... The 25% limit only applies when (a) you're primarily concerned with limiting radiator area, and (b) the maximum operating temperature of the radiator is...
93574
skirnir@...
skirnir...
Aug 14, 2012 11:23 pm
Thanks for the info, very enlightening! Hmmm in that case... it indeed does look like the 25% figure is rather irrelevant. I never bothered to check before,...
93575
Isaac Kuo
mechdan
Aug 15, 2012 9:10 am
This paper proposes detection of stealth aircraft via gravitational triangulation. http://arxiv.org/abs/1208.2377 - Gravimetric Radar: Gravity-Based Detection...
93576
Henry Cobb
henry_cobb
Aug 15, 2012 9:20 am
Actually only useful against submarines on Earth as multi-passive radar is MUCH better against stealth aircraft, which tend not to weigh all that much and the...
93577
skirnir@...
skirnir...
Aug 15, 2012 9:40 am
I thought it was long agreed that you can forget about stealth in space anyway?...
93578
deltapavonis11
Aug 15, 2012 9:48 am
What is the highest performing method of fusion propulsion yet devised? Are there proposals which could conceivably achieve an ISP of 2,000,000s or more? There...
93579
Henry Cobb
henry_cobb
Aug 15, 2012 10:14 am
Welcome to the beating dead space horses mailing list. Please pick up your green or purple party hat at the door....
93580
skirnir@...
skirnir...
Aug 15, 2012 11:23 am
Green!...
93581
Gregory Muir
gmuir1977
Aug 15, 2012 2:32 pm
... And allow me to describe how manned space fighters make perfect sense. [Non-text portions of this message have been removed]...
93582
skirnir@...
skirnir...
Aug 15, 2012 2:41 pm
I didn't follow the particulars of the 100YSS, but generally, the fusion process best suited for space propulsion appears to be D+3He, at a gross energy yield...
93583
Joey Beutel
beutelj
Aug 15, 2012 3:14 pm
More like you could forget about most conventional ideas about stealth (nothing equivalent to the cloaking devices of Star Trek, for example). There were still...
93584
Psiweapon
psiweapon@...
Aug 15, 2012 3:14 pm
How do I FTL ??? :P ... [Non-text portions of this message have been removed]...
93585
warnerd_x
Aug 15, 2012 3:24 pm
It proves that mathematics can be used to derive tracking information from gravitational field sensors. But it admits that we don't have the sensors, and the...
93586
Psiweapon
psiweapon@...
Aug 15, 2012 3:38 pm
You can cook a rabbit with a gravometric radar???? ... [Non-text portions of this message have been removed]...
93587
Anthony Jackson
ac_jackson
Aug 15, 2012 4:18 pm
... I doubt the range is very impressive by space combat standards....
93588
Anthony Jackson
ac_jackson
Aug 15, 2012 4:24 pm
... Though you'd probably want to avoid thermalizing the reaction products (or you'll get lots of energy lost to radiation), meaning you actually get protons...
93589
deltapavonis11
Aug 15, 2012 4:43 pm
... My goal is an interstellar propulsion system, so I'm specifically interested in approaches allowing for very large mass ratios. According to Winterberg,...
93590
Anthony Jackson
ac_jackson
Aug 15, 2012 5:40 pm
... If you don't have the ability to capture neutrons, which probably isn't practical on less than a nuclear bomb scale, D-3He is probably the best you can do...
93591
deltapavonis11
Aug 15, 2012 6:13 pm
... For that reason I don't consider internal fusion drives. Only external pulse propulsion could theoretically achieve the power-to-mass ratios and the high...
93592
skirnir@...
skirnir...
Aug 15, 2012 6:20 pm
Ah I see. Well, if you're looking for high performance, D-D is not a very good choice for several reasons: - First off, the Lawson Criterion is almost twice as...
93593
glitterboy2098
Aug 15, 2012 6:24 pm
it would also make star trek style cloaking devices useless as well, since they are supposed to use gravitational lensing to hide the ship. which would just...
93594
Anthony Jackson
ac_jackson
Aug 15, 2012 6:49 pm
... I doubt you can achieve the required power to mass ratios without a fission trigger. Is there some reason you aren't willing to use a fission trigger? Some...
93595
Isaac Kuo
mechdan
Aug 15, 2012 6:50 pm
From: Henry Cobb <henry.cobb@...> ... Unlike heavier-than-air aircraft, submarines are neutrally buoyant. That means they displace fluid mass equal to...
93596
matt picio
matt.picio
Aug 15, 2012 7:02 pm
... Submarines are not neutrally buoyant. They are 10%-20% buoyant under normal conditions (when surfaced), and *may* be neutrally buoyant when submerged....
93597
Isaac Kuo
mechdan
Aug 15, 2012 7:17 pm
From: deltapavonis11 internetmail20@... ... Small decimeter scale light sails can work. You just need an extremely large number of them; they...
93598
Henry Cobb
henry_cobb
Aug 15, 2012 7:22 pm
Are the subs moving? If so are they moving water around in order to do so? If so doesn't the agitated water weigh several times more than the sub itself?...
93599
Joey Beutel
beutelj
Aug 15, 2012 7:38 pm
Heh, never knew they tried to technobabble an explanation for those cloaking devices. ... [Non-text portions of this message have been removed]...
93600
Isaac Kuo
mechdan
Aug 15, 2012 7:44 pm
From: matt picio matt.picio@... ... When surfaced, they definitely displace an equal mass of fluid to their own mass (just like any other ship or boat...
93601
Isaac Kuo
mechdan
Aug 15, 2012 7:47 pm
From: Henry Cobb <henry.cobb@...> ... Who cares? The agitated water has practically constant density. As far as a gravitational detector is concerned,...
93602
skirnir@...
skirnir...
Aug 15, 2012 8:41 pm
Compiled and installed geant4 but am too dumb to use it. I don't suppose there's a point-n-click graphical frontend for it?...
