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International dignitaries gathered in Italy last week to sign a treaty that will take us back to the dark era. This alternative treaty of Rome has fortunately nothing to do with regressive policies, but rather a historic agreement for the construction of the largest radio telescope in the world.
One of the main goals of the mega-scientific project of 1.8 billion euros, dubbed "Square Kilometer Array", will consist of scrutinizing what is called the Dark age of the cosmos. This period began about 380,000 years after the Big Bang, when the universe was a swirl of mostly hot hydrogen and that the stars were still shining. It ended perhaps half a billion years later, when matter began to melt into the stars and galaxies that lit up the cosmos. In addition to describing how this "cosmic dawn" unfolds, the telescope will test Einstein's theory of general relativity, map the distribution of dark matter, and scrutinize planets orbiting stars to determine the chemical signs of darkness. life. It will start operating in 2020.
While optical telescopes capture the wavelengths of light that we can see, visible radiation is only a fragment of the electromagnetic spectrum. In fact, celestial objects emit various types of radiation, including visible parts, X-rays, ultraviolet and radio.
Radio broadcasts have longer wavelengths and lower energies than visible light, which means that radio telescopes require large areas of collection and are usually bent to focus. The huge parables are doing wonders: The Arecibo Observatory, a 305-meter-diameter receiver dish tucked into a picturesque setting in Puerto Rico, has been featured in the movies Contact and Golden eye. It was replaced in 2016 by the 500-meter Fast Telescope built in China.
As its name suggests, the Kilometer Array Square, already under construction, will have a catchment area of 1 square meter, a new record. But rather than a single gigantic dish, it will be a network of thousands of small dishes and up to a million antennas.
To minimize terrestrial radio interference, the network will be split into two remote sites: Murchison Shire in Western Australia and the Karoo Region in South Africa. The collection, linking and analysis of data is part of the scientific challenge: SKA should generate more traffic than the entire Internet. The project will also push back the limits of electricity generation and storage. The Jodrell Bank Observatory, located in the north of England, will be the headquarters.
The convention that designates the SKA as an intergovernmental organization – like the CERN, the particle physics center in Geneva – was signed in Rome last week by Australia, the 39; South Africa, China, Italy, the Netherlands, Portugal and the United Kingdom. India and Sweden are expected to sign soon, with other countries having expressed interest. Germany was withdrawn in 2014 for cost reasons.
The observatory is a remarkable step for an accidental science. In the 1930s, Karl Jansky, a scientist at Bell Labs in New Jersey, was asked to study static signals in radio signals abroad. He mounted a 100-foot antenna on Ford Model-T wheels and used it to identify three types of pests: a local thunderstorms; one of the distant storms; and, he writes, another "composed of very stable static whistles whose origin is not yet known." It reappeared like a clock every day; Jansky followed the source at the heart of the Milky Way.
His discovery of extraterrestrial radio waves made the headlines and gave astronomers a new way to detect celestial objects. Radioastronomy unveiled pulsars, which are the rotating nuclei of dead stars, and captured the "echo" of the Big Bang, known as cosmic background radiation.
Jansky, according to today's scientists, could very well have won the Nobel Prize – but died at the age of 44 from a stroke.
The author is a scientific commentator
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