New British Prime Minister Theresa May announced six members of her Cabinet Wednesday.

Amid a sweeping crackdown on dissent in Egypt, security forces have forcibly disappeared hundreds of people since the beginning of 2015, according to a new report from Amnesty International.

It's an "unprecedented spike," the group says, with an average of three or four people disappeared every day.

The Republican Party, as it prepares for its convention next week has checked off item No. 1 on its housekeeping list — drafting a party platform. The document reflects the conservative views of its authors, many of whom are party activists. So don't look for any concessions to changing views among the broader public on key social issues.

Many public figures who took to Twitter and Facebook following the murder of five police officers in Dallas have faced public blowback and, in some cases, found their employers less than forgiving about inflammatory and sometimes hateful online comments.

As Venezuela unravels — with shortages of food and medicine, as well as runaway inflation — President Nicolas Maduro is increasingly unpopular. But he's still holding onto power.

"The truth in Venezuela is there is real hunger. We are hungry," says a man who has invited me into his house in the northwestern city of Maracaibo, but doesn't want his name used for fear of reprisals by the government.

The wiry man paces angrily as he speaks. It wasn't always this way, he says, showing how loose his pants are now.

Ask a typical teenage girl about the latest slang and girl crushes and you might get answers like "spilling the tea" and Taylor Swift. But at the Girl Up Leadership Summit in Washington, D.C., the answers were "intersectional feminism" — the idea that there's no one-size-fits-all definition of feminism — and U.N. climate chief Christiana Figueres.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.

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Tons Of Molten Glass Go Into Making Mirror For Giant Telescope

Aug 24, 2013
Originally published on April 5, 2015 1:23 pm

Technicians on Saturday are set to cast 20 tons of glass for the third of seven ultra-precise primary mirrors that will make up the 72-foot Giant Magellan Telescope, scheduled for completion in northern Chile's arid Atacama Desert in 2020.

The parabolic mirror will be cast at the University of Arizona's Steward Observatory Mirror Lab. The molten borosilicate, made by the Ohara Corporation, will be spun cast at 2140 degrees Fahrenheit.

Describing the production of the first such mirror in 2005, the Lab explained the process:

The glass was "... melted in a rotating furnace until it flowed into a honeycomb mold. Once the glass had cooled and the mold material was removed, scientists at the lab used a series of fine abrasives to polish the mirror, checking its figure regularly using a number of precision optical tests."

How precise?

Once the mirror cools, and the polishing is complete — a process that is expected to take a year — it will be accurate to within 1/20the wavelength of light, or put another way, "one part in 10 billion in terms of precision manufacturing," according to Patrick McCarthy, the project's director.

When finished, the telescope — which includes another seven smaller mirrors to direct the collected light to a focal plane — will employ adaptive optics to compensate for atmospheric disturbances that might otherwise blur the image. The GMT is expected to offer 10 times the resolution as the Hubble Space Telescope.

"We have to make this optic precise enough so that when the light travels five, 10 billion light years and comes and hits our telescope that we don't scramble and lose that information that's traveled for so long," McCarthy says in the video below describing the mirror-making process.

Scientists hope the new telescope will give them a better look at super-massive black holes that are believed to be at the heart of most large galaxies and to detect and characterize new planets outside our solar system.

"Astronomical discovery has always been paced by the power of available telescopes and imaging technology," said Peter Strittmatter, head of the Steward Observatory's astronomy department, in a press statement, according to SPACE.com. "The GMT allows another major step forward in both sensitivity and image sharpness."

Copyright 2015 NPR. To see more, visit http://www.npr.org/.