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> egg|nomz|egg: generally if your eyes are dewing over, that's not the weather. | <ferram4> I shall beat my problems to death with an engineer. | We can haz pdf
<egg|anbo|egg>
raptop: currently using the ANBO imaging computer via remote desktop from another computer in a room hidden from the telescope by building geometry
<egg|anbo|egg>
ANBO has an observatory control room now
<egg|anbo|egg>
(pointing is still manual though)
<UmbralRaptop>
\o/
<egg|zzz|egg>
UmbralRaptop: re that eleggtromagnetism question, I wonder how one would do it without using that reciprocation thingy
<egg|zzz|egg>
(though obviously, if you have a hint, take it, I don’t think you are at a point where you want to ignore the hint because æsthetic preferences)
<egg|zzz|egg>
you still have the q_inner + q_outer = -q part, since that follows from the grounding of the faraday cage
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<egg|zzz|egg>
raptop: and the field inside is equal to that arising solely from q_inner and q, because inside a conducting sphere, right?
<raptop>
Inside the inner sphere, just q_inner I think. All of those from region in between
<raptop>
!8 Is a faraday a kind of bird?
<galois>
raptop: no
<raptop>
(Then why are you keeping it in a cage?)
<egg|zzz|egg>
isn't the field zero inside the inner sphere?
<egg|zzz|egg>
you are inside a grounded faraday cage
<egg|zzz|egg>
with nothing inside
<raptop>
Hm. \nabla^2 V == 0
<egg|zzz|egg>
raptop: what do you mean
<raptop>
I want to say you can have a non-zero field still
<raptop>
Just, it needs to have del * E be 0 (because it payed cash)
<egg|zzz|egg>
raptop: the electric field derives from a potential; the conductor is an equipotential; you are surrounded by an equipotential, and as you point out the field inside is divergence-free
<egg|zzz|egg>
it is also rotation-free, because it is the electric field
<egg|zzz|egg>
(and we are in electrostatics)
<egg|zzz|egg>
so there is not much that this poor field can do
<egg|zzz|egg>
raptop: if you are not familiar with the concept of a faraday cage you are going to have a problem with the electrostatics problems
<galois>
[WIKIPEDIA] Faraday cage#Continuous | "A Faraday cage or Faraday shield is an enclosure used to block electromagnetic fields. A Faraday shield may be formed by a continuous covering of conductive material, or in the case of a Faraday cage, by a mesh of such materials. Faraday cages are named after scientist Michael Faraday, who invented them..."
<egg|zzz|egg>
raptop: similarly the field is 0 outside, because there is an outer shell
<egg|zzz|egg>
(and it is grounded)
* raptop
wants to say that the outside field is only 0 in the limit of r-> infinity
<egg|zzz|egg>
raptop is wrong
<egg|zzz|egg>
the outside field is 0 immediately after leaving the outer conductor
<egg|zzz|egg>
(note, the grounding of the outer conductor is required for this to be true)
<raptop>
blarg
<egg|zzz|egg>
again, you have an equipotential, no net charge thanks to the grounding, so no field
<egg|zzz|egg>
yeah I think the problem solves itself by looking at the field line between the spheres opposite the charge q and a symmetry argument
<egg|zzz|egg>
(no integrals need to be harmed here)
<raptop>
egguipotentials
<egg|zzz|egg>
raptop: this is a lot like the lunar egglipses; you immediately set out to brute-force it from first principles, but it turns out that most problems become horrible if you try that, be that in real life or in exams
<egg|zzz|egg>
(also, you should learn how hollow spheres behave in electrostatics problems, since they are full of that)
<egg|zzz|egg>
hmmmmmm
<egg|zzz|egg>
> the field inside is equal to that arising solely from q_inner and q, because inside a conducting sphere
<egg|zzz|egg>
wait no, that is false
<egg|zzz|egg>
that only works if the charge distribution is spherically symmetric
* egg|zzz|egg
slaps egg
<egg|zzz|egg>
!wpn raptop
* galois
gives raptop a bayonette
<egg|zzz|egg>
should I bring the scope back in before going to bed or leave it out to take flats if needed tomorrw
<egg|anbo|egg>
mew
<egg|anbo|egg>
ok so, spheres
<egg|anbo|egg>
so, our problem has an axis of symmetry
<egg|anbo|egg>
on one side of that axis we have the charge q
<egg|anbo|egg>
on the other side, the field must be 0 along the axis
<egg|anbo|egg>
otherwise there would be a net field between two grounded surfaces
<egg|anbo|egg>
OK I am not awake enough for this I think
<egg|anbo|egg>
raptop: keep poking and dump thoughts here and I'll look at it when I have slepd
* raptop
is still poking/working through the eggsample
<egg|anbo|egg>
raptop: the planes?
<raptop>
yeah
<raptop>
spheres are just finite planes, right?
<raptop>
(also with nonzero curvature)
<egg|anbo|egg>
I would want to say yes but there is that whole concept of inside which always trips me up in electromagnetism
<egg|anbo|egg>
the electric field inside an empty faraday cage is 0
<egg|anbo|egg>
but the electric field outside a charged (ungrounded) faraday cage is nonzero
<egg|anbo|egg>
because there is a charge inside
<egg|anbo|egg>
but if you start seeing planes as spheres and vice-versa, the inside becomes a silly concept
<egg|anbo|egg>
your spheres would want to turn into planes and back into spheres from the other side
<egg|anbo|egg>
which is very nice and projective, but projective space is not orientable, so you don't have insides
<egg|anbo|egg>
so let's not go here
<raptop>
note to self: turning yourself into a projective space is like turning yourself into a pool toy
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<egg|zzz|egg_>
!wpn UmbralRaptop
<egg|zzz|egg_>
!wpn UmbralRaptop
* galois
gives UmbralRaptop a gnome
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<egg|anbo|egg>
UmbralRaptop: I wonder whether I can use a cow to take flats,
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<raptop>
...has anyone done a version of papyrus for U+13000 through U+1342F?
<SnoopJeDi>
!wpn -add:adj papyrus
<galois>
Added adj 'papyrus'
<SnoopJeDi>
!wpn -add:adj sans serif
<galois>
Added adj 'sans serif'
<SnoopJeDi>
!wpn -add:adj monospace
<galois>
Added adj 'monospace'
<SnoopJeDi>
!wpn -add:adj monospaced
<galois>
Added adj 'monospaced'
<SnoopJeDi>
!wpn -del:adj monospace
<galois>
Deleted adj 'monospace'
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<_whitenotifier-d13c>
[Principia] pleroy synchronize pull request #2610: The vector space of Poisson series - https://git.io/JfpYC
<_whitenotifier-d13c>
[Principia] eggrobin opened issue #2611: Vessels vibrate and disintegrate, sending pieces flying off at absurd speeds, in Galileo - https://git.io/JfhLb
<_whitenotifier-d13c>
[Principia] eggrobin assigned issue #2611: Vessels vibrate and disintegrate, sending pieces flying off at absurd speeds, in Galileo - https://git.io/JfhLb
<_whitenotifier-d13c>
[Principia] eggrobin labeled issue #2611: Vessels vibrate and disintegrate, sending pieces flying off at absurd speeds, in Galileo - https://git.io/JfhLb
<_whitenotifier-d13c>
[Principia] pleroy commented on issue #2611: Vessels vibrate and disintegrate, sending pieces flying off at absurd speeds, in Galileo - https://git.io/Jfhmh
<SnoopJeDi>
!wpn -add:adj tiling
<galois>
Added adj 'tiling'
<SnoopJeDi>
!wpn -add:adj compositing
<galois>
Added adj 'compositing'
<SnoopJeDi>
!wpn -add:adj OpenGL
<galois>
Added adj 'OpenGL'
<SnoopJeDi>
!wpn -add:adj DirectX
<galois>
Added adj 'DirectX'
<SnoopJeDi>
!wpn -add:adj Direct3D
<galois>
Added adj 'Direct3D'
<SnoopJeDi>
!wpn -add:adj Vulkan
<galois>
Added adj 'Vulkan'
<SnoopJeDi>
!wpn -add:adj vectorized
<galois>
Entry already exists!
<SnoopJeDi>
good
<egg|zzz|egg_>
!wpn -add:wpn tiling
<galois>
Entry already exists!
<egg|zzz|egg_>
!wpn -add:wpn honeycomb
<galois>
Added wpn 'honeycomb'
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<_whitenotifier-d13c>
[Principia] pleroy synchronize pull request #2610: The vector space of Poisson series - https://git.io/JfpYC