We say that light - is electromagnetic waves. We talk about the wavelengths of light, their speed and frequency msolebanky. But this inevitably raises the question: what range? When it comes to water waves, we can see that msolebletsya (though our visual perception of wave-like motion, and is false). In the case of the air ranges of sound. But in the case of electromagnetic waves varies "field". Up until the 1900 physics again and again tried to prove the existence of fluctuating environment in the form of an invisible gas - ether, which allegedly distributed light. But all the experiments proved unsuccessful or led to the opposite conclusion, arguing that the ether does not exist. Today, we are comforted by comparison: if the room temperature regularly falls and rises again, we can consider this process as oscillation.