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John Rennie

05:50

The broad peak shows when the two stars are superposed, and the spike appears when the planet crosses the distant star. So the spike will lead or follow the broad peak depending on whether the planet was on the leading or trailing edge of its star when the transit occurred.

Though the first animation looks odd as the planet is on the trailing edge of its star but the spike appears before the broad peak.

5 hours later…

Manas Dogra

10:56

Can it be intuitively understood why we need the Ricci scalar while defining a scalar field theory conformally coupled to gravity?

ACuriousMind

11:14

@ManasDogra I mean, there isn't a lot of other scalars you could write in front of the $\phi^2$ term, is there?

In a conformally-invariant theory, you have that the stress-energy tensor vanishes, so the trace of the Einstein equations says that $R$ is simply proportional to the cosmological constant, so the $R\phi^2$ is really "just" a mass term on-shell and not something weird

if you're looking for "intuition" that that matter action is really conformally invariant, I don't know of any, this computation is notoriously so annoying that everyone just cites some other poor soul who actually bothered to do it :P

Dabed

11:44

@JohnRennie thanks, yes the planet is trailing in both but I had actually my bets on the first one since I thought that when the planets goes over the background star a dip should occur similar as in the transit method (en.wikipedia.org/wiki/…) only that here the planet transits over the background star rather than in its orbit over the leading star but totally unsure on it.

Slereah

12:01

You basically just have elements made from the Riemann tensor, the metric and the covariant derivative

At lowest order there aren't that many combinations that are scalars

5 hours later…

Emilio Pisanty

17:04

Q: Relation between Area under $I$-$H$ Hysterics Loop and $B$-$H$ Hysterics Loop

If the area under the I-H hysterics loop and B-H hysterics loop are denoted by $A_1$and $A_2$ (The symbols have usual meaning as set in electromagnetics), then $A_2=\mu_oA_1$ $A_2=A_1$ $A_1=\mu_oA_2$ $A_2=\mu_o^2A_1$ The correct answer for this problem is option 1) $\boxed{A_2=\mu_oA_1}$. M...

I love a good hysterics loop

ACuriousMind

17:17

We've made it a long time without a hysterics loop and I hope that trend continues :P

I wonder whether OP misspelled that all on their own or whether some autocorrect that didn't know what hysteresis is was in play here

1 hour later…

Slereah

18:35

ACuriousMind

18:55

that looks as if it only understood the "diagram" part

Slereah

19:41

it is not very good at letters in general

Physics Meta

Q: We shouldn't answer homework question directly, should we?

Taking the question as example, where someone solved the problem for the author whereas mine was related to hint (cause there's some steps left to think/solve). But -1 on my answer is for what? Solving a homework question isn't our goal. IIRC, it's (solving homework for someone) against the rules...

discussion homework-and-exercises

3 hours later…

Physics Meta

22:18

Q: (How) Should I move a quation from Math SE to Phusics SE?

I asked a math question https://math.stackexchange.com/q/4475036/342834 in an area where physicists are likely to have a great deal of practical background. I had originally intended to post the Physics SE, but forgot to switch communities. I believe posting the same question to both communitie...