How can electromagnetic waves travel in a vacuum?

Answer 1

Elctromagnetic radiation is a moving "pair" of "waves" in space. One is a magnetic wave and the other is an electric wave, and they move in phase and at right angles to each other. When they are created by a moving charge or charges, the energy of the wave is "bundled" into this pair of waves or fields, and moves away from the source like the ripples across a pond. Except the moving fields do not need anything to "carry" the energy. No medium is required. In contrast, a water wave or a sound wave is mechanical energy, and the source transferred energy into the medium, and the medium must carry it. the electromagnetic wave is sulf sustaining and can move through a complete vacuum. Use the links below to related questions and related articles.

Answer 2

Electromagnetic waves travel in space because their nature is to "leave" their point of creation. If we toss a rock into a smooth pond, ripples move out from where the rock come down. The rock gave kinetic energy to the water, and the water can't "hold" the energy stationary in one place. The energy moves away from where it was initiated.

Light is a different critter in that it is electromagnetic energy, and, as such, it does not need a medium to travel through. It moves very well through the vacuum of space. But the idea that it won't stay where it was created makes it similar to the water wave. Wherever this little electromagnetic ray began, it didn't stay there. Light is electromagnetic energy, and it has an innate desire to move. Movement is actually part of what light is. Light is a moving electric and magnetic field. Both. At the same time, and at right angles to each other. By definition light moves, and it will travel anywhere it can. That's why light rays, little bundles of electromagnetic energy, move through space or any other medium that they can move through.

Answer 3

Max Equations describes the EM fields. Assume you have a electric field that is changing with respect to time, it will generate a time dependent Magnetic field (This is ampere's law with Maxwell correction.) That magnetic will in turn induce a time dependent electric field (Faraday's Law) And the process continue indefinitely unless the Permittivity or the Permeability of the medium changes.

Answer 4

Electromagnetic waves can travel in a vacuum because this wave is a moving magnetic and electric field. These fields do not require a medium to travel in, and they "carry" the energy of the electromagnetic wave with them. This makes the electromagnetic wave different from mechanical waves like sound.

With mechanical waves, we find the source putting the energy of the wave into the medium through which it is going to travel. Electromagnetic waves carry the electromagnetic energy away from the source without a need for a medium through which to travel. The moving fields carry the energy of the wave, and a vacuum presents no obstruction to the waves at all.

Answer 5

-- I can see the sun and, even with my eyes closed, feel its warmth upon my brow.

-- Mine eyes behold the moon, the stars, planets, and sundry other wonders of the

cosmos, revealed by their beams of light across the trackless and vacuum-filled void.

-- When our intrepid astronauts stood upon the surface of our moon, their radio

transmissions were heard clear and crisp by their colleagues and loved ones, all

safe on terra firma and separated from them by a quarter million miles of vacuum.

Answer 6

Because we use satellites in space to relay radio and TV signals.

Of course, once we realized that light and heat are, themselves, electromagnetic waves, it became obvious. The light from the Sun manages to travel through the vacuum of space to reach the Earth.

Answer 7

Heat radiation is electromagnetic waves, and those travel best in a vacuum.