image credit: N.A.Sharp, NOAO/NSO/Kitt Peak FTS/AURA/NSF; image source.
This image (hi-res version) shows sunlight spread out according to its color like the text in a page of a book (moving from left to right across the page, and then dropping down to the next line). The many dark vertical strips are absorption lines in the sun's visible spectrum. These lines are produced by atoms in the outer part of the sun, which absorb energy selectively. To find out more, see Atomic Absorption and Emission Spectra.
Analysis of these lines determines the chemical composition of a star. To learn more, visit Spectra.
(This feature was updated on April 26, 2014.)
Eames Office: Powers of Ten
To see the universe at different scales, from the most distant galaxies all the way down to subatomic particles, visit these sites:
Secret Universe: The Worlds Within by Molecular Expressions
Powers of Ten by Charles and Ray Eames.
One of these sites shows the same image for six consecutive powers of ten. Can you find it? Do these six images make sense?
(This feature was updated on 5/21/2013.)