UmbralRaptor changed the topic of #kspacademia to: https://gist.github.com/pdn4kd/164b9b85435d87afbec0c3a7e69d3e6d | Dogs are cats. Spiders are cat interferometers. | Космизм сегодня! | Document well, for tomorrow you may get mauled by a ネコバス. | <UmbralRaptor> … one of the other grad students just compared me to nomal O_o | <ferram4> I shall beat my problems to death with an engineer.
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<UmbralRaptor>
"Congratulations! It is our pleasure to offer you admission to the Doctor of Philosophy in Physics for the Fall 2017 semester in the College of Science. You should take pride in this admission and we are certain this will be the first of many great accomplishments you'll achieve with George Mason University!"
<egg>
UmbralRaptor: yay?
* egg
pets UmbralRaptor
<UmbralRaptor>
yay
<egg>
UmbralRaptor: are there feathers on the nose of a dromeosaur, and which way do they run
<UmbralRaptor>
>_>
<Iskierka>
is that face meant to suggest there'd be anyone else more likely to know in this room?
<UmbralRaptor>
It's more that I can't come up with a witty response.
<egg>
UmbralRaptor: I wonder whether we could use conservation of energy to derive a minimum Δv for maccollo's challenge
<Iskierka>
dV is disconnected from energy due to relativity, no?
<egg>
Δv is a different thing, because Oberth
<egg>
but if we can find bounds on the speed at which Δv is applied, we can perhaps say things
<SnoopJeDi>
Iskierka, it's not disconnected per se, but the relationship between the two is not always exactly straightforward
<egg>
oberth essentially is about the fact that (v+Δv)²-v² is larger for larger v
<SnoopJeDi>
I find the \vec{F}\cdot\vec{v} explanation the most satisfying, personally
* egg
prefers just dealing with energies, forces are confusing
<SnoopJeDi>
Well I meant for the Oberth effect
<egg>
yes
<SnoopJeDi>
Energy is definitely a less confusing quantity when you're considering things like "the space of all trajectories I might be able to achieve"
<egg>
indeed
<SnoopJeDi>
state vs path functions \o/
<SnoopJeDi>
Though the squareness is also a property of the reference frame from which you view the orbit?
<egg>
well it's a square only in the MCI frame, an ellipse centred on kerbin (centred, not focused) in the KCI frame, and a weird blob around the Mun in the KMB frame
<egg>
SnoopJeDi: maccollo also made orbits that were pentagons in either inertial frame iirc
<SnoopJeDi>
Neat. I saw the discussion about "what about other shapes" but didn't think about it too much
<SnoopJeDi>
Reading that thread gave me an itch to dive back into KSP
<egg>
:D
<egg>
tfool: the principia thread is sort of getting mixed with a lot of spam from people who try to build their own principia by randomly editing makefiles, which sort of distracts from the overall theme of talking about the actual mod; do you think it would make sense to have a dedicated thread on the subject "build your own principia"?
<egg>
there are too many "sort of" in that sentence, ignore them as needed
<UmbralRaptor>
sort of ignore them?
<egg>
UmbralRaptor: yes, but it means that instead of seeing information about the mod, people who read the thread see that spam
<e_14159>
I believe UmbralRaptor made a joke about "sort of" by adding it to your own "ignore them [the sort-ofs]" to make "sort of ignore them [the sort-ofs]"
<UmbralRaptor>
I did.
<egg>
aaah
<tfool>
I'm kind of surprised it's all stuck in one thread if it's getting that popular. Look at stuff like ModuleManager, and it spawns its own threads all over the place.
<tfool>
guess this is where "discussion" vs "development" vs "releases" forum threads come in :P
<egg>
tfool: not sure it's getting "that popular" tbh
<egg>
:-p
<egg>
I have a couple hundred users maybe
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<SnoopJeDi>
...huh. I never wondered whence the name "Fortran", but apparently "formula translation"
<SnoopJeDi>
(today's mostly ineffectual wander through human knowledge is on compiler design)
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<egg>
FORTRAN \o/
* UmbralRaptor
stares at GMU. "patriotpass account?"
* UmbralRaptor
would just barely accept that in a MA school, but VA?
<SnoopJeDi>
eh?
<SnoopJeDi>
VA's history is not exactly unstoried in that sense (you can make an excellent case that it's far more relevant than MA)
<SnoopJeDi>
It's no PA, but...
<UmbralRaptor>
Well, I'm expecting to see an uncomfortable number of stars and bars.
<UmbralRaptor>
>_>
<SnoopJeDi>
Probably less than you'd think, that far in NoVA
<SnoopJeDi>
GMU is basically DC
<SnoopJeDi>
Now, Richmond area...Well, it *was* the Confederate capitol >_>
<SnoopJeDi>
If you do go there UmbralRaptor, you should visit the Shenandoah region at some point. Skyline Drive is one of the prettiest parts of the country I've been to.
<SnoopJeDi>
And you'll be spitting distance away from where MAGFest is held each year ♥
<SnoopJeDi>
Sorry, my east coast is showing
<UmbralRaptor>
MAGFest?
<UmbralRaptor>
Ooh, chiptune concerts…
<SnoopJeDi>
Music And Game Festival held at the Gaylord each year.
<SnoopJeDi>
It's a very fun "con"
<SnoopJeDi>
Also you can have real crabcakes \o/
<UmbralRaptor>
Blarg, a Gaylord.
<UmbralRaptor>
Sounds really spendy.
<UmbralRaptor>
(This was an issue at the AAS)
<UmbralRaptor>
Though I suppose that can be worked around, depending on what's nearby.
<SnoopJeDi>
Staying at the convention center itself is pretty expensive, yea. I just stayed at a nearby motel when I attended
<UmbralRaptor>
ah
<SnoopJeDi>
Baltimore's Otakon is also a pretty big deal AIUI if that's something you're into
<SnoopJeDi>
(definitely important grad school criteria, here)
* UmbralRaptor
snerks.
Thomas is now known as Thomas|AWAY
<egg>
UmbralRaptor: isn't MAGFest one of the numerous things @fioraaeterna goes to?
<UmbralRaptor>
Yes.
<egg>
!acr -add:PCR3BP Planar Circular-Restricted 3-Body Problem
<Qboid>
egg: I added the explanation for this acronym.
<egg>
UmbralRaptor: so, my computations tell me that the minimal Δv to reach L1 from the initial orbit is ~827 m/s, and L2 ~828 m/s; to get to the energy of the target in one Δv (which is probably entirely useless for rendez-vous, but that's the faster place where you can apply your Δv), you need 843 m/s, so that's probably a lower bound
<egg>
at the very least 828 m/s would be a lower bound (maybe you can do something smart with solar influence if you escape the Kerbin-Mun system
<egg>
)
<egg>
UmbralRaptor: not sure if those bounds are any use though, they're stupidly slack
<egg>
in practice I was not able to get to the Mun with less than 858 m/s, and that's quite a bit more than 827 m/s
<egg>
though I did so with a 3-orbit thing, maybe I can use moar lobes
* UmbralRaptor
doesn't have the initial or final orbital parameters on hand.
<egg>
we start on an orbit whose altitude is between 74757 m and 74927 m
<kmath>
<whitequark> "the Gender originally flowed just north of the medieval city walls, serving as the north part of the city moat" #wikifinds
* egg
wonders whether he should put his Δv lower bound results in the thread
<egg>
hmm, apparently if I use an instant impulse I can get over L1 with 834 m/s (compare with the theoretical minimum of 827 m/s), so the 858 is probably just inertial burn at low thrust being shit
<egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a flammable constant
<egg>
!wpn SnoopJeDi
* Qboid
gives SnoopJeDi a platinum edge
<egg>
!wpn e_14159
* Qboid
gives e_14159 a culverin which vaguely resembles a mandelbrofl
<egg>
UmbralRaptor: SnoopJeDi: I wonder how to interpret the Oberth effect in a rotating frame
<egg>
with the centrifugal potential, if you go sufficiently far away, the potential goes very low again (so you go fast, so your burn is efficient), and there is no limit (whereas typically the central body is not actually a point), so this suggests going really far away to make an efficient burn?