australia, it's just for the U.S.

You can click on a spot on the map, and it will find the darkest locations within 60 miles. They used census data to estimate the amount of light pollution in a given area based on population, so it might be a good idea to do a sanity check before heading out somewhere in the middle of the night.

Happy viewing!

For those interested, the IDA provides information on what the problem is, how to help, and has some pictures that illustrate the problem well.

For those interested, the IDA provides information on what the problem is, how to help, and has some pictures that illustrate the problem well.

What happened to the anti-light pollution movement?

They are here..

Steve M

Website using CGI script to estimate light pollution:
http://www.darksky.org/ida/darksky/

Java Applet to estimate light pollution:
http://www.darksky.org/ida/darksky/darksky.html

To help you use the above tools, you'll need to know your latitude and longitude in degrees. Just type in your zip code at the bottom of this page:
http://tiger.census.gov/cgi-bin/mapbrowse-tbl/

When converting latitude and longitude for use in these tools, use a negative number to denote South and West (W); use a positive number to denote North (N) and East (E). For example, "49.147247 N" = "49.147247" and "73.996206 W" = "-73.996206".

Website using CGI script to estimate light pollution:
http://www.darksky.org/ida/darksky/

Java Applet to estimate light pollution:
http://www.darksky.org/ida/darksky/darksky.html

To help you use the above tools, you'll need to know your latitude and longitude in degrees. Just type in your zip code at the bottom of this page:
http://tiger.census.gov/cgi-bin/mapbrowse-tbl/

When converting latitude and longitude for use in these tools, use a negative number to denote South and West (W); use a positive number to denote North (N) and East (E). For example, "49.147247 N" = "49.147247" and "73.996206 W" = "-73.996206".

The worst, it seems to me, are large car dealerships.

IDA also likes to talk about gas stations. Some are more brightly lit at night than most offices are during the day! It's as if each gas station feels a need to light itself more brightly than its neighbors, assuming a correlation between foot-candles and sales revenue. I think I will start boycotting the worst offenders just to be contrary.

That line is a bit west of the Mississippi River.

It's way further than a bit. I'd say Oklahoma City and Dallas are over 400 miles west of the Mississippi River.

The American conquest and subsequent resettlement of North America was a movement westward.

Geez, why is it that everyone with an axe to grind has to find some excuse to whet it, no matter how unrelated it is to the topic at hand. You seem to be enjoying the fruits of this conquest. If you don't like it, go back to your ancestor's country, wherever that is.

The history of the world is one people displacing another. If we are going to redress the wrongs in America, why don't we redress them worldwide back to the dawn of time, instead of singling America out as being somehow unique in this regard.

Back on topic. Yes, light pollution sucks. Go to the International Dark-Sky Association site to see what you can do to curb it.

bit far north for that ;)
However, http://www.darksky.org/ida/graphics/europe_lights_ high.gif (big file) does appear to have lights in the right location. Sealand is so nearthe coast thoug, it may be somethig on te mainland.

You're just one more person with an agenda claiming unrelated benefits for compliance ... After reading this story, almost everyone will forget about it, because it's really not very important.

Perhaps you should stay more in tune with current events. Like the power crisis in California. Using less energy is not an unrelated but a pretty direct benefit.

The folks up in Clagary thought so, as you can read here. They expect significant savings in energy by changing to full cutoff light fixtures.

A similar law recently passed in Connecticut and another is awaiting the governer's signature in New York.

Light pollution also takes its toll on the environment in more subtle ways then wasted energy.

From a story at ABCNews.com:

"Darkness for Health

Scientists have now discovered that only when it's really dark can your body produce the hormone called melatonin. Melatonin fights diseases, including breast and prostate cancer. "It turns off the cancer cells from growing," says Joan Roberts, a photo biologist. But if there's even a little light around your bed at night, your melatonin production switches off. "So there may be this natural way that Mother Nature has given us, that is, dark night to keep certain cancers under control," Roberts says. Even watching TV turns on other immune system hormones that should be active only in daytime. They get depleted, and you're more likely to get a cold. Nature needs darkness, too. The immune systems of animals grow weak if there's artificial light at night."

Not getting cancer seems like a pretty significant benefit.

Light pollution also has adverse effects on migrating birds and plant life (the plants can't track the natural light curve and don't properly prepare for winter).

Interested readers my wish to check out the International Dark-Sky Association for more info on light pollution and its effects.

Steve M

I'm not a member, but I know these folks have been getting a lot of press lately. Check them out at:

http://www.darksky.org/

Also, an August 8th interview on NPR's "All Things Considered" featured Elizabeth Alverez from the IDA. You will need the evil RealPlayer to listen to the interview here:

http://www.npr.org/ramfiles/atc/20010808.atc.04.rm m

Hey! Great news for the poeple at the Dark Sky Association. Besides, if I want to look at something grey and lumpy in the sky, I think they should just start throwing old people out of airplanes. Hey that solves the United States' Social Security problem too!!

Your best bet for meteor watching is to find a comfortable chair and a place where you can watch a large part of the sky. And make sure to find the darkest skies possible. (Insert rant about light pollution here.) You might also want to make sure it's not cloudy.