tingilinde

light pollution

Only 80% of North Americans can see the Milky Way. (five year old study - probably worse now)

 

The new world atlas of artificial night sky brightness

 

Fabio Falchi,1* Pierantonio Cinzano,1 Dan Duriscoe,2 Christopher C. M. Kyba,3,4 Christopher D. Elvidge,5 Kimberly Baugh,6 Boris A. Portnov,7 Nataliya A. Rybnikova,7 Riccardo Furgoni1,8

Artificial lights raise night sky luminance, creating the most visible effect of light pollution—artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world’s land surfaces between 75°N and 60°S, 88% of Europe, and almost half of the United States experience light- polluted nights.

INTRODUCTION
Light pollution is the alteration of night natural lighting levels caused by anthropogenic sources of light (1). Natural lighting levels are governed by natural celestial sources, mainly the Moon, natural atmospheric emission (airglow), the stars and the Milky Way, and zodiacal light. During moonless nights, the luminance of the clear sky background far from the Milky Way and zodiacal light is about 22 magnitude per square arcsecond (mag/arcsec2) in the Johnson-Cousins V-band (2), equivalent to 1.7 × 10−4 cd/m2. Artificial light scattered in the atmo- sphere raises night sky luminance, creating the most visible negative effect of light pollution—artificial skyglow. In addition to hindering ground- based optical astronomical observations, the artificial brightening of the night sky represents a profound alteration of a fundamental human experience—the opportunity for each person to view and ponder the night sky. Even small increases in sky brightness degrade this experience. Light pollution is no longer only a matter for professional astronomers (3, 4). Although researchers from disparate fields are now interested in light pollution, its magnitude is poorly known on a global scale because mea- surements are sporadically distributed across the globe. To overcome this, we present the world atlas of artificial sky luminance, which was obtained with our dedicated light pollution propagation software using the new calibrated, high–dynamic range, high-resolution data from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB), new precision charge-coupled device (CCD) brightness measure- ments, and a new database of Sky Quality Meter (SQM) measurements.

Light pollution is one of the most pervasive forms of environmental alteration (5). It affects even otherwise pristine sites because it is easily observed during the night hundreds of kilometres from its source in landscapes that seem untouched by humans during the day (6), damaging the nighttime landscapes even in protected areas, such as national parks (for example, the light domes of Las Vegas and Los Angeles as seen from Death Valley National Park). Notwithstanding its global presence, light pollution has received relatively little attention from environmental scientists in the past. This is changing, as attested by the rapidly increasing rate of published works on the subject.

The atlas we present here is intended to help researchers in all fields who may be interested in the levels of light pollution for their studies (for example, in astronomy, ecology, environmental protection, and economics).

 

 

what if the entire tropics were reforested?

Not the climate win some expect.  

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The reason is that other parts of the Earth system counteract the effect of the new tree growth. If the tropics were reforested, our model predicts that the oceans, soil and vegetation would absorb less carbon dioxide. By the end of the century, tropical trees would take up an extra 124 billion tonnes of carbon (or 124 gigatonnes, Gt), but tropical soils would take up 83 Gt less carbon, as the turnover of dead plants is much slower in forests compared with grasses and crops that die annually, meaning lower carbon inputs in forest soils and lower carbon storage.

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We need to stop emitting green house gases.

 

 

"glacier blood"

I've seen this in Montana and in Yoho Park in Canada - we called it pink snow.

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Eric Maréchal, a coordinator at the ALPALGA project, told Live Science that people who frequent the Alps are seeing more red snow, and he recalled eyeing huge swaths of “glacier blood” on a 2019 hike. “Everywhere I put my eyes, it was red,” he said. “We walked all day, seeing surfaces stained in red.”

Scientists believe that rising levels of carbon dioxide may be fueling the growth of the photosynthesizing snow-borne microalgae. Likewise, changes in wind and snowfall may be delivering additional nutrients to algae, leading to the spread of “glacier blood.” However, researchers have yet to quantify changes in algae over time.

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what can possibly go wrong

Drought in the West

 

 

from herring to smelt

An antifreeze gene keeps them from freezing, but how did it move across species?  After all, horizontal DNA transfer isn't possible in vertebrates...

Or is it?

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It isn’t surprising, then, that herrings and smelts, two groups of fish that commonly roam the northernmost reaches of the Atlantic and Pacific Oceans, both make AFPs. But it is very surprising, even weird, that both fish do so with the same AFP gene — particularly since their ancestors diverged more than 250 million years ago and the gene is absent from all the other fish species related to them.

A March paper in Trends in Genetics holds the unorthodox explanation: The gene became part of the smelt genome through a direct horizontal transfer from a herring. It wasn’t through hybridization, because herring and smelt can’t crossbreed, as many failed attempts have shown. The herring gene made its way into the smelt genome outside the normal sexual channels.

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what happens if you crash your car into breakfast cereal

C'mon .. you really want to know, don't you?

 

early color photography

I was away of early three exposure color photography and that Gabriel Lippman won the Nobel Prize in Physics for his work in color photography, but I had no idea how novel his approach was.

the relevant paper

 

Shedding light on 19th century spectra by analyzing Lippmann photography

Gilles Baechler, Arnaud Latty, Michalina Pacholska , Martin Vetterli , and Adam Scholefield

Significance

Gabriel Lippmann won the 1908 Nobel Prize in Physics for his method of reproducing colors in photography. Despite the significance of this result, there are still misconceptions regarding the approach. We provide a complete end-to-end analysis of the process and show, both theoretically and experimentally, how the spectrum reflected from a Lippmann plate is not the same as the exposing spectrum. In addition, we demonstrate that, given the spectrum reflected from a Lippmann plate, together with the plate’s color absorption properties, the original exposing spectrum can be algorithmically recovered.

Abstract

From uncovering the structure of the atom to the nature of the universe, spectral measurements have helped some of science’s greatest discoveries. While pointwise spectral measurements date back to Newton, it is commonly thought that hyperspectral images originated in the 1970s. However, the first hyperspectral images are over a century old and are locked in the safes of a handful of museums. These hidden treasures are examples of the first color photographs and earned their inventor, Gabriel Lippmann, the 1908 Nobel Prize in Physics. Since the original work of Lippmann, the process has been predominately understood from the monochromatic perspective, with analogies drawn to Bragg gratings, and the polychromatic case treated as a simple extension. As a consequence, there are misconceptions about the invertibility of the Lippmann process. We show that the multispectral image reflected from a Lippmann plate contains distortions that are not explained by current models. We describe these distortions by directly modeling the process for general spectra and devise an algorithm to recover the original spectra. This results in a complete analysis of the Lippmann process. Finally, we demonstrate the accuracy of our recovery algorithm on self-made Lippmann plates, for which the acquisition setup is fully understood. However, we show that, in the case of historical plates, there are too many unknowns to reliably recover 19th century spectra of natural scenes.

 

 

 

modern code-talking

Astrophysics into Blackfoot.

a few examples

 

suction feeding by elephants

It looks like interesting work, plus I'll hazard a guess that it will catch the attention of the IgNobel Prize committee.

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An elephant eats about 400 pounds of food a day, but very little is known about how they use their trunks to pick up lightweight food and water for 18 hours, every day," said Georgia Tech mechanical engineering Ph.D. student Andrew Schulz, who led the study. "It turns out their trunks act like suitcases, capable of expanding when necessary."

Schulz and the Georgia Tech team worked with veterinarians at Zoo Atlanta, studying elephants as they ate various foods. For large rutabaga cubes, for example, the animal grabbed and collected them. It sucked up smaller cubes and made a loud vacuuming sound, or the sound of a person slurping noodles, before transferring the vegetables to its mouth.

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forecasting eruptions

Fascinating piece on volcanos.

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Increasingly intense tectonic earthquakes had been rumbling beneath Iceland’s Reykjanes Peninsula since late 2019, strongly implying that the underworld was opening up, making space for magma to ascend. Early in 2021, as a subterranean serpent of magma migrated around the peninsula, looking for an escape hatch to the surface, the ground itself began to change shape. Then in mid-March, the first fissure of several snaked through the earth roughly where scientists expected it might, spilling lava into an uninhabited valley named Geldingadalur.

Here, locals immediately flocked to the eruption, picnicking and posing for selfies a literal stone’s throw away from the lava flows. A concert recently took place there, with people treating the ridges like the seats of an amphitheater.

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