Efforts to communicate with aliens

Desire to communicate with life on other planets longer than the fondness of UFOs and hope for SETI. Some nineteenth-century scientists have proposed how we can contact Mars and Venus.

These proposals - 150 years ago when the first extraterrestrial message was sent in 1974 - relied entirely on visual signals, because radio was only invented decades later.

In fact, the idea of ​​interplanetary communication comes from what technology at the time allowed - lights, radios or lasers.

"You use what you know," said Steven Dick of NASA .

Are we alone?

More than 200 years ago, the ancient Greeks argued about the existence of life on another planet, which really began after the Copernican revolution.

Dick said: 'When we realize that all the planets spin around the sun, it's not hard to imagine that other planets can be like Earth.'

Galileo, Kelpler and others considered life on the planets, while being careful not to offend the church government.

Dick, who has written several books on the subject, commented: 'This idea blossoms in the 17th century into a' multi-world 'debate, but has yet to fall out.'

One of the most influential proposals on extraterrestrial life was Bernard le Bovier de Fontenelle, who wrote the Talk of the Multi-World in 1686.

Despite the interest of a large community, there has been no discussion about how we can locate or communicate with aliens until a century later.

Tree triangles and fire canals

Florence Raulin-Cerceau of the Alexandre Koyre Center in Paris recorded the attempts to communicate with extraterrestrial intelligence (CETI), or is now commonly referred to as the SETI activity.

Raulin-Cerceau and his colleagues wrote in the French magazine Pour la Science: 'In the 19th century, inventors imagined the device' sky telegraph 'to communicate with the inhabitants on planets in the Solar System. God'.

The first of these inventors was Carl Friedrich Gauss, a German mathematician.In the 1820s, he spoke about reflecting sunlight toward the planets with the discovery of Mr. heliotrope's ground. He was also credited with the idea of ​​creating a triangle in Siberian forest and growing wheat inside.

Raulin-Cerceau wrote: 'Contrast colors and colors will make objects visible from the moon or Mars, and the shape of a row can only be interpreted as intentional construction'.

UFO? (Photo: aday.com.vn)

Twenty years later, astronomer Joseph von Littrow came up with the same idea, pouring kerosene into a 30-kilometer circular canal that was burned in the evening to signal our presence.

Focus light

The second half of the 19th century saw more realistic proposals, according to Raulin-Cerceau.

In 1869, the French inventor and poet Charles Cros envisioned using a parabolic mirror to focus light from electric lights towards Mars and Venus. He calculated that light could be turned on and off to encode a message.

Raulin-Cerceau wrote: 'Cros thinks that planets are inhabited by creatures that cannot respond, but he is still convinced that the permanent isolation of the planet will be liberated.'

The light-based 'Morse code' was considered by British statistician Francis Galton in 1896. He thought that Martians had no 10-digit counting system like us, because they probably didn't have 10 fingers.

At the same time, A. Mercier, a member of the French Astronomical Association, came up with a plan to put some reflectors on the Eiffel Tower to direct the sun toward Mars. He also considered using the moon as a giant mirror to project light rays.

Can aliens observe those light signals?

Seth Shostak of SETI Academy said: 'Depending on how much you think Martians use to develop their telescopes'.

Turn on the radio

Radio is now thought to be a better tool for communicating with life beyond Earth. Radio waves are less affected by cosmic dust than white light, and there are fewer radio stations to deal with in the sky. Two radio pioneers have shown interest in interplanetary radio communication. In 1901, Nikola Tesla reported receiving a strange signal, possibly from Mars, on his giant broadcasting tower in Colorado Springs.19 years later, Guglielmo Marconi told reporters that he had detected radio waves from the planet.

However, the conversion of radio-based SETI does not happen immediately.

In the 1920s, many people (including Albert Einstein) still believed that image-based communication was more realistic, because radio transmitters were still unable to focus signals on a distant planet.

In addition, scientists are gradually convinced that Mars does not have the right conditions to support life, so extraterrestrial life can live somewhere farther away.

Shostak explained: 'There seems to be no hope of receiving messages from other stellar systems, so people' ignore '.

Only in 1959, radio-based SETI was taken seriously. In that year, Giuseppe Cocconi and Philip Morrison showed that radar generators were strong enough to send signals over many light years in space.

Shostak said: 'If we can do this, aliens can also'.

In the following year, Frank Drake performed Project Ozma, the first radio sky survey to search for extraterrestrial signals.

Then in 1974 - a century and a half after Gauss - Drake transmitted the first SETI message using the Arecibo radio telescope. Scientists are still waiting for an answer.