ScienceVerseLearning path: Telescopes
The concepts to learn before Telescopes, in order. Each step links to its page and, where one exists, its quiz.
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Your path
- LightDirect prerequisite
Light is an electromagnetic wave that travels through vacuum at exactly 299,792,458 m/s and more slowly through materials. At a boundary it reflects (angle of reflection equals angle of incidence) and refracts according to Snell's law, n₁ sin θ₁ = n₂ sin θ₂. Visible light spans roughly 400–750 nm, and it also behaves as a stream of photons, each with energy E = hf.
- TelescopesYour goal
A telescope collects light (or other radiation) from the sky over a much larger area than the eye, letting us see fainter objects and finer detail. Its power depends mainly on the size of its main mirror or lens. Because Earth's atmosphere blurs images and blocks many wavelengths, astronomers combine giant ground-based telescopes with observatories in space such as Hubble and the James Webb Space Telescope.