Friday, November 27. 2020Who came up with the idea of a Dyson Sphere?
Freeman Dyson may be gone, but his famous alien-hunting idea will likely persist far into the future. Dyson, a quantum physicist who died at age 96 on Feb. 28, recalled in a 2003 interview just how he first advanced his concept of a "Dyson sphere," which could betray the existence of an advanced alien civilization. A Dyson sphere is a theoretical mega-engineering project that encircles a star with platforms orbiting in tight formation. It is the ultimate solution for living space and energy production, providing its creators ample surface area for habitation and the ability to capture every bit of solar radiation emanating from their central star Because of their infrared radiation, Dyson spheres are considered a type of technosignature — a sign of activity that distant astronomers could use to infer the existence of intelligent beings in the universe, according to a NASA report. A handful of Earth-based researchers have scanned infrared maps of the night sky in hopes of spotting Dyson spheres, but so far, nobody has seen anything out of the ordinary. In 2015, astronomer Tabetha Boyajian, then at Yale University, reported on the mysterious dimming of light from a star called KIC 8462852, whose irregular flickering looked like nothing researchers had ever seen before. Other scholars suggested the weird light dips could result from a partially built Dyson sphere, and the idea caused a media sensation. Campaigns to look for other signs of technological activity from the entity, which came to be known as Tabby's star in honor of Boyajian, have turned up empty, and most researchers now think the object's light patterns have some kind of nonalien explanation.
Picture Credit : Google Friday, November 27. 2020What is the life story of Stephen Hawking?
The genius in the wheelchair When Stephen Hawking was 21, he was given only a few years to live after being diagnosed with a rare form of motor neurone disease. Undaunted, Hawking made breakthroughs in quantum physics and cosmology with his "The Theory of Everything" and his work on black holes. Although a number of biographies have been written about the genius, a new memoir gives an affectionate account of Hawking and his indomitable spirit. Written by Leonard Mlodinow, who worked closely with Hawking for nearly 11 years and co-authored two bestselling books with him ("A Briefer History of Time" and "The Grand Design"), "Stephen Hawking - A Memoir of Physics and Friendship gives fresh insights into Hawking's character and his famous sense of adventure and fun. A daredevil Hawking was born on January 8, 1942 in Oxford. At 17, he won a scholarship to study at University College, Oxford. Despite his brilliance in academics, Hawking hated studying. According to his own estimates, he studied for only 1,000 hours during his three undergraduate years at Oxford. Once he even joined the college boat dub. But earned himself a daredevil reputation as he steered his crew on risky courses that often damaged boats. Living with a rare disease After being diagnosed with a rare form of motor neurone disease known as ALS, Hawking sunk into depression. Though the disease progressed slowly, it began to interfere with his daily activities, and his condition worsened in 1985 during a trip to Cern. Hawking underwent a tracheotomy, which saved his life but destroyed his voice. He started using a voice synthesiser. The early diagnosis of the terminal disease ignited a sense of purpose in Hawking and he embarked on his career in earnest. He pursued his work with black holes and relativity with new zest. In 1988, Hawking published "A Brief History of Time, which turned him into an instant icon. Writing for children Hawking and his daughter Lucy came up with a series of illustrated books to explain the "secret keys to the universe" to young readers. The books deal with complex topics, including the Big Bang, black holes, atoms. planets and their moons, in the form of space adventures embarked on by junior astronaut George and his best friend Annie. The series helped simplify cosmology for children. Love for adventures Hawking enjoyed his fame, taking many opportunities to travel and to have unusual experiences such as going down a mine shaft visiting the south pole and undergoing the zero-gravity of free fall, and to meet other distinguished people. Legacy Hawking died at his home in Cambridge on March 14, 2018, at the age of 76. In the same year in June, Hawking's words, set to music by Greek composer Vangelis, were beamed into space from a European Space Agency satellite dish in Spain with the aim of reaching the nearest black hole 1A 0620-00.
Picture Credit : Google Friday, November 27. 2020How was the moon formed?
The Moon has fascinated us for centuries with several countries already having sent their probes and people to explore it But how was Earth's closest companion formed? Well there have been many theories about the formation of the Moon. The one that many scientists agree with the most is the giant-impact hypothesis. When Earth was hit by Theia Scientists believe the Moon was formed when a planet about the size of Mars collided with Earth Theia, as dubbed by scientists crashed into Earth when it was still a very young planet This collision sent dunks of Earth's cast into space Gravity then bound these particles together in space forming the Moon. The Apollo missions conducted by NASA between 1969 and 1972. brought back over a thing of a tonne of rock and soil from the Moon. When this was analysed it was found that the Earth and the Moon hat some chemical and isotopic similarities, suggesting that they have a linked history. However, this theory has its challenges with many models suggesting 60% of the Moon would have been made up of Theia's rocks if the giant-impact hypothesis is true. The other theories Prior to the Apollo missions, there were three theories that were speculated about the formation of the Moon. Capture theory: This suggests the Moon was a wandering body in space, like an asteroid which formed elsewhere in the solar system and was captured by Earth's gravity when it passed near the planet. Accretion theory: This theory suggests the Moon was created along with Earth during its formation Fission theory: According to this theory, the Earth was spinning so fast that some of its material broke away and began to orbit it after being captured by its gravity.
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