Dark Skies: State of the Science 2022
Advocating for Sufficient and Sensible Lighting
The story of light pollution is about understanding change in the natural order. We humans and the entire natural kingdom have evolved on a spinning planet that segues, as Louis Armstrong noted, from "the bright blessed day (to) the dark sacred night." Errant and excessive light seriously impinges on that delicate balance.
I regularly advocate for dark skies, and convey that message through my Blog. Emerging scientific research is revealing a new understanding of how our bodies respond to light and darkness. The story is no longer just about astronomy.
Results from some community sky surveys I have conducted using Sky Quality Meters (SQMs) are at nightwise.org/sqm.
See the report
Artificial Light at Night: State of the Science 2022
By International Dark-Sky Association (IDA)
See my 100+ actions to inspire better lighting practices and to lessen your impact on the nighttime environment.
St. Joseph County, IN
Measurements of the SJC night sky--using visual and instrument observations-- are compiled in part at nightwise.org/sqm.
Two articles summarize some important issues related to lights at night.
The first article is Seeing Blue, a summary by the International Dark-Sky Association (IDA) that notes how blue-rich light coincides with the peak sensitive region of the human circadian system.
The second article is Human and Environmental Effects of Light Emitting Diode (LED) Community Lighting by the American Medical Association. In responding to breast cancer research in particular, the report recommends the "AMA encourage the use of 3000K or lower lighting for outdoor installations such as roadways. All LED lighting should be properly shielded to minimize glare and detrimental human and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods."
The purpose of outdoor lighting is to see better. However, blue-rich light scatters within the eyeball, so the light effectively blinds you rather than serves you. This negative effect is amplified for older eyes as proteins build up over the years.
One of the reasons this website's design is so red relates directly to the need to get away from bluer light waves at night. Unfortunately, a peak in blue is one of the shortcomings of the otherwise promising LED light. The IDA recommends you only buy LED lights that are under 3000K (see the label or packaging). Currently outdoor lights rated 2700K are the preferred temperature that is readily available commercially, though purveyors may try to unload lighting stock that has higher temperature ratings.
To lessen the blue light to which you are exposed through computers, cell phones, and other digital media, consider an app that automatically shifts the color output to "warmer" colors instead of the harsh blues. You can always override the app if you seek full color. From the IDA website:
F.lux is available for Mac OS/X, Windows, Linx, iPhones and iPads
Twilight is available for smartphones or tablets
iPhones now come with Nightshift, and other apps are available for Androids
If you are purchasing LED light bulbs, look on the label and only choose those which are no higher than 3000K, which is an indicaton of temperature. The greater the number, the bluer the color.
See blog posts that are tagged "dark skies."
The Original Nightwise.org
The original Nightwise website was a collection of material that supported dark sky awareness and student projects. Excerpts are at the Original Nightwise page, and four projects are included below.
Let There Be Night is a combined planetarium program and school district-wide experiment to assess a community's sky glow. Developed for IYA2009 with contributions from Toyota and other supporters, the experiment parallels the Globe at Night initiative. The planetarium program and DVD resources are available to prepare the teachers and students, who will assess sky glow from within the school district boundaries. See the Results from one community's vast experiment in 2009, in which teams of students made a 3-D model out of 35,000 LEGO blocks to convey visually how much of the local night sky has been lost to light pollution.
Night Vision is a NASA-supported program in which observers quantify the sky glow over their community. Families and teams use hand-held Sky Quality Meters (SQMs) to measure the the amount of light reflected back down to earth from multiple sites. They will manually plot the SQM readings on a county map and create "contour lines" of equal brightness. The baseline map can be used in the future to suggest changes in the local light pollution level. After discussing the trade-offs of lighting technology and the social decisions related to outdoor lighting, participants will report their findings to the community through self-designed presentations.
For a science project named Sorry Starry Night, a student measured the sky glow from seven sites adjacent to a new retail development. From March to December, 2006, she plotted a downward slope of Sky Quality Meter (SQM) readings, which suggested the sky glow increased. The student attributed the increase to new lights from the development, additional reflectance from snow on the ground in the latter portion of the experiment, and holiday lights in the neighborhood.
How can you convey the impact of glare and the benefits of light shields? Try this simple experiment--so easy it was borrowed from an 8-year old. (Reproduced from Paper Plate Education, http://analyzer.depaul.edu/paperplate/lights.htm).