The difference between photons and electromagnetic waves lies in their fundamental nature and how they are conceptualized in different frameworks of physics.
Electromagnetic waves:
- Electromagnetic waves are a type of wave that consists of oscillating electric and magnetic fields. They are described by classical electromagnetism, which treats them as continuous waves propagating through space.
- Electromagnetic waves have properties such as wavelength, frequency, amplitude, and speed of propagation. They obey the wave equation and exhibit phenomena like interference, diffraction, and polarization.
- Electromagnetic waves include a wide range of phenomena, from radio waves to microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. They span a spectrum of frequencies and wavelengths, each associated with different types of electromagnetic waves.
- These waves can be described by Maxwell's equations, which are a set of mathematical equations that describe the behavior of electric and magnetic fields and their interactions.
Photons:
- Photons, on the other hand, are discrete particles of electromagnetic radiation. They are quanta of light, meaning they are indivisible packets of energy.
- According to quantum mechanics, photons are considered elementary particles and are the carriers of electromagnetic force. They are massless particles that travel at the speed of light in vacuum (c).
- Photons exhibit both wave-like and particle-like behavior, as described by the wave-particle duality. This means that while photons are particles, they also exhibit wave properties such as interference and diffraction.
- The energy of a photon is directly proportional to its frequency (E = hf), where E is the energy, h is Planck's constant, and f is the frequency of the associated electromagnetic wave.
- Photons are fundamental to our understanding of light and play a crucial role in various phenomena, including the photoelectric effect, where the energy of photons is absorbed by matter, and in processes such as emission, absorption, and scattering of light.
In summary, electromagnetic waves are continuous waves that consist of oscillating electric and magnetic fields, described by classical electromagnetism. Photons, on the other hand, are discrete particles of electromagnetic radiation, considered as quanta of light in quantum mechanics. While electromagnetic waves are continuous and wave-like, photons are discrete particles that exhibit both wave-like and particle-like behavior.