Questions tagged [electromagnetic-spectrum]
Questions about a certain range of frequencies of electromagnetic radiation, given e.g. as wavelengths or wavenumbers. Consider using the tag "wavelength" as well.
4
questions
9
votes
1
answer
1k
views
Why is Ganymede's aurora only visible in ultraviolet while Earth's is bright green and red?
GANYMEDE AURORAE
NASA's Hubble Space Telescope observed a pair of auroral belts encircling the Jovian moon Ganymede. The belts were observed in ultraviolet light by the Space Telescope Imaging ...
- 1,489
27
votes
3
answers
4k
views
Why do some electromagnetic waves continue travelling while others disappear?
Cosmic background radiation emitted when the Universe was very young still exists. But my wifi signal seems to disappear a short distance from my apartment. Why?
- 555
5
votes
1
answer
759
views
Would a red dwarf star resemble our own Sun at sunset to an observer on a nearby planet?
Suppose you're observing a red dwarf star at Noon from the surface of an Earth-like planet orbiting in the red dwarf's habitable zone, so that the red dwarf's luminosity is equal to our own Sun.
Aside ...
- 183
1
vote
0
answers
28
views
do we observe emission spectrum? [duplicate]
When light generated by the fusion in the sun goes through the layers of the sun and finally reaches outer layers and in the end atmosphere of the sun, we know it goes through hydrogen for example. ...
- 203