A unique telescope that focuses light on a slightly rotating liquid mercury instead of a solid mirror opens its eye to the sky above India. Such telescopes have been built before, but the 4-meter-wide International Liquid Mirror Telescope (ILMT) is the first large-scale astronomical design target, with a spectator award-winning 2450-meter Devasthal spectator. Observatory in the Himalayas.Although astronomers have to satisfy only by looking upward, the $ 2 million tool, developed by the Belgian, Canadian, and Indian allies, is much cheaper than telescopes with glass mirrors. The stone’s throw from ILMT is 3.6 meters, the steerable Devasthal Optical Telescope (DOT) – built by the same Belgian company at the same time – but for $ 18 million. “Simple things tend to get better,” says Project Director Jean Surdej of Liège University. Some astronomers say that liquid mirrors are the perfect technology for a giant telescope on the Moon that can see back to the time of the world’s first stars.
When a container of refleive liquid mercury is rotated, a combination of gravitational force and a medium force pushes the liquid into exactly the same shape as a normal telescope — but without the expense of throwing an empty glass mirror, it grinds its face into a parabolic. , and cover it with light aluminum.The International Liquid Mirror Telescope (bottom left) at the Devasthal Observatory in India sits next to the 3.6-meter Devasthal Optical Telescope (center) .ANNA AND JEAN SURDEJILMT was a dream come true in the early 1990s. A mercury-powered ship was brought to India in 2012, but construction of the telescope fenced off was delayed. Then the researchers found that they did not have enough mercury. As they waited for more, the COVID-19 epidemic struck, making travel to India impossible. Finally, in April, the team set up 50 liters of mercury spinning, forming a parabolic layer 3.5 mm thick. After such a long pregnancy, “we are all very happy,” said team member Paul Hickson of the University of British Columbia, Vancouver.
Looking straight up, the orbiting mirror will see the sky almost as wide as the full Moon while the earth’s orbit around the sky from dusk to dawn. “Just open it and let it go,” Hickson said. Objects appear as long lines in a picture; different pixels can be added together afterwards to create a single long exposure. Because the telescope sees almost the same line of the sky on a consecutive night, the exposure that occurs overnight can be added together to capture the most sensitive images of unconscious objects.
Alternatively, a one-night stand can be removed from the next to see what has changed, revealing transitory objects such as supernovae and quasars, bright hearts of distant galaxies that expand and shrink as large black holes eat away at objects. Surdej wants to hunt down magnetic lenses, where the gravitational force of a galaxy or a collection of galaxies bends the light of a distant object like a giant glass. ILMT’s critical measurement of light intensity reveals the size of the galaxies and can help measure the rate of expansion of the universe. The study suggested that about 50 lenses could be seen on the ILMT blue line. Regular survey telescopes, such as the Zwicky Transient Facility in California and the upcoming Vera C. Rubin Observatory in Chile, cover the sky extensively. But they are less likely to return to the same place every night to make changes. “We’re forced to have a niche,” Hickson said. ILMT has the added power of staying close to the DOT, equipped with tools that can quickly process any passing objects detected by its immediate neighbor. The tag team approach is “broad, and scientifically rich,” said Dipankar Banerjee, director of the Aryabhatta Research Institute of Observational Sciences, which heads the Devasthal Observatory.
If ILMT is successful, Surdej says the technology could be upgraded to build larger liquid mirrors on the Moon, which is an attractive place for future big telescopes because they do not operate on Earthquakes like Earth and do not have space. On Earth, the effect of Coriolis, from the orbit of the planet, can trigger mercury movements in mirrors larger than 8 feet. But the Moon rotates slowly, allowing for much larger fluids — even though they are not mercury. It is very difficult to transport to the Moon and can freeze at night and evaporate during the day. But more than a decade ago, liquid mirror mirrorErmannoBorra of Laval University showed that “ionic liquid,” a lightweight molten salt with low frosting points, can survive moon conditions and can be made to glow with a thin silver.
In the 2000s, both NASA and the Canadian Space Agency commissioned a telescope study of the moon’s liquid crystal but did not proceed. Astronomers hope that the current interest in exploring the Moon and the cheap launch offered by independent space companies like SpaceX will inspire a revival. In 2020, a team from the University of Texas, Austin, proposed the Ultimately Large Telescope, a 100-foot-long [100 m] liquid mirror that would focus on the same sky for years on end from one of the Moon’s poles. Such a giant was able to collect small amounts of photons from the first stars that illuminated the entire universe, before even the galaxies existed. Veteran mirror designer Roger Angel, of the University of Arizona, states that “there is a unique place for a large [liquid] mirror that surpasses what others can do.”
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