Description of electromagnetic waves and electromagnetic radiation

By Robert M. Hazen, PhD, George Mason University

James Maxwell’s four equations give the first complete description of electromagnetism, and he tells us that light is a form of electromagnetism. But there is more – an introduction to the concept of electromagnetic waves that has far-reaching consequences for science.

Digital wave with purple and blue colors.
Electromagnetic waves follow the same rules as other waves. (Image: Shutterstock)

Power transmission

The first law of thermodynamics states that waves provide the same energy. You can transfer power from one place to another without moving. Therefore, waves on the surface of the ocean, or waves, sound that travels toward you, earthquakes – they do not move much, they only move their energy in bulk. Waves always transmit energy through the medium.

It can be solid, it can be liquid, it can be gas. And for decades scientists have thought that light must also travel through the medium, in small quantities of medium ether. We now realize that electromagnetic waves can travel through space. He is a strange concept, but that is what makes the light shine, and we must accept that it is a characteristic of Him.

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Expressing waves

We can use four different variables to define waves. The first is wavelength. This is only from one wave to the other. You also have something to say; That height of the storm. The third variable is frequency, and that’s how many beats per second. You may have a relatively low frequency, or you may have a very high frequency, with a number of beats per second.

Frequency per second is also related to the length of the storm in some cases. This is also true of light. And finally, you have the speed of the waves, the speed of the waves. Those are the four variables of any wave – its length, width, frequency and velocity.

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Wave variables

There is a simple formula that matches all three of these variables. The wavelength, velocity, and frequency are related as follows: velocity is equal to the frequency wave (v = λf). In other words, the speed is per second in meters. That is, the wavelength of each wave is equal to the number of waves passing per second. And we can do simple calculations.

For example, suppose you have a wave that is two meters long and travels at six feet per second. Well, you can apply this formula. Velocity is equal to the frequency (v = λf) of the wavelength. Therefore, if you want to solve, for example, frequency, frequency divided by wavelength (f = v / λ).

In this case, we know that the speed is six meters per second and the wavelength is two meters. Thus, frequency, divided by six meters per second, two cycles per second, three waves per second. And you can distort this formula the way you want it to be.

Applying wave theory

Basic concepts of how waves travel are easily applied to electromagnetic waves. First, Maxwell’s formula is that the only limit to a wave is that it travels at a constant speed in an empty space. That is often called the letter C. For example, in Einstein’s famous E = mc2, C is the speed of light – 300,000 km / h.

An important point about light is that the shorter wavelength, the higher the frequency, the more powerful a wave is. The maximum electromagnetic radiation therefore has a short wavelength.

The concept of light speed.
All electromagnetic waves travel at light speeds. (Image PiakPPP / Shutterstock)

Adjusted speed

There is no limit to wavelength or frequency. Be aware, however, that the tide is in perfect balance. The wavelength and frequency are then interrelated. The wavelength is equal to the velocity of light emitted by electromagnetic waves. Frequency for electromagnetic waves is equal to the wavelength of light. There is an inverse relationship here.

Now, let’s understand the nature of electromagnetic waves. Think of a single split strand that is produced by running a comb through your hair. The comb is now charged. Think about what would happen if you swung this comb. There are electric charges moving forward and backward in space. And these electric charges exert power on everything in the universe, including every electron around it.

Every electron is everywhere – in the air, in the solid, in your body. The idea is that as the electrons in the comb move forward and forward, they exert slightly different forces on the electrons in the air and elsewhere, and these forces travel only outward through the movement of particles filled with other particles around them. .

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Self-propagating wave

This is, in fact, the only consequence of Columbus’ law that says that every accused person has power over the other. It was this interaction built into Maxwell’s equations, and Maxwell realized that the information that one electron is oscillating travels to other electrons at 186,000 miles per second – that is the speed of light.

Now think of the effect of electrons moving back and forth. That movement is a small variable electric current in motion, and a variable electric current must also produce a magnetic field. But different magnetic fields must produce electric current, so only the process of oscillating an electron creates an electric field, a magnetic field that connects the magnetic field back and forth at the same time, and that is electromagnetic radiation emitted in all directions.

It’s not just an electric field, it’s not just a magnetic field, it’s interconnected. And these are like waves of light coming out of every moving object. This is how you produce electromagnetic radiation; It is a complex electromagnetic wave that travels through everything around it.

Common questions about electromagnetic waves and electromagnetic radiation

Q: What are the variables used to describe waves?

We can use four different variables to define waves – length, the Width, Frequency and speed.

Q: How do wavelengths, speeds and frequencies relate?

Wave length, velocity, and wave frequency are related as follows: velocity from Wave length Frequent repetition.

Q: What is Maxwell’s formula for electromagnetic waves?

The only limitation on Maxwell’s formula Electromagnetic waves It is moving at a constant speed in an empty space. This is the speed of light, 300,000 km / h.

Q: How are electromagnetic waves generated?

An electron is a small dynamic electric current that moves back and forth, and various electric currents must also produce a magnetic field, which must produce an electric current, and so on. Only the process of electromagnetism on the surface creates an electric field, a magnetic field intertwined back and forth simultaneously, and that is it. Electromagnetic radiation.

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