Green Baron

That's the thing. An organism only exists because it takes energy from its environment and because it exists in the right environment it is adapted to and were all necessary interactions can take place. Take it out of its natural environment and it stops working or starts to stutter :-) The fact that some organisms can survive some time in vacuum and low temp near earth does not change this. Their decay is slowed down, but still takes space. In the end intelligence is only a body function, not higher or lower than digesting which as well extends beyond itself. Keeping a brain working needs a lot of energy btw. Edit: nevertheless as time goes by and even under optimal conditions, no energy intake can keep body functions from failing.

Na, life doesn't reject entropy. In order for an organism to keep up its functions it needs energy which must be provided by the environment. In the end, the upkeep is only borrowed for short time, on a cost elsewhere, e.g. a food chain that is based on solar or geothermal power. Sooner or later everybody realizes that entropy is taking its toll ;-) Think i.

At 28N, 18W, visible planets' situation after sunset is Venus in the West, followed by a bright shining prominent Jupiter, a pale Saturn right in the Milky Way and Mars rises in the East.

Silicates themselves not. Large areas on earth are covered with them, we call them sands. That's because sands are at the end of the weathering process, SiO2 (Quartz) is hard and lasts a long time. The dust gets blown around, frequently here on the Canaries we have Sahara dust in the then hot and dry air. The dust shields the sun, light is dull and yellow/orange and some people have respiratory problems from the dryness and temperature, less from the dust. Cars must be washed afterwards ...

Minerals aren't much different. Mostly basaltic stuff in its various forms and its p/t-variations and weathering products. Marsian surface is old. But there is of course not earth's variety of sedimentary and metamorphic/diagenetic and soil building processes, etc. blabla :-) Life - none detected until now, as we all know. Life affects mostly soil,but of course all the other spheres as well. Earthly soil is by a large part composed of life(tm). Even the upper crust if i may say so holds life. Plate tectonics: not existent on Mars. It would show. Thought to be a prerequisite for life over longer times as it renews elements, offers sinks and wells and many sorts of cycles, has equalizing effects on temperature and composition in the spheres ... etc. Water: there was a work published recently on the possibility that marsian water might have been drawn into the mantle in an early marsian phase, when atmosphere was thicker and temperatures were higher, before it would have escaped to space. That water would reside between 0 and 100km below marsian surface now, either as pore water or locked in minerals. Marsian minerals we have on earth show no cristalline water, but these are from a greater depth (100km and more, assumed to stem from a giant impact in mars' younger days), so that is not necessarily a counter argument. Newer hints to surface or subsurface water are all based on remote sensing, so there may still be we can be sure of many surprises. I love surprises :-)

... and is there a correlation between bandwidth and Schwarzschild radius ?

Counterargument: We find a way because there are resources that can be exploited. Alaska is a nice place. If these are used up, we move on. If we can't move on any more, we die out. It has always been that way. There are no resources on Mars, it is being radiated, the soil is poisonous, water is lacking, there is nothing to breathe and nothing to eat. We can't terraform the place, we don't have billions of years. Nuking the place might be [insert cultural reference of your imagination] style, but is grossly counterproductive to "terraforming", which apparently is thought of to be like going shopping down the road to the chemist. But the task is mindbogglingly huge :-)

Nature article about terraforming Mars. Summary: no, it is not possible to terraform Mars. There isn't even enough CO2 to produce decent atmospheric pressure so that somebody could walk around without a pressure suit. Not mentioning all the other elements necessary in fantastillions of tons. We can bring a rover weighing a ton or three on earth, but not even a human. But we can marsiform earth and are doing so in more and more places, cut down forests, fill areas with radiation .... Btw. yesterday was Earth Overshoot Day, the day humanity used up all resources that regenerate during a year.

Euros in my case

After 25 years and 4 months one of my stereo loudspeakers got a raspy voice. A quick check revealed it's 3 of the mid/bass drivers that gave in to entropy. I hoped it was the crossover because that is relatively cheap to mend ... I checked the web, original replacement drivers are long sold out, but there are replacements from another brand. A pair of comparable modern speakers would cost 1500 to 3000 funds, but i don't spend that much money without prior listening connected to my equipment. So, i'll refurbish the old carcass with new drivers *starts searching the soldering iron*.

For the hand negative, i agree. But the animal scenes are clearly more artistic and expressive, more realistic and less stereotypical, for the time, or not ? :-)

Can't find it in my favourite dictionary, what is a manga ?

Humans never lived in caves, life in the open savanna is more like their original habitat. "Living in the trees" has become a saying more than anthropological reality, or at least one must go many millions of years back with the danger of ending up in the wrong line of evolution. We find things in caves and rock shelters and their sediments more often than elsewhere only because of preservation. Deep caves with middle and upper paleolithic finds can more be seen as ritual places. At least those well researched ones in France and Germany. And then there is that gray zone between cave and abri or rock shelter, where fire places and stone tool knapping, mending and repair over longer periods took place. But these were mostly open to one side and frequently offered a nice view over the landscape. Things in the open are much rarer (though they exist) because they were exposed to weathering and/or transported away by sedimentary processes. Ha, that was the view until February ! But meanwhile it is clear that Neandertals did not copy and had the same cognitive abilities. Published in Science in February (i linked it in the Random Science Facts thread) :-) Only gradual differences remain, easily attributable to the much greater number of the likes of us. Yeah, hunting and gathering is easier than farming and keeping life stock.

The Perseids may produce a spectacular spectacle in August. High time is expected for the night from the 12th to the 13th, but the nights before could be good as well. After mid august they'll be gone. They are very fast (60km/s) and might contain some really nice meteorites. And no moon to disturb the darkness. In the morning hours, when the place faces in flight direction, long exposures with a fisheye lens aimed at Perseus, stacked over several hours, could produce nice images. If i get out i'll try. Anybody else ?

If i think about, this certainly includes uncertainty ? Edit: i mean, if something went just a tiny little bit different in an early phase, then things come out very different at the distal end. But i think you didn't mean that deterministic ?

Afaik they don't even use tools, if i consider the shell stapling similar to a bird's nests, the latter not really being "tool use". But "tool use" has seen quite some inflation in the past :-/. Many vertebrates have larger capacities than cephalopods, and nobody would expect ravens or elephants to build a civilization, or would they ? :-) Anyway, why didn't Neandertals, not really being much different in cognition than ourselves, start the "Now we build civilization, *hough* !" thing, let's say in the last warm phase, 125.000 years ago ? Because they were wiser, eh :-)

I too think it is hard to imagine that the steps from standardized stone tools via soft metals like copper and tin to iron smelting can be performed underwater. Besides the difficulty to cut a tree and make a fire, Fish don't have fingers or similar manipulators to work things (though they had enough time to develop some), the brain alone isn't enough, one needs something to actually make a step from cognition to "handling", i guess. The octupuses i met when diving were curious, but that's it. Humans with big brains and tool production too lived on the planet for 2.5 million years without anything that we can call a civilisation. It was just the hardly explainable step from living for the day to production planning that more or less accidentally happened some 12.000 - 5.000 years ago that made us long for the neighbour's stuff :-)

"Bronze age collapse" (what a wording ...) is attributed to climate deterioration, possible causes volcano eruption(s), maybe cultural changes in conjunction with iron working technology, who knows ... Yeah, i too can hardly imagine an aquatic civilisation, apart from Hollywood themes :-) The open sea is a desert, little raw materials, no fire. Life is mostly concentrated on the continental shelves and upwelling zones ... etc. Ocean floor is renewed every now and then, only the clays from weathering processes ... naa, there is a reason why we are pedestrians (if we are not in front of our pc) :-) Upper paleolithic stone tool industries. Blade production, composite tools, exchangeable insets. Highly standardized to sub millimeter sizes ! ;-)

No problem in principle, better than copper and bronze at the time of the construction of the Great pyramids. Soft metals don't help carving granite. Experiments have been conducted with limestone concrete, material science has found evidence that this (besides manpower and a long construction time) technique might have been used. One doesn't need metal for a civilization. All of the neolithic ones were built without. You need to feed the stock and people, which means nice climate, water, reliable food production. Climate deteriorates, civ dies out.

Sorry to correct, but @magnemoe is right, most of Egyptian history is neolithic. No metal, no wheels, even the potter's wheel came late. Actually, with the onset of the metal ages, the Egyptian civ started to decay and others entered the scene, like Hetites, Assyrians, Babylonians, and Greeks and Romans. At the time the Romans entered (iron age) there were merely city states left. In a ridiculously small nutshell :-) But people are still working on correlating Egyptian chronology with absolute dates.

Here's a how-to for dslrs :-) - switch off stabilizers, use the timer and mirror lockup. This is to avoid any inferred blurriness from finger or vibrations while on the tripod. - choose manual focus (or some "remember" function of the electronics). Better equipment has a switch at the camera and/or objective. This is for keeping the once chosen focus. - choose an aperture one or two below the maximum of the lens (e.g. 4 or 5.6 if the maximum is 2.8). This is for optimal sharpness and to avoid vignetting. - focus on something in the very distance. For a telelens this should be many many (>100) km away, or stars if available. Usually not as you build your equipment during sunset when there is still light. - don't touch the focus or aperture any more until end of the session. If you need to vary do this with exposure time or if you must with iso setting. Mind air movement in the atmosphere. This is ... hard to keep up. If you want to take photos from another object in the meantime, come back another day or bring 2 cameras ;-) Not a joke :-)

Hi :-) Moon under total eclipse, Mars peeps through the twigs: Moon stepping out of the totality: Nikon D700, 200mm telelens, 1600asa, f/4, 1sec/0.5sec exposure time, tripod. Cumbre Nueva, La Palma island.

Thanks, and sorry. Yeah, you're probably right ...

Camp ? [snip] Huesos. Arago is Homo erectus (You mean Tautavel, right ?). Atapuerca the same, maybe early heidelbergensis. There is no genetic information from these. Snipped pop science. The cell article has nothing to do with migration of Africa into Europe or Sardinia. It is about interbreeding, based on one (1) Denisovan individual and a pack of Neandertals. Relevance ? Yeah. It states older mixture not supported in Africa, newer more probable. Actually a contradiction to your claim that several waves migrated directly out of Africa into Europe. Got the wrong paper ? What ? Neandertals after the last glacial maximum ? Together with Dinosaurs ? I'm sure there is genetic evidence

Last Neandertals (Chatelperronien) apparently retreated to the southwest of Iberia with a climatic deterioration after 30.000bp. I would say (and if you call for a proof i will try to find something) that it is improbable that there was no coexistence, as in southwestern France at that time we already have around 10.000 years of Aurignacien, which is the first cultural appearance strongly connected to modern humans. Well, cough, nothing human related precedes prehistory per definition :-) I never did. I said the paper doesn't name a date for the mixture (nobody can at this time) but a group that separated from N before 70k. Which i will live with until it is corrected again :-) Sorry, i can't find anything about this ... Modern humans (Aurignacien) in Cantabria date to 32.000bp. I must admit that it's 15 years since i last was deeper into that and will have to look up the find sites and their interpretation if asked. Early upper palaelithic in Portugal dates to at least 24.000bp (Lagar Velho). So that seems to be all on the same rail. Well, that is not that clear. Lagar Velho 1 could be interpreted as a hybrid. It is still an open question. Well, then that's a fro and to and one best awaits the future. My last stand is that the DNA evidence of interbreeding is solid, and that is just 2 years ago. Find sites almost leave no other interpretation. So, where is the work that says otherwise ? The above surely doesn't ! https://www.sciencemag.org/news/2016/02/humans-mated-neandertals-much-earlier-and-more-frequently-thought https://www.sciencemag.org/news/2015/01/humans-and-neandertals-likely-interbred-middle-east Hypothetically, could it be that poor preservation or preparation, contamination, handling and deterioration still might have a slight influence on some of the analyses ? Where is it ? Am eager to read ! [rest snipped, i am having a problem finding a clear line ...]