This project is supervised by Dr Robert Harris, Centre for Advanced Instrumentation (Physics), Durham University.
Research and Background
According to the World Atlas of Light Pollution, the skies above the largest cities in the UK can be up to 50 times brighter than a natural, unpolluted dark sky. The cause of this is ALAN, or Artificial Light at Night. This is a crucial sustainability issue which I believe is not discussed enough.
The wide-ranging negative effects of ALAN include habitat disruption to nocturnal animals, and disruption of both human and animal circadian rhythms which is linked to health problems such as depression and reduced immune function. As well as this, reduced night sky visibility is problematic for both professional and amateur astronomers.
While most of England has transitioned to LED street lighting, which is less harmful than mercury or high-pressure sodium lamps, there is still a long way to go. I aim to investigate LED sources to find an optimum model streetlamp to reduce glare, light dispersion, and upward flux, which is light escaping upwards into the atmosphere- when this reflects from atmospheric particles, it contributes greatly to ALAN by obscuring dark sky features.
Methodology
My project will take place in two parts:
Part 1: Modelling LED Streetlamps
Research aim: To find a model for an ideal LED lamp with minimal contribution to light pollution.
An illuminance meter will be used to measure the lux of different LED sources. I have chosen to measure lux as it adjusts for the human eye's perception of different wavelengths, which is crucial in understanding visual light pollution. Lux will be measured for the following variables: a) the peak wavelength of the source, b) the shapes of model hoods placed over the lamp, and c) distance from the source. Analysis of the results using graphical methods and a scoring system will be used to form the model for an ideal LED based on these variables.
Part 2: The Importance of Public Participation
Research aim: To investigate how raising awareness in members of the public about light pollution can alter perception of it as an important sustainability issue.
I will work with a group of 12-16 local volunteers, who will first be asked to complete a survey about their knowledge and opinions regarding light pollution and other sustainability issues. The survey answers will use the Likert system, which allows for data analysis using statistical hypothesis tests. In the darkened lab, the volunteers will be shown a projected image of an unpolluted night sky and asked to record how visibly obscured it becomes when each LED source used in Part 1 is placed in front of it- this is a small-scale visual simulation of light pollution. After this demonstration, they will be asked to complete the same survey once more, to gauge any changes in opinion. Qualitative analysis of the survey answers will show how effective this participation was as a method for raising awareness about light pollution, and will suggest how important this is on a wider scale.
Predicted Impact
I hope that my LED streetlamp model can be used as a reference or suggestion for future engineering projects or street lighting replacements, as well as creating interest for larger-scale research. Besides raising awareness in the volunteer participants, I hope my survey research can demonstrate the importance of involving the public with sustainability issues, and pave the way for significant changes if larger-scale, nationwide surveys are carried out.