The Large Binocular Telescope

The Large Binocular Telescope (LBT) is an optical telescope located on Mount Graham at an altitude of 3,200 meters in the Pinaleno Mountains of southeastern Arizona. Its design was inspired by the more modest optical equipment we usually carry around the neck. The Large Binocular Telescope has two identical 8.4 m telescopes mounted side-by-side on a common base that has the same light gathering ability as an 11.8 m wide single circular telescope and the resolving power of a 22.8 m wide one. The binocular design, combined with advanced adaptive optics, gives the telescope exceptional sensitivity for the detection of faint objects. The LBT is currently one of the world’s highest resolution and most technologically advanced optical telescopes.

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Especially praiseworthy is the adaptive optics device, called the First Light Adaptive Optics system. Traditional ground based telescope has to see through the Earth’s thick atmosphere that absorbs a significant amount of light before it reaches the telescope’s mirrors. But the real problem is wavefront distortion caused by atmospheric instability that distorts the light passing through much the way water blurs the view from the bottom of a swimming pool.

To correct atmospheric distortion, astronomers use adaptive optics technology. The LBT has a very thin secondary mirror that can be easily deformed by devices pushing on the 672 tiny magnets glued to its back. A special wavefront sensor measures atmospheric distortions in real time. A computer then calculates the optimal mirror shape required to correct the distortions and the surface of the mirror is suitably adjusted to compensate the distortion. The mirror can make adjustments every one-thousandth of a second, with accuracy to better than ten nanometers.

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Image sharpness is measured in Strehl ratio, where 100 percent represents a perfect image. In the initial testing phase, the LBT’s adaptive optics system achieved unprecedented Strehl Ratios of 84 percent, when existing adaptive optics systems on other major telescopes today score between 30 percent to 50 percent in the near-infrared wavelengths where the testing was conducted.

“The results on the first night were so extraordinary that we thought it might be a fluke, but every night since then the adaptive optics have continued to exceed all expectations,” said astronomer Simone Esposito,of the Istituto Nazionale di Astrofisica (INAF) who collaborated with the University of Arizona’s Steward Observatory to build the adaptive optics device. “These results were achieved using only one of LBT’s mirrors. Imagine the potential when we have adaptive optics on both of LBT’s giant eyes.”

When compared to images taken by the Hubble Space Telescope, LBT’s images were three times as much sharper. When light from both mirrors are combined, the LBT is expected to achieve image sharpness ten times that of the Hubble.

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Shark researchers size up real ‘Megalodon’ for first time

The enormity of a prehistoric mega-shark made famous in Hollywood films has finally been revealed by researchers.

Until now, only the length of the Otodus Megalodon, as featured in the 2018 film The Meg, had been estimated from fossils of its teeth.

However a team from Swansea and Bristol universities have combined maths with nature to reveal just how big it was.

The study has been published in the journal Scientific Reports.

Researchers used mathematical methods and comparisons with living relatives to find the overall size of the megalodon, which lived from about 23 million to three million years ago.

Results suggest a 16m (52ft) megalodon – almost three times as long as a great white shark – is likely to have had a head about 4.65m (15ft) long, a dorsal fin as large as an entire adult human and a tail about 3.85m (13ft) high.

Jack Cooper, who is to study a PHD in palaeobiology at Swansea University, described the research as his “dream project”.

“Megalodon was the very animal that inspired me to pursue palaeontology but studying the whole animal is difficult considering all we really have are lots of isolated teeth,” he said.

“It’s significant that we have now been able to produce estimates of proportions and dimensions of the body parts when there are no fossils to go off.

“However the dimensions in the film were actually pretty accurate.”

Previously, the shark was only compared with the great white, but the latest analysis was expanded to include five modern sharks, including the makos, salmon shark and porbeagle shark.

Mr Cooper added: “We could take the growth curves of the five modern forms and project the overall shape as they get larger and larger – right up to a body length of 16 metres.”

Half a Century in the Making: Tree ‘Crop Circles’ Emerge in Japan

Two peculiar ‘crop circles’ have recently been spotted in Japan’s Miyazaki Prefecture. Viewable only from above, they were formed by sugi (Japanese cedar) trees.

Conspiracy theorists will be disappointed to learn that there is a very practical explanation for how these shapes emerged: science. Specifically, it was the result of a scientific experiment that spanned close to 50 years.

According to documentation (PDF) we obtained from Japan’s Ministry of Agriculture, Forestry and Fisheries, in 1973 an area of land near Nichinan City was designated as “experimental forestry” and one of the experiments was to try and measure the effect of tree spacing on growth. The experiment was carried out by planting trees in 10 degree radial increments forming10 concentric circles of varying diameters.

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Part of what makes the crop circles so alluring are their concave shape, which was an unexpected result of the experiment that would suggest tree density does indeed affect growth. The trees are due to be harvested in about 5 years but officials are now considering preserving the crop circles.

Below is an image from Google Earth, which is unfortunately a bit dark.

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Essays reveal Stephen Hawking predicted race of ‘superhumans’

The late physicist and author Prof Stephen Hawking has caused controversy by suggesting a new race of superhumans could develop from wealthy people choosing to edit their and their children’s DNA.

Hawking, the author of A Brief History of Time, who died in March, made the predictions in a collection of articles and essays.

The scientist presented the possibility that genetic engineering could create a new species of superhuman that could destroy the rest of humanity. The essays, published in the Sunday Times, were written in preparation for a book that will be published on Tuesday.

“I am sure that during this century, people will discover how to modify both intelligence and instincts such as aggression,” he wrote.

“Laws will probably be passed against genetic engineering with humans. But some people won’t be able to resist the temptation to improve human characteristics, such as memory, resistance to disease and length of life.”

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In Brief Answers to the Big Questions, Hawking’s final thoughts on the universe, the physicist suggested wealthy people would soon be able to choose to edit genetic makeup to create superhumans with enhanced memory, disease resistance, intelligence and longevity.

Hawking raised the prospect that breakthroughs in genetics will make it attractive for people to try to improve themselves, with implications for “unimproved humans”.

“Once such superhumans appear, there will be significant political problems with unimproved humans, who won’t be able to compete,” he wrote. “Presumably, they will die out, or become unimportant. Instead, there will be a race of self-designing beings who are improving at an ever-increasing rate.”

The comments refer to techniques such as Crispr-Cas9, a DNA-editing system that was invented six years ago, allowing scientists to modify harmful genes or add new ones. Great Ormond Street hospital for children in London has used gene editing to treat children with an otherwise incurable form of leukaemia.

What is Crispr?
Crispr, or to give it its full name, Crispr-Cas9, allows scientists to precisely target and edit pieces of the genome. Crispr is a guide molecule made of RNA, that allows a specific site of interest on the DNA double helix to be targeted. The RNA molecule is attached to Cas9, a bacterial enzyme that works as a pair of “molecular scissors” to cut the DNA at the exact point required. This allows scientists to cut, paste and delete single letters of genetic code.

However, questions have been raised about whether parents would risk using such techniques for fear that the enhancements would have side-effects.

The astronomer Lord Rees, who was a friend of Hawking at Cambridge University but often disagreed with his peer, noted a sperm bank in California offering only “elite” sperm, including from Nobel prize winners, had closed due to lack of demand.