Spectrum — Science definition

Defined in 2 courses:

Where it is taught

In use

Violet slows most and bends most, red slows least and bends least, and white light entering a prism therefore spreads into a spectrum.

Refraction, Color & Transparent Materials

A spectrum is evidence about the light interacting with matter, not a sample of the star brought to Earth.

Spectra & Evidence for an Expanding Universe

Questions using spectrum

Problem 1

Which statement correctly uses spectrum in Refraction, Color & Transparent Materials?
  1. spectrum: A range of light components distinguished by wavelength.
  2. Every ray must bend sideways at every transparent boundary.
  3. An object appears the same color under every possible light source.
  4. One illustrative result establishes every real condition and needs no further evidence.
Answer and explanation

spectrum: A range of light components distinguished by wavelength.

A range of light components distinguished by wavelength. The ray bends toward the normal because 22° is less than 35° in this air-to-water model. The card appears dark because the red-only source supplies no blue for it to reflect. These diagrams omit detailed wavelength response, intensity, and actual material variation; they are not universal measurements of every card or liquid.

Problem 2

Why does a galaxy redshift–distance pattern support expansion more strongly than one spectrum?
Hints

State what the supplied observations or conditions establish, and separate that from any assumption.

Answer and explanation

A systematic relationship across many galaxies tests a global model rather than one object's local motion.

Problem 3

Light from distant galaxies is shifted toward the red end of the spectrum, which indicates they are
  1. approaching
  2. receding
  3. stationary
  4. hotter
Answer and explanation

receding

Redshift corresponds to increasing distance between us and the source.

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