UmbralRaptor changed the topic of #principia to: READ THE FAQ: http://goo.gl/gMZF9H; The current version is Darboux. We currently target 1.3.1, and 1.4.3. <scott_manley> anyone that doubts the wisdom of retrograde bop needs to get the hell out | https://xkcd.com/323/
awang has joined #principia
maccollo has quit [Quit: webchat.esper.net]
something6 has joined #principia
something6 has quit [Quit: webchat.esper.net]
rsparkyc has joined #principia
rsparkyc has quit [Quit: rsparkyc]
Mike` has quit [Ping timeout: 182 seconds]
Mike` has joined #principia
NolanSyKinsley has quit [Remote host closed the connection]
Wetmelon has quit [Ping timeout: 194 seconds]
egg|z|egg has joined #principia
egg|z|egg has quit [Ping timeout: 194 seconds]
egg|z|egg has joined #principia
<GH>
[Principia] pleroy opened pull request #1845: Fix a bug and run the optimisation with nonzero ascending nodes (master...MoreTrappist) https://git.io/vh23M
<GH>
[Principia] pleroy closed pull request #1845: Fix a bug and run the optimisation with nonzero ascending nodes (master...MoreTrappist) https://git.io/vh23M
<1NVAAARZS>
[Principia] pleroy pushed 7 new commits to master: https://git.io/vh2sF
<1NVAAARZS>
Principia/master 87b5303 pleroy: Fix an optional bug and restart the DEMCMC.
<GH>
Principia/master e3e556b pleroy: Merge branch 'master' into Kopernicus
<GH>
Principia/master c323909 pleroy: First cut of a configuration.
<GH>
Principia/master 98a9987 pleroy: Final configuration.
<GH>
[Principia] pleroy closed pull request #1848: A Kopernicus configuration for use with SLIPPIST-1 (master...Kopernicus) https://git.io/vh2B0
<GH>
[Principia] pleroy closed pull request #1849: Do not concatenate . into a token. (master...##) https://git.io/vh2RP
rsparkyc has joined #principia
rsparkyc has quit [Quit: rsparkyc]
UmbralRaptor has quit [Ping timeout: 202 seconds]
pizzaoverhead has joined #principia
Iskierka has quit [Ping timeout: 194 seconds]
Iskierka has joined #principia
Wetmelon has joined #principia
NolanSyKinsley has quit [Ping timeout: 202 seconds]
NolanSyKinsley has joined #principia
UmbralRaptop has joined #principia
egg|work|egg has quit [Quit: webchat.esper.net]
UmbralRaptop has quit [Ping timeout: 202 seconds]
egg|z|egg has quit [Ping timeout: 182 seconds]
egg|z|egg has joined #principia
egg|z|egg has quit [Ping timeout: 194 seconds]
egg|z|egg has joined #principia
<GH>
[Principia] eggrobin opened pull request #1850: More of the same (master...##) https://git.io/vh2Kb
egg|z|egg has quit [Ping timeout: 198 seconds]
egg|z|egg has joined #principia
Iskierka has quit [Ping timeout: 198 seconds]
Iskierka has joined #principia
egg|z|egg has quit [Ping timeout: 194 seconds]
egg|z|egg has joined #principia
<GH>
[Principia] pleroy closed pull request #1850: More of the same (master...##) https://git.io/vh2Kb
pizzaoverhead has quit [Quit: Leaving]
egg|z|egg has quit [Ping timeout: 198 seconds]
<GH>
[Principia] pleroy opened pull request #1851: Fix the configurations and upgrade to 15.8 preview 2 (master...Preview2) https://git.io/vh21t
egg|z|egg has joined #principia
UmbralRaptop has joined #principia
Rokker is now known as RokkerAway
RokkerAway is now known as Rokker
GregroxMun has joined #principia
<GregroxMun>
Do you want me to create a patch that adds a visual atmosphere and a cloud texture to Planet B?
<GregroxMun>
in SLIPPIST-1/TRAPPIST-1?
<GregroxMun>
btw, the alternate name for Seven Worlds of SLIPPIST-1 should be considered "The Terrestrial Worlds of TRAPPIST-1" :)
<egg|zzz|egg>
ohai
<egg|zzz|egg>
was about to reply to your tweet, that's going to be easier here :-p
<egg|zzz|egg>
GregroxMun: So if we go with https://arxiv.org/pdf/1802.01377.pdf table 4, b is actually the one with the denser atmosphere assuming hydrogen-dominated, 5 bar rather than 1 at the surface
<egg|zzz|egg>
GregroxMun: so just switching the textures of c and b would be an improvement from that point of view :-p
<GregroxMun>
oh interesting
<GregroxMun>
can you give me the short version of how the authors of this paper got their results?
<egg|zzz|egg>
GregroxMun: note that we know from https://arxiv.org/abs/1802.02250 that def (maybe g) are not hydrogen-dominated, so you can't use table 4 of that other paper for them
<GregroxMun>
ok
<GregroxMun>
do we know that b and c probably *are*?
<egg|zzz|egg>
nope? :D
<GregroxMun>
or wouldn't it imply that if defg aren't, b and c shouldn't be either.
<egg|zzz|egg>
GregroxMun: the first paper says that b is beyond the threshold for runaway greenhouse
<GregroxMun>
right
<egg|zzz|egg>
to quote the relevant paragraph
<egg|zzz|egg>
Planet b however, is located beyond the runaway greenhouse
<egg|zzz|egg>
limit for tidally locked planets (Kopparapu et al. 2016; Turbet
<egg|zzz|egg>
et al. 2017) and could potentially reach – with a thick water
<egg|zzz|egg>
vapour atmosphere – a surface temperature up to 2000 K (Kopparapu
<egg|zzz|egg>
et al. 2013). Assuming more realistic mean temperatures
<egg|zzz|egg>
of 750-1500 K, the above estimate yields pressures of water
<egg|zzz|egg>
vapour of the order of 101
<egg|zzz|egg>
-104 bar, which could explain its
<egg|zzz|egg>
relatively low density (assuming Ptransit = 20 millibar). As such,
<egg|zzz|egg>
TRAPPIST-1 b is the only planet above the runaway greenhouse
<egg|zzz|egg>
limit which seems to require volatiles.
<egg|zzz|egg>
[yay pasting from PDFs into IRC]
<egg|zzz|egg>
UmbralRaptop: thoughts on atmospheres?
<egg|zzz|egg>
GregroxMun: so basically TRAPPIST-1b is a hot Venus
<GregroxMun>
as opposed to a cold Venus? :P
Rokker is now known as RokkAway
<GregroxMun>
ok
<egg|zzz|egg>
GregroxMun: a hotter venus, which is saying something :-p
<GregroxMun>
yes indeed
<GregroxMun>
and that's before accounting for the tidal volcanism
<GregroxMun>
I imagine
<egg|zzz|egg>
GregroxMun: re. how they got their results
<egg|zzz|egg>
the first paper (Grimm et al.) is assuming an atmospheric composition and running simulations
<egg|zzz|egg>
the second is looking at spectra and noting that if it were hydrogen they would see something and they don't
<kmath>
YouTube - Kerbal Space Program: Under a Cold Red Sun
<egg|zzz|egg>
we have run into a bug where there's a phantom acceleration preventing us from timewarping when sufficiently high in space though, we must investigate; this is really annoying >_<
<kmath>
<GregroxMun> @SarahTStewart @jgrplanets Here is my attempt from a few weeks ago at rendering a synestia as a mod for the game Ke… https://t.co/KgTr0xghUC
<GregroxMun>
here's my attempt
<GregroxMun>
oh
<GregroxMun>
kmath pretty much said what needed to be said
<egg|zzz|egg>
Ꙩ_ꙩ
<GregroxMun>
so yeah I want to make a synestia in KSP
<kmath>
<S_J_Lock> @GregroxMun @SarahTStewart @jgrplanets Based on calculations of water-vapor dominated atmospheres, the radiative te… https://t.co/hQdP68LsM2
<GregroxMun>
according to this, c is denser than b
<UmbralRaptop>
I mean, I'd risk being dull and going with a warm mars, but I just don't know what eg: a world with 100s of km of ocean would do there.
<egg|zzz|egg>
UmbralRaptop: mildly lower than venus, denser than mars
<egg|zzz|egg>
aaaaaaaaaaaa because the runaway greenhouse limit for tidally locked planets lies near the orbit of planet d (Kopparapu et al. 2016; Turbet et al. 2017), the large amount of volatiles needed to explain the radius of the most irradiated
<egg|zzz|egg>
planet b is likely to reside in the atmosphere (possibly as a supercritical fluid) aaaaaaaaaaaaaa
<GregroxMun>
wait do you mean the planetary density or the atmospheric density? Because what I just said was planetary density
<GregroxMun>
and anyway not sure if it comes from the same source as what you're talking about anyway
<GregroxMun>
planet d is so un-dense that it really does look like a water world
<egg|zzz|egg>
UmbralRaptop: mildly higher insolation than venus too
<egg|zzz|egg>
UmbralRaptop: so colud be a cooler Venus rather than a warm Mars?
<egg|zzz|egg>
GregroxMun: "TRAPPIST-1 b, d, f, g and h require envelopes of volatiles in the form of thick atmospheres, oceans, or ice, in most cases with water mass fractions . 5%. For comparison, the Earth’s water content is < 0.1%."
* UmbralRaptop
wishes Ceres, Pluto, Eris, and the largest dozen or so moons were on there.
<GregroxMun>
why do they require these?
<egg|zzz|egg>
to explain the density
<GregroxMun>
most of them are dense enough to be rocky planets though?
<egg|zzz|egg>
and you know the density because you know the (visible) radius by transit depth, and the mass by TTV
<GregroxMun>
right let's pretend there's someone on this channel that doesn't know what TTV is
<egg|zzz|egg>
(simulating till you get the right transit times, and saying hey the mass are probably right)
<GregroxMun>
unless the mass has very recently gone *way* down I don't see why they can't be mars-like densities
<GregroxMun>
d maybe not
<GregroxMun>
but the others have earthlike or marslike density
<egg|zzz|egg>
d is Moon like density or lower
<egg|zzz|egg>
the others, yes
<egg|zzz|egg>
let me reskim the paper
<GregroxMun>
TRAPPIST-1 is another system in which writing a science fiction story could be interesting.
<GregroxMun>
especially now that it seems a little more interesting
<GregroxMun>
I wonder how the high percentage of comets might affect the planets--comet strikes in even higher stellar gravity may be yet another danger to consider.
<GregroxMun>
You know what, I think I'm going to redo planet B right now.
<GregroxMun>
It needs a new heightmap, I didn't realize until recently that a lot of the heightmap comes from the Mun's that I never removed.
<egg|zzz|egg>
GregroxMun: so basically the answer is there's more to the radius-mass relation than the ratio