It is interesting that as early as 5 BCE humans had already started theorizing atoms. Early knowledge of an infinitesimal, indestructible particle was flowing through the minds of great sages and philosophers in both India and Greece.
At around 2nd century BC, plainly out of curiosity, Indian Sage Kanada theorized that there exists a physical partical in nature which cannot be divided further. He named this particle parmanu or anu. His curiosity sparked by simply observing a grain of rice and then trying to splitting it up into as many small pieces as possible. He also stated that this indivisible atom (anu) can have two states – state of rest and state of motion; which can be compared with the Bohr’s atomic model theory of energy levels. Later he extended his study to explain ‘dyanuka’ or a diatomic molecule and ‘tryanuka’ or a triatomic molecule.
At around sometime similar as Sage Kanada there were two Greek philosophers equally curious also scratching their scalp to theorize the smallest element. Leucippus and Democritus defined that the natural world is built on two fundamental elements, the indestructible atom which is infinite in quantity filling up the infinite void.
Democritus hypothesized that different material posses small indestructible atoms that individually have some qualities and when all these atoms combine together they provide the material as a whole a specific quality. An example would be, atom of fire is sharp and pointy (hence it hurts when touched), atom of water would be round and soft etc.
The Greeks were so impressed by this theory that they decided to commemorate their philosopher on their national currency Drachma.
However, the atom wasn’t practically observed until Dalton in the 18th century practically observed and proved the basic fundamentals of atoms and developed the law of multiple proportions. You can read about this theory here.
Then, in late 19th century, sir J.J. Thomson through a practical experiment split open the unsplittable, the indestructible, the smallest element found in nature into its elementary particles and finally discovered the humble electron. The source of electricity and all of the underlying technology, I believe this is where it all began.
So we have reached first checkpoint:
- Where did it all began. The History
- What is the basic fundamental element for technology. The Electron
Electricity + Magnetism = Electromagnetism
Okay, now bear with me here, in order to understand the radiation we are all talking about, we will have to learn something about its basic fundamental elements: Electricity & Magnetism. I will try my best to explain it in the best and shortest possible way. So lets get on with it.
There are two types of electric charge present in every object, the positive and negative. Its the movement of these charges (explained soon) that creates electric current and their quantity determines the strength of this current. In an atom, an electron is negatively charged and proton (contained inside the nucleus) is positively charged.
But, in order to actually conduct electricity there has to be an imbalance in their quantities. Because, if the quantity of both positive and negative charges are the same then the object is said to be uncharged, because the net charge is 0 since there won’t be any kind of attraction or repulsion.
So, how does an imbalance of charges conduct electricity?
The imbalance makes the object to have more of one type of charge and less of the another type making it hungry for the another charge.
This imbalance, for e.g., can be an excessive positive charge, making it hungry for negative charges. When this positively charged object comes in contact with an object which has excess of negative charge, there is an exchange of charges between them to compensate for the imbalance causing flow of charge. This flow of charge creates an electric current. In fact, this phenomenon is so common that we have experienced it in our everyday life when we (excess negative charge) touch a metallic object or someone else and we get a small static shock. This is caused due to an imbalance in the charges.
In an electric circuit, the battery (or any other source of current) creates a voltage difference creating a permanent imbalance causing the electric charges to constantly flow between the ends of the battery creating an constant electric current, thereby supplying electricity to our houses.
Magnetism like electricity also attracts and repels objects. But a magnet has a north and a south pole as compared to positive and negative charges. However, we can generate a magnetic effect by passing an electric current through a wire. What does this mean? Remember the electric charge we talked about! That charge while its flowing creates a magnetic field around itself. If observed the animation below, and if you imagine the electric charge (yellow circle) flowing towards you outside the screen, then the white ring can be imagined as its magnetic field.
This is because every moving electric charge creates a physical phenomenon called magnetism. A solid example of this are speakers in your home theater systems.
Hence the concept of Electromagnetism was introduced by a Scottish scientist James Clerk Maxwell explaining the interaction of electricity and magnetism creating electromagnetism.
Wikipedia defines radiation as “the emission or the transmission of energy in the form of waves and particles through space or material medium“. We are exposed to radiation every single day. In fact the very source of life, the sun, radiates electromagnetic waves.
Basically there are 2 types of radiation:
- Ionizing: The ones which have the capability to change the chemical composition of an element. Yes, it has mutating effect and are dangerous for living beings. They do so by changing the electron count of an atom.
- Non-Ionizing: These waves do not have enough energy to knock out an electron but have sufficient energy to make them vibrate violently. Feeling warm in sunlight? Well, this is the reason!
Now, enough of reading lets actually watch a video to fixate in our minds what exactly is radiation?
So we have reached our second checkpoint:
- Electromagnetism. Charge, Electricity and Magnetism
- Radiation and its types.
We have reached the end of our first chapter, and have touched the basics that are essential for subsequent chapters.
Next up in 5G Literacy: Do we need 5G? Follow on and be ready to up skill your knowledge further in 5G.
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