@PM2Ring .... aaaaand, done.

@EmilioPisanty Looks good, but it's way over my head. But at least I could tell that the question was in your field before I read you were a coauthor. :)

@PM2Ring =/

Ah, well

Thanks for the ping, anyway

Riddle me this, GR people

Does Regge calculus depend on the polytopes used to tile the spacetime

I'm pretty sure that if a square tiling is acceptable on that manifold, then it would give the same results

But the GR people mostly do simplexes

Speaking of GR, can anyone shed light on this question regarding gravitational waves in a head-on collision of non-spinning black holes?

This sounds like an unpleasant problem

i'm sure there's a paper about it somewhere but it's probably not very palatable

I have vague memories of reading that in a head-on BH collision that up to half of the mutual KE + PE is shed as gravitational waves, but that might've assumed spinning BHs.

@Slereah Ok. But in that case, it sounds like you can't simply say there's no waves just because there's no angular momentum. ;)

It's probably doable in some approximation of linearized GR

@PM2Ring it's a duplicate anyway

My heuristic is that because during the collision there isn't a nice simple spherical EH, there must be waves emitted while the curvature changes, until it settles down into a single spherical EH.

@JohnRennie Looks good to me, although it doesn't specify non-spinning BHs. But it does say the wave production is pretty small, and simple.

@PM2Ring I'd advise just computing the quadrupolar moment of two point particles hurtling toward each other

@Slereah does anyone actually care about Regge calculus

i've never heard the phrase uttered in real life

care?

@RyanUnger you can use it for GR numerical simulations

the weather is so hot

@CaptainBohemian apparently France has recorded its hottest every recorded temperature. 44°C.

It's hot in the UK, but not that hot.

fortunately I'm not in the eye candy of the storm

@JohnRennie I agree, the UK is not that hot =P

I guess we should be grateful that we're just getting a regular summer here

if we were at the levels of anomaly northern Europe is getting now (and got last year), boy, that'd be the signal to flee...

@JohnRennie at night it's less than 30 C: 28<T<30, but I felt so hot earlier. Now with air conditioner, I feel fine. but in the last daytime, it reached 35.8 C as the highest.

@JohnRennie I'm seeing reports of 45.9 C from the BBC

and them joking that it happened on the same day that France plays the US :-)

@vzn As a classical fluid they choose a picture of jupiter, I gotta say that's pretty cool

Can Astro please get some quality questions...

@SirCumference From Muze? That's not going to happen in a hurry.

To be fair, Muze has been trying to improve his old questions (I think he had /has a question ban in Physics) and to ask better new ones. But without an adequate knowledge base, that's not an easy task.

@Hotlab If only that creative imagination could be harnessed for good instead of batshit insanity...

@PM2Ring I haven't seen much evidence of that on the other sites i've seen their questions

It's bad enough when someone's science knowledge comes mostly from pop-sci books. When it comes from random YouTube videoes, the situation is almost hopeless. At least books can present info in a structured fashion. Sure, there's some great stuff on YouTube, but you need to know where to find it. And you need to know how to recognize drivel when you see it.

@JMac He went through a phase a while ago of editing his old closed questions, as is recommended when you have a question ban. Unfortunately, the edits didn't help much. But at least he tried.

@PM2Ring That's what I've always noticed. He seems to acknowledge and somewhat understand when people explain his issues... but then his actions just show the exact same behaviour

True. It can be hard to assimilate new info when it clashes with your preconceptions.