Green Baron

They'd chase the sun away before it went out Can we use that on the kraken ?

A jellyfish with crown & scepter Why are there no ac-batteries ?

[sarkasm]Advances in evolution[/sarkasm]: Drake equation evolved to version 2.0 to include abiogenesis. The link i had yesterday is broken today, i'm sure it'll be someplace else soon(tm).

And that's why it should in the Lounge ...

It's only links that are missing in the record. The big picture is clear and documented, palaeontologists are no dorks. "Invention" of the amniotic egg: about 320my before now. From then on, amphibious life was was able to multiply on land, which was as close to mars' surface as to that of today at that time. Before it creeped between shallow water and the barren shores in a landscape of ferns and horsetail. That's the beginning of (edit: vertebrate) evolution on land. 300my, guys ! "Plastic only lasts for 1000s of yrs" is just a statement and most probably wrong. "plastiglomerate" found it's way into sedimentary geology already. Using isotopic signatures (if it's far enough ahead, otherwise other methods apply) one can easily date the forming of its ingredient oil as well as the time of deposit in the surrounding soil, or layers in few hundred my, if someone really wanted to know by then. Get a book on evolution, guys ! I'd suggest vertebrate, it's easier to understand and not as complicated as invertebrate evolution. The latter being more interesting for palaeontologists cause much more interesting ;-) Yes, mountains get worn away. They form then sediments, sediments can become metamorphic rocks. And all that tells a lot about the sequences and processes that formed landscapes over time. There is much less room for speculation than you think. Edit: i partly apologize for my rude commentary, but threads like these drive ME crazy cause that kind of speculation makes scientists lifes difficult. They ask themselves what are we doing if noone wants to hear it ? Why are we presenting our findings in museums and exhibitions for the public ? For those in the US: Fields museum in chicago, Smithsonian in washington, New York has a good one, close to the central park, forgot the name. I can understand K^2's eruption in another thread about physics. And that's it from me about that. Have a nice one, everybody. Edit: corrected "animal" into "vertebrate" evolution, otherwise someone could heavily pay me back ;-)

One word: nonsense (had repurposed bovine waste at first). Like those dinosaurs in startrek? Sorry, that's 3rd class afternoon entertainment (though i watched it too). Dinosaurs never had a brain capable of such a thing. There are no remnants of another civilization. The fossil record is quite continuous and the development is conclusive and coherent. Continents didn't look the same but the development of the wilson cycles from precambrian to today are quite well understood and comprehensible, see eg. scotese's website from the early 2000's. And: continental crust lasts forever, is not subducted. So traces would have been preserved, macroscopic and e. g. in isotopes. We e.g. have printed isotopes until the end of the planet with our atomic tests and accidents. Pls. get a decent book on vertebrae evolution, afterwards you'll shake your head about your own question, really. I know this is close to an offence, but let me give you a comparison: me in a hospital looking at a guy with a cut finger and asking the doctor wether that guy is going to die. The doctor would probably throw me out. And, mods, please ! Would someone move this in the lounge and out of science & spaceflight ? Sorry for being so rude. Clear answer: if there had been a civilazation we would see it in the record. Fullstop.

errr ... you mean doubling whet mass, same engines ? For a craft on the pad that could (would for my crafts) bring TWR below 1. For a craft in space where TWR doesn't matter dV stays the same when the dry mass fraction doubles equally. If dry mass stays the same - or only the bigger tank has a higher mass and the rest (payload) remains the same - then dV will be higher, but not double (ln applies). You're right. If you want more payload and still lift off you need more thrust on the pad. That leads to more fuel. That would be a bigger rocket with higher thrust, same Isp than before and same burntime to keep the dV.

Tsiolkovsky says (cheat sheet http://wiki.kerbalspaceprogram.com/wiki/Cheat_sheet), when Isp is the same for both crafts and the quotient of mass before / mass at end for the burn is the same for both crafts then both have the same dV. Which means: sizing a craft up without changing the mass-ratio and/or specific impulse does not change it's dV. So, yes, your basically right i'd say. That is why we do staging to get rid of dry mass and use different engines for different jobs :-)

Yeahyeah :-), there are some old shields in Canada dating 2.5 to 4.0by or so, i don't have the exact numbers right now. That's the oldest part of the north american continent and belong to the oldest rocks on earth. Everything else is younger, red creek quartzite late archean and Jesse ewing formation middle proterozoic, uinta late proterozoic, too young by 1,5-3by. That's already eurcayotes' times ;-) All these very "old shield rocks" like those in Canada are highly metamorphic and tell little about the environment. There are no rocks from the time when RNA is supposed to have formed and hence no record of the conditions of ocean or atmosphere at that time (that would be hadean, 4.5 to 4by). Only a few zircons ... and assumptions. Because of that chemist's can speculate of what the primordial soup was like. Hope we're talking not totally different languages here and always ready for correction :-) Edit: it is because that with the forming of the ocean and a few hundred my time the basis for life is ready, my opinion is that microbes are "not a big deal".

The chemism of the *real* primordial ocean and atmosphere at the time the RNA is supposed to have formed (more or less directly after that ocean had formed) is not known. That is because there are (nearly) no traces left of that timespan of almost 500my (the Hadean). I just browsed through the wikipedia article and must say that it's rather daring to give out details on atmospheric or oceanic composition from 0 to 4by. The first rocks we can look at are already metamorphic, which means they have gone through a process of orogeny. At that time, a little less than 500my after solidification of the crust, the above process had happened long ago, the "cheese was eaten" (german saying). The whole plate tectonic was already up and running, beginning with a totally water covered basaltic surface and had probably already completed a "wilson cycle" (no supercontinent of course), the ocean floor exchanged at least once (*). There are only a few zircons from the time before that. Temperature is unclear (some say warm and others cool :-)), but microcontinents (cratons) and an ocean existed. Until someone corrects me ... (*) Tectonic processes are assumed to have been much faster than they are today cause at the end or the archaean 70% of todays continental crust was fromed.

Matter

That's indeed the main criticism on the RNA World Hypothesis. I personally just find it more conclusive in terms of step-by-step than "Metabolism First", which leads to the hen/egg-problem. Also, those geoscientists should start to hand over a few reesonable early-surface scenarios. In the moment we're stuck with "surface covered with water, no continents, heavy volcanism and every other day a meteorite" ...

Yes. That was a silly question of mine. There were ions, i now recall :-) And it just never came to me to combine ants/sparks with a large tank. And asteroids were just decoration of the Kerbin-system. Or Dres. I'm probably just too ... conservative :-)

Possible prebiotic forming of RNA / RNA World Hypothesis: http://science.sciencemag.org/content/352/6287/833 It would be so cool if the first steps weren't as impossible as sometimes thought :-)

25 minutes or so to circularize a class e below muns orbit. And i had to watch all the time cause the cartload wasn't centered exactly. Won't do it again. I'm curious: how do you do hourlong burns without infinite fuel cheat ?

Way back in .90 or so i tried that as well and gave up. Even with proper staging and asparagus it might be cheaper to split the flight in two (should funds matter). Though i don't know where the break-even between single and multiple launch is. Also upsizing a rocket doesn't necessarily increase dV, i've noticed :-) oh, ninja'd Edit: why won't you split that thing in several functional parts, like lander, isru-unit and a drive-stage for the interplanetary shots ? On your way back and out there you don't have to accelerate the whole behemoth, just the lander with kerbals and science.

:-). Since entropy knows only one direction nobody is wrong predicting an end of everything. Those were hard times between the medieval and the renaissance. Plague, scattered regionalism, battling bishops and profane leaders, anabaptists (e. g. Jan van Leiden, Zwingli), marauding hordes of lansquenets, brutally suppressed peasant uprisings, deteriorating climate and the protestant reformation, the schism of the church. End-time-prophets arose in every city preaching something they had picked up from hokuspokus-preachers. Few preachers even understood what they were telling cause they did not understand latin. He was just one of hundreds of self-proclaimed prophets, though more educated than most of the rest. All of them had to fear prosecution of the catholic church and thus somehow coded their phrases. That makes it easy for today's wannabe prophets to "decipher" and sell it ... Girls & boys, looking back i must say, we're really fine today :-)

Hyperbolic trajectory

Was just reading a news-article and stumbled upon this. Before someone posts it in Science & Spaceflight: The french plague-doctor oracled the conquest of space, according to some bragadocios who demand interpretive sovereignty. Well then, off to the stars. It's a pity that so many credulously fall for such a bogus. Nice weekend everyone

Mass, yes. Mass is a property of matter. Mass matters sotosay :-) Weight comes if an acceleration is applied to the mass and something works against the acceleration. As long as the ships coast they have a mass but no weight. As you point out: different planets, different gravity -> different acceleration. The weight comes into pley as soon a force works against the acceleration (like a scale on the ground). In your example the ships (suppose they are flying close together and are only exposed to the same overall gravity) arrive at the same time cause nothing works against the gravity induced acceleration.

@Robotengineer, i agree to almost everything in your post. I stumbled over that statement as well, but not every oldtimer thinks so. That's the "almost". Safe landings everyone !

RC planes as a boy (in the 70s), had a privat pilote licence (motor) in the 90s until 2004, but the joy about motorized flight and the licence expired. Flew paragliders for 10 years in the alps and southern german midranges (got an elbow prosthesis from that :-/). Built strong wooden longbows, but moved to spain this year and these things are weapons here, i'd have to register myself and apply for a weapons license, so i smuggled all the stuff back and its now stowed in a garage in germany. There's not the right wood around here anyway. Remains sailing. Sailed the northern atlantic isles and the western mediterrian on my Rosinante, mostly single handed, In the moment i'm without an own boat, helping out a friend who does boat trips for tourists. But one day i'll hoist the rags again ... Besides: Prehistory, palaeontology. And i'm trying to learn C++. Which is a mess for someone who was raised on curly brackets, pointers and function calls. And no, i'm not playing KSP right now :-) lol: just realized: "Single handed" doesn't mean that i only have one hand, i have two. The prosthesis is inside and replaces the joint, i don't even realize that thing. There is a rule among seafarers: "One hand for the boat, one for the man". ("All hands on deck !" got it ?). So "single handed" just means sailing alone.

So you think you don't get enough respect from the next generation ? And you feel insulted by my remark about the orientation towards the future ? I am sorry (and surprised), i meant no insult, believe me. Maybe i just don't see things that serious. I don't think a subforum titled "elder" will solve the problem of respect between generations. That's a constant over time in human behavior since at least the iron age (at least since the first philosophers). The youngsters have to make their own experiences and won't listen to the old ones. On the other hand the old ones push their problems over to the next generation. So it's a draw then, we won't solve it here :-) Well, if we sum it up the elder have an advantage .... could be a reason for being more relaxed :-) There are likewise discussions where elder start to bark and bite or drum their chests with phd's and whatnot, i don't feel like being bullied by the younger ones. I'm probably on the nasty side myself sometimes, but i don't have any problem with being paid back. Compared to other forums i've been in the tone here is quite civil. You seem very frustrated and i seem to have triggered a lot of anger, i'am sorry that this is the case. My remark that made you so upset wasn't meant to be nasty and maybe just isn't worth your anger. Overall i doubt that a subforum will serve your needs because i don't see a reason why things would run different. Hope that calms the seas ...

Ok. Just to do something meaningfull: reentry of an MK1-2 from 13k km, pe 25km: 4min48.90sec, of wich 30sec coasting from 300m to the ground. No timewarp. Want timewarp ? 4 78888888888888888888854 sorry, that was the cat.

I'm somewhat in the middle agewise and asking myself: why should we distinguish the elder from the younger ? I see no advantage in this. Mun landing for example has been discussed before, someone wrote about watching sputnik in the sky, so there seems to be enough room for discussions about the past. Most people here are oriented towards the future anyway ... People age 40 and above have usually seen much more than the younger (though not all), and they have usually already had all the thoughts the younger are just experiencing and thus have to bite their tongue every once and so often, especially in a computer game forum where young people are naturally the majority. I find this works pretty well here, have had worse experiences. So, no, i'd probably not join you in the balcony, Stadler, but i pop over every now and then for a impudent comment. ;-)