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09:22
@kimholder - Thank You, and best wishes to you also.
 
5 hours later…
14:51
I posted an answer on my solar sail question, as it is too long for a comment, and works as an answer by itself. If anyone comes up with a way of integrating the expression given, my problem is pretty much solved.
15:12
@Hohmannfan it's an interesting exercise
perhaps it will become applicable if some fantastic material is found, or a way of cooling a sail, or a way of creating a field that acts as a mirror.
15:24
When I calculated the opportunity of sending interstellar probes using solar sails, the performance was pretty much limited by the perihelion. The melting point of the sail was therefore actually more important than its reflectivity. (tungsten?)
...or diamond coated liquid aluminium, perforated graphen, impossible electromagnetic fields, or avoiding the problem with laser propulsion and Fresnel lenses. (Robert Forward style)
I have also heard a proposal about holding a liquid aluminium sail (!) in place by inducing a magnetic field in it. No idea if it actually works.
ooo, i like the list of fun ideas, though.
i did search for plasma mirrors and found stuff
I searched for Dr. Forward, and found out he died over ten years ago :(
just to see if they existed really. i imagine either it would take ridiculous energy or impossible configurations to make them work
I am not that good at calculating the properties of charged plasma. (No clue)
aw, forward wasn't that old either...
yeah, i just was curious. at least they exist.
15:37
I love the Rocheworld series :) It seems like there exists two different concepts, magnetic sails and plasma mirrors
magnetic sails are interesting because they make me think more of real sailing.
they'd need to respond to the shifts of the solar wind.
Real sailing is interesting because it makes my think about magnetic sails
The solar wind is a lot weaker than the radiation pressure though.
@kimholder he was 70 when he died
15:41
that isn't that old
yeah I know
we lost Robert Farquhar in 2015
Niels Henrik Abel (Norwegian: [ˈɑːbɛl]; 5 August 1802 – 6 April 1829) was a Norwegian mathematician who made pioneering contributions in a variety of fields. His most famous single result is the first complete proof demonstrating the impossibility of solving the general quintic equation in radicals. This question was one of the outstanding open problems of his day, and had been unresolved for 250 years. He was also an innovator in the field of elliptic functions, discoverer of Abelian functions. Despite his achievements, Abel was largely unrecognized during his lifetime; he made his discoveries...
26
Évariste Galois (French: [evaʁist ɡaˈlwa]; 25 October 1811 – 31 May 1832) was a French mathematician born in Bourg-la-Reine. While still in his teens, he was able to determine a necessary and sufficient condition for a polynomial to be solvable by radicals, thereby solving a problem standing for 350 years. His work laid the foundations for Galois theory and group theory, two major branches of abstract algebra, and the subfield of Galois connections. He died at age 20 from wounds suffered in a duel. == LifeEdit == === Early lifeEdit === Galois was born on 25 October 1811 to Nicolas-Gabriel Galois...
20
Note that they did important contributions in the same field
@TildalWave You seem to be able to edit comments that are more than 5 minutes old. Moderator superpower?
yup
mods can edit anything
i've heard that mathematicians peak young
well, I tried editing my bank statements and that didn't work, so not exactly everything
15:55
i saw it in a movie once...
@TildalWave maybe if you try harder
brute force it? I could try that
maybe you'd need a few friends
 
1 hour later…
17:15
Is a C3 group of triangular lamina symmetries a Coxeter group?
Oh gosh, wrong chat :x
I'm leaving it here in case any of you are here.
 
5 hours later…
22:47
@HopDavid Did you get that tether equation by the way?
23:33
@Hohmannfan you can't ping people in chat who haven't been in the chat room in the last week or so - i don't know exactly how long.
you'll have to ping him in a comment
if you think you'd like to talk to him about it, you can create a chat room just for the topic and invite him to it
hi. awful nice hat.
XD thanks
May I ask what this room is for, cuz i accidentally clicked a link i think
like whats the even
*event
23:37
space exploration chat
I heard its an event?
Oh well
Bye
um, well there's lots of events - none at the moment?
english language learners, huh
there sure are a lot now
uh, SE's i mean
23:41
This network of sites is very useful. There are places here to ask about pretty much anything.
I joined the german language SE. :P
DuoLingo says I'm 5% fluent in German, but I think that's a very generous overestimation of my ability.
@Hohmannfan you'd probably like his blog, if you don't already know it - hopsblog-hop.blogspot.mx
@duzzy why german?
I dunno. I just felt like learning german. I don't know any other languages.
Only English.
It sounds like a very powerful language.
but it's very confusing with all the der, die, das, etc...
it's pretty neat knowing a second language. it gives you a window on a whole different way of seeing things.
Yeah, I wish I had learned a few languages.
I was once a friend with a Belgian guy. He spoke English as his fifth language, and spoke it better than many people I knew who only speak English.
i'm pretty happy with spanish, because there are so many countries that speak it
23:45
Yeah, it seems like a very useful language.
@duzzy Ich bin auch zirka so fließend auf Deutsch :)
ah, i was counting the seconds :))))
@TildalWave Google translate says "I am also fluent in German about as"
what does Google know? :P
More than me. :P
23:46
word order nothing about
should be "I'm also about as fluent in German"
vielleicht 6% :P
Oooooh... you're beating me.
I bet I could get to 6% today.
but, this site is very generous with its estimation.
Ja, das ist ganz Möglich :)
...Yes, that is... (google translate)... quite possible.
Korrekt
23:50
@duzzy is it a good learning site?
It seems extremely popular. I'm enjoying it so far.
I've talked to several people who love it.
that's great. i don't think i have time any more, but the world would be well served by a really great language teaching service
Yeah, I'm only spending a few minutes a day on it.
The lessons are extremely short, and can be done in just a couple minutes.
I'm just hoping to absorb it over a long period of time.
btw - what was the exam that you had the bad time with a month ago?
Cisco CCNA
I'm actually studying for that right now.
Cisco Certified Network Associate
23:56
what's it for?
A piece of paper that says Cisco has decided that I understand how to configure Cisco switches and routers, and understand the common protocols used.
are you interested in a particular type of related work?

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