Hounslow Council's 'too bright' street lights...

[JamesF]

It would be interesting to get the council to explain, through an FOI request if necessary, what types of lamp were considered for installation in residential areas and what sort of impact assessment was carried out to determine which might be the most appropriate choice.

The way it is presented in the news (which may not be that close to reality, I admit), makes me wonder if there wasn't something of a knee-jerk reaction to install LED lights to save money and insufficient consideration was given to the design and consequences.

James

[JamesF]

I think there is a case against any council in this kind of situation on health grounds alone - http://thenakedlabel.com/blog/2012/02/16/sleepingindarkness/

I'm not sure I'd suggest using a piece on sleeping in darkness written by a nutritionist as a compelling argument

I appreciate where she's coming from, but I struggle to agree with her assertion that we should ideally sleep in a totally dark environment.  I could be persuaded (fairly easily,. probably) that it's preferable to sleep in an environment that is free of artificial sources of light, but I'm not inclined to believe that we evolved to sleep in total darkness.

The problem with providing good advice in this area is that we're in an artificial situation to start with.  Going to work in an office 9-5 is not exactly natural

James

[Hertford Stargazer]

I'm not sure I'd suggest using a piece on sleeping in darkness written by a nutritionist as a compelling argument

I appreciate where she's coming from, but I struggle to agree with her assertion that we should ideally sleep in a totally dark environment.  I could be persuaded (fairly easily,. probably) that it's preferable to sleep in an environment that is free of artificial sources of light, but I'm not inclined to believe that we evolved to sleep in total darkness.

The problem with providing good advice in this area is that we're in an artificial situation to start with.  Going to work in an office 9-5 is not exactly natural

James

The connection between sleep, melatonin production and darkness has been common knowledge for several years - http://www.britastro.org/dark-skies/health.html 

[sharkmelley]

I appreciate where she's coming from, but I struggle to agree with her assertion that we should ideally sleep in a totally dark environment.

Although trying to sleep with street lamps pouring light into the bedroom is one extreme, sleeping in complete darkness every night of the month is the other extreme - it doesn't seem totally natural.  Humans had to "endure" bright moonlit nights well before artificial light came along.  So one would think our natural bodily rhythms should be able to cope well with moonlight - at least during that part of the lunar month.  Maybe sleep in complete darkness for just part of the month?

Mark

[JamesF]

The connection between sleep, melatonin production and darkness has been common knowledge for several years - http://www.britastro.org/dark-skies/health.html

I'm not disputing that connection at all, but there's no logical path from saying "exposure to artificial light at night is bad" to "no light whatsoever at night is best".  As I said however, I wouldn't take a lot of persuading that exposure to artificial light at night is not a great idea.

James

[Carina Lass]

My ancestors slept in a cave - way back as far as I recall anyhow. They were well known for their melatonin moments.

I sleep in total darkness now - I have shutters on my windows - and I live in the tropics so light is distributed pretty evenly throughout the year (and the moonlight can't get through shutters)

I don't really care what they do with street lights as long as they do away with HPSL. They are s narowband that you can't see anything when it rains - everything is the same colour

[Hertford Stargazer]

I don't agree with the 100% darkness aspect, I think the key thing is the difference between natural and artificial light. Our entire natural rhythm is based around a lunar or monthly cycle, a good example is a womans menstrual cycle which is estrogen related, estrogen is melatonin related and melatonin is light related 

[JamesF]

Although trying to sleep with street lamps pouring light into the bedroom is one extreme, sleeping in complete darkness every night of the month is the other extreme - it doesn't seem totally natural.  Humans had to "endure" bright moonlit nights well before artificial light came along.  So one would think our natural bodily rhythms should be able to cope well with moonlight - at least during that part of the lunar month.  Maybe sleep in complete darkness for just part of the month?

It may well depend on where you are in the world, too.  Here in the southern UK even a cloudless, moonless night is never completely dark, even if you have no LP whatsoever.  My experience is that it's actually darkest when there's very thick cloud.  My suspicion is that we're evolved to be comfortable with (or perhaps even require) varying amounts of light during the night with "very little" at one end of the scale and "bright full Moon" at the other.

James

[JamesF]

I don't agree with the 100% darkness aspect, I think the key thing is the difference between natural and artificial light.

Yes, I think that's likely to be the major issue too.

James

[Bukko]

Running a post on SGL on street lights must be the most difficult game of keepy-uppy going... Nearly two pages done and still going...

On the use of street lights and sleep depravation, I understood the problem was Blue light. There is a receptor in the back of the eye that responds to the loss of Blue light that triggers the production of Melatonin, making us sleepy.

Sodium light does not produce it, but fluorescent does. LED's are the worst; as a green LED is difficult and expensive to make, to produce the white light effect, there is more blue added.

So, on the basis that we need to avoid Blue light (The Moon is not really that bright.. Compare ambient light levels on a full moon to the new street lights) how do other animals adapt? I don't know, as I am not an animal expert, but we are probably messing up the wildlife too.

Did any of the councils do a full environmental study before approval? I spoke to one of our local councillors a while back and he suggested not...

Hmmm...

Gordon.

[DaveS]

"White" LEDs use a powerful BLUE LED and a phosphor to produce the continuum. They are deficient in the cyan region where the Stoke's Gap lies. If you look at the spectrum there's a huge blue spike, then a gap, then the broad continuum. They are also deficient in the far red.

Theatre LEDs are now going to RGB+White and RGB + White + Amber to give good colour rendition. ETC lanterns have up to 7 colours.

[BlueAstra]

This was my 'Battle of the LED Streetlights'!

http://stargazerslounge.com/topic/191067-streetlight-success-story/