PB666

It is 2 fem : 1 male based on the genetics (I stick by this, you need to do more research). That is an average in some peoples there are no cohesive breeding units, in other places its 1:1. The unit does not have to be chronologically intact, it can male can have a mate for one period lose her and acquire another. This is the reason mitochondrial eve coalesces later and adam (although less so now than it used to be, so it might actually be 1.5:1). It has also been noted in the merger of cultures were males have annihilated they xeno-male counterparts (or collective wife stealing incidences). Matriarchy has the advantage in many cultures that send the males out to 'prove' themselves, the resources under the control of the women. Males then join other groups (cause 50 individuals is too small to retain genetic viability over long periods). Oh yes, there were houses, people carried their houses with them, in the same way that nomadic reindeer herding groups in siberia carry their houses. This was particularly true in Europe where the winters were devistatingly cold, there are sites in Europe that have evidence of prolonged and repeated habitation at spots. Europe was not one climate in the ice age, it was a generally bad climate that became worse from time to time, and peoples would migrate back to the refuges in Iberia, then flow out, this of course was late paleolithic behavior. (off topic however in this group so . . . ) When you say village, what you mean is a permanent habitation. The late paleolithic is characterized by activities of individuals generally in the lead up to the end of the Younger dryas. This basically means for Europe if you build a permanent settlement outside of the ice-age refuges, your group was dead. But they did travel out with the protection of mobile habitats (i.e. the village moved), they did keep them and repitch these places in France (some areas showing long durations) as they harvested favored resources (one of the questions is what did people do when they were not at the site since 95% of their carbon came from seafood, did they simply move to another warmer site in iberia). In the Mesolithic however, the major focus of what I was talking about things began to change, there was alot of trading going on. Mesolithic people were very mobile, but that does not mean they lack favored places of camping out, the difference between Neolithic and Mesolithic peoples left the sometime harsh conditions of N.Central Europe. But there is one major difference, the Mesolithich people drafted trade even with Neolithic into these migrations. In Europe you see migrating tracks of items that come from the Black Sea, Iberia, Ionian sea that cycle in and out of different parts of C and Western Europe. Which Neolithic Europe are you talking about, there is the LBK, there is the Iberian mesolithic/neolithic transition, there are two French neolithic cultures, there is the Iron gorges culture, there is the Ionian neolithic there is invisible transition that takes place in anatolia (cultivation for them begins 12 kabp). But this is off-topic, the minutia of how intelligent culture from one spot to the next on earth is immaterial Yep, tremendous amounts of cultural variation. Only the genetics show us what the averages are.

What!? We want voyagers to learn about earth, not develop our bad habits. It will be in a earth mars-eccentric orbit, some day it may come crashing back to earth, then you can ticket if for speeding . . . . .in Australia.

The minimum size of a cohesive unit is about 50 individuals. The male to female rate of paleolithic societies is typically 1:2 in a reproductive unit. However in many paleolithic societies there was a tendency to matriarchy, so it would be women ruled the houses and most of the village and the men were sent out to hunt, herd, war . . . whatever. Another consistent feature is that in village massacres its the women and children that are found and not the men. The EQ is reflective of some kind of brain power, Neandertals had a more developed occipital bun, better processing of visual data, humans in comparison are more prefrontal. Its genetic in the sense that the individuals do not see the value of the tribe and are anarchist to a fault then there is no cohesive unit. There have been arguments that bipolar disorders and types of schizophrenia had selective value in past societies by adding drive an instability into group behaviors not to push them apart but when people are too social (like a herd of sheep) what happens is they fail to evolve in the face of variable selection. Lets take a look at some of the stuff, In Japan apparently 30,000 years ago some people took off across the pacific ocean (about 100 kilometers) and left human remains on Islands of the Okinawana chain. It now seems likely that around 15,000 years ago people took of across a sizable voyage in the pacific traveling down the NW American coastline and rapidly b-lined to South America. No-one in their right mind says, hey lets go hunt seals off this coast 3000 maritime miles away. We know why Leif Ericson did it, his family was basically fringe looking for someplace where he had a better rap. My opinion is behavioral variance is as much a part of the human social evolution as immune variation it apart of the 'herd immunity'. With every variable trait (afterall selection is variable) there is the good and the bad. Then gene that may have prevented shellfish sickness in mesolithic societies seems to cause T1D and celiac disease in cereal based societies. And if behavioral variance was a really bad thing why would so many societies dabble in narcotic chemicals (Vikings had mushrooms, Native americas had Cactus, Middle easterners had hemp, . . . . . ) Where would the music of the 70s be without LSD, pot, heroine . . . .but then what happened to all the greats of the 60s and 70s. . .Janice Joplin. . .Hendrix...Morrison. Creativity that we associate with intelligence is often risky. Newton apparently dabbled with Mercury and the occult. It goes back to the tragic hero painted by the Greeks. I should point out that being raised by animals is not nearly as bad as being socially isolated in childhood by humans . Animals do have a language that humans can mirror, even twins create their own language, but isolation is probably the worst way to bootstrap the human mind. We are social creatures and social intelligence is a currency in our civilizations.

Language is a problem for the intelli-genesis. The one major reason is that we don't actually know when grammatical language evolved, it was likely very long ago. There are predictions ranging from (50) 125 kabp to 1 Mapb (even 2.6 Mabp). To be certain Turkana Boy likely had a language much more sophisticated than chimpanzees. And it should be noted that somewhere between 2.1 and 1.8 M years ago turkana's ancestral population had members that ventured out an survived in places like China, the Caucasus, Indonesia (which appears to include Flores Island). When we talk about humans and our manipulative behavior a key hallmark of that behavior is to explore new habitats and exploit them creating the necessary technologies and educating other tribe members. They had it, in fact if we ask the question about what happened to the asian variants of H. erectus, at least one of the answers lies in the mitochondria of Desinovan late archaic that shares common recent genetic ancestry with Indonesians (the node is about 8%). So they had enough language to qualify them as mates for people who did speak human language. Its not clear that there was sufficient enough gene flow from africa to Asia in the 1 to 2 million year period to justify unidirectional geneflow of language from Africa to Asia. (So either they develope language independently or it existed 0.5 million years before Turkana Boy. If you are looking for major differences between Turkana boy and Tuang Child (2.8 Mabp) you will find differences in the size of the calvara but not much else, and more importantly Tuang lived in africa at a time we first start seeing stone tool use increase (2.6 Mabp) over and above what other apes use. The importance is that the same parts of the brain used for language are also used for tool synthesis. One of the articles that studied Tuang child basically identified some slight enlargment of the Broca's region of the brain not seen in parallel or earlier lines of hominids. This area is also responsible for motor skills involved in action recognition and reproduction, something very beneficial for tool production. So that a good guess is that an increase in crafting skills was associated with improved language over what we observe in chimpanzees and gorillas. This was followed be increases in stature of homo erectus and then increases in EQ and areas devoted by language and logic. The process occurred rather quickly in the animal kingdom which had and EQ of 2.5 going into the process and 7.5 leaving the process in period of 3 million years. OK the next reason is why. There are a couple of base reasons, between the time of gorillas and chimpanzees, protohumans may have engaged in panspermy, that is bonobo-like mating arrangements (make love not war). Humans and chimps are certainly a departure from gorilla-like (Winner takes all, though this is in question). Panspermy increases the rate of evolution in males and the study of human-chimpanzee Y reveals a rapid acceleration of evolution. The second reason why is the movement of Miocene anthropoid apes from Asia to Africa about 10 million years ago, the rate of evolution of apes baseline mutation rate is higher in the tropics. A third reason is about 2.5 million years ago there was a shift in the periodicity of climate cycles from short brief cycles to cycles that lasted many 10s of 1000s of years. This began to dry the climate of Africa and create more complex habitats. Water was no longer widely available, and animals became migratory. So there was a push in the change in mutation rates and a pull in the forces of selection. Despite the current modern appearance Africa continued to be the driving force human evolution even after humans left Africa, this is probably due to the hominid-technology level carrying capacity of Africa during the ice ages. Gene flow appears to generally have been from Africa outward on multiple occasions after 1.8 Mabp although counter flow is likely. Some of the most genetically isolated areas on the planet are still in Africa with still buried pockets of long-held diversity. An example of this is the recently discovered Y-chromosomal 'Adam' chromosome in an African American male whose ancestors came from central Africa. All of these signs present Africa as both a genetic and cultural pulse that at first occurred at period of 100,000s of years and later 10,000s of years. So looking at Modern Europeans there are signals of egression from the horn of Africa, from the middle east, from Morocco and as far and east as Nigeria, even within the isolate Irish population you see signs of recent contribution from West Africa. Within Asia's the highest signal from neanderthals comes from middle-east/NE Africa is found in Japanese. Later middle eastern contribution was diluted by African migration since 80000 years ago. So this is basically the intelligence pre-technology. One oddity in the data the first pottery is from the sea of Japan, but there appears to been some pottery in Africa and some form of math before 10,000 years ago. One of the ironies is that Spain, which had the last signs of Neanderthals have just about the lowest percentage of Neanderthal genes compared to other Eurasians. Spain genetically looks more like an extension of Africa than of Europe. The signs of late paleolithic African migration are far reaching including India, Pakistan, the Turkic people (but not Japanese), Australia, Indonesia Taiwan aboriginal population and even Pacific islanders. Thus each migration from Africa may have brought better mobility technologies. This is on top of technologies that allowed people to travel over the Wallace line 1.3 million years ago (in Indonesia). Its not surprising that Egyptian civilization, with an emphasis on the Nile was the first great civilization. So in the perspective we need : Millions of years (at least 3) and a good baseline species An environment that forces evolution and promotes new forms of selection [Optional] Some sort of brain-tying of language-to-technology allowing for bipartite selection on one benefiting the other. Places for technology to travel to and be shared. A development of travel/trade technologies (very much favors trading but also hoarding trees-rollers- to build magnificent monoliths) With trade comes a need for math skills With trade comes the need for negotiating and record keeping (How many oxen do you owe me after I sold you ten carts of wheat). With record keeping comes writing, laws, proclamations, manuscripts, papers, journals, science. . . . . . . . --- Success of the individual in commerce being tied to success of society (efficient economies tend to build successful societies) --- Success of the individual in matters of state and religion ~ sometimes ~ beign tied to long term success of societies. 3 million years ago it would have been very difficult to predict when a naked-ape would generate the critical mass to become sophisticated, even 100 kya it would have been difficult, there were signs (blombos cave). This is the period with the greatest change in EQ, but civilization was not inevitable, around 12,000 years ago, when you see the cultivation of rye in Greece and turkey ....and also the first carvings of the Sphinx. You can look at South America, virtually unoccupied 14000 years ago, by 12,000 years ago scientist find the remains of plants, the overwhelming majority of which are now cultivated as crops and have been so for 8000 years. 16,000 years ago in Japan, pottery; a little later pottery with covers for storing dried fish an entire winter season, beans, etc. Right there, about 12,000 years go and outsider might look and reflect that there were signs of an inflection in process. Another issue is self-criticality are they aware that something has changed. Obviously if last year a car did not exist and this year you are driving a model -T then you probably can philosophize about it. When I was 8 I watched on TV a man land on the moon, i kind of knew from my parents that TVs were a new thing, but then I saw that an I knew humans had done something, at the age of 10 i got my first handheld transistor radio (god I wish I hadn't throw it away) for a few bucks. You know things are changing when children who, only have a few years of experience, can see it. We go back to the mythologies 4 to 6 thousand years ago . . the great flood . . . .fruit from the tree of knowledge of life .. . the lost garden. Are these not self-recognitions that the laws and norms of the uncivilized had given way to the constrictions as well as benefits of civilized society. About the same time we see Hammurabi's stele. Laws are to prevent people from doing things you don't want them to do, often animistic things that mess up civilizations (like sneaking in the middle of the night and stealing the kings daughter as your princess). These things fall along the lines of social intelligence - - - - Do I live in a civilation, do I recognize the good it does me, do I grow/defend it, corrupt it or leave it. Obviously we are aware of the rise-and-fall of empires (Roman, Third Reich, Czarist), but its also true that the ancients were equally aware of civil faux-pas (from Samuel to the Maccabean revolt is a repeat lesson in this with a religious spin on everything) the question is whether they were aware at their time or after in the writing of philosophers and Theologians. A key point about self-criticality is whether one or two sacrificial philosophers point out problem behaviors or the entire society is aware (example would be electing a president who has 20 claims of sexual harassment against him). Are we aware or just not enough aware to save ourselves only after the waterfall is in site, that is the question? Where do we draw the line on social intelligence. Along the way of civilization there was Samuel, Socrates and his Syracrus, Jesus and the sins of the fathers versus Nero and Emperial rome, Atilla, Khan, Richard III, Hitler, Stalin, Tojo, Pol Pot, Amin. Do societies recognize a digressive force or only when that digressive force is of immediate socially erosive nature. Have there always been benefits of such autocrats for those who support them or are they supported just because a system deems it a prerequisite. The Ancient Greek's had a knack for painting the hero's as tragic and is probably the best evidence of self-criticality, that somehow while the god's promoted you in life, the also tied you so that your self-promotion would be your downfall. Philosophically we can paint this as a vestigial behaviors, but then we look at our most popular politicians ("this is going to be the greatest thing ever") and wonder why 'socially-intelligent' people now fall for the propaganda that a 2500 year old Greek philosopher would not fall for. This type of intellectual evolution is slow and very cyclical in its nature.

Thats what I thought, it sounded like it was going to be the next mission. So it came a surprise to me that this is news, but OTOH I just saw news that Musk is going to send his personal car into space, apparently because its not of any value to him. lol.. Better.

Well, uh . . .as for the title, I placed "Part I:" exactly for that reason, there was nothing in that site that convinced me that they were attempting part II: The return in 2024? The video basically was emphasizing 'Search and Collect'. So yeah in that light he was being a bit (see def); having said that the site had great graphics but the site itself lacked many details that members of our group would appreciate. The thread is begging for confirmation of Part I and what the plan is for Part II (obviously nothing more than handwaving in the video). We spend alot of time in this forum talking about silly Mars landing. Consider the value that science got out of the Lunar sample return, some forbearance of fluff is warranted given the magnitude of fluff devoted to manned missions to Mars (including posts with trash-talk between astrotechnology companies)

Human intelligence is self-defined. To the victors go the spoils of war. If you want to go into paleoanthropology its called the encephalization quotient. Somewhere about 1 mabp hominids achieved half of the human value, about 350,000 years ago homo heidelbergensis/rhodesiensis achieved an EQ not-statistically different from our own. So from objective criteria intelligence and civilization are not well correlated with time or EQ. What we commonly refer to as intelligence is more or less events that have occurred since the end of the last ice-age, and it largely the result of an expansive global population (something to begin with humans had little control over, although now it appears we have faulted the climate cycle and ended the transition from the mini-ice age into a full fledged ice age). The intelligence, IQ, that typically gets ranked has really more to do with socialization and communication than anything else. [Although I dare say that in the information age good information appears to be a premium]. Civilization in and of itself appears to have been problematic. During the Mesolithic-Neolithic boundary in Europe denoted by the demarcation of the dolmen and LBK cultures, the Mesolithic peoples were eating a better diet, longer lived, better bones, healthier. In the case it would appear that having more children beats having a better or more stable culture. As is the case the LBK cultures eventually collapsed, but in their wakes more resilient culture and waves of settlers came from S.Europe and Mediterranean with waves of new technology and eventually cultural replacement occurs. In fact if one looks at the historical record and historical archaeology the one consistent feature is that dominant intelligence culture of the period essentially collapse, often for internal reasons sometimes for external. We can take the zoroastrian culture, during the period of its expansion it was one of the most progressive cultures of its time, the magi became the teachers of kings well outside the area of Persian domination (these were well sought after teachers, similar to the oracles of ancient egypt). But look at the culture now, its virtually vanished from Persia, Iraq, Near East, Afganistan, Pakistan. When we talk about the emphasis of monotheism in the bible it largely is due to the influence of the Magi. Collective intelligence is not really about a people or civilization, as we inspect the near eastern cultures one can see that over time apex of western 'intelligence' flowed from place to place, first from Anatolia to Egypt and Mesopotamia, then to Greece and Persia, then Italy, then back across Asia and back into Italy and into the heart of Europe (with the break down of centralized religion) and then into the Americas. Centralization of control appears to be rather counter productive to the growth of modern intelligence, collective intelligence tends to flow to where it can essentially rule itself (sort of like the schools of the ancient Greek philosophers . . . and of course we know what happened to Socrates when he question the politics of his time). The point is that no-one really owns it, if one society takes a ludite view to science and technology (or is ruled by insecure autocrats), the apex of intelligence simply moves, some of the motion follows genetics, but alot is just flow of ideas and retrospectives on failure as the stepping stone of next apex. (We can see for instance very astronomical growth of science and technology in the East: Japan, Korea, China!!!, Vietnam, Indonesia, Taiwan. A child of the south, it is very well apparent in our system of education why the US is falling behind and Asian (non-x-ian societies are moving upwards). When I talk to my Asian friends none of them put the obstacles in front of their child's education that typical native born southerns do. But given that communal intelligence is not necessarily genetic, if you are in proximity to an apex, the access to the intelligence increases markedly, its just no a guarantee that the intelligence of the geographically defined culture will pass to the next generation efficiently. I used to review alot of manuscripts from china, two decades ago the quality of submitted manuscripts was terrible, over time the number of papers submitted increased 20 fold and the quality greatly improved. With alot of plagiarization but in plagiarizing other papers it does mean that the authors are at least familiar with what good argument is, that they choose to organize their logic according to something that has already worked. The improved science in china in the last 20 years would reflect 50 years of science evolution in the west for decades earlier. So basically what would happen if humans and another less intelligent species came in contact, if that culture was capable of learning from humans it could advance in intelligence quickly. If that culture was not capable of learning, even if energy was put into the process then I would argue it was not capable of human intelligence. For that intelligence to persist in subsequent generations requires a genetically encoded facility to learn. Thus if the intelligence does not stick between at least one generation, it was not intelligence, just mirroring behaviors. Again how do we define intelligence, well put KSP in front of them and see if they get a kick-out-of building rockets and watching them blow up. That rise in blood pressure that happens trying to see if you have enough dV to reach orbit, or whether you began your landing burn soon enough. If that individual is putting stress on the bodies system in order to learn then the facility probably exists.

[Face palm] Star wars people.

Amorphous solids do not behave like crystals. Think of glass like glycerol. If you cool it to a low enough temperature it behaves like a solid, increase the temperature a few degrees and it viscocity drops, heat it up enough and it flows. Glass is pretty much the same, before it reaches the point were it glowing red you can flex it; heat to red hot and its often too plastic to mold.

I got the point. There is a reason for a mid-ocean surface to be relatively sterile and its not UV radiation. The problem is that the autotrophs are constantly surrounded by heterotrophs, even if the heterotrophs are not at the surface, the autotrophs move down and up on a daily cycle and heterotrophs wait in the aphotic zone for a meal. The food chain is initiated. Micronutrients move from the surface of the ocean down and out (out meaning they travel up your rivers or in the bellies of birds). The action of surfs along the margins however has a propensity to remove organic micronutrients (a rather nifty protein skimmer) and these are utilized in the creatures that live in the sand, if you dig down you can find a black layer, this is iron-sulfide caused by the anoxic metabolism of sulfate, one of the most potent cleansing mechanisms in the ocean; however it also take micronutrients and energy and puts it roughly them back on land. There are other issues, while calcium is relatively soluble in rain run-off in the mid ocean with calcium is unstable and tends to precipitate over time. More-so iron is very unstable, and iron is attracted to the sea floor in the form of iron-sulfite (on land we call the crystals fools gold). There is considerable magnesium. We could in fact green the ocean very quickly by adding iron chelates and other micronutrients. The scheme would not be stable, however unless you controlled the fauna problem (a proposed method of dealing with greenhouse gases). You constantly would need to be pulsing the oceans with micronutrients and the preferred autotrophs and they would be constantly consumed and removed from the system. A per Europa, there are no photoautotrophs and there is too little photon energy to allow them to move to the surface, so all life would sink to the mud, over time they would use all the available energy and life would enter a permanent stasis (for example as the bacteria surrounding oil reserves are very slow growing and long-lived) since anoxic respiration would eventually come to an end. This probably would have happened 4 billion years ago, autolysis would have then basically turned whatever life that lived remains into clay. The exception would be volcanically active submarine areas in which the heat and acids in the water eroded the moons surfacewhere heat/chemical and radioactive processes fuel life. Unless the probe targets these submarine sites its likely a wasted trip.

That was a typo, the natural molecular silicon is almost always found in silicates. I work with borosilicate glass alot and I can assure you I never heated it to 2600'F. I think you are familiar with amorphous silicon.

The problem is that you are ignoring the fact they need a power supply, and a fusion reactor is incapable of producing that level of ship. The only power supply so far dreamed-up is a black-hole drive, which falls in the realm of science fantasy. We have been through this exact conversation 2 years ago. This comes under that category of belief that somehow you can wave energy into existence, stabilize it and transform it. As I said previously, talking about power supplies which don't exist and that you couldn't cool even if they did exist does not aid the conversation. Here is the sense of reality, to get a particle to relativistic speeds, requires a type of accelerator that is much more powerful than ION drive. Consider how much heat is wasted per proton to reach 0.8c, sure it gains mass, but you are no longer talking about plates 0.1m thick, you are talking about extremely massive structures and hefty arrays of supercooled magnets. Daedalus again. " Project Daedalus was a study conducted between 1973 and 1978 by the British Interplanetary Society "-wikipedia. Science fantasy. You claim that Wendelstein 7X 'isn't' a viable fusion reactor, the Daedalus pulse fusion rocket design is a paper design, that its. Its a handwaving argument on how to initiate and contain the reaction, nothing more. So at the time Daedalus was proposed the inertial confinement was to be done by electron beams, this has apparently failed. So that now everyone appears to be using lasers, but they can only be powered up at a rate of 0.0001 not the 10 s-1. The bottom line is to cause inertial confinement fusion you have to have enough power to initiate the reaction, which as it turns out is very power intensive. Also, the expulsion of waste in the nozzle of a space ship provides no means of recovering that power. I should also note that if ICF worked tomorrow, the raw materials would not be cost effective power production in the commercial market. It is considered one of the more power inefficient fusion methodologies. All it takes is one that isn't. The ships protections are not against things that don't exist. If you imagine a ship whose cross-sectional area is say 10,000 meters and you are traveling to a star 10 ly away. 1E17 then you are covering a space that has a volume of 1E21 in size. If we were to compare this to our solar system it would represent a sphere the volume of the Earth. If you were to then ask the question, scouring the areas outside the solar system what is the likelihood of finding a granule in Earth sized volume of space. Im not even convinced that the gas encountered by the system in the course of travel would make radiant heating more problematic that my 2 year old calculations. But that is wasteful, that which you do need or want on the ship is best accelerated off the ship , if you just dump it, and then you use the energy to pulse light, you have wasted about over 90% of the thrust you could have generated. Oh, and I would like to see the expression on NASA director's face when they are directed to launch a working version of ITER into space. "Uh, Mr. President . . .we don't have " "Well how long to dev . . . . ""15 years"

When you get beyond the capacity to harness the power, then power is unlimited, for all intents and power. As for ITER, no, look at Germany Wendlestein. ITER is a big political boondoggle. My point is that the weight of fusion and the inability to dissipate heat (plus the seed energy for the reactor) may ultimately prevent its use for a while. Fusion will not get you to 0.1 of speed of light except on paper, see threads from a couple of years ago on fusion, we pretty much covered all the bases. I could see a fusion design in which ships are couple together in a wide array like a snowflake with the reactor at its core and each branch and subbranch taking a liquid energy converting to power and radiating the waste and going close places like Mars or asteroid belt object. For mercury the sun will suffice to get your there. This is a 10th scale version, prototype galaxy ship. Check the dV. This added weight for shielding (need at 0.001c and higher, cells for fusion reactors, space for ION drives, the stats are real. A full scale version would hold 2400 individuals because after all we are talking about a generational ship. 0.01c means 444 years to alpha centuari. Above 0.01 c your acceleration is pityful because the ISP used requires acceleration to relativisitic speeds to gain the mass. It took some time to realize there is an acute marginal utility of gain once Vexhaust is above 0.1 C because your waste products are more than exhaust weight. A full sized ship would probably overheat because of inadequate radiant heating. IIRC maximally you get 4% of the fusion reaction as energy gives a preferred exhaust velocity of something like 80 Mm per second. If the fuel is one third of the weight (remember its got to be liquified hydrogen, very difficult to store in a ship where you are trying to dissipate alot of heat gives a total dV of 22,000,000 m/s for start-stop ip mission it was 0.04c. There are a ton of tradeoffs with fusion powered interstellar, ultimately I decided it would be unlikely that any fusion ship would push higher than 0.005c. The major problem we discussed in the group was risk avoidance (a speck of dust is a nuclear warhead at near light speeds). The shape above is designed to deflect most of the impact energies. The other problem was providing the crew a lifelong livable ship, which means the reactors at the back could be discharged in the even of an emergency (much discussion of fusion instability). The reason for the lower ISP is that power had to be diverted to other ship systems such as life support, food production, waste recycling, cooling. Every bit of power used for these reduces the power that can be devoted to the very hot fuel you needed to get rid of and fast. So pretty much you don't get 0.1c > members of the group concluded that if 0.005c was as high as could be obtained then interstellar travel would never be possible. Their opinion not mine, but you see what I mean by unlimited power, its limited, power is its own limitation.

They said the lunar lander was just wide enough on the inside for an astronaut to sleep on a hammock with about a 20' tilt.

They put alot I don't I know Curiosity, Spirit, Opportunity, Sojourner . . . . .then two stationary probes Viking 1 and 2 ... everyone generally forgets about Phoenix. https://en.wikipedia.org/wiki/File:Mars_Viking_11h016.png

I dunno, they just talked about the search and destroy part, no details about how to get it back into space.

I thought this was already a done deal. http://www.businessinsider.com/nasa-mars-2020-mission-step-toward-first-mars-sample-retrieval-2017-12 Apparently the robot will have a biotype search and destroy mission. Well not destroy, just search, remove, put in a canister, put it on this big explody thing, send it on a mission in the cold deep of space, then burning into earths atmosphere, landing but . . . . .not destroy.

By oceans you mean that thin film of water under the ice, yes and without radiation from surface there is also little prospect for resource energetics, also. The most likely place for life is in the crust of the planet where the heat of accretion is still abundant enough to fuel life.

LOST IN SPACE DON'T LOOK DOWN. Front: MINE ME. Back: NEAR MARS ASTEROID TRANSFERRED Bumper sticker: Court-ejudicated property of my ex-wife Bumper sticker: Hey Scottie! you made a wrong turn. (in reference to the burial of his ashes in space). Bumper sticker: That last bump in the road was a duezzy. Bumper sticker: For sale. Air freshener and roads not included. Bumper sticker. If you can read this bumper sticker you f-d your launched. Bumper sticker. If you see the bumper rocking and Sigourney Weaver in the front seat don't make any deliveries.

It gets even crazier if you learn to harness neutrons, most of the energy in the reaction is in neutrons that wander off an make things heavier. All fusion is simply extracting energy from stuff that holds nucleus together, but real energy comes from converting normal matter to antimatter and then annihilating it. If you can create a fusion reactor that converts neutrons into anti-matter by some step-wise process then you really have a power source. The problem with fusion, and in particular unlimited fusion power in space is this as I see it. In space limitless energy is not exactly unlimited unless it is distributed over time, mass and space or to phase properly we soft fleshy things like to keep our body parts together and so we don't generally take kindly to power conversions of great power in small spaces over brief periods and small heat sink mass. And this is the power problem. The famous example is the big bang, at the beginning there was infinite energy in a point, as soon as you have space-time, energy density becomes finite, and entorpy that ensues sees energy all but disappear the only thing that is less is the non-zero vacuum energy of space. Pretty much the same thing happens with space craft energy. Power is the transformation of energy per unit of time into something that eventually all becomes waste heat. Its not exactly true but basically true. Some of you will say 'yes it becomes heat, but not in a relevant context'. I would argue maybe but we sure don't want unlimited waste energy in our living quarters the food storage coolers. Thus we need to control energy flow very carefully in a space craft, it just can't go anywhere. Here is why. When traveling in space the primary outlay of energy is phase transitions from high-energy space-time isoquants to low-energy isoquants and back to high-energy isoquants. The conversions require PE->KE. This is denoted as SKE. unlimited energy - SKE = unlimited energy until you add mass. Unlimited energy - SKE * mass = you're screwed. Here is the proof, suppose we have a 1 TW reactor (1012 Watts). Now suppose we have a [reaction]mass-less drive system. Ok it has mass we just accelerate the hell out of the mass. N = 2 * P / Ve. So that close to the speed of light the equations becomes N = P/c (i.e the u-r-f-d-and-bad equation) which means you get 3,333N of power, you jump up and down with joy, except . . . . . . . wait that 3 kn of thrust, thats like the tiniest thruster in KSP. Hmm and that TW reactor weighs a >KT (we wont worry about its weight at the moment, the biggest problem is latent heat). In this particular solution we generated pure light - somewhere a billions of light years away some race will see a blip in the MW background energy, i.e. heat. And what you got out of it was 0.00333 m/s2. Hmmm, something forgotten, thrusters . . . . . .thrusters that use energy also waste energy, in space they cannot dissipate energy except by radiation. An ION drive is essentially a mass that conducts fuel-mass and heat at the expenditure of power. The heat limit of the device determines the power per unit area (something like 70kw per meter at 80% efficiency means 14 KW per meter is about 10 time more energy than ensolance energy on Earth, some of that goes into the xenon the rest is radiant heat) and the mass. So that you end up with somewhere between 29 and 58 kg of drive per 70 kw per meter. If you have a TW of power you need to get rid of equates to 415 kt of mass. That translates to an acceleration of 0.00008 m/s2 (a) of acceleration. When you are talking about interplanetary travel and acceleration, once you get below about 0.01 a your oberth effects are lousy inefficient, in addition you can waste almost half your power trying to spiral out of planetary orbits in order to escape. This can be corrected by raw material ships by kicking and wasting time doing nothing, which for fusion is great because it does not require critical mass like fission reactors. But its very difficult to capture the oberth-like effect for planetary transfer orbits you get from combined burns at low planetary orbits. The savings are almost half of what an infinitely slow ION drive craft would spend. I don't know if this is apparent but let me make it clear, a chemical thruster puts the bomb (the energy conversion over short time and space) into a combustion chamber and expels most of the waste heat as exhaust. A fusion reactor has (for reactor and humans to survive) place most of the energy conversion inside or near the reactor, about 1/3rd is in the thruster and 2/3rds approximately has to be dissipated over a 2-dimensional surface around the reactor into space. The latent heat is an inherant problem with larger amounts of energy (addressed below). So correcting the problem of the u-r-f-d equation is to add mass to it in the form of lower exhaust velocity. So if we cut the Vexhaust by 625 fold we bring acceleration up to 0.01 but we add fuel mass. This is an ISP of approximately 50,000 which means we could travel to places in the solar system, carry landers ect. But in handwaving that thrust power into existence I have failed to reveal one tiny detail, yes the thrust is possible, its effects are not. Above we said we are not going to worry about a 1 TW reactors weight, the problem is now we do have to worry, the heat expulsion is heat is expelled through infrastructure mass. In this case we have a reactor, the reactor does not produce high potential electrons that then flow into ION drives, it produces radiation that is converted to heat, hopefully by some state-phase-transition power generator which drops the energy potential by at least half, and maybe another potential that drops it again and so on . . eventually you have reactor waste heat. But in addition you have pesky waste and reactor erosion (very very hot stuff) that will be ejected or accelerated into space. Neutrons could be absorbed by sacrificial boron and ejected along the way however you have heat generated and alot that is expensive to capture. So now we have the big problem. Lets say we had 300 GW of waste heat, now lets say we had a very black transfer foil and we can evolve heat at 1 kg per one meter, the thermal limit is 50 degrees and into the black of 5 kelvin space. Your differential is 293 kelvin. The bottom line is that you need to all but double the mass of your ship, meaning that to maintiain a, ISP will need to drop by 25000 to about 25000. Im saying this in a future thinking that fusion will be a thing and we will have better ion drives yada, yada. At the moment 10,000 ISP is the practical limit. (because energy density of solar panels is alot less than fusion reactors and cooling mass). To restate, there is no limit to the ISP of an ION drive like system, the limits lie in its practical application. So here is what happened. Fusion power = unlimited energy but not perfect efficiency energy. Thrust conversion is also not perfectly efficient. Thrust efficiency has a dependency on mass. a = (Unlimited energy - Power conversion losses - Thrust conversion losses)/ (ISP * thruster mass + reactor mass + converter mass + radiator mass + PL mass + fuel mass/2) = you're screwed. heat = Unlmiited energy*(power conversion inefficiency + thrust conversion inefficiency + PL waste) = ........ So this is the reason unlimited energy is self limiting, the problem is if we look at space we can think of it as a 2 dimensional manifold that captures heat from whatever 2-dimensional radiators are present. Lets say we can dissipate power over 1 meter of space, but at most we can fold the surface and double heat dissipation. This means that our effective heat loss is roughly 8* pi * r2. For the nay-sayers lets say its 100 * pi * r2 Equally generous lets say the we can dissipate 100 times ensolance (reality is that this would mean glowing orange hot). OK so lets dissipate fusion reactors. (IOW we have some ungodly means of dumping heat in the future) 1 watt reactor generating 0.3 waste heat would require a 'rough' sphere of radiators of r = 0.00008 10 watt, r = 0.00026 100 watt, r = 0.0008 1000 watt, r = 0.0026 10000 watts, r = 0.008 100000 watts, r = 0.026 1000000 watts, r = 0.08 10000000 watts, r = 0.26 100,000,000 watts, r = 0.8 1,000,000,000 watts r = 2.6 (yes, I am very generous with the radiative heaters) 10,000,000,000 watts r = 8 meters (the radiators would be visible at many places on the ship) 100,000,000,000 watts r = 26.6 meters (the radiators now completely surround the ship except the radiators 1,000,000,000,000 watts r = 80 meters. (the PL is now buried inside a large manifold of radiators, finding difficulty to keep cool). So lets tinker with this lets say the rate of dissipation is 3 times ensolance at best, and we can oscillate the manifold 3 fold. The equation for 1 TW of power is now 1306 meter in radius. Up to this point for each point in which power presented a problem we have provided a work around that cost mass, but not space. Now we have a work around that cost space, and the cost of space is mass. So that at some point mass as a function of heat has a second hyperbolic term. IOW the heat eqaution eventually mutates into this type of thing radiator mass + structure = k*( KWheat + 0.00001 KWheat2) where k is the radiative heat capacity per radiator mass. Fundamentally, this drafts the question when we look at Universal events, (big bangs, intergalactic speeds, intra galactic orbital velocities) we can examine these in the context of very high energy events that occur over relatively short periods of time (the accretions of a solar system, a super nova, the initiation of fusion of a star). The speeds that we see are often the result of catastrophic events, for example the momentum created by inflation that is fed into expansion, the particle formation energies and the resulting momentums. IF you want to generate huge relative velocities you have tolerate rather erosive power conversions. IN the case above we might want a 1 TW fusion reactor in a ship, we just would not want to use it much of the time, and we are more mass efficient by having a 1 GW fusion reactor, we can easily scale down the ION drives and heaters. But lets say the smallest fusion reactor is 1GW, then what, you have a reactor that can only be used for a few seconds a minute and the other 57 seconds are devoted to dumping heat. My bottom line on Space fusion (not ground based fusion) is that it has to be able to generate power, convert power and do so in a specified power range, say 10 MW to 100 MW. The alternatives are we have to create power transformation fundamentally more advanced in technology than fusion reactor or abandon space fusion. I want to make this point, we had a 2 year argument about the Cannae drive and how it would answer all the space problems, it lowers the space problems only about a factor of 3. The problem with the massless drives primarily is a time constraint that travel has, to make the point, if you are on the moon and you need to orbit there are no intrinsic electric propulsion system, extrinsic maybe. If you are in GSO transporting underwear and two-by-fours to Martian GSO, its not a problem, but to transfer from LEO to proxima centauri is the same problem as launching from the moon, except that for the moon chemical propulsion would work, for proxima Centauri your acceleration to 100 years and deceleration another 100 years and of course nobody lived. To utilize Cannae for manned space flight would require many things that would be extremely difficult to do or currently impossible even if there was unlimited power to do those things. Unllimited power, as we see above, limits itself.

They apparently have their mass fraction numbers screwed up. With today's modern turbopumps you would not need a nozzle quite so large. For a horizontal take-off rocket design to be taken seriously it would need to be a Mach capable design. That space craft does not appear to be able to generate enough lift to take off from water or survive a low altitude MACH speed.

Your proof, has it been tested in -150'C ice, . . . .not in alaska the ice is just below the melting point. That is not what they tested, they used a 5 KW cable laser, you are offering up fluff again as fact.

Note 1. Device not tested in ice, but via computer similation. Note 2. The paper you reference did not use nuclear power at all, they use a laser-fiber driven conbination heat sink and photovoltaic to produce an autonomous bot. The device was a 5000 watt laser powered by a 30 kw diesel generator. The hole that was generated was > 30 cm in diameter (0.702 Square meters) and the rate of flow through ice was never measured, they only demostrated that the could boil water with it. Europa has 1/25th the sunlight as Earth, to generate 30,000 watts of power at 16 watts per meter2 would require 2000 square meters of solar panels. IOW, once again you have brought a method to the group that cannot be powered. Note: bunker buster bombs are conventional weapons.

Silicon starts becoming plastic at around 600'F and melts well over 1000'F, many of the other components of rock, particularly the alkali metals will decompose and form a powder when exposed to air that is difficult deal with.

No, this is what you do, haul it to the nearest river, fill the fuel tanks with air and cap . Throw it in the nearest river (legs retracted of course) tug it down to the ocean and haul it from wherever to Florida or Texes. Pull it into a dry dock and and take it over from there. Or you could take an Old russian whaling ship and hoist it unboard from the point of disembarkment, then taunt Greenpeace as you hauled your load into Florida. You could try to land it in the Congo River, its nice and wide and deep. Probably wouldn't make it to the coast in one piece since the aluminum would command a decent price on the black market.