Stars 1

Flashcards covering key vocabulary related to electromagnetic radiation, wave properties, photons, the electromagnetic spectrum, and atmospheric transparency from the lecture notes.

Electromagnetic radiation

A kind of radiation in which electric and magnetic fields vary simultaneously; commonly known as "light" and composed of oscillating electric and magnetic fields perpendicular to its direction of travel.

Radiation

Describes how the energy of light is transported from one location to another.

Wavelength (λ)

The length over which a wave repeats in pattern, typically measured in meters.

Frequency (f)

How often a wave repeats itself, measured in cycles per second or Hertz (Hz).

Speed of a wave

Equal to the length it travels over time, calculated as its wavelength multiplied by its frequency.

Speed of light in a vacuum (c)

A constant speed for all electromagnetic radiation in a vacuum, approximately 3 x 10^8 m/s.

Photon

The particle-like aspect of light, representing a quantum or "bundle" of energy.

Planck’s constant (h)

A fundamental physical constant, approximately 6.626 x 10–34 J·s, used to relate the energy of a photon to its frequency or wavelength.

Electromagnetic Spectrum

The full range of all types of electromagnetic radiation, which differ in wavelength and frequency but all travel at the speed of light in a vacuum.

Visible Light

The portion of the electromagnetic spectrum that human eyes can detect, roughly ranging from 400 nm (violet) to 750 nm (red).

Nanometer (nm)

A unit of length equal to one billionth of a meter (10^-9 m), often used to measure the wavelength of light.

Transparent (atmosphere)

Allows the passage of a specified form of radiation, such as Earth's atmosphere to visual and radio wavelengths.

Opaque (atmosphere)

Blocks or prevents the passage of a specified form of radiation, such as Earth's atmosphere to X-rays and Gamma Rays.

Transverse wave

A wave in which the oscillations are perpendicular to the direction of its motion.