There are three modes of energy transmission from the source to the observer: conduction, convection, and radiation. However, the meaning of radiation is little different from that understood by the public. It is the mode of transmission of energy from source to observer without the presence of any material medium, i.e., solid, liquid, or gas. They move in the form of electromagnetic waves with the universe’s ultimate speed.
Radiation carries energy with them and brings it from source to receiver. And according to Einstein’s E=mc2, the mass and energy are inter-convertible and are the verso of the same entity. Therefore, it can be concluded that radiation can be taken as the channel to carry mass or energy swiftly, in invisible form.
Have you ever thought about how your sound energy is carried over long distances via cell phones?
Obviously, it is radiation. Firstly, your sound enters your cell phone in the form of an electric current. Then, the current goes to the receiving station in the form of electromagnetic radiation. It is sent off to the canopy via electromagnetic radiation and then sent to the receiver from that station.
Radiations cause many apocalypses. Because of the radiations emitted from the Nuclear Bombs deployed during World Wars named Little Boy and Fat Man, many genetic disorders have been being seen in Hiroshima and Nagasaki, Japan. Harmful radiations are mainly ejected by the radioactive elements such as Uranium, Polonium, Plutonium, Thorium, Actinium, etc., during radioactive decay and in the nuclear reaction. These elements are the heart of carrying out the atomic reaction.
In turn, these nuclear reactions can be used both for constructive and destructive purposes. The energy released from the nuclear reaction can be used as a nuclear weapon and can be used to produce electricity and run devices. A small piece of a radioactive element can produce a substantial amount of energy. Therefore it can be favored over other sources of energy.
The prototype is the space rover launched by NASA named curiosity, which is made to run for about 3-4 years on the Martian surface the nuclear fuel. Many radiations such as X-rays, Gamma –rays, etc., are used in medical diagnostics and cancer-curing and to detect the presence of any prohibited items at the Airports and other borders sites.
X-ray was accidentally discovered in 1895 by Roentgen. He was a German Physicist who studied at the Polytechnic Institute in Zurich and at the universities of Strasbourg and Wurzburg. For this discovery, he was awarded the Nobel prize for Physics in 1901. This discovery became a milestone for the development of modern Physics and medicine research and diagnosis. Once Roentgen was carrying out an experiment with a discharge tube and suddenly observed the fluorescent screen coated with barium platinocyanide in the neighborhood of the tube became luminescent when the tube was about 0.001mm of mercury pressure.
A photographic plate was affected, although it was completely covered by a black sheet of paper. He concluded that this is a new type of invisible radiation not discovered then. He named it X-ray, where X in algebra stands for unknown. Thus X-ray implies an unknown ray. Soon, he realized that this X-ray could pass through various solids materials up to different extents depending upon the nature of the material. It could pass through human flesh; however, it can’t penetrate bones. This helps to locate the fracture of bones.
It was found that X-rays were not deflected by electricity and even by a magnetic field which means that radiation was chargeless; otherwise, it could have been affected by electric or magnetic fields. But like regular light, it exhibits reflection, refraction, interference, diffraction, and polarization phenomena.
X-rays can be produced whenever a fast-moving electron strikes a rigid target such as tungsten metal. It is made in an X-ray tube called Coolidge Tube, invented in 1916 A.D. In this tube, the wavelength and intensity of the X-ray can be controlled.
In a nutshell, radiations are godsends or boons for life if used safely. If used devastatingly by wrong hands and minds, they can destroy many lives, be they humans, animals, or vegetation and property, with the long–term devastating side effects. Nature itself has provided us with the ozone layer in the Stratosphere to keep the inhabitants on Earth safe from the toxic radiation of the Sun.
The writer holds an M.Sc. degree in Physics and is currently teaching Physics in Colleges, Nepal.