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#artificiallight

1 post1 participant0 posts today
Public
Dr. John Barentine FRAS

"From the first traces of the mastery of fire as a light source up to the 'electronic' light of LEDs, we will travel through more than 500,000 years of history of lighting technologies and more particularly over the last 150 years which have ended with the LED revolution."

hal.science/hal-04867347/ (paper in press)

hal.scienceHistory of artificial lighting, from fire to LEDHaving become so present and accessible, artificial light has been forgotten in the same way as the air we breathe. It is obvious and is only noticed by its often-exceptional absence. Its omnipresence is such that it goes to excess, resulting in light pollution, its environmental impact, impact on fauna, flora and even more serious, on human health. But it is also the one that has been an essential driving force in the evolution of humanity. From the first traces of the mastery of fire as a light source up to the "electronic" light of LEDs, we will travel through more than 500,000 years of history of lighting technologies and more particularly over the last 150 years which have ended with the LED revolution.
#History#Lighting#ArtificialLight
Public
DoomsdaysCW

#LightPollution May Harm Our #Ocean’s Water-Filtering ‘#Ecosystem Engineers’

ByAllison Eck
Friday, May 1, 2015

"#SeaSquirts are the ocean’s ecosystem engineers, siphoning #plankton from the water and keeping #CoastalEcosystems healthy. They’ve done their job for millennia relatively unscathed, in part because they have no predators. But now, they have one: #ManmadeLight [#ArtificialLight].

"A new study published in Biology Letters suggests that the artificial light from #cities might prevent the #larvae of some marine species—like sea squirts, #barnacles, and #corals—from finding appropriate habitats to settle in. Without landing on the right substrate, sea squirt larvae have little chance of surviving.

"Thomas Davies, an ecologist at the University of Exeter in the #UK, wanted to see which species are the most affected. He studied the #MenaiStrait, which separates the mainland of northwest #Wales from the island of #Anglesey. This area is largely unaffected by light pollution, which led Davies and his team of experts to suspect that an experiment conducted there would provide a good measure of the effect light pollution has on populations.

"By their measurements, the '#SkyGlow,' or ambient manmade light reflected onto the water by the atmosphere, is at a minimum—it barely amounts to the light emanated from the moon at night.

"To investigate the effect of artificial light on the area, they placed 36 plastic panels into the water and waited to see which organisms would settle on the panels. Some panels were exposed to light from cool, white #LEDs that emitted about the same amount of light produced by #streetlights, while the control panels mimicked just the small amount of ambient light scattered in the sky.

"The team retrieved the panels after 12 weeks to see how much of the panels’ surface area had been colonized. Sea squirts and sea bristles, both filter feeders, had lower colonization rates on the artificial light panels than the controls. On the flip side, #foulers like barnacles ended up clinging to the artificial light panels, which could explain why they so often attached to boat hulls and jetties. Barnacles in particular cost the global economy millions of dollars in reduced fuel economy and cleanup costs.

"Here’s Katie Wheeling, writing for Science: 'Overall, the study found that the lights either encouraged or discouraged settlement in 39% of the taxa, or groups of species, living on the panels by the end of the experiment period. Artificial light may be negatively impacting marine ecosystems by driving away certain invertebrate species, like filter feeders, and attracting others, the team reports.

"'More work needs to be done to understand how brightness, cycle of exposure, and wavelength of light affects individual species. In the future, experts may be able to configure exact spectra that work well with ocean species but also fill our own needs. For now, the team’s complex results indicate that we may need to pay more attention to how manmade light is damaging marine environments.'"

Source:
pbs.org/wgbh/nova/article/ligh

Nova · Light Pollution May Harm Our Ocean’s Water-Filtering ‘Ecosystem Engineers’By Allison Eck
#DarkSkies#Extinction
Public
Dr Sam Morrell

Happy #InternationalDayOfLight! The myriad ways that humans harness light is vital for powering our modern society. As an astrophysicist, I already had an appreciation for the deep understanding of light and how to measure it that underpins the entirety of the subject. My recent research on #artificiallight and its #ecological impacts have given me a further respect for lights role mediating our ecosystems.

Find out a bit more about the International Day of Light:
lightday.org/about

Public
Dr. John Barentine FRAS

"A second piece of legislation, the Dark Skies Protection Act, S.7663/A5632 would significantly reduce #LightPollution in #NewYork by requiring most non-essential outdoor #lighting be covered by an external shield, be motion-activated, or be turned off between 11 PM and 5 AM. ... The Dark Skies Act will help create a safer environment for #birds by reducing the #ArtificialLight in our night skies."

nysenate.gov/newsroom/press-re

NYSenate.govLegislators, Advocates Rename Statewide Bird Safe Buildings Act the “FLACO Act”NEW YORK — Today, in the wake of the untimely death of Flaco, the Eurasion eagle-owl that captured the hearts and minds of New Yorkers upon escaping from the Central Park Zoo after an individual vandalized his enclosure, New York State Senator Brad Hoylman-Sigal (D/WFP-Manhattan) and Assembly Member Anna Kelles, along with New York City Audubon and Audubon New York (the state office of National Audubon Society), are announcing a renewed push for two pieces of legislation that will make the skies safer for birds.
#UnitedStates#LightingPolicy#ALAN
Public
Dr. John Barentine FRAS

🤔 "The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has identified a lack of consensus among public health officials regarding whether short wavelength light (SWL) from artificial sources disrupts circadian rhythm, and if so, whether SWL-disrupted circadian rhythm is associated with adverse health outcomes."

journals.lww.com/health-physic

LWWICNIRP Statement on Short Wavelength Light Exposure from... : Health Physicse., 555 nm). Some experimental studies have demonstrated effects on the circadian timing system and on sleep from SWL exposure, especially when SWL exposure occurs in the evening or at night. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has identified a lack of consensus among public health officials regarding whether SWL from artificial sources disrupts circadian rhythm, and if so, whether SWL-disrupted circadian rhythm is associated with adverse health outcomes. Systematic reviews of studies designed to examine the effects of SWL on sleep and human health have shown conflicting results. There are many variables that can affect the outcome of these experimental studies. One of the main problems in earlier studies was the use of photometric quantities as a surrogate for SWL exposure. Additionally, the measurement of ambient light may not be an accurate measure of the amount of light impinging on the intrinsically photosensitive retinal ganglion cells, which are now known to play a major role in the human circadian timing system. Furthermore, epidemiological studies of long-term effects of chronic SWL exposure per se on human health are lacking. ICNIRP recommends that an analysis of data gaps be performed to delineate the types of studies needed, the parameters that should be addressed, and the methodology that should be applied in future studies so that a decision about the need for exposure guidelines can be made. In the meantime, ICNIRP supports some recommendations for how the quality of future studies might be improved....
#HumanHealth#ArtificialLight#CircadianRhythm
Public *
Raul Cerveira Lima

Another excellent article by Paul Marchant and Paul Norman, demonstrating the non-detection of road (and criminal) safety benefits of road lighting nor in the recent replacements from sodium #HPS to #LED (in particular, #whiteLED ). It questions the high public investment in road lighting when that supposed benefit is not verified, & recalls the impacts of #artificiallight at night.
academic.oup.com/jrssig/articl

OUP AcademicIn the best light? Road safety and public spendingAbstract. How do different types of street light affect road safety? Paul Marchant and Paul Norman call for more rigorous statistical work to be carried out bef
#poluiçãoluminosa#lightpollution
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