I know it is because the electrons in hydrogen and helium absorb them however, they also drop back to ground state immediately and emit the previously absorbed photon. So there should be no net difference as absorbed photon gets emitted. Therefore the emission spectrum should not have missing lines. But they do. What am I missing?
1
-
7$\begingroup$ Does this answer your question? Why don't absorption and emission lines cancel out in our Sun? $\endgroup$– John RennieCommented Nov 6, 2020 at 5:19
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
4
The elements in the hot atmosphere surrounding the Sun absorb their preferred wavelengths of light being beamed out of the sun, but they then re-emit those absorbed photons in random directions- most of which are not aimed at us here on earth. So we see a solar spectrum with dark lines in it- representing those "missing" photons.
answered Nov 6, 2020 at 5:40
-
$\begingroup$ how about for a flame test? the colours absorbed are clearly seen as they get emitted. Why? Shouldn't they cancel each other out? $\endgroup$– mad112Commented Nov 6, 2020 at 7:05
-
$\begingroup$ @mad112 What do you mean by a flame test? $\endgroup$– gerritCommented Nov 6, 2020 at 9:27
-
$\begingroup$ This is incorrect. After all, if you extend this to every point on a spherical surface at Earth's radius, you would be claiming that these re-emitted photons don't show up anywhere, and that obviously is impossible if in fact they are re-emitted so as to escape the Sun. See the linked answer in the Close comments $\endgroup$ Commented Nov 6, 2020 at 13:08
-
$\begingroup$ That is not my claim. and do not the linked answers also make the point that the re-emitted photons are randomly aimed? $\endgroup$ Commented Nov 6, 2020 at 15:14