Photons - The Particles That Make Up Light | World Of Quanta

INTRODUCTION TO QUANTA

A photon is a particle of electromagnetic radiation. Although electromagnetic radiation behaves like a wave, we know that the waves can only occur in packets of particles with a certain definite energy. The energy of the packet is proportional to the frequency of the radiation. The German physicist Max Planck was the first to realize this. Photons also produced light. The production of photon particles by electrons in various metals clauses them to shine and that's the property of luster in metals.

So, now let us assume that you already do not have any knowledge on photons. So what are they basically?

Well, a photon by definition is a particle  representing a quantum of light or other electromagnetic radiation. WHOA~

So many terms in this definition. Let us understand it more clearly. We all know what a particle is, don't we? A particle is simply a very very small ball like substance that contains some charge. Well, simply, a particle is a very minute portion of matter. 

Now, a photon is a particle representing a quantum of light. Wait, what is quantum of light? And first things first, what is quantum itself? Now, quantum of light means Light quanta or photons, which is the other way round of telling them, yeah, so these are the discrete or the smallest amounts of light! You can use the words quanta and photons interchangeably. One additional thing you can keep in mind is that for light quanta or photons, we have a formula which is:

Photon = Planck's Constant x Frequency.

Now, we know that photons are the smallest amount of light. Well, if we go with the formula, what is this Planck's constant hanging in there? Well, it is a very small number = 6.626 x 10^-34!

Do you see that! That small number is Planck's constant. Now curious one amongst you might ask, hey, what is this Planck's constant about? Well, the answer is, this number, also known as Planck's constant, describes the behavior of particles and waves on the atomic scale, including the particle aspect of light.

Planck's constant, symbolized h, relates the energy in one quantum (photon) of electromagnetic radiation to the frequency of that radiation. In the International System of units (SI), the constant is equal to approximately 6.626176 x 10^-34 joule-seconds.

Now, what is frequency? You all know it. Right? Frequency is how much something occurs again and again or more frequently or more often. Well in physics, frequency is the number of waves that pass a fixed place in a given amount of time. 

And when we multiply the plank's constant with the wave frequency of light, we get the photon's energy.

AN EASIER FORMULA

The quantum of electromagnetic radiation is known as photon. Quantum here means to the smallest elementary particle and one amount of electromagnetic energy is called a photon.

The energy of a photon is inversely proportional to the wavelength of a photon.

A photon is characterized either by lambda λ (Wavelength) or Energy E.

Thus, the photon energy formula is given by:

E = hc/λ

Where,

E = Energy Of The Photon

h = Planck's constant

c = speed of light

λ = lambda / wavelength of light

THE DEEP QUANTUM

Now, you must ask this curious question, that why is the energy of a photon is equivalent to the wavelength of a photon.

First things first, if you are already not familiar with the terms like energy, frequency, wavelength, light etc. then why don't you try reading our other articles explaining it! Here are some links that must help you.

1) Energy | Mass Times Speed Of Light

2) Waves | Wavelength | Frequency

3) Light

Now, the amount of energy is directly proportional to the photon's electromagnetic frequency and thus, equivalently, is inversely proportional to the wavelength. The higher the photon's frequency, the higher its energy. Equivalently, the longer the photon's wavelength, the lower its energy.

ALBERT EINSTEIN: QUANTA AND QUANTUM

Einstein was the first to explain the concept of photons. He theorized that electromagnetic energy (light) comes in packets, or quanta as he said, which we now call it as photons. So, light behaves as a wave and as a particle, depending on the circumstances and effect being observed. This concept is more popularly known as the Wave Particle Duality.

Wave Particle Duality

Max Planck (The Planck's Constant Man) and Albert Einstein changed the world of physics by introducing the term quanta which were small packets of light at the dawn of the 20th century.

On December 18, 1926, Gilbert Newton Lewis coined the term Photon instead of quanta.

In a nutshell,

Quanta = Quantum Of Light = Small Packets Of Electromagnetic Energy (Light) = Photons.

ELEMENTARY PARTICLES

Photons are elementary particles which are the smallest particles in the world. Like Quarks, Leptons, Hadrons And Bosons. A photon is a type of an elementary particle.

A photon is a type of a Boson which is an elementary particle which has 4 more types. Basically Bosons are of 5 types: Photon, Gluons, W Bosons, Z Bosons And Higgs Boson.

Elementary Particles | Introduction

Check out the above link to know more. You'll also get to know the Standard Model Of Particle Physics.

WHOO~

THANK YOU FOR READING