Green Baron

No formal language is actually difficult to learn. Grammar, syntax, it's all done in a few hours to days. Compared to German or Spanish, Chinese, Japanese ... To write a well defined and behaved program is something different, though ... :-) I'd recommend C for the beginning. Good for everything, simple, fast and just about to regain place 1 among the programming languages (tiobe). Here is an open source interpreter written in C (lua), often used in games etc. for scripting.

Engineers in L2 ? *scratchhead*

Yep, build up enough pressure and greenhouse warming to be able to walk outside without a pressure suit. But still an oxygen mask of course. They cancel out the availability CH4 and H2 as these are too volatile, and water itself could no provide significant warming. Anyway one needed some warming before one could puff smoke rings release H2O as a greenhouse gas into an atmosphere. So it boils down to where has the CO2 from the ancient atmosphere gone, could it be mobilized from the reservoirs it is in, would it provide enough warming ? They estimate the amount of CO2 needed to get to 1bar by building different scenarios for the sinks it may be in (polar ice, mineral carbon, ... etc. blabla) and losses, e.g. to space (O2 is lost to space, as measured by Mars Express). In the end and after having chewed through the case, naming piles of uncertainties and future explorations, the conclude: There is not enough CO2 and anyway, with current and imaginable future tech, it can't be released. There is enough mobilizable CO2 from ice caps etc. for 0.02 bar (20mbar), which would lead to 10K warming, but ~60K is needed. Anyway, the dream of hiking about the place without a pressure suit is just that. That's in a small nutshell. Peanut.

Yeah, that's the usual stuff you'd expect from tabloid. I can assure you, the cited paper is not tripe nor made up and totally based on current knowledge. https://www.nature.com/articles/s41550-018-0529-6

I have access, and i strongly recommend to support science and spend the 100 bucks or so for a Nature Astronomy subscription. It is fun to read, though one needs a little knowledge base to actually understand all of it. I freely admit i don't in every case :-) The paper actually sets reasonable and thoughtful estimations against mere guessing and wishful thinking. And it is not about sequestered CO2 alone, but about all CO2 being available or not for "terraforming", here: getting the atmosphere to do the greenhouse. Btw,. talking about sequestration, another work that estimated the amount of water having been drawn into the marsian crust in an early phase instead of or additionally to that having been lost into space, part of which could be available as pore water between 0 and 80km depth. That fits right in the latest interpretation of a reflective below the south polar ice, that could be interpreted as a surface of a watery brine.

My favourite saying: predictions are difficult, especially those regarding the future :-) I am not a specialist, but afaik overpopulation refers to a capacity in a certain environment. According to this, high industrialized countries including were i am from and were i live now could even carry more than they do right now. But this is at an expense, economically (debt for the future), ecologically (resource exploitation and destruction elsewhere) as well as politically (exporting wars, banana states, ...) Not sure if it is that clear, a measurement is just a few years (20 at most) old and i am eve not sure if the World Bank can be regarded a reliable source. Before 1980 or so it was based on mere asking, and everyone would say "i am poor" (exaggerating). Never trust a statistic you haven't made up yourself ;-) Also, 2 funds per day as the lower border to extreme poverty (regionally adapted worth of a dollar, or so ?) is enough to starve(*) here. 2 bucks are a coffee (with milk). In Germany not even that. What i want to say, i don't really trust it :-) Waiting for correction ... :-) (*) Edit: which nobody does. It is a highly civilized country !

*slapsforehead* Sure ! How didn't i think of that ! :-))

Clear so far ... but where do i get the oxygen from ?

In contrary, the numbers were outmatched by magnitudes. We are getting worse at using the resources, world overshoot day was 1. of August. People actually are dying in 10s of millions right now in Somalia, Yemen, East Africa, elsewhere. It's not in the western news, ( yes, it is) so it is out of our minds. But it is happening. Btw. last year islands were destroyed by hurricanes, official numbers of deaths are bogus. Just one out of many sources for that. 2017 monsoon season in India and Pakistan is believed to have killed 10.000s (single events already killed a thousand and more) and made millions homeless. It is all there, one only has to look. Actually, relying on second hand news is a factor that does make people more careless and oblivious, which is a sad thing. Edit: That is why i liked @sevenperforce's point. A large number running in the same direction doesn't mean that it is the right direction. Or, people all being content with "everything is just fine" don't realize a large part of reality. I hope nobody feels offended :-)

Oh, i wasn't aware. You mean this and this ? (Am trying to avoid tabloid links when searching "Xanthoria elegans") Not sure if its edible, maybe the fungus part (with ham and eggs) :-) Strategy seems to be "go to sleep and wait for better times". So they survive some time, but don't really live long & prosper, did i get that right in the seconds i had to scan it ?

None. They would have to grow under Marsian conditions (impossible) or in greenhouses. People are working on the latter, i read a many months long experiment on Antarctica went well. Edit: overtaken by @sevenperforce. I mean, you can only grow anything if temperature/water/nutrients/soil permit. Or you must take a suitable environment with you. Assuming that we agree that building one is far beyond our possibilities, as suggested/proven/imagined by the Nature paper.

Definitely not i think too.

Everything evolves, even if it becomes extinct. Because adaptation plays such a big role (it is all about filling in niches), one should always look at an organism and its environment. Both allow conclusions of the other, in certain limits of course. The term "food" means all the intake of an organism to keep up its metabolism. That may be a just a few carbon dioxide molecules or a freshly killed unlucky animal, depends ... As an example for microbes, relatively well explored are Stromatolites and BIFs, they have an economic value as well. They were formed from the Archaen on by (mostly) shallow marine algae. And yep, they work similar to today's lifeforms. From very early life we only have the assumed products of their metabolism. For example fractionation of stable carbon isotope can give hints if something has biotic or abiotic sources. There is a lot of reading out there :-)

It is probably much older, almost seeming a spontaneous natural reaction (don't cite me ;-)). Latest work hints to 4.2by (even 4.3 is in discussion), but still needs more confirmation. It might have been wiped out by impacts/environmental changes and formed over and again at vents (many more of them over the thin crust at that time), shallow warm seas, until it got more stable after 3.6by. That is why i think no problem for microbes, and it is the chance to look in our solar system (*). Long term stability, constant slow change to allow for adaptation, no or few abrupt steps with enough time in between to recover, constant exchange of nutrients, self sustaining and stabilizing circuits, that's what it needs. I'd look for stars that formed in the same cluster as our sun, they are from the same stuff and they may have shared the same fate over much of their time. But its just an opinion. (*) Edit: though i have grave doubts that they find something clear anywhere else right here.

That's the point imo, time & conditions is the limiting factor. Microbes come & go, from first oceans 300my after solidification of the crust (probably that early) until today. But >3 billion years +/- 15°C, low radiation, protected from impacts, supernovae and things, aka peace & quiet, that's a word, even on astronomical scales. We're early ;-) ----------- Ok, but i have been here too often. I better quit again. In the end, idk better than anyone else.

For now and until proven otherwise it looks like and we must assume that. As a professional agnostic, and after weighing all that i have heard of, read and talked about, i can easily imagine (trying to avoid "believe" ;-)) that self replicating chemistry and microbes are no big deal, an ongoing evolution over hundreds of millions of years, or even billions, that might lead to multicellular life or even biocenoses, is pretty improbable and may well, until now, not have happened elsewhere.

I shortly heard that, according to the Vulcan Academy of Science, A is the case. But that is just a rumor ...

Oh, i was not implying that people grew as old as today or claiming anything of the above. I would have written so ;-) Were i am from ? That's southern Germany. So probably early modern times (plague). I don't have statistics at hand. Graveyrads usually are biased towards older people due to taphonomy. Edit: there are no epidemics in the early middle ages that i am aware of ... Accident victims are usually buried @home. Depends. Between days and millennia. Often, especially in narrow situations near churches and so on. But that is usually found out about. I have no idea. Between 0 and .... ? But less than modern day leaders i would guess ... :-)) I have no tax declarations of anybody :-) Christian burials usually are just burials without much knick-knack :-) If you feel criticized, i didn't mean to do so, i am sorry. I just wanted to say that once people were out of infancy they grew pretty old in the early middle ages.

We are straying far, but its fun :-) It is hard to generalize life expectancy. Climate wasn't bad (reaching an optimum around 700-1000 iirc). Times weren't as bad as the misleading word "dark middle ages" might suggest. At birth, a girls or boys life expectancy might have been in the range you're suggesting (20 to 40), because of a high infant mortality. But once people were out of infancy they could (and did) well reach an age of 50+. Early medieval graveyards i heard of (most in Germany, France, Switzerland) held many bones of really old people.

There are a thousand years between late Roman/early medieval Arthur and late medieval/early modern Renaissance ... iirc ? if that arthur guy ever existed

... just a side node that always makes a modern day paleo-guy grin when reading "women's work" It was the result of a faux pas to foolishly name a symposium "Man the Hunter". It right away triggered a counter statement "Woman, the Gatherer" and the stereotypes were complete. Guess were ;-) Gender roles were, of course, never as strictly assigned as some limited "modern day" notion might make one believe ;-) Women went hunting and men went gathering.

You don't need to look at northern America for early medical advances. Romans and medieval Islam are examples for earlier advances.

Levis & Co., eh ? e.g. traces of infections on skeletal remains, more dental abscesses with the change in nutrition, age and cause of death, way of living in general ... i think you get it ;-)

In a nutshell: Hygiene was no problem during most of the paleolithic, we have enough evidence of that. It became more evident in the neolithic, when people and animals lived together and the life style of wandering around ceased. That had over hundred thousands of years helped controlling birth rate. In the neolithic, otoh, there was no necessity any more of only having one child at a time, which caused new problems like women dying giving birth, population pressure, fights over resources ... blabla :-) And, of course, peaceful together over much of the time. --- If you transport the guy into the early neolithic instead of what i first assumed paleolithic, he'd rather get recruited for field work, herd the stock and to clean up stuff, after being stripped of his/her fancy stuff. No talking old about "do this/do that", time and work force is limited and people are already struggling enough for their upkeep and to have enough for the winter. You can't bring them solutions from our world of plenty (solely based on depth for the future) when they have to care about every day stuff. There is no shop to buy a pot, someone has to make it and it takes time and effort. There is no mall to buy a t-shirt, you have to kill a beast, skin it, work the skin (that is hard work, guys !), prepare it, mend broken or torn things, etc. Corn and crop must harvested, new patch prepared, trees felled (now, it'll rain tomorrow) corn must be dried and flailed, milled and stored away dry (construct and maintain a dry place in a clay hut). All these things, where we push a button today or pay a buck or two, had to be done manually and it was a days work or more. The early neolithic guys didn't sit around, waiting for a saviour. Now imagine someone breaking in that romantic scenery where everybody is occupied to the limit, but the number is going down because of some disease, causing even more work/individual. Still want to intervene ? If they listen at all you'd probably make things even worse, killing the rest because they didn't have enough to eat for the winter and the life stock died of starvation or thirst. ------ A package is needed that gives people enough freedom to do things besides the obvious and directly necessary every day work. Once that package of division of work, more effective agriculture, spare time for some, etc. blabla is available you can start filling in their minds with modern stuff. Maybe then they listen.

Stone age archaeologist here. @vger, your case is constructed so that the brilliant mind of the future can heroically do it. As such, there is nothing one can do put in on somewhat realistic feet. The future guy can only order the people to do things at his command. But why should they do it ? The shaman knows what's good for the individual and the society. It probably would be the other way round, another mouth to feed by the tribe. Hope you're not a vegetarian ;-) @kerbiloid got a point. The guy from the future would have to adapt to the conditions he/she is in. And do not underestimate the art of the healers/shamans/whatever. They probably cure the thing before the futuristic hero has learned their language. As material you have horns, bones, skin and leather (it's hard to work), stone and bone tools, fibre from plants. Try to scratch a fresh bone with your pocket knife. The knife will probably break. They know how to work them, you don't. So they would teach you how to survive. You cannot build an oven with let's say upper paleolithic tools that is able to heat quartz enough.. Let's say, you are stranded with a sailing boat on the Salvage Islands (right around the corner here :-)). The two rangers that usually guard the nature reserve are dead, the radio out of order, next ship expected in 2 months. You probably weren't even able to make a fire (idk, maybe you are) or make some garment to warm you overnight. So, i'd rewrite the story. Poor guy gets stranded 30.000bp and has to make contact with the folks to learn how to survive. The night temp drops below 0°C, will he make it ? Says a friendly Green Baron