AI Tutor
Your eyes only detect less than one ten-trillionth of the light existing in the universe around you right now.
The entire family of light waves is called the electromagnetic spectrum, stretching from kilometer-long radio waves to subatomic gamma rays.
How do these wildly different waves all move, and why do some carry vastly more punch than others?

The Wave-Energy Connection

Every electromagnetic wave travels through a vacuum at the constant speed of light, cβ‰ˆ3.00Γ—108Β m/sc \approx 3.00 \times 10^8\text{ m/s}, governed by the wave equation c=fΞ»c = f\lambda, where ff is frequency in hertz and Ξ»\lambda is wavelength in meters.
In 1900, Max Planck discovered that light transfers energy in discrete packets called photons, where energy is directly proportional to frequency: E=hfE = hf (h=6.626Γ—10βˆ’34Β Jβ‹…sh = 6.626 \times 10^{-34}\text{ J}\cdot\text{s}).
Because energy scales directly with frequency, we can split the spectrum into distinct zones tailored for specific technologies. Let's look at the lowest-energy waves first.

Radio Waves and Microwaves

Radio waves have the longest wavelengths (from meters to kilometers) and pass easily through Earth's atmosphere and interstellar gas, making them ideal for long-distance telecommunications and radio telescopes that map distant galaxies.
Microwaves have shorter wavelengths (millimeters to centimeters) that match the rotational frequencies of water molecules, allowing microwave ovens to heat food efficiently while also powering radar and Wi-Fi networks.