Category Science

Why are astronomers concerned about light pollution?

Light pollution is very much a concern across the globe, something astronomers and skywatchers are trying to bring attention to. It not only takes away the right to enjoy the night skies and explore the celestial bodies with the naked eye but also affects the circadian rhythm of humans and wildlife.

Have you seen a sky spangled with stars winking at you from light years away? Have you ever spotted the Milky Way?

Well with the amount of artificial light strewn across the sky. it is a fact that dark skies that bring out the beauty of the cosmos are a rarity.

Light pollution is very much a concern across the globe, something astronomers and skywatchers are trying to bring attention to. It not only takes away the right to enjoy the night skies and explore the celestial bodies with the naked eye but also affects the circadian rhythm of humans and wildlife. So what is light pollution?

Light Pollution

Across the world, people have to deal with the nighttime glow caused by artificial light. This has been affecting humans, wildlife, and the environment equally. There is a global movement to reclaim the dark sky and reduce light pollution.

Sources of light pollution

The major cause of light pollution is misdirected light which scatters out into the open sky caused by human activities. From street lights to lights from buildings, boats, and outdoor advertising to illuminated sporting venues, every misdirected light leads to light pollution. High levels of sky glow mean fewer chances of seeing enough celestial bodies in the sky.

The circadian rhythm and light pollution

Artificial light can affect the circadian rhythm in both humans and animals. The circadian rhythm is the natural process regulating the sleep-wake cycle. The production of the hormone melatonin is linked to this. This sleep-inducing hormone gets released when it is dark. The presence of light inhibits it. If the ambient light is high at night, then it lowers the production of melatonin and leads to sleep deprivation, stress, fatigue, and anxiety.

Animal behaviour and light pollution

It has been proven that wildlife has also been affected badly by light pollution. The animal behaviours such as migration patterns and wake-sleep habits of animals have been affected. Birds and sea turtles have been found to lose their way and get confused due to the presence of increased ambient light. Light also affects the circadian rhythm of animals.

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How border wall affect wildlife?

Barriers of any kind affect movement and migration of animals. For instance, the wall could come in the way of an animal’s search for water and food nearby. It could also stop animals on their long-distance migratory paths.

When he was the U.S. President, Donald Trump set off the expansion of the border wall between the U.S. and its neighbouring country Mexico. While he’s not the country’s President any longer, the incomplete construction stretching miles on end stands today, silently bearing testimony to human prejudice. It divided people on both sides physically and emotionally. But it appears to have affected more than just humans as with barriers anywhere globally, it has affected wildlife too.

Wildlife has no concrete borders, created singularly by and for humans. When humans introduce these barriers, wildlife struggle, to put it mildly. It has come to light that the case is no different with the U.S.-Mexico barrier. According to Cuenca Los Ojos (CLO), a transfrontier wildlife organisation, “camera trap photos and the conservationists own observations have revealed deer, mountain lions and black bears pacing along the border wall, confused and unable to access their former ranges”. “One family of boars spent five hours trying to get past the wall in search of water, according to CLO. Barriers of any kind affect movement and migration of animals. For instance, the wall could come in the way of an animal’s search for water and food nearby. It could also stop animals on their long-distance migratory paths.

Apart from animals, such walls can harm birds too. When these barriers are lit up at night, it can disorient both nocturnal birds and those on their long migratory journeys. While it is easy to presume that birds can effortlessly cross such barriers in daylight, the reality is different. A few birds are low-fliers, and different types of interferences in a natural landscape can leave them trapped in one place due to their inability to fly from it. According to research conducted a few years ago on the U.S.-Mexico border, “not only large roadways but also big agricultural fields and other types of landscape disturbance and segregation” affected the movement of ferruginous pygmy owl, a low-flying bird.

Erecting walls or barriers is not new. However, with the natural world already under threat from climate change, these human structures, especially in places rich in biodiversity, are likely to put further pressure on wildlife.

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Do penguins face threat of extinction?

As much as 98% of colonies of this penguin species is at risk of extinction by 2100. So, the U.S. has listed the bird as “threatened” under the Endangered Species Act. There’s still hope to save them.

Where do emperor penguins live?

Different species of penguins are found in different parts of the Southern Hemisphere. The emperor penguins are found only in Antarctica, where they live and breed. Emperor penguins thrive on Antarctica’s coastlines in icy conditions any human would find extreme. The penguins breed on fast ice, which is sea ice attached to land But they hunt for food within the pack ice-sea ice floes that move with the wind or ocean currents and may merge. Sea ice is also important for resting, during their annual moult, and to escape from predators.  

The U.S. lists them as “threatened”.

If current global warming trends and government policies continue, Antarctica’s sea ice will decline at a rate that would dramatically reduce emperor penguin numbers to the point that 98% of all their colonies would become quasi-extinct by 2100, with little chance of recovering, a new study has shown. That’s why the U.S. Fish and Wildlife Service finalised a rule listing the emperor penguin as “threatened” under the Endangered Species Act, effective November 25, 2022. The director of the service said the listing “reflects the growing extinction crisis”. The U.S. Endangered Species Act has been used before to protect other species that are primarily at risk from climate change, including the polar bear, ringed seal, and several species of coral, which are all listed as threatened.

But, these penguins don’t even live in the U.S.!

Sure, these penguins don’t live on US. territory, so some of the Endangered Species Act’s measures meant to protect species habitats and prevent hunting them don’t directly apply. Being listed under the Endangered Species Act could still bring benefits, though. It could provide a way to reduce harm from U.S. fishing fleets that might operate in the region. And, with expected actions from the current administration, the listing could eventually pressure U.S. agencies to take actions to limit greenhouse gas emissions. However, the Bureau of Land Management has never acknowledged that emissions from oil and gas extraction on public lands and waters could harm climate-imperiled species. It issued more than 3.500 oil and gas drilling permits in New Mexico and Wyoming on public land during the first 16 months of the Joe Biden administration.

What’s harming the birds?

The greatest threat emperor penguins face is climate change. It will disrupt the sea ice cover they rely on unless governments adopt policies that reduce the greenhouse gases driving global warming. If there’s too much sea ice, trips to bring food from the ocean become long and arduous, and their chicks may starve. With too little sea ice, the chicks are at risk of drowning. Climate change is now putting that delicate balance and potentially the entire species at risk. Emperor penguins are adapted to their current environment, but the species has not evolved to survive the rapid effects of climate change that threaten to reshape its world. Major environmental shifts, such as the late formation and early loss of sea ice on which colonies are located, are already raising the risk.

How can we save them?

Decades of data since the 1960s are now helping scientists gauge the effects of anthropogenic climate change on the penguins, their sea ice habitat and their food sources. Meeting the Paris Agreement goal could still save the penguins. The results of the new study showed that if the world meets the Paris climate agreement targets, keeping warming to under 1.5 degrees Celsius (2.7 F) compared with pre-industrial temperatures, it could protect sufficient habitat to halt the emperor penguins decline. But the world isn’t on track to meet the Paris Agreement goals. The future of emperor penguins, and much of life on Earth, including humanity, ultimately depends upon the decisions made today.

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How do barcodes work?

Barcodes- those simple labels with black stripes-have revolutionised the retail industry. The stripes printed on product packaging contain important information regarding the product. Each barcode is made of varying widths of bars and spaces between them. The barcodes can be decoded only through special devices such as a laser or optical scanner, the kind used at supermarkets. Barcodes enable easy and fast transaction as well as analysis of sales data stored in the computer.

The information contained in barcodes is called Symbology. As soon as a barcode is passed through a scanner, all information pertaining to the product is shown on a computer screen. Shopkeepers love this system because it enables easy and fast transaction as well as analysis of sales data (stored in the computer). This system has a very low margin of error during sale. Barcodes are also useful for manufacturers since a unique identity can be inserted for each box of products to help in packaging and transportation

These days other geometric patterns are used in place of the original parallel bars but they are all generally referred to as barcodes.

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What is Self-Publishing?

Several species of agricultural crops depend on bats for pollination. In addition, fruits bats help in the dispersion of seeds, keeping several species of fruit-bearing trees alive. Some species of bats consume insects, considered agricultural pests. This not only prevents the use of billions of dollars worth of pesticides annually but also allows the soil to remain free from harmful chemicals.

The fungus Pseudogymnoascus destructans causes white-nose syndrome in bats, and “is responsible for the deaths of over six million bats in North America”. This is one of the reasons for the decline in the population of bats globally. And, scientists say that this decline is of concern. What causes the plunge in their numbers, and why should we be worried? Come, let’s find out. Often labelled blood suckers and disease carriers, bats seem to get short shrift. Pop culture portayals of vampires and the endless speculation over the origins (often pointing to bats, albeit scientifically unproven) of the ongoing pandemic make it even worse for the world’s only flying mammals. Add to the fact that these nocturnal creatures usually do their work under the cover of darkness, their role in healthy ecosystems may not be appreciated by laypeople. Several species of agricultural crops such as banana, mangoes, avocadoes, and figs are said to depend on bats for pollination. In addition, fruit bats help in the dispersion of seeds, keeping several species of fruit-bearing trees alive. Some species of bats consume insects, considered agricultural pests. This not only prevents the use of billions of dollars worth of pesticides annually but also allows the soil to remain free from harmful chemicals. In fact, guano – the excrement of bats – makes for excellent manure. Found in all continents except Antarctica, bats are a part of different types of ecosystems – from rainforests to deserts. Irrespective of the region they inhabit, they play crucial ecological roles, keeping alive the biodiversity and the health of their ecosystems.

While the population of bats in North America has taken a huge hit due to the white-nose syndrome, there’s a general decline in their population in other parts of the world too. The reasons for this include climate change, invasive species, loss of habitat due to urbanisation and agriculture, lack of food, especially when pesticide is used to kill the insects they feed on, etc. There’s still a lot to be studied about bats. But an aspect of concem in studying bats is that they “roost in lots of different places, from caves to barns to attics, and scientists can’t monitor bats in all places at all times”.

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Which is the largest bird?

The largest bird on the planet is, rather ironically, the flightless ostrich. It also lays the largest eggs among any living land animal. Ostriches are also the fastest birds on land with an ability to run at 70 kilometres per hour. They are found in the African savanna and desert lands, where they meet most of their water requirements from the plants they eat.

Unlike other birds, ostriches use their wings as “rudders” to help them change direction while running. Their powerful and long legs cover about 3 to 5 metres in a single stride. These legs are also rather formidable weapons. An ostrich kick can kill a human or a potential predator such as a lion! Their feet have long, sharp claws too. Ostriches live in small herds with less than a dozen birds in one herd. They mostly eat plants, roots, and seeds but also consume insects, lizards, and other creatures that are found in this harsh habitat.

Although there is a popular belief that ostriches bury their heads in the sand, this is not true. Perhaps the saying would have originated because of the bird’s defensive behaviour. When faced with trouble, ostriches lie low and press their long necks to the ground as a means to become less visible. Since their plumage blends well with sandy soil, from a distance, it gives the impression that they have buried their heads in the sand.

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