pressures

A Room-Temperature Superconductor | Earth Wise

November 18, 2020 By EarthWise Leave a Comment

One of the Holy Grails of science has apparently been found: a room-temperature superconductor. In a paper recently published in Nature, scientists from the University of Rochester and collaborators announced that they had observed superconductivity at 59 degrees Fahrenheit in an exotic material they produced in the laboratory.

Superconductivity is a phenomenon occurring in certain materials characterized by the total absence of electrical resistance. Current flowing in a closed loop of superconducting wire can go on forever. Superconductors have other unique characteristics as well, all of which combine to make them quite useful in a number of applications. Superconductors are used in high-powered magnets in particle accelerators and in MRI machines. They continue to be developed for use in electrical power transmission, energy storage, communication filters, magnetic sensors, and more.

The problem with superconductors is that they only work at very low temperatures. For most of a century – after superconductivity was discovered in 1911 – those temperatures were very close to absolute zero: 459 degrees below zero Fahrenheit. (In the late 1980s, so-called high-temperature superconductors were discovered. Those materials superconduct at the temperature of liquid nitrogen: about 320 degrees below zero).

The dream has been to find a superconductor that works at ambient temperatures. The Rochester team has produced tiny amounts of a mysterious combination of hydrogen, carbon, and sulfur which, when subjected to extraordinarily high pressures (over 2 million atmospheres), superconducts at the temperature of a pleasant fall day.

There is no practical value for this first room-temperature superconductor, but it proves that superconductivity can exist at ambient temperature. Once something is shown to exist at all, there is reason to hope that it can occur in ways that are easier and more practical to attain.

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First room-temperature superconductor excites — and baffles — scientists

Photo, posted June 18, 2013, courtesy of Oak Ridge National Laboratory via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Banning The Shark Fin Trade

July 4, 2019 By EarthWise Leave a Comment

Shark fins are considered a delicacy in many parts of the world, especially in China. Shark fin soup, for example, is often served at engagement parties and weddings. But the use of shark fins has come under increasing scrutiny in recent years, especially since an estimated one-third of fins are harvested from species deemed at risk.

Many of the fins used in shark fin soup come from a practice known as “finning,” which is an inhumane and wasteful practice where the fins are hacked from live sharks and then the sharks are thrown back into the water and left to die. According to U.N. estimates, 73 million sharks are killed every year for their fins.

The possession, sale, and distribution of shark fins is banned in 12 U.S. states, as well as in all European Union member states.

In 1994, Canada banned the practice of finning in its own waters, but allowed the import of fins to continue. Canada has been one of the largest markets for shark fins outside Asia, importing nearly 300,000 pounds of shark fins last year. But in late June, Canada passed a bill that bans both the import and export of shark fins harvested by shark finning. They are the first G7 and the first G20 country to do so.

But shark fins taken from sharks sustainably harvested for their meat will continue to be allowed in Canada. While demand for shark fins is decreasing globally, demand for shark meat is rising.

Since sharks still face a myriad of environmental pressures, including illegal fishing and high bycatch rates, there are concerns that this Canadian ban oversimplifies the threats facing global shark populations.

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Canada becomes the first G20 country to ban shark fin trade

Photo, posted January 4, 2013, courtesy of Andrew Currie via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Endangered Language Species

January 14, 2019 By EarthWise Leave a Comment

There are approximately 7,000 languages spoken in the world today but only about half of them are expected to survive this century. There are many factors contributing to the decline in languages. Perhaps the most significant is globalization, which pushes countries and individuals to shift to national or international languages for economic reasons. Other factors include the lack of support for regional languages in educational systems and mass media, persecution of minority linguistic groups by governments, and disruption of communities during war and emigration.

Predicting which languages will survive and which won’t is difficult. A potential tipping point for languages is the same one affecting the survival of species: climate change. Many small linguistic communities are located on islands and coastlines that are vulnerable to hurricanes and rising sea levels. Other communities live in places where increases in temperatures and erratic rainfall threaten traditional farming and fishing economies.

These climate-related changes will force communities to relocate,creating climate change refugees. Dispersing these people will lead to the splintering of linguistic communities and the need for the use of other languages. Such changes will place additional pressures on languages that are already struggling to survive.

There are endangered languages in many places around the world. Some are exotic such as the island of Sulawesi in Indonesia, which is home to dozens of distinct languages spoken by no more than a few thousand people. Others are much closer to home, such as in indigenous communities in Canada.

The rich tapestry of human language is just another of many things threatened by the changing climate.

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The Conversation: The impact of climate change on language loss

Photo, posted May 19, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sea Turtle Populations Are Rebounding

November 7, 2017 By EarthWise Leave a Comment

The increasing disappearance of so many plants and animals around the world has made many scientists believe that we are experiencing a sixth mass extinction. Despite ongoing conservation efforts, living things are struggling with habitat loss, climate change, and many other natural and man-made pressures. Conservation success stories seem to be rare events.