What is a electromagnetic waves?

Answer 1

Usually we call it light but it includes micro waves, infrared light, visible light, ultraviolet light, x- rays, and gamma rays. Electromagnetic rays (light rays) are those in which both electrical and magnetic components are oscillating prependicular to each other these electrical and magnetic components oscillate in a plane perpendicular to plane of propogation suppose an electromagnetic wave is propogating in Xplane then its two components oscillate in y and z directions (in a cartession system) Electromagnetic radiation is the term given to a type of radiation which includes, in order of decreasing energy: gamma rays; X-rays; UV rays; visible light (from violet to red); Infra-red; microwaves; radio waves. All EM radiation travels at the speed of light because all it is is different forms of light, only a very small part of which humans can see.

All EM radiation has FREQUENCY and WAVELENGTH. They are inversely proportional to each other, and FREQUENCY x WAVELENGTH = SPEED OF LIGHT. High frequency radiation is dangerous to living things because individual photons (or "particles of light") carry enough energy to break the chemical bonds which hold DNA together, and this can lead to cancer. This is why X-rays and UV light should be avoided. This is also the reason why in theory microwaves and radio waves cannot cause cancer; the individual parcels of energy are not powerful enough to break bonds. Because electrons in bonds can only accept one photon at a time, the number of photons (aka the intensity of the radiation) is irrelevant; only their strength matters.

Answer 2

Usually we call it light but it includes micro waves, infrared light, visible light, ultraviolet light, x- rays, and gamma rays. Electromagnetic rays (light rays) are those in which both electrical and magnetic components are oscillating prependicular to each other these electrical and magnetic components oscillate in a plane perpendicular to plane of propogation suppose an electromagnetic wave is propogating in Xplane then its two components oscillate in y and z directions (in a cartession system) Electromagnetic radiation is the term given to a type of radiation which includes, in order of decreasing energy: gamma rays; X-rays; UV rays; visible light (from violet to red); Infra-red; microwaves; radio waves. All EM radiation travels at the speed of light because all it is is different forms of light, only a very small part of which humans can see.

All EM radiation has FREQUENCY and WAVELENGTH. They are inversely proportional to each other, and FREQUENCY x WAVELENGTH = SPEED OF LIGHT. High frequency radiation is dangerous to living things because individual photons (or "particles of light") carry enough energy to break the chemical bonds which hold DNA together, and this can lead to cancer. This is why X-rays and UV light should be avoided. This is also the reason why in theory microwaves and radio waves cannot cause cancer; the individual parcels of energy are not powerful enough to break bonds. Because electrons in bonds can only accept one photon at a time, the number of photons (aka the intensity of the radiation) is irrelevant; only their strength matters.

Answer 3

Electromagnetic waves are the mechanism by which electromagnetic energy (electromagnetic radiation) moves. They are composed of two components: an electric wave, or an electric field, and a magnetic wave or magnetic field. The fields are in dynamic motion, and these two waves are in phase and move at 90 degrees to each other. The orientation of this "package" can vary in the space through which it moves, which leads to what we term polarization, but the electric and magnetic components always maintain the right angle relationship to each other. Draw an "X" with the angles it creates equal to 90 degrees. Got it? A cross? Now rotate it just a bit. The whole thing. Now a bit more. Now a bit more. You are looking at the electromagnetic wave as it's coming at you (or going away), and you're changing the polarization of the cross without changing the cross itself. Let's jump.

One of the four basic forces in the universe is the electromagnetic force. Not the electric force, not the magnetic force, but the electromagnetic force. You can't have one without the other. Ever. A magnetic field is alaways created by some sort of charge movement. It is the only way a magnetic field can be created. Just like you can't have gravity without mass, you can't have magnetism without some sort of charge movement. Any time a charge moves, a magnetic field is created. All the time. Every time. No exceptions. Let's jump to go a step further.

Let's take a simplified example. Picture a pond as smooth as glass. We walk out on a low dock and kneel down at the water. Then we take our index finger and just "tap" the surface of the water one time. A ripple is generated, and it moves out away from the point where we initiated it. We good? Let's bounce a bit. If we take a charged particle like, say, an electron that is in orbit around an atom, and we give it some energy to kick it out to the next higher orbital; we have ionized the atom. The electron will then "dump" that extra energy and return to its original orbital. That energy it dumps will take the form of a "particle" or "package" of energy - a quantum of energy. And it is a moving electric and a complimentary moving magnetic field - just like the ripple on the pond. Only it is this "coupled" electric and magnetic "bundle" of energy. It's a photon, or a quantum of electromagnetic energy.

The energy of the wave is carried in the moving fields, and that is why the wave does not require a medium through which to travel. In fact, anything other than a vacuum will attenuate or "suck energy" out of the wave a bit at a time through the distance through which the wave travels in that medium.

As you might have guessed, electromagnetic radiation comes in different "amounts" or amplitudes, and in different frequencies (energies). From radio waves through microwaves, and through infrared light, visible light, ultraviolet light and X-rays all the way to gamma rays, there is a full spectrum of this energy.

This gets deep, but the essence of what is happening is here. Simple, but subtle and elegant. Reachable by even elementary school investigators. It is the essential nature of the universe we live in.

Wikipedia has more information, and a link is provided below to their post on electromagnetic radiation. Further investigation is encouraged. At least surf on over and look at the drawing of the moving and electric and magnetic fields to lock that in. Maybe skim the article while you're there, or at least bookmark it. You've just peeked through the window in the quantum mechanical universe. Enjoy the view. Wonder at it. It is the reality in which we live.

Usually we call it light but it includes micro waves, infrared light, visible light, ultraviolet light, x- rays, and gamma rays.

Electromagnetic rays (light rays) are those in which both electrical and magnetic components are oscillating prependicular to each other

these electrical and magnetic components oscillate in a plane perpendicular to plane of propogation

suppose an electromagnetic wave is propogating in Xplane then its two components oscillate in y and z directions (in a cartession system)

LightElectromagnetic radiation is the term given to a type of radiation which includes, in order of decreasing energy: gamma rays; X-rays; UV rays; visible light (from violet to red); Infra-red; microwaves; radio waves. All EM radiation travels at the speed of light because all it is is different forms of light, only a very small part of which humans can see.

All EM radiation has FREQUENCY and WAVELENGTH. They are inversely proportional to each other, and FREQUENCY x WAVELENGTH = SPEED OF LIGHT.

High frequency radiation is dangerous to living things because individual photons (or "particles of light") carry enough energy to break the chemical bonds which hold DNA together, and this can lead to cancer. This is why X-rays and UV light should be avoided. This is also the reason why in theory microwaves and radio waves cannot cause cancer; the individual parcels of energy are not powerful enough to break bonds. Because electrons in bonds can only accept one photon at a time, the number of photons (aka the intensity of the radiation) is irrelevant; only their strength matters.

Answer 4

a wave of energy propagated in an electromagnetic field