As we look up at the starry sky on a clear night, what we see is a vast expanse of emptiness, or void. But this emptiness isn’t entirely empty as it’s filled with tiny particles that can facilitate the transfer of energy from one place to another. Waves are disturbances that travel through these particles and carry energy along with them.
There are many types of waves ranging from sound waves to electromagnetic waves such as radio waves, infrared radiation, visible light, ultraviolet radiation, X-rays etc., which travel through different media like liquids, solids and gases but there exists only one type of wave that can travel through empty space – electromagnetic waves.
Electromagnetic (EM) waves consist of two interacting fields called electric fields and magnetic fields. These fields oscillate perpendicular to each other in mutually perpendicular planes and propagate in free space without requiring any medium to travel through. This means they can traverse vacuum i.e., regions completely devoid of matter like outer space. It was James Clerk Maxwell who first predicted the existence of electromagnetic waves by using mathematical equations known as Maxwell’s equations.
Properties Of Electromagnetic Waves
– EM Wave Speed: The speed at which an EM wave travels in a vacuum is denoted by ‘c’, which stands for ‘speed of light’. In SI Units c = 299792458 m/s.
– Wavelength And Frequency: Electromagnetic Radiation has both wavelength (λ) and frequency (ν). The relationship between these two properties is given by λ * ν = c.
– Polarization: As mentioned earlier an EM wave consists of oscillating electric and magnetic fields perpendicular to each other but also perpendicular to its direction of propagation too. Plane polarized light refers to a beam in which all the activated electrons vibrate parallelly while circular polarization describes a situation where electrons rotate about their axis at regular intervals giving rise to either clockwise or anti-clockwise-handed circular polarization. Elliptical polarization occurs when electrons undergo some combination of the two other kinds.
– Energy and Intensity: Electromagnetic radiation carries energy in the form of photons. The number of photons per second that cross a unit area is known as flux or intensity.
Types Of Electromagnetic Waves
There are several types or classifications of electromagnetic waves, which sorted according to their wavelength (or frequency), but at the far ends of this spectrum we have radio waves and gamma rays, respectively:
(i) Radio Waves – Longest Wavelengths/Lowest Frequencies
(ii) Microwaves – Around 1MM cm range for wavelengths
(iii) Infrared Radiation – Wavelengths between 780nano meter (nm) to 1000um micrometer(λ= r.T)
(iv) Visible Light – Wavelengths from violet to red colors roughly about 400-700 nanometers(nm),
(v) Ultraviolet radiation – Wavelength ranges between nm to , where luvlx>Luv)
(vii ) Gamma rays – Shortest wavelengths/highest frequencies
The unique properties of electromagnetic radiations make them useful in a wide variety applications including:
(i). Medical Applications: X-rays are used extensively for taking diagnostic images as they penetrate through human skin with ease without any harmfull effects . On the other hand, MRI uses non-ionizing radio waves plus magnetic fields within an imager-like device to map local changes in brain activity;
(ii). Communications Technology: Radio waves such as those broadcast by radio stations are utilized for communication purposes over long distances via antennas while microwaves are used for your everyday cell phone signals.
(iii). Astronomy: Astronomers use virtually any frequencies in the EM spectrum to study celestial objects like planets, comets, stars and galaxies. The cosmic microwave background radiation (CMB) is light that dates back to just before the formation of atoms emitting at a wavelength of about 1100nm , it was first detected by a radio telescope in New Jersey in 1965;
(iv). Energy Production: Electromagnetic waves play crucial roles during both nuclear reactions taking place within stars as well as what happens when we convert sunlight into electrical power using photovoltaic cells which absorb very high-energy photons from UV-rays or X-rays .
Electromagnetic waves aren’t just fascinating phenomena either; they also have tremendous practical applications across many fields. Being able to travel long distances through empty space without being stopped by anything makes them ideal for communication purporses too-whether broadcasting via radio antennas or sending signals between satellites orbiting our planet among other things.. They’re equally central forces within modern technology and medicine more broadly speaking because again electromagnetic radiations reveal information about biological structures including both normal tissues as well tumors depending on their location frequency level.From an astrophysics standpoint, elecrtomagnetic wave emitters such as Supernova explosions produce high-frequency gamma rays whereas stars emit ultraviolet wavelengths visible only with specialized telescopes where images showcase unique phenomenon showcasing different wavelengths around observed celestial bodies.Although some types of electromagnetic radiation can be dangerous if not handled correctly so precautions must always be taken when working with them but generally the existence of this one type is exciting news!