A bleak future for light pollution
pete
( http://www.economist.com/node/16886228 ). It's about how more
efficient lighting could smply have the effect of increasing the
amount of light we produce - rather than the intended consequence
of reducig energy consumption.
If the predictions in the article (light output to increase 10-fold
by 2030) come true, it could have dire consequences for astronomy
both at the amateur and professional level.
--
http://www.thisreallyismyhost.99k.org/0120100913175317930.php
Chris.B
> I've just been reading a rather depressing article in The Economist
> efficient lighting could smply have the effect of increasing the
> amount of light we produce - rather than the intended consequence
> of reducig energy consumption.
> If the predictions in the article (light output to increase 10-fold
> by 2030) come true, it could have dire consequences for astronomy
> both at the amateur and professional level.
>
I'm not sure their arguments hold true when street lighting (the
greatest contributor to outdoor light pollution) is becoming more
downward orientated. At least when when it is replaced. The advantage
of downlighting street lamps is the lack of direct glare. Glare from
widely radiating light sources "blinds" the victim and requires yet
more light to overcome the natural contraction of the iris and loss of
partial night adaptation. Leading to inevitable heavy shadows and
"dancing lights" due to persistence of vision.
Gas mantles, and the bare incandescent bulbs which replaced them, were
almost all, naked, intense, light sources. Only much later did shading
become the norm. The easiest experiment in lighting discomfort and
inefficiency is to temporarily remove a shade from an existing light.
Only arrogant fools ignore this simple and obvious fact and design
"floodlights" to light our world. Floodlights are neither comfortable,
efficient nor secure. Ask one of the retarded "professional" lighting
designers if they would rather drive "into the sun" or with the sun
(safely) behind them. On present form it seems that most of them would
prefer to commute into the rising/setting sun while wearing sunglasses/
shades.
Brad Guth
> I've just been reading a rather depressing article in The Economist
> efficient lighting could smply have the effect of increasing the
> amount of light we produce - rather than the intended consequence
> of reducig energy consumption.
> If the predictions in the article (light output to increase 10-fold
> by 2030) come true, it could have dire consequences for astronomy
> both at the amateur and professional level.
>
> --http://www.thisreallyismyhost.99k.org/0120100913175317930.php
More light is always a good thing. Less air pollution is also an even
better thing.
Our physically dark moon only has a wee bit (few million tonnes if
including its comet like tail) of hot sodium for natural and
artificial light to react with, so go there if you want absolutely
terrific illumination that's clean and fully renewable and with loads
of raw UV at no extra charge, and there's hardly if any refracted
atmospheric light, even in full daylight plus having 1225 w/m2 of
secondary/recoil IR plus Earth-shine and vibrant Venus-shine to deal
with, whereas it's still essentially crystal clear unless all that
pesky hot sodium plus other electrostatic charged dust gets to be an
issue, not that the lunar gamma should be anything to worry about,
especially when you're getting full-body nailed by those solar CMEs
plus soft and hard X-rays.
According to all things NASA/Apollo and DARPA, our moon is so inert
and monochromatic that none of that solar UV reacts with anything
(including those ultra-white moonsuits and American flags).
You'd actually be better off at the Earth-moon L1 (Selene L1).
~ BG.
Davoud
> I've just been reading a rather depressing article in The Economist
> ( http://www.economist.com/node/16886228 ). It's about how more
> efficient lighting could smply have the effect of increasing the
> amount of light we produce - rather than the intended consequence
> of reducig energy consumption.
> If the predictions in the article (light output to increase 10-fold
> by 2030) come true, it could have dire consequences for astronomy
> both at the amateur and professional level.
I would have rephrased the subject based on my own somewhat cynical
view: "A bright future for light pollution, a bleak future for
astronomy."
One respondent noted improved street lighting. I'm happy for him. Anne
Arundel County, MD, has decided that "old-fashioned" fixtures that
throw all of their light and glare horizontally and upward are really
cute for roundabouts and other public places where motorists and others
need to be blinded at night, without regard to what the purpose of the
lamps ought to be.
I am utterly pessimistic about the future of intelligent use of
lighting, and not just in my county. Raise the issue with
politicians--at any level--and 99 percent of them look at you like
you're crazy. "With all the other problems we have, our streetlights
aren't right, and you want us to spend money to do something about
that?" Not gonna happen. The national and world situation will get
worse and worse. Just wait 'til rural China is electrified and you'll
see what I mean. Think they're going to go for smart fixtures?
Davoud
--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.
usenet *at* davidillig dawt cawm
Martin Brown
> On Sep 1, 6:39 pm, pete<no_one_you_k...@notthisaddress.com> wrote:
>> I've just been reading a rather depressing article in The Economist
>> (http://www.economist.com/node/16886228). It's about how more
>> efficient lighting could smply have the effect of increasing the
>> amount of light we produce - rather than the intended consequence
>> of reducig energy consumption.
Unfortunately this could easily be true at least until light levels at
night are increased to be the same as daytime. This is most likely to
happen in major city centres and shopping malls.
>> If the predictions in the article (light output to increase 10-fold
>> by 2030) come true, it could have dire consequences for astronomy
>> both at the amateur and professional level.
>>
>
> I'm not sure their arguments hold true when street lighting (the
> greatest contributor to outdoor light pollution) is becoming more
> downward orientated. At least when when it is replaced. The advantage
> of downlighting street lamps is the lack of direct glare. Glare from
That only really works if you treat light as "Fire and forget". The
point remains that downward full cutof lighting doesn't directly light
up the sky but 10-30% of the light emitted is reflected by the ground
about 20ns later. And a *much* higher proportion when it is snowy.
> widely radiating light sources "blinds" the victim and requires yet
> more light to overcome the natural contraction of the iris and loss of
> partial night adaptation. Leading to inevitable heavy shadows and
> "dancing lights" due to persistence of vision.
The problem is that mall owners think that a big bright light halo
attracts passing trade. And they could well be right about that.
>
> Gas mantles, and the bare incandescent bulbs which replaced them, were
> almost all, naked, intense, light sources. Only much later did shading
> become the norm. The easiest experiment in lighting discomfort and
> inefficiency is to temporarily remove a shade from an existing light.
> Only arrogant fools ignore this simple and obvious fact and design
> "floodlights" to light our world. Floodlights are neither comfortable,
> efficient nor secure. Ask one of the retarded "professional" lighting
> designers if they would rather drive "into the sun" or with the sun
> (safely) behind them. On present form it seems that most of them would
> prefer to commute into the rising/setting sun while wearing sunglasses/
> shades.
Strangely I have found that the professional lighting engineers are
generally sympathetic to astronomers needs. It is the general public,
politicians and police who associate bright glare with security lighting
which explains why 1kW quartz halogen insecurity lamps in crude oilcan
type enclosures sell so well at DIY places.
Observatories around San Diego will soon be blinded by new improved LED
lighting. They are resigned to their fate. The local lighting engineers
do not seem to have grasped that it was the very narrowband emission of
NaD that is easily filtered and not the "yellowness" of the light.
Regards,
Martin Brown
pete
Actually I could see the chinese installing smart lighting fixtures
if that is the first time they install outside lighting in a location.
I wouldn't expect the cost of smart lighting to be much higher than
that of dumb lighting if you start from zero. It's only when there is
"perfectly good" lighting fixtures already in place that it becomes
a difficult sell to have them torn out and replaced. You generally
only get improved lighting when the existing stuff goes through an
end-of-life replacement. (Or if the mayor's brother starts a street-
light supply company.)
Where it will affect us amateur astronomers is when the powers that
be decide that outside lighting is now so cheap to run it can be
installed in parts of the country that didn't have it before. Even
smart lighting will create some light pollution, where there was no
outside lights before. In established light pollution "black spots"
(should that be "white spots?) it's already a lost cause, it's just
a shame that improved efficiency means there will be more lighting
in otherwise dark places, in the future.
--
http://www.thisreallyismyhost.99k.org/012010091939016583.php
Martin Brown
> pete:
>
>> I've just been reading a rather depressing article in The Economist
>> ( http://www.economist.com/node/16886228 ). It's about how more
>> efficient lighting could smply have the effect of increasing the
>> amount of light we produce - rather than the intended consequence
>> of reducig energy consumption.
>> If the predictions in the article (light output to increase 10-fold
>> by 2030) come true, it could have dire consequences for astronomy
>> both at the amateur and professional level.
>
> I would have rephrased the subject based on my own somewhat cynical
> view: "A bright future for light pollution, a bleak future for
> astronomy."
>
> One respondent noted improved street lighting. I'm happy for him. Anne
> Arundel County, MD, has decided that "old-fashioned" fixtures that
> throw all of their light and glare horizontally and upward are really
> cute for roundabouts and other public places where motorists and others
> need to be blinded at night, without regard to what the purpose of the
> lamps ought to be.
You can have old fashioned looking fixtures that are still full cutoff.
There is no-one to see the light that goes skywards so it may as well be
directed downwards. Some modern designs use Fresnel optics in the glass
panes - which works OK until sufficient dead moths accumulate in them.
>
> I am utterly pessimistic about the future of intelligent use of
> lighting, and not just in my county. Raise the issue with
> politicians--at any level--and 99 percent of them look at you like
> you're crazy. "With all the other problems we have, our streetlights
> aren't right, and you want us to spend money to do something about
> that?" Not gonna happen. The national and world situation will get
> worse and worse. Just wait 'til rural China is electrified and you'll
> see what I mean. Think they're going to go for smart fixtures?
Rural China and Japan are places where I expect respect for nature and a
pressing need for energy efficiency to influence their choice of
lighting fixtures. Where I lived in suburban Japan there were no street
lights on some of the outer city roads. Isolated roadside Pachinko
parlours were pretty amazing sources of light pollution though!
They were early adopted of fluorescent lighting for domestic use and
CFLs are mass produced both for domestic and export markets.
Regards,
Martin Brown
David M
"Martin Brown" <|||newspam|||@nezumi.demon.co.uk> wrote:
> Observatories around San Diego will soon be blinded by new improved LED
> lighting. They are resigned to their fate. The local lighting engineers
> do not seem to have grasped that it was the very narrowband emission of
> NaD that is easily filtered and not the "yellowness" of the light.
Do you happen to sell such filters? :-P
Chris.B
media.
How about?
The only advantage of dumb lighting is being able to read porno mags
while driving.
Or, the only advantage of dumb lighting is being able to easily
identify kerb crawlers.
Or, the only advantage of dumb lighting is being able to recognise
that the girl in the mayor's limo may well be under the age of
consent.
Or, the only advantage of dumb lighting is giving drug pushers plenty
of warning that a cop car is approaching from over two blocks away.
Or, the only advantage of dumb lighting is that it blinds the public
to the activities of the vast fleet of the alien invasion forces at
night. 8<|
"Read all about it!" "Politicians sell out to alien invasion force by
deliberately installing dumb lighting!"
"Professor Hawking warns of Alien Invasion!" "Blames dumb lighting for
them finding us!" "Read all about it!" :-)
Davoud
> > One respondent noted improved street lighting. I'm happy for him. Anne
> > Arundel County, MD, has decided that "old-fashioned" fixtures that
> > throw all of their light and glare horizontally and upward are really
> > cute for roundabouts and other public places where motorists and others
> > need to be blinded at night, without regard to what the purpose of the
> > lamps ought to be.
Martin Brown:
> You can have old fashioned looking fixtures that are still full cutoff.
> There is no-one to see the light that goes skywards so it may as well be
> directed downwards. Some modern designs use Fresnel optics in the glass
> panes - which works OK until sufficient dead moths accumulate in them.
Heloo-oo! Are you preaching to me, a member of the choir? I'm not the
one who installed the fixtures--I'm the one who removed all outdoor
lighting from his home. And there is no use trying to preach to those
who like those cutesy fixtures. "But they look like antiques." "They do
not look like antiques, you fucking idiot. They look like they belong
in a /Schutzstreifen/ ."
> > I am utterly pessimistic about the future of intelligent use of
> > lighting, and not just in my county. Raise the issue with
> > politicians--at any level--and 99 percent of them look at you like
> > you're crazy. "With all the other problems we have, our streetlights
> > aren't right, and you want us to spend money to do something about
> > that?" Not gonna happen. The national and world situation will get
> > worse and worse. Just wait 'til rural China is electrified and you'll
> > see what I mean. Think they're going to go for smart fixtures?
> Rural China and Japan are places where I expect respect for nature and a
> pressing need for energy efficiency to influence their choice of
> lighting fixtures.
Get real. The Japan you lived in put conversation and respect for
nature above commercial interests? That was an alternate Japan, not
found in this Universe. Japan is more likely to install whale-oil lamps
than modern shielded fixtures. Respect for nature in China? Maybe in
some of esoteric little cult that the government is trying to
eradicate, but it's the People's Government that controls public works.
Their environmental record is not sterling.
lal_truckee
Almost everybody does.
<http://www.telescope.com/control/accessories/telescope-and-eyepiece-filters/ultrablock-narrowband-light-pollution-telescope-filters>
Or were you being smarmy?
Brad Guth
> pete:
>
> > I've just been reading a rather depressing article in The Economist
In a few more years (possibly a decade) China will have added a
terawatt of efficient street and outdoor area lighting. Commercial
aviation currently contributes several gigawatts that does nothing
except illuminate the atmosphere.
~ BG
Martin Brown
> On 9/2/10 5:39 AM, David M wrote:
>> "Martin Brown"<|||newspam|||@nezumi.demon.co.uk> wrote:
>>
>>> Observatories around San Diego will soon be blinded by new improved LED
>>> lighting. They are resigned to their fate. The local lighting engineers
>>> do not seem to have grasped that it was the very narrowband emission of
>>> NaD that is easily filtered and not the "yellowness" of the light.
>>
>> Do you happen to sell such filters? :-P
YES :-)
>
> Almost everybody does.
> <http://www.telescope.com/control/accessories/telescope-and-eyepiece-filters/ultrablock-narrowband-light-pollution-telescope-filters>
>
The filters you refer to above are narrowband emission line isolating
filters. That isn't quite the same as a broadband light pollution filter
or as is possible uniquely with low pressure sodium a notch reject
filter. Serendipity allows a relatively cheap anti-sodium notch filter
to be made with neodymium doped glass - glass blowers use it to see into
the sodium flare when working hot glass.
It is to all intents and purposes a minus-yellow filter. This has the
effect visually of creating out of gamut colours in the brain since our
eyes RGB sensitivity is actually from YGB sensors and some clever post
processing. You get to see colours redder than red and greener than
green through the filter as the brain struggles with novel inputs.
>
> Or were you being smarmy?
No. I usually remember to point out my commercial interest. A sideline
started because I wanted one and there was a minimum batch size.
http://www.nezumi.demon.co.uk/nonad/nonad.htm
I think he was commenting on the fact that I sell a NoNaD filter that
blocks the sodium D-line and not much else. It is only really useful
photographically in the right environment of LPS light. Low pressure
sodium lights in full cutoff fixtures are mandated around world class
observatories. Some UK amateurs use them for photography in mostly LPS
environments. Cutting the sodium line by a factor of 200x or so makes
sky fog less and allows longer exposures in semi-urban environments.
Baader neodymium is another filter in the same vein. They make rather
more grandiose claims for its efficacy than I do.
Unfortunately most new street lights in the UK are now HPS.
For visual observing the Orion Optics UK sodium light filter is best and
works for both HPS and LPS streetlamps. It is way better than the US
branded products that target predominantly mercury lights.
http://www.orionoptics.co.uk/ACCESSORIES/filterspage.html
Regards,
Martin Brown
Bob Myers
>
>
> It is to all intents and purposes a minus-yellow filter. This has the
> effect visually of creating out of gamut colours in the brain since
> our eyes RGB sensitivity is actually from YGB sensors and some clever
> post processing. You get to see colours redder than red and greener
> than green through the filter as the brain struggles with novel inputs.
In a word, no - I don't think that's quite right. The color receptors
in the eye (the three types of "cone" cells) are in no way themselves
narrowband receptors that could be characterized as either "RGB" or
"YGB". They are more accurately referred to as the "short," "medium,"
and "long" receptors (re where their peak sensitivities show up in terms
of wavelength), and while the "long" receptor does peak somewhere close
to 575 nm (which is quite "yellowish"), it has a pretty broad overall
response curve which covers almost the entire visible spectrum.
Notching out yellow from a given light source will certainly change the
perception of any given object or the source itself, but it doesn't
somehow magically create colors outside the range of normal human
vision. An observed object will certainly appear differently-colored
than it would without the filter, IF the object's emitted or reflected
light has significant content in the range notched out by the filter,
but then that is true of ANY sort of notch filter you'd insert into the
optical path. It's not really a "novel input" situation, just a
different spectral distribution than would otherwise be the case. We
don't, for example, get to see novel colors from, say, an RGB LED-lit
LCD monitor just because there is basically nothing going on in the
yellow wavelengths.
And while "redder than red" might have some meaning (I would have to
assume it would mean seeing "colors" which are normally in the
near-infrared range), I have no idea what "greener than green" might mean.
Bob M.
Martin Brown
> On 9/2/2010 1:37 PM, Martin Brown wrote:
>>
>>
>> It is to all intents and purposes a minus-yellow filter. This has the
>> effect visually of creating out of gamut colours in the brain since
>> our eyes RGB sensitivity is actually from YGB sensors and some clever
>> post processing. You get to see colours redder than red and greener
>> than green through the filter as the brain struggles with novel inputs.
>
> In a word, no - I don't think that's quite right. The color receptors in
> the eye (the three types of "cone" cells) are in no way themselves
> narrowband receptors that could be characterized as either "RGB" or
> "YGB". They are more accurately referred to as the "short," "medium,"
> and "long" receptors (re where their peak sensitivities show up in terms
> of wavelength), and while the "long" receptor does peak somewhere close
> to 575 nm (which is quite "yellowish"), it has a pretty broad overall
> response curve which covers almost the entire visible spectrum.
You have obviously never tried it then.
I agree that the cones are best described as short medium and long in
sensitivity. But the short (B) and medium (G) sensors have only a small
overlap whereas the medium (G) and much broader long (Y) sensors are
almost totally overlapping in their shortwave spectral response curve.
The red channel is computed as Y-G in the brain.
http://en.wikipedia.org/wiki/Spectral_sensitivity
The other strange feature of the glass is that its apparent colour is
dichromic and strongly dependent on the colour temperature and character
of the incident radiation. Grey or pink in daylight and green in
fluorescent light. It would be useful as a pink or amethyst glass colour
if it didn't change colour depending on the light.
I am not the only one to have noticed this. Glassblowers have known
about it since didymium was isolated from the rare earths and used to
colour glass. And before chemistry was advanced enough to split out
neodymium. Hence the usage in the glass industry of dydimium glass.
Blocking sodium flare and UV is very useful for hot glass work. A
derivative has found its way into the consumer market as ACE tinted
glass designed to improve colour perception (and claimed by some to help
with dyslexia).
> Notching
> out yellow from a given light source will certainly change the
> perception of any given object or the source itself, but it doesn't
> somehow magically create colors outside the range of normal human
> vision. An observed object will certainly appear differently-colored
> than it would without the filter, IF the object's emitted or reflected
> light has significant content in the range notched out by the filter,
> but then that is true of ANY sort of notch filter you'd insert into the
> optical path. It's not really a "novel input" situation, just a
> different spectral distribution than would otherwise be the case. We
> don't, for example, get to see novel colors from, say, an RGB LED-lit
> LCD monitor just because there is basically nothing going on in the
> yellow wavelengths.
There is considerable overlap between the spectral response of the green
cones and the nominally "red" ones which are truly a very broad yellow
mostly overlapping green. Since the red channel is computed in the brain
from these two signals it isn't too surprising that the perception of
some colours are seriously altered by this glass.
>
> And while "redder than red" might have some meaning (I would have to
> assume it would mean seeing "colors" which are normally in the
> near-infrared range), I have no idea what "greener than green" might mean.
No it means seeing some colours that appear strangely luminous and over
saturated for want of a better description. A bit like the effect you
see on red fire engines with dayglo paint on the front but with a much
deeper red. And the same in the green but to a lesser extent. Only
objects with the right pigmentation are significantly affected - book
covers provide a decent range of different dyes and pigments to try.
The filters have some popularity in the photographic industry for making
postcard images more punchy particularly in fall. eg
http://www.bhphotovideo.com/c/product/142161-REG/Hoya_017321_58mm_Enhancing_Intensifier_Glass.html
Sort of shows what I mean. You actually have to see it first hand to
understand what it looks like. Words are not very good for describing
perception of colour - particularly in uncommon situations like this.
Regards,
Martin Brown
Chris.B
glasses. Many colours are accentuated. To the extent that the desire
to get the camera out to capture the wonderful landscape or a flower
garden is suddenly damped upon removal of the glasses. Colours on
steroids without the dangers of drug taking. Or the effect of using
35mm Kodak film instead of Fuji. ;-)
Chris L Peterson
<|||newspam|||@nezumi.demon.co.uk> wrote:
>Observatories around San Diego will soon be blinded by new improved LED
>lighting...
Maybe, maybe not. In fact, much of the existing lighting is not LPS,
which is the only lighting fairly easily filtered. LED lights have a
huge advantage over other lighting in that it can be dimmed. If this
feature is taken advantage of, and the new lighting is well shielded,
there may be no loss at all. Also, it remains to be seen what sort of
LED technology will win out. Not all "white" LED sources used for
general illumination are broadband.
In any case, ground-based observatories are increasingly being used for
very high resolution, very narrow FOV work, which is much less sensitive
to light pollution than wide field work (which is increasingly the
domain of space telescopes).
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
palsing
>...LED lights have a
> huge advantage over other lighting in that it can be dimmed. If this
> feature is taken advantage of, and the new lighting is well shielded,
> there may be no loss at all.
San Jose, Ca. is replacing all of its street lighting with dimmable
LED's, and there is even talk of enabling Lick Observatory with the
ability to control the dimming after midnight.
\Paul A
Bob Myers
> On 03/09/2010 00:25, Bob Myers wrote:
>> On 9/2/2010 1:37 PM, Martin Brown wrote:
>>>
>>>
>>> It is to all intents and purposes a minus-yellow filter. This has the
>>> effect visually of creating out of gamut colours in the brain since
>>> our eyes RGB sensitivity is actually from YGB sensors and some clever
>>> post processing. You get to see colours redder than red and greener
>>> than green through the filter as the brain struggles with novel inputs.
>>
>> In a word, no - I don't think that's quite right. The color receptors in
>> the eye (the three types of "cone" cells) are in no way themselves
>> narrowband receptors that could be characterized as either "RGB" or
>> "YGB". They are more accurately referred to as the "short," "medium,"
>> and "long" receptors (re where their peak sensitivities show up in terms
>> of wavelength), and while the "long" receptor does peak somewhere close
>> to 575 nm (which is quite "yellowish"), it has a pretty broad overall
>> response curve which covers almost the entire visible spectrum.
>
> You have obviously never tried it then.
Actually, I have; I'm not disagreeing with the reported effect, just the
explanation for it. In particular, what you are seeing is not the
creation of "out of gamut" (presumably, referring to the normal color
range of human vision) colors. It is certainly an effect which shows an
alteration in perceived colors, but there's no creation of "new" colors
somehow.
Bob M.