# How light wave have thermal effect [duplicate]

In many books it is written that light is an electromagnetic wave, as we know there does not exist any oscillator that can oscillate an electron with a frequency of light.

My question is, how can we prove that light is electromagnetic in nature? what is light ? is there any physical meaning. Edit -after reading the articles i have one more question since light also carry heat radiation, heat can only transfer when there is a temperature difference, it mean light and heat both are same thing because we do not know about temperature of space so how can sun heat radiation can reach us A big EDIT -as my question about light is already answer by most of all ,BUT MY QUESTION WAS HOW HOW A LIGHT CARRY THERMAL ENERGY

This question comes from a false premise.

To say "you can't oscillate an electron at the speed of light" is like saying you can't drive a car at the temperature of boiling water. They're not measuring the same thing. Oscillation is a measure of cycles-per-unit-time. Speed is a measure of distance-per-unit-time. They're different things with different units.

We can absolutely oscillate electrons at the frequency of light. That's how radios work. A properly functional radio is proof that light is electromagnetic in nature. If light wasn't electromagnetic then it wouldn't induce a current in a radio antenna.

"What is light?" is a philosophical question with many different answers depending on the context. That's because a single "thing" can have multiple definitions. You could say the USA is "the country founded by George Washington" or "the nation-state immediately south of Canada" or "the federal republic formed in 1789". All three definitions refer to the same United States of America.

In physics, the word "light" has a well-defined physical meaning. But there's multiple ways of defining that one thing. You can define light as "electromagnetic wave", "photons" or "that stuff a lamp shoots at you". Which definition you use depends on who you're talking to and what you're talking about.

• The frequency of radio waves is a lot lower than that of visible light. – PM 2Ring Jun 9 at 10:33

how can we prove that light is electromagnetic in nature ?

The easiest way is to observe that it interacts with charged particles. The electromagnetic force is by definition the force that acts on charged particles. Furthermore, it is a long range force, unlike the strong and weak forces which act only over nuclear distances. So light acts at long distances and interacts with charged particles, therefore it is an electromagnetic force.

Besides this, it behaves as expected regarding electromagnetic interactions with materials. It is reflected by smooth conductors and dielectrics, and when it is reflected from dielectrics it becomes polarized.