3 ms·
You nerd sniped me :) In this context, I believe it is a kilo-Jansky, not a kilo-Joule * year. https://en.wikipedia.org/wiki/Jansky https://en.wikipedia.org/wi
by bqmjjx0kac 1y ago
You nerd sniped me :) In this context, I believe it is a kilo-Jansky, not a kilo-Joule * year.
https://en.wikipedia.org/wiki/Jansky https://en.wikipedia.org/wiki/Jansky
- dotancohen 1y agoI don't think that replacing two ill fitting but probable units with a single obscure unit is much of an improvement!
- 8bitsrule 1y agoIt appears to have something to do with CGS units. 1 Jy = 10-23 erg s-1 cm-2 Hz-1 (cgs) only their figure: L9.9 GHz < 2.1 × 10^25 erg s−1 Hz−1 leaves out the cm-2. (So not a density, like Jy. Perhaps 'L' is luminosity? ... As in: "The solar luminosity unit is a measure of the Sun's radiant energy and is equal to 3.828×10^(26) Watts." -(NRAO) While groping, I found this helpful page called Brightness in Radio Astronomy: http://physics.wku.edu/~gibson/radio/brightness.html http://physics.wku.edu/~gibson/radio/brightness.html
- dotancohen 1y agoI was thinking maybe joules/year e.g. energy/time might be some brightness indicator for some astronomical definition of brightness - especially in the non-optical wavelengths. But that's division, not multiplication. Another thread in my brain thought maybe the product of the two could be useful for people in that field, sort of how ISP is useful to people in rocketry but us normal people need to divide it by G(earth) to get something intuitive.
- guenthert 1y agoI don't think it's obscure in that field or for the target audience. You might want to read the soon to be published distilled and transposed article in popular mechanics ...
- rbanffy 1y agoIt’s mentioned in Contact, both movie and book.
- dotancohen 1y agoThanks. That was one of only two movies based on a book that I enjoyed as much as the book.