Photon

A photon is a fundamental particle of light and all other forms of electromagnetic radiation. It's a quantum of electromagnetic radiation, carrying energy and momentum but having no mass or electric charge. Photons exhibit wave-particle duality, behaving as both a wave and a particle. They are the force carriers for the electromagnetic force and mediate interactions between electrically charged particles. Their energy is directly proportional to the frequency of the electromagnetic wave and they travel at the speed of light in a vacuum.

Photon meaning with examples

• Solar panels convert photons from sunlight into electrical energy. When light strikes the silicon, photons excite electrons, creating a current. This process relies on the photoelectric effect, where photons transfer energy. Each photon carries a specific amount of energy related to its wavelength. Therefore, capturing photons is crucial for solar power generation.
• In medical imaging like X-rays, photons are used to create images. X-ray machines emit high-energy photons, which pass through the body. Dense tissues absorb more photons than less dense tissues, producing a contrast. This contrast is then captured and displayed to reveal internal structures. The type of the photon influences the outcome.
• Laser technology depends on the controlled emission of photons. Lasers emit coherent photons with the same wavelength and phase, creating a highly focused beam. Applications include cutting, welding, and data storage. The purity and intensity of the photon stream are essential for these different applications of photons.
• Digital cameras use photons to capture images. The camera's sensor detects incoming photons and converts them into electrical signals. Each photon triggers a pixel to record intensity. The number of detected photons determines the brightness and color of the image. Proper calibration ensure an effective use of all the photons.