WOAH, SCIENCE!

(Sorry, I’m hyper.)

Today I finished formatting a business textbook (barf) and actually started working on a fun textbook for once.

Astronomy! In the second chapter I read about something I’d never heard about before: forbidden lines.

What’s a forbidden line? According to Encyclopedia Britannica, it’s an emission line in the spectra of certain nebulae that is not observed for those same gases on earth. Why? Because apparently, on earth those gases cannot be rarefied sufficiently.

Forbidden lines result from electrons in the upper energy levels of gases transitioning to a lower energy level. This transitioning requires the atoms to be undisturbed (i.e., not bumping into other atoms) and takes a long time. The resulting photon emissions are very weak. In labs on earth, these transitions are even rarer (“highly improbable”) because the excited atoms have a much greater chance of hitting other atoms and disrupting the level transitions of the electrons.

In interstellar space, however, the atoms are able to be undisturbed long enough for the electrons to make these transitions. In fact, according to the Encyclopedia of Science, up to 90% of the visible brightness of some nebulae can be attributed to these forbidden spectral lines.

Cool, huh?