To Our Children...
the Stars

Information and advice for countering light pollution

Let There be Dark

"Not to spend time under the stars is as cruel a dispossession as not to spend days in the open countryside."

(Daily Telegraph, 18 February 1992)

As we move into the 21st century, a valuable and beautiful part of our heritage is being taken away from us. For the first time in history, vast numbers of the human population are being denied a view of the night sky by poorly designed and badly aimed lighting of various kinds. Urban sky glow now pollutes nearly all of Britain's night skies. Is there any hope of regaining natures grandest free show? How can astronomers educate and campaign for a return to the dark skies of the past?

What is light Pollution?

Light Pollution is the popular name for sky glow - a brightening of the night sky caused by the scattering of artificial light by aerosol particles (e.g. water droplets) and dust in the air.

What Causes it?

Artificial light gets up into the sky in two ways. By far the greater proportion of this upward light arises because the design or installation of many light fittings allows a significant fraction of the light produced to be emitted above the horizontal, so it goes up into the sky. This is the direct upward light. A much smaller proportion is light that is reflected upwards from roads, pavements and buildings. This is the indirect upward light.

Saving the Stars

Find out about different kinds of lights. How do they cause light pollution? Look for good and bad designs. Praise and publicise individuals, councils and organisations using well-designed, well-aimed light fittings, shielded floodlights, and sensor-switched security lights.

Complain politely about poor quality lighting, making sure you have the facts to back up your arguments, condemning badly designed, poorly installed and intrusive fixtures. More importantly, go to the root of the problem and try to influence county and city lighting engineers, conservation officers, manufacturers, planners, architects and builders - those who make, choose and install lighting.

Our arguments against Light Pollution are:

• The massive waste of energy and fossil fuels caused by poorly designed street and external amenity lighting which, in many cases, sends 30 per cent of the light above the horizontal - more than 50 per cent in the case of some globe lights. Light reflected from the ground and buildings contributes little to sky glow compared with that coming directly from the light fittings themselves. Re-directing all the wasted energy will save money and help the environment.
  
  
• Glare and over-lighting: It is noticeably more comfortable to drive at night with the sun visor down, as many light fittings create so much sideways glare. A good light should be well-directed and almost invisible from a distance. Flat glass, full cut-off fittings, if correctly installed, emit no light above the horizontal.
  
  
• The wastefulness of all-night shop, advertising and display lighting, building illumination, upward floodlighting and permanent domestic and industrial security lights, both in terms of the energy they consume and the vast amounts of greenhouse gases produced. There is little point in leaving most shop advertising and display lights and floodlights on after 11 o'clock at night.
  
  
• The right of the individual to pursue legitimate interests and to be able to appreciate the natural environment.

Promote the Facts

Some people say...

"You can't have to much light"

Glare, energy waste, environmental damage, and the wasting of taxpayers' money are the result of over-lighting and poor lighting policy.

"But astronomers are in the minority"

Everybody should have the right to see the stars, an important part of our total environment and culture. Astronomy is now taught in our schools as part of the National Curriculum and as a separate GCSE subject. Young people should be able to undertake projects work and appreciate the wonder of the Universe at first hand. The BAA Campaign for Dark Skies is NOT just for the benefit of astronomers.

"We can't get rid of all the street lights"

Of course not! Astronomers have the same lighting needs as everyone else. We all need good quality, well-directed street and amenity lighting which serves the needs of the community, saves money and preserves the darkness of the night sky for our descendants. Everybody wins.

"More Light Less Crime."

There is contradictory evidence for and against this. Crime rates have soared as street lighting and security lamps have proliferated. Interviews with 300 burglars (ref. Home Office Crime Prevention Unit. Papers 28 and 29) indicated that lack of occupants and risk-taking were the greatest stimuli to commit a crime, while the absence or presence of light was unimportant. Bright, poorly positioned, misdirected lights may well assist wrongdoers by creating deeply shadowed areas and glare which dazzles passers by. Fear of crime may well be reduced by exterior lighting. For astronomers, good security lights are well-aimed, shine only downwards and are passive, infra-red sensor-triggered fixtures (retaining an element of surprise to deter would-be intruders).

"I have never really looked at the stars. You can't see much from the town. What you've never seen you do not miss, so why bother?"

Most of us have never seen a whale, and have no urgent desire to go and find one. Does this mean that such beautiful creatures should therefore be exterminated? Everybody has the right to experience the night sky. The Universe is in a very real sense part of our natural heritage, involving the origin and destiny of the Earth and everything on it.
Important inroads have already been made in tackling the problem of light pollution. Government departments, local, town and county councils, lighting designers, manufacturers, engineers and architects are at last beginning to see the importance of, and need for, quality lighting.

If all those who value the night sky can work together, our children and grand-children will never have to ask us...

"What were the Stars?"