Discovery of cosmic rays
In the end of the XIX century physicists, studying gas conductivity with electroscopes, discovered that they slowly discharged despite being isolated from radiation sources. In 1901 Wilson suggested that gas ionization could be due to radiation coming from sources external to earth atmosphere and with high penetrating power.
Investigations by Theodore Wulf (1907) and Domenico Pacini (1907-1910) demonstrated that radiation was not decreasing when moving away from earth surface and sometimes it was even increasing, strengthening the extraterrestrial hypothesis.
On August 12th 1912, Victor Hess measured radiation with two hermetically sealed ionization chambers flying on a balloon up to 5350 m. He observed that ionization increased starting from 1500 m and doubled at about 5000 m. Hess concluded that ionization was due to high penetrating radiation coming from outer space and in 1936 he won the Nobel prize for Physics.
The name of cosmic rays was proposed by Robert Millikan when in 1925 he started studying this kind of radiation. He thought that they were mainly composed by gamma rays.
Unlike Millikan, Bruno Rossi and Arthur Compton assumed that cosmic rays were composed by charged particles: further measurements showed that this hypothesis was correct. Radiation distribution was in fact related to magnetic latitude as one would expect from charged particles interacting with earth magnetic field. This measurement was performed in 1927 by Clay during a trip from Amsterdam to Java. Clay observed that CR intensity decreased approaching equator.
In 1930 the Italian physicist Bruno Rossi observed that, if particle charge was positive, cosmic rays would come preferably from east direction. This effect was measured in 1933 by two American groups, T.H.Johnson and L.Alvarez with A.H.Compton.
Human exploration of space
About thirty years later, on October 4th 1957, from Baikonur cosmodrome, in the current Kazakistan, the first artificial satellite was launched: the Sputnik. The space race was started.
Only four years later the first man was flying in space: the russian cosmonaut Yuri Gagarin completed one orbit around the earth with the Vostok 1 spacecraft. He landed after 88 minutes. It was April 12th 1961.
United States replied with Alan Shepard launch on May 5th of the same year, but this was only a sub-orbital mission. To see the first american astronaut in orbit we have to wait until February 20th 1962. In the Mercury 6 mission John Glenn with Friendship 7 spacecraft completed three orbits for a total time of 5 hours.
On June 16th 1963 Russians launched the first woman cosmonaut, Valentina Tereskova, with Vostok 6 spacecraft. She completed a mission of three days in orbit.
After Mercury project, that consisted of single astronauts, Americans started Gemini project with a crew of two astronauts. The Gemini project was composed by 10 flights and 20 astronauts in orbit between 1965 and 1966.
In March 1965 the russian cosmonaut Alexei Leonov performed the first spacewalk (12 minutes) during Voskhod 2 mission. Few months later, during Gemini IV mission, also an american astronaut completed an EVA (Extra Vehicular Activity) for a total time of 22 minutes. For the first time ever, a man was exposed to space environment being protected by his suite only.
Effects of cosmic rays on human being
In 1964 there was the first evidence of cosmic rays interacting with human beings. Four astronauts, Reed Richard, Ben Grimm, Susan Storm and Johnny Storm were launched on an experimental rocket to a space mission. But during the navigation they were hit by cosmic rays that deeply modified their bodies.
Reed Richards started to stretch because his cells became similar to rubber.
Benjamin Grimm became a rocky monster with the streght of a thousand men. During the transformation Susan said: “Ben , you are turning into a thing…” The Thing was born.
Johnny Storm body started to burn and being lighter than air he started to fly. He could even launch fireballs: he was called the Human Torch.
Susan Storm started to fade. She will be the Invisible Woman. Susan could also create an invisible force field, useful to protect the four from the enemies.
From the mind of Stan Lee the Fantastic Four were born.