COSMIC RAYS: -
These are the highly charged invisible particles. These rays originate from Space or Exoplanet and arrive in the atmosphere of Earth. Such rays are formed either by the star explosion [supernova] or in space or from an unknown resource. Its speed is closer to the speed of light.
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BRIEF Information: -
Name: Cosmic Rays
Discoverer: Austrian physicist Victor Hess
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Year of Discovery: 1911-12
How Discovered: While measuring radiation in the atmosphere
Sometimes this type of highly energised particles is also known as primary particles. These particles mostly contain protons and small nuclei. Cosmic rays enter the Earth atmosphere but do not touch the surface of Earth because of the collision. There is a collision between air molecules and cosmic rays’ density, due to difference in density.
The Earth atmosphere has a low density but also it is dense enough to collide with particles arriving from outer space. Thus, they create a small amount of energy and secondary particles after the collision. These rays are too extremely dangerous. These rays [acting as radiation] have high frequency and penetrating power.
But the question arises why we don't get any harm?
This ray contains the most energetic energy ULTRA HIGH ENERGY COSMIC RAYS [UHECR]. We are safe from this invisible highly energised particle because of our Atmosphere. Our atmosphere prevents the entry of these particles.
The radiation which we detect is the minute particles or shower of these cosmic rays, which got divided after the collision. There are mainly two devices that are used to measure or detect the ray’s particles.
It is the detection of secondary particles. In this Extensive Air Shower [EAS] formed.
It is the measurement through Electromagnetic radiation emitted in the atmosphere.
One important fact about Cosmic rays is that it might travel millions of years across space before reaching the Earth. The term ray, that we used is a misnomer and was put there due to a historical accident.
The main uses of this ray are to study those atoms which are smaller than cosmic.
It is classified on the basis of two types: -
a]. Galactic Cosmic Rays [GCR]: -
b]. Solar Energetic Particles: -
Antiquity:-
As we know, Cosmic rays were discovered in the early 1900s. But a few centuries before, approximately in the year 1780 some scientists knew about it. Among these scientists, the famous is CHARLES AUGUSTEN DE COULOMB [known for the discoverer of charge]. He observed that a charged sphere suddenly got discharged mysteriously.
The discovery of radioactivity led to the belief that the reason behind atmospheric electricity and ionisation of air was just due to radiation from radioactive elements that are present either in the atmosphere or surface of Earth. In the year 1909, a scientist named THEODOR WULF constructed an electrometer, that is used to measure the rate of ions produced inside a hermetically [ an element that is used to make an object airtight]. He took his device and measured the radiation at the top and bottom of the Eiffel Tower. The end of this experiment is that the higher the height, the higher the radiation. His probation was published on Physikalische Zeitschrift but was not accepted by all.
A few years later, about [1.5- 2 years] the same conclusion was witnessed by Domenico Pacini. He observes the variation in the rate of ionization at a different place like, at the lake, over the sea, at a depth of 3 metres from the surface. His conclusion was that these are happening due to the presence of some electromagnetic elements instead of Earth's radioactivity.
All the scientists started discovering just after one another. The year was 1992, when a physicist Victor Hess, carried 3-enhances accuracy Wulf electrometer with him to an altitude of 5300 meters in a free balloon flight. He found the ionization rate increased approximately fourfold over the rate at ground level. Hess claimed the sun as the radiation source by making a balloon ascent during a near-total eclipse.
He concluded that “The results of the observations seem most likely to be explained by the assumption that radiation of very high penetrating power enters from above into our atmosphere”.
