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Giant telescope with mirror to explore

Scientists have developed the most challenging astronomical mirror - ten times more powerful than any other ever made - for a giant telescope to explore the outer space and early universe.

Researchers at the Steward Observatory Mirror Laboratory, University of Arizona and in California, working underneath a football stadium have been polishing a 8.4-meter diameter mirror with an unusual, highly asymmetric shape.

By the standards used by optical scientists, the “degree of difficulty” for this mirror is 10 times that of any previous large telescope mirror.

The mirror surface matches the desired prescription to a precision of 19 nanometers – so smooth that if it were the size of the continental US, the highest mountains would be little more than a half-inch high.

This mirror, and six more like it, will form the heart of the 25-meter Giant Magellan Telescope, providing more than 380 square meters, or 4,000 square feet, of light-collecting area.

The Giant Magellan Telescope will lead a next generation of giant telescopes that will explore planets around other stars and the formation of stars, galaxies and black holes in the early universe.

The Telescope will be located on a remote mountaintop in the Chilean Andes where the skies are clear and dark, far from any sources of light pollution.

It is slated to begin operations late in the decade, will allow astronomers and students across the US and from around the world to address critical questions in cosmology, astrophysics and planetary science.

The mirror was cast from 20 tons of glass, melted in a rotating furnace until it flowed into a honeycomb mold.The mirror has an unconventional shape because it is part of what ultimately will be a single 25-meter optical surface composed of seven circular segments, each 8.4 meters in diameter.

Gender bias makes women opt out from hard sciences

Scientists have solved the mystery behind women opting for careers outside hard sciences, citing gender discrimination as a major reason.

Both male and female scientists view gender discrimination as a major reason women choose to pursue careers in biology rather than physics, researchers from Rice University claim.

The new study surveyed 2,500 biologists and physicists at elite institutions of higher education in the United States. Researchers also interviewed a smaller scientific sample of 150 scientists about the reasons they believe there are gender differences in scientific disciplines.

“The distribution of women and men across various science-related occupations has long drawn both popular and scholarly attention,” said lead study author and principal investigator Elaine Howard Ecklund, an associate professor of sociology.
Other reasons scientists gave to explain the different numbers of women that pursue biology when compared with physics include mentorship of students in the fields of biology and physics and “inherent differences between men and women”.

One female scientist said, “I think women want to have more of a sense that what they are doing is helping somebody. Maybe there are more women in biology (because) you can be like, ‘Oh, I am going to go cure cancer’.” Whereas women often explained sex differences between the disciplines using reasons of emotional affinity, men stressed neurological differences as being responsible for personal choices.

Arctic deep-sea litter doubles in last decade

Scientists have found the amount of debris lying on the ocean floor in the Arctic has doubled over the past decade. Melanie Bergmann, a biologist and deep-sea expert at the Alfred Wegener Institute (AWI) for Polar and Marine Research, revealed it Tuesday.

Her findings were published in the scientific journal Marine Pollution Bulletin and based on photos of the seafloor taken near the AWI deep-sea observatory Hausgarten.

Bergmann studied 2,100 seafloor photographs made at a depth of 2,500 metres in the Fram Strait near Hausgarten deep-sea observatory. The camera took a photograph every 30 seconds.

“When looking through our images I got the impression that plastic bags and other litter on the seafloor were seen more frequently in photos from 2011 than in those dating back to earlier years.

“For this reason I decided to go systematically through all photos from 2002, 2004, 2007 and 2008. Waste can be seen in around one percent of the images from 2002, primarily plastic.