Green Baron

Afaik (but i may be wrong) Marsian volcanism is assumed to have been mostly effusive, though the lesser gravity causes gases to bubble out at greater depth than on earth. Some plinian fireworks shows may have occurred Marsian Volcanoes grew so huge because the magma chambers may have been larger than those on earth and Mars has no plate tectonics, thus the lava dikes and vents remained stable over longer periods of time and, equally important, there is much less erosion than on earth. On earth, after 10s of millions of years, there is not much left even even of great mountain ranges, after a few 100 millions of years surface features are completely gone and only the outcrops of the metamorphic basement tells: here was a mountain range. But there is no general rule for the speed of erosion. Mars surface features like the volcanoes are very old compared to earth. I mean very old. :beardedkerbal:

Gimme a broom, i'll dust the I-5. And afterwards Lagrange point 5 of the Earth Moon System. Though there is little, as far as i can see. "Dirt, dirt, dirt, dirt, dirt. Everywhere dirt" :-)

ESA puts it as a probable interpretation. Idk if there is spectroscopy of it. One can find reports of the cloud from 2002 and 2005 as well (Nasa). I am on the side of atmospheric origin. But we cannot totally rule out a volcanologic cause but afaik there is no more crustal heat available or mantle convection going on on Mars that could cause it. Though this is half a speculation/question ...

The article @Shpaget linked says it is a lee cloud, a regular seasonal phenomenon. Has been observed 2009, -12 and 15. Lee clouds on earth can be for example tail of varying length of fractus clouds from turbulence, or lenticularis clouds from waves on the lee side of mountains. At least future inhabitants will have some weather phenomena to observe ;-) -------- Different phenomenon of dynamics, but equally of orographic nature, lee vortices "behind" the Canary islands: https://eoimages.gsfc.nasa.gov/images/imagerecords/60000/60766/Canary.A2002186.1155.1km.jpg

Brain mass shrinks in long term spaceflight missions Long term spaceflight lets brain mass shrink . Some of the effects, but not all are reversed after several months on earth. Visual abilities suffer from a long stay in weightlessness. Moar investigations.

I am still waiting for corrections ... but so it seems. But once you get to relativistic speeds you must mess with the Lorentz factor .... may be one of out physicists shows up and clarifies. It seems to me that the first 0.2c dV are the easier impossibility of all the impossibilities of interstellar travel. but 3000km/s are .01c. :-)

I used the simple term Mstart = Mend * e(dV/v exhaust) from the wikipedia article about the rocket equation. With a v exhaust of 100km/s, to accelerate Mend of 1t to 0.2c, we need ~3.8 * 10²⁶⁰ tons. What i am up to is that dreaming of interstellar travel is totally in vain if reaction mass must be taken along. Which leaves us with our imagination about wormholes and vacuum energy or whatever.

According to Ziolkovsky, assuming an exhaust velocity of 5200m/s, to accelerate a mass of 1 ton to 0.2c(*) takes 10²⁶⁰⁵⁷ tons of fuel. (From a book, exceeds double precision ;-)) This is ludicrously more mass than the entire observable universe contains (~10⁵¹ tons). Assuming an ion thruster with 50km/s v exhaust still needs 10⁵²¹ tons of propellant, which still is ~470 magnitudes off the entire mass in the obs uni. Corrections ? (*) Calculation does not work for relativistic speeds !

Anybody here doing a little tinkering with rendering ?

Well, if you want to create an own universe with physics and everything you're probably better off with an own renderer uisng libraries and APIs, which isn't too difficult when using C++/OpenGL. The problem is that a game engine can be like a corset, as we have seen in the case of KSP. Even multi platform development (Windows, Linux) isn't that impossible with the above combination and loader libraries and a lib for event handling. For simple games like platformers, shooters, grab the flag, crawl the dungeon and do so on apple, windows, linux, android, ..... game engines are almost inevitable, as @Orc said. For things more on the simulation side where the renderer and sound aren't the main problem, but all those algorithms that make up the sim are, one is probably faster in time to market and definitely in execution time with an own engine. That code you know and you don't have to run after the development of an external engine. avoiding trouble with version transitions, etc. Just my humble dabbler's opinion. For more info, there is for example gamedev.net with forums etc. ------------ Also, the first renderer is really fun :-) And sooo buggy and primitive ....

So do i :-) If i get it right Newton actually did away with the elder concept of entities (identities ?) and put masses and quantities instead, thus principally enabling calculation of forces like the one that pull a planet into a sphere. But that is just an interpretation, i have not read his work myself.

An experiment worthy of the brilliant Klapaucius :-)

Simplest i can imagine, without any graphical help: a course correction. You measure a difference between "should be" and "is". So you apply in a first step a correction that brings you towards an intersection between your current course and your "should be" course in a finite time. In a second step, shortly before you actually cross your "should be", you apply a second correction that adjusts your intersecting course to match the "should be" course. Don't we do this every day ? ;-) A PID controller would do this constantly. Of course (off course :-)) in a manner that does not lead to resonance or over- or under-correction.

There is no hard limit for an altimeter. It just gets more and more inexact because the change in pressure with an altitude step gets ever smaller. Still, for use in aircraft, it is far more exact then GPS. A radar could be equally or better, but needs a lot of energy. Also, the barometric pressure height is the same for all participants if they all set their instruments to the same base value. Which avoids controversy about the occupation of the same spot at the same time ;-) (*) For a pitot tube the same holds in principle, though here the difference between a static and a dynamic pressure is used. Correction for compressibility of air (speed), pressure (height) and temperature are applied. In every day aviation life a limit plays no role. (*) Edit: I just read (on stackexchange) that the ISA standard atmosphere definition and the derived mode of computation and calibration will probably render the reading of a normal altimeter useless at an altitude of 80-100.000 feet. So, that might be your number.

https://www.dlr.de/dlr/desktopdefault.aspx/tabid-10081/151_read-30322/#/gallery/32416 "We want to investigate whether a breathable atmosphere and food for astronauts can be generated from their own waste in space." The plants will "receive everything they need to grow" and an artificial gravity like that on Moon and later Mars will be simulated by rotating the satellite. --------------- Doesn't sound like it could be done on the ISS. If it works, it could make one more data point on the way, i would say, nothing outstanding. Supervision is by a medical department.

A greenhouse experiment (with the silly name eu:cropis) is planned to launch on Falcon 9 on November 19th. Nothing huge, just a small satellite (230kg) that contains several tomato seeds to grow under controlled conditions, nutrient supply, lighting and gravity. Not only but also for possible Mars/Moon applications. Just sayin' ...

Well, e=0.5mv² ... ... okok. Do you mean this ? https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL073191 ... or maybe this ? https://impact.ese.ic.ac.uk/ImpactEarth/ImpactEffects/effects.pdf for a numeric approach ?

No no, keep them ! They automagically adopt the new flavour. Don't be fooled by somebody telling you "Hey, pssst, I can trade all your old kg into new ones. Special price."

Wow. That was about time. I knew that the prototypes had problems holding their weight mass. Glad to read that a kg is still a kg :-)

Microbial life on earth is probably 3.5by old (e. g. Pilbara Craton), though arguments wave back and forth. In discussion are furthermore 3.7by, 3,9by and questionably even 4.1 to 4.3by with the first open water. One of these interpretations for very early life, structures resembling stromatolites in the Isua belt of Greenland being 3.7-3.8by old, has now been re-assessed as being of geological, not biological origin. Study. Because all of the very early interpretations are based on indirect markers, this is probably not the last word, but very interesting.

Esa mission page: http://sci.esa.int/bepicolombo/ Jaxa mission page: http://global.jaxa.jp/projects/sat/bepi/ Hopefully we will have KSP 2.1 ( because "never trust an ending zero") until the arrival in 2025 ;-)

Everywhere. Some developed further, some abandoned, some put on the shelf for later use. Again, people here have told you, these companies are largely funded by NASA. And NASA overlooks their work, helps avoid problems, provides technology and help in case of mishaps. None of them would exist without a civil space program. The cause of the two SpaceX accidents might even be somewhat nebulous without the help of NASA. The ISS would not exist, and thus there would be no need for the development of manned capsules. People are not on the moon because there is no incentive, no need. There is absolutely nothing interesting there. Technologically it is not that big a problem as it was in the 60s, but why spend that money and resource ? It is still a huge enterprise. Exploration inform of telescopes, probes, etc. brings us much farther these days. Until some day maybe someone starts again with manned spaceflight. [snip]

Wow, you can play the queen of instruments, i am impressed. I wish i could play an instrument ... When i was in school, one of our teacher was the organist in church. He invited the whole class to visit him and hear the organ. He started to play a church song, then something more neutral, a classic riff, and finished the gig with a blues and a boogie. The pastor was not amused.

paper-clips ?

Yeah cool. And archive it on microfiche for eternity longer than you will live :-) btw.: classical films are either negatives or diapositive slides. Both with variants and so. Edit: oh, complaining about ... about ... about the weather ! It is raining.