Artificial Light Pollution On The Rise Globally, LEDs Might Be Making It Worse

City lights drive back the night a little more each year, disrupting ecological cycles. Now, energy-efficient lights could be making light pollution worse.

Earth's total artificial light at night brightened by at least 2.2 percent each year from 2012 to 2016, most notably in South America, Africa and Asia, according to satellite research published in the Nov. 22 edition of Science Advances.

Co-author Franz Hölker of the Leibniz Institute of Freshwater Ecology and Inland Fisheries said these lights place unprecedented stresses on plants and animals, including humans.

"It threatens biodiversity through changed night habits, such as reproduction or migration patterns, of many different species — insects, amphibians, fish, birds, bats and other animals," Hölker said.

The switch from orange-yellow sodium lights to bluish-white LEDs worsens the problem. Blue light scatters farther in the sky and is more harmful to insects and mammals.

That shift also means that the study likely underestimates artificial light emissions in areas lit by LEDs. The Visible Infrared Imaging Radiometer (VIIRS) satellite sensor used by the researchers only detects light in the 500-900 nanometer bands and therefore does not "see" blue light, which occurs at wavelengths below 500 nm.

The authors hypothesized that broad-scale efforts to save energy by transitioning to solid-state technologies like LEDs might be undercut by an economic rebound effect, in which lowered costs spur cities to add more lights.

The American Medical Association issued a health and safety warning last year concerning LED streetlights.

The authors said cities could possibly address these problems by using LEDs with their blue light component removed. They could also switch to true amber LEDs, which shine in a spectrum similar to low-pressure sodium lights and could be especially useful in areas of ecological concern.

Technology will bring 'revolutionary changes' in education sector: Ram Madhav

NEW DELHI: There would be "revolutionary changes" in education sector with the use of technology and the Internet in the future, BJP general secretary Ram Madhav said today, and asked whether teachers were ready to face the challenge.

"Ten years from now, you will be seeing a totally different education in the world. There won't be classrooms any more. You need to have online teachers. It is going to be totally different sceniario...Are our teachers ready for that?" he asked.
Mahdav was addressing a gathering on 'Vision India-New India', organised by the National Democratic Teachers' Front (NDTF) at Delhi University.
First class institutions can be created only when there are first class teachers, he said, adding that the Indian education system will improve but it will take some time.
"There are many of you who have nothing to do with modern technology. I know many professors who cannot operate a mobile phone," he said, adding the situation is like turning an elephant.
Elephant cannot take an about-turn. They have to turn slowly and guided into the right direction...we are doing," he added.
Madhav, however, said the entire education system cannot be termed as failure as India has produced some of the world class institutions such as IISc, Bangalore, and the IITs.
To a query over allegation of lack of employment by opposition parties, he said there was some "stress" in the job market but the situation was not so grave, otherwise there would be protests on roads.

NASA collects 20 years of satellite data, makes video of Earth’s transformation

NASA scientists have compiled a captivating video that maps how the Earth’s surface has changed over a span of 20 years, using data from various satellites.

In the Northern Hemisphere, ecosystems wake up in the spring and sprout new leaves, while a fleet of Earth-observing
satellites track the spread of the newly green vegetation. Meanwhile, in the oceans, microscopic plants drift through the sunlit surface waters and bloom into billions of carbon dioxide-absorbing organisms, and light-detecting instruments on satellites map the swirls of their colourSatellites measured land and ocean life from space as early as the 1970s. However, it was not until the launch of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) in 1997 that the space agency began what is now a continuous, global view of both land and ocean life.

A new animation captures the entirety of this 20-year record, made possible by multiple satellites, compressing a decades-long view of life on Earth into a captivating few minutes. “These are incredibly evocative visualisations of our living planet,” said Gene Carl Feldman, from NASA’s Goddard Space Flight Centre in the US.

“That’s the Earth, that is it breathing every single day, changing with the seasons, responding to the Sun, to the changing winds, ocean currents and temperatures,” said Feldman. Since the fall of 1997, NASA satellites have continuously and globally observed all plant life at the surface of the land and ocean. Twenty years of satellite data has helped scientists track phytoplankton populations in the ocean, study changing vegetation in the Arctic reaches of North America, monitor crop yields and more.

 

ISRO’s satellite-based chips to alert people at unmanned rail crossings

Satellite-based chip systems will now alert road users at unmanned level crossings about approaching trains and also help in tracking train movement on a real-time basis.

On a pilot basis, the Mumbai and Guwahati Rajdhani trains will be equipped with this system.

Road users will be warned by hooters once a train approaches an unmanned level crossing as railways are installing ISRO-developed integrated circuit (IC) chips on locomotives of trains.

There will be hooters at 20 unmanned level crossings on Rajdhani routes for Guwahati and Mumbai, said a senior railway ministry official involved with the project.

More trains will be equipped with such technology in a phase-wise manner, according to the plan.

About 500 metres before the level crossings, the hooter will be activated through the IC chip, warning road users as well as the train driver near the crossing.

The hooter will be louder as the level crossing nears, and finally it will be silent after the train passes by.

Besides alerting road users, the satellite-based system will also be used for tracking trains for disseminating information about their movement on real time basis.

This will be of great help to passengers as currently train movements are tracked manually.

Safety at unmanned level crossings is a cause of serious concern for railways and the public transporter is exploring various ways to address the issue.

There are about 10,000 unmanned railway crossings in the country which account for around 40% of accidents involving the railways.

While the Railways have eliminated 1,148 unmanned crossings in 2014-15 and 1,253 in 2015-16, it has scaled up its target and now plans to eliminate all such crossings in the next 2-3 years, the official said.

The satellite-based system will also help railways in mapping the area and the technology will come in handy at the time of accidents when it can be used to ascertain the exact location of trains and topography