The electromagnetic spectrum

By Samar Bhatia

The electromagnetic spectrum is the range of frequencies of electromagnetic radiation, along with their corresponding wavelengths and photon energies. It is a fundamental concept in physics and is widely used in a variety of fields.

The range of wavelengths in the electromagnetic spectrum can vary from 1 Hz to 10^25 Hz. These wavelengths can vary in size from that of a kilometer to that of an atomic nucleus. Electromagnetic waves are divided into different bands, ranging from low frequency (long wavelength) waves such as X-rays, gamma rays, infrared, and microwaves to high frequency (short wavelength) waves such as extreme ultraviolet rays and hard X-rays.

To understand the different types of waves in the electromagnetic spectrum, we can look at the individual properties of some of them. For instance, gamma rays, which are denoted by the symbol Y, have a wavelength of 1 picometer (pm), a frequency of 300 exahertz (EHz), and an energy per photon of 1.24 megaelectronvolts (MeV). Hard
X-rays, which are denoted by the symbol HX, have a wavelength of 10 picometers, a frequency of 30 EHz, and an energy per photon of 124 kiloelectronvolts (KeV). Here, the wavelength is measured in picometers, which is one trillionth of a meter.

The frequency of these waves is denoted by the symbol lambda (λ), which was Einstein’s most famous mistake. Lambda helps to calculate the length of these wavelengths and the speed at which they travel. Max Planck, who created the Planck constant, also discovered that light is absorbed by a quanta, which we now call a photon in modern science.

It is interesting to note that the electromagnetic spectrum is not just limited to the visible light that we can see. It also includes radio waves, which are used for communication, and gamma rays, which are produced by the decay of radioactive atoms. X-rays are used for medical imaging, while microwaves are used in cooking and communication. Infrared waves are emitted by warm objects and can be used for thermal imaging, while ultraviolet rays are responsible for sunburns and skin cancer.

Overall, the electromagnetic spectrum is a complex and fascinating concept that has
wide-ranging applications in various fields. It helps us understand the nature of light and how it interacts with matter. The different types of waves in the electromagnetic spectrum have varying properties that make them useful for different purposes. The study of the electromagnetic spectrum continues to advance our understanding of the world around us.