Faraday - Maxwell - Hertz - Popov - radio. This chain shows how fundamental science turns into applied science. The turning point happened precisely between Hertz and Popov. In 1888, Heinrich Hertz stood at the blackboard and explained his new work, On the Rays of Electric Power. "So what's next?" one of the students asked him. Hertz shrugged his shoulders and replied: "I guess - nothing."
And after 7 years, Russian physicist Alexander Popov stood at the blackboard, demonstrating wireless remote registration of electromagnetic oscillations from a lightning discharge, and an elementary radio receiver assembled by him. It was on May 7 - on this very day we annually celebrate the professional holiday "Radio Day".
RIA News. Alina Polyanina
"The era of radio" - this will be the name of the time in which we live in a few years. Radio, television, navigators, radars, mobile phones - everything that transmits and receives information now operates on radio waves. Rather like this: it worked! And now the “era of radio” is gradually ending. It turned out to be cheaper to transmit information over fiber, and you can throw a picture on the moon using a laser. In addition, experiments are underway to establish quantum communication. But, from the beginning of the twentieth century to the 80s, there were more and more radio towers, television stations, military radars. Therefore, astronomer scientists looking for intelligent life in the Universe absolutely rightly believe that if aliens notice us, it will be in the radio range.
After all, our planet is very dim, next to the bright Sun it is practically invisible. However, you can look at the sky with telescopes that register only a certain type of wave: gamma, X-rays, radio - the picture of the night sky can change dramatically! If the huge Sun is not disturbed by something (and this happens quite rarely), then a small planet next to a dim star comes to the fore. And this planet is our Earth, which has strong sources of radio waves: television towers and military radars.
Military radar shoots hard, but in a narrow beam, like a laser pointer. And the television signal goes in all directions, like the light from a light bulb.
Explains astronomer Vladimir Surdin, associate professor of the physics faculty of the Lomonosov Moscow State University, senior researcher at the P. K. Sternberg:
Artificial electromagnetic signals have one advantage: they are generated in a very narrow frequency range. It is like a bird that we hear through the noise of the forest, despite the fact that the trees are huge and move a lot of air. If we look at the solar system with a radio that emits a specific wavelength, as we do when we tune in to a specific station, we can hear the Earth, despite the fact that there is a giant source of electromagnetic noise in the form of the Sun next to it. And if you look at a person with the help of a radio receiver, he will also "give off", as in the X-ray and infrared ranges.
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Man and his radiation in different ranges. Illustration by RIA Novosti. Alina Polyanina
What does our rotating Earth look like in the radio range? Powerful radiation from Japan, then from China, then silence for a long time and, starting from Moscow, all European countries shine in radio beams. Then again a long time of silence, as the Atlantic Ocean goes, and again a powerful glow: the USA and Mexico. It is quite difficult to confuse such an artificial signal with something else.
Anna Urmantseva