Green Baron

I don't understand what you mean. Soils were the point. Here's official stuff, the (world reference for soil resources): http://www.fao.org/soils-portal/soil-survey/soil-classification/world-reference-base/en/

More than one branch is involved, geography, hydrology, geology, chemistry, biology ...

Soil and geology ... soil is the dirt that's hiding the geology ! Soils are incredibly complicated due to their nature as outcome of weathering, sink and source of all kinds of circuits and heavy intermix with biology. Organics and micro- as well as macroscopic life form a good part of most soils. Soils depend on original rocks, climate, weathering processes, local weather, topography, animal activity, plant activity, fluid throughput, ... everything. So, either geology, or soil, not both :-)

Mammals are not amphibians. Amphibians need water for reproduction (hence the name: they have an ambiguous life between land and water) because of the construction of their eggs. In the end mammals stem from amphibians, which stem from fish, which and so on until you arrive at chemistry, supernovae and star evolution. Or are you just joking ? I never know ... :-)

A classification as valid as saying that mammals are fish. From a phylogenetic point of view all vertebrates have a common ancestor, but a finer grained classification is more than useful for every day use.

https://cloudatlas.wmo.int/home.html

Lämmergeier, actually Lammergeier is an anglification, anglicism, angwhatever :-) If you meant the bearded vulture ...

F :-) -------- If somebody is interested, here is an addition to the case of behavioural modernity in our ancestors: http://www.sciencemag.org/news/2018/03/signs-symbolic-behavior-emerged-dawn-our-species-africa tl,dr: Pigment use (possible symbolic behaviour), long distance raw material transport and African MSA stone tools 20ky earlier than before (320,000bp). It is reasonable to connect it to early modern humans, as oldest fossil evidence unitl now dates to 300,000bp. But fossils are missing in this context. This cannot be compared to the dating of cave art reported upthread, it is by far not as sophisticated and the evidence as well as the implications are weaker. Yeah, not exactly world moving, but still a nice random fact, somehow :-)

Yes. So it seems.

I had forgotten them for .... 20 years ? Thijs van Leers voice is crazy. Thanks, man, for the refresher !

Or medium things (mass of a ton) like Dawn or New Horizons over a loooong time. Anything that is based on reaction, like harpoon, tether, etc. needs some mass. Imagine ESA shoots the harpoon, the harpoon stays where it is and the empty tube flies in the other direction. Kerbal style :-) Ion drives of the day don't have enough oomph to adjust orbit of a deorbit satellite in LEO. In less than months or even years of time, and then the problem might be gone anyway, or has changed orbit due to interaction, or just because ... Sorry for being unclear, i mean, shooting something with a certain reaction mass up to bring something else down is probably a little impractical, at least as long as launch costs really count, so yeah, not cheap. I mean this is all a very premature discussion about details nobody really knows of. The tether thing needs a mass at the other end, the more the quicker it works. Just in principle, no nitpicking about the number of molecules please *propellerhatkerbal* Be it as it may, good night everybody :-) Throw a laser ? *duckandcover* I think there is a proposal ....

No need to get personal ... Tethers have been thought of before. I don't remember by whom. But i think the basic idea is that it makes little sense to shoot something up to bring something else of similar size down. Also the big hunks can easier be taken care of than all the small little bullets buzzing around. I first thought the harpoon is an April joke but then realized that the idea isn't new either. It reminds me (as somebody who has studied archaeology) of a spear thrower, the cruise missile of the late ice age :-) Ion drives are nice for interplanetary travel where they burn for days, weeks or months, i doubt you can use them to alter an orbit quickly near a gravity well like earth's (this isn't KSP, ya know :-)), which would be a prerequisite for something trying to rendezvous something else in LEO. We'll see. As satellites grow in number and shrink in size the harpoon will probably end up at the side of the atl atl/spear thrower/propulseur/Speerschleuder in a museum. Enter the fly swat. With a hole to give 'em a chance :-)

ESA never had a strong affinity to manned space programs, besides thought experiments and mockup technology demonstrators. A manned space program is strongly connected - and this can even be read from the voices in this thread - to a national identity. Europe does not have such a thing, it is a conglomerate of different nations all with their cultural specialties and many different voices. Nevertheless, with a relatively limited budget, ESA is contributing a lot to the scientific community with research in many fields, probes, earth observation and telescopes. Just look at the VLT, Gaya, comet missions. The first two produce an incredible number of papers and knowledge.

At the extreme outer edge, where gravity and speeds are low. Maybe. I won't read it all, not enough time :-) If it's important there'll be a discussion soon(tm) :-)

I am not sure if the original article can be interpreted that way, the interpretation sounds nonsensical to me. What it says is that there is a relationship between radius and rotation for galaxies when looked at in the 21cm (neutral hydrogen) wavelengths. But i have only coarsly browsed it. http://s3-ap-southeast-2.amazonaws.com/icrar.org/wp-content/uploads/2018/03/13111412/Cosmic-Clocks-Paper.pdf Our galaxy for example has different rotation speeds. The sun needs ~250My for a roundabout once. The surroundings are slightly different, which makes for a crossing of a spiral arm from time to time. http://curious.astro.cornell.edu/physics/55-our-solar-system/the-sun/the-sun-in-the-milky-way/207-how-often-does-the-sun-pass-through-a-spiral-arm-in-the-milky-way-intermediate http://www.messier.seds.org/more/mw_arms.html So there is a discrepancy between observation of our galaxy and what the "discovermagazine" text states.

Since it is pi day in America, due to their weird style of writing dates ;-):

Really ? Ahahahaha ! I wasn't even aware . I thought it was pi day per definition, like one of the saints or so. Fool, European, that i am. Ok, then byebye American Pie drove my ... gosh ... new earworm ... :-)

Trying to jump in. The problem seems to be a different one. We need to know which mods you want to get running and if you have any error messages. A general "i don't get it running" leaves us guessing, which is a waste of time. If you have problems with English then pls. post your problem again in the German subforum and i'll try to help you there. But anyway we need more info about what you're trying to do and how you do it. Meaning of the last paragraph in OP's language: Wenn's mit englisch nicht klappt bei Dir dann bitte beschreib Dein Problem noch mal aber etwas ausführlicher im deutschen Unterforum. Da wird Dich geholfen :-) In jedem Fall benötigen wir aber mehr Infos über das, was Du vorhast.

Do you mean friction belts ? If you don't get it running due to the long overhang, friction loss, and asymmetric load then try something like a paternoster drive. Cogs in ball rests at the ends and the rail fixed to bycicle chains. Or endless and more than one rail. That may be overengineered but probably not as failure prone. https://en.wikipedia.org/wiki/Paternoster#/media/File:Paternoster_animated.gif

Yes, as @PB666 pointed out, it was rated for a load under certain circumstances. But -180°C and vibrations under g loads exceeded these circumstances. For example, a steel has, depending on the alloy and conditions, certain ductile values. But at low temperatures the material gets brittle, so that a relatively weak blow or heavy vibes can cause cracks and weaken the material and when it is under stress it will give in earlier than the rating states. What NASA criticised is that the material SpaceX used was not suitable for the conditions, which makes it a potential and probable failure cause. SpaceX should have tested it before using it and/or used the right stuff in the first place. It is history now, on to new failures adventures :-)

Do the steppers drive threaded rods ? I have seen such a contraption that had problems like you describe, when one of 4 motor looses a step the thing canted and squealed for help. How about strong motors that drive axles, like one at each end and one in the middle with cogs and endless chains around each cog and fixed axles under the ceiling ? Thus a missed step doesn't stall the thing .... know what i mean ? The board can still run in rods that fix horizontal position.

Just got another stack of lumber for an annex of 1.6*1.6m so that i can fit my plans. And i am doing version 3 of the struts that hold the helix. This time with threaded rods like everybody else does. 5mm plywood is a little flabby, as @Shpaget has warned me, but i can save it with a lot of struts (8 on either side around the circle) plus eventually a skirt around the outside to avoid bending. Will then begin with a lot of jigsaw for the first series of ribs.

Yeah. Hopefully SpaceX stays away from (i exaggerate) diy stuff and this kind of failure can be excluded for the future. There is still enough room for bad things :-)

Squaring the circle. Assuming the sphere has a radius of 1 and the squares' edges have a length of sqrt(pi) ... Or so. Or different. Or similar. :-)

It only has ~3.1 pieces ? Happy pi day :-)