Green Baron

Answering with a more profane Alice Cooper: "Aspirin damage, aspirin damage, kills the pain but destroys the brahahain. Aspirin damage, aspirin damage, sometimes i find myself shakin' from the medication taken oh yeah ..." :-) It is 26°C in the late afternoon and extremely dry, continental African air here (La Palma). But temps are forecast to drop by 8° or so the day after tomorrow, which would bring them back to average for the season. Life is good :-)

Well, if there are like 22°C right now and blue sky ? But i doubt i have the qualification you need :-) Right now i sat down from gluing cork strips on the parade track (no photo because cork on plywood isn't that thrilling). But i have another project i may show off soon, implementing this little algorithm, and i am trying to do so since 6 weeks now and i don't really get it. Soon(tm).

It is a common shortcut for banded iron formations (attention, wikipdia, not everything is necessarily correct :-)). I thought you knew. Kindly suggest to go through it, as these are very frequently used for the analyses of early life on earth and a climate indicator as well in various forms. Nor did i. But i did and do say that life as part of the natural evolution is hugely (not solely) responsible for the climatic stability of earth. I think we all agree here :-) Earth's endogenic factors (those below the crust) are often overrated in pop science, especially when it comes to short or medium term effects. They influence more the long term (10s and 100s of millions of years) processes. Outgassing is a huge field. What brings CO2 back into the atmosphere these days ("modern style tectonics") is what has been dragged down before in subduction zones (and was built up by life forms as long as it was above surface), and this recycling style is thought of to be required for CO2 outgassing. The effect was probably even stronger in times when the crustal renewal processes were faster, e.g. during the Archaean, but i don't know if one can say that outgassing rates and for example mantle temp. are necessarily connected or if it is rather the speed of crustal processes that is responsible for CO2 out and in. I vote for the latter :-)

I am so jealous about your work, @Shpaget My little model train project is making slow progress, though my style of tinkering is more like this guy's: :-)

Welcome back ! One more reason why i will never announce a farewell :-)

Which somehow reminds me of a white dwarf with an accretion disk ...

2557 https://www.chiefdelphi.com/t/pic-first-team-2557-rebound-rumble-robot/177270 (big image)

2543

The snowball depiction is only hypothetical and the evidence holey. Climate models have their difficulties with it. One would need really high CO2 levels to get out of it by atmospheric heating alone. Widespread glaciation at certain times is undisputed, a totally overfrozen planet is not.

That is a misunderstanding i assume. The assumed lack of biogenically induced cloud nuclei (presented without explanation) does not exclude life. Essentially, the cited BIFs are assumed to be in vast parts the outcome of biological activity. They argue with some reason that a lower albedo due to less continental crust played a bigger role in keeping the temperature low. But, as we know, at the end of the Archaean 70% of today's continental crust (*) had been formed. The processes were much faster, a softer mantle had higher convection rates, etc. I only wanted to present different views on the matter, i am not siding with the one or the other (but accepting all if reasonable). And so I concede radiogenic heating may have played a role, how big i do not know, but i can imagine that radiogenic heating is less needed for the modeling than other effects, that is probably the difference in our views. Edit: according to other sources >80% by 2.5Gy (https://www.sciencedirect.com/science/article/pii/S1674987118300501). So i probably can put the paper to the archives of science anyway, the crustal albedo argument is a weak one :-) It so happens sometimes ....

Welcome :-) I don't play much any more, but when i did i always installed Engineer Redux, Transfer Planner, Alarm Clock, Waypoint Manager, Joint Re-enforcement, Scan Sat, Near Future Solar, Real Plume, KW Rocketry, and the one or other station part or exploration mod. Oh, and i found the Buffalo rover is really fun.

Welcome ! Safe landings :-)

Yep, that was a Nature paper in 2016, based on a model calculation. But it isn't necessarily real, and somewhat contradictory to other models like https://www.nature.com/articles/s41561-017-0031-2 or https://www.nature.com/articles/nature08955 that suggest biogenic activity to play the biggest role. Don't get me wrong, i am not against the one or the other ! I readily accept outgasing, a much more "mushy" mantle in the early days, methane and CO2 as part of a bundle of reasons for earth's climatic stability over billions of years. And of course a favourable galactic environment ! We can't exclude categorically any of these and it is not a single one source, e.g. primordial heat probably played a bigger role in the past than radiogenic heating. But the amounts and contributions are all debated and nobody can look inside the earth deep enough. I as well count myself to the "rare earthers" (for now(*)). At least when it comes to explaining the complex interactions that started in the Archaean and have developed further since then. On a high level, one can see evolution is consisting of self regulating processes, but this system is fragile to interruptions and depends on long term stability. Edit: rare, not raw unique !

CO2 concentration is what is mentioned most frequently in papers on the matter. Who knows. Probably not. These events are assumed to be connected to the arrangement of continents, snow cover, circulation patterns, moisture in the atmosphere, concentration of elements in sinks and wells. isolation of highly reflective continental mass, shallow oceans ... or, in one word: complicated :-) But earth probably never was totally covered with snow and ice, because of lack of explanation of how to free itself from that state, even taking into account huge flood basalt or other things that change the albedo. We need insolation, without ... red nose :-) When was that ? But otoh red dwarves are stable over a long time (palereddot.org). Good point. Earth will reach the state in ~500million years. It is a gradual process, some plates will get stuck in the transition zone between crust and upper mantle. Stabilizing processes like the carbon cycle will stop and that's it with diversity. Not advocating Gaia because not science, but the biosphere (aka life(tm)) has a decisive effect on stabilization, the fossil record is absolutely clear there. The biosphere (besides other sources like tectonics of course) is responsible for the composition of atmo- and hydrosphere and the upper layer on the geology. It offers sinks and wells for C, N, O and others on short- and medium terms. It binds C in warm times and can release it in cold times through activity, just as an example. It is comlicated. And thrilling :-)

Colonization or settlements are not a thing. Mars 2020 is a rover mission in preparation. Its goals are to look for signs of life and eventually gather data in preparation of possible future human visits. The still working MAVEN apparently can be used as a communication relay for years, besides its primary use to explore the exchange between space and the Marsian upper atmosphere. MAVEN has lots of fuel left. https://mars.nasa.gov/mars2020/mission/overview/ https://mars.nasa.gov/maven/

Good point, the faint young sun "paradox", a comfortable system of feedback and circuits that built up and made the earth maintain a surface temp of +/-15°C (which is well above its equilibrium temp.), on a geological scale. Another interesting question is, if there was a global ice age (the earth near its equilibrium temp), how did the earth get out of it ? But be it as it may, let's see what our solar system has in store for us, before we can get better data about other worlds because imo much is guesswork and speculation.

Though staged or choreographed water "battles" in the Colosseum are unclear ...

2503

The are only very few new discoveries of large NEOs (>1km), most of them are known and tracked by now. Small and midrange objects still show up every now and then. Impact risk table from jpl https://cneos.jpl.nasa.gov/sentry/ Though some objects will come pretty close in the coming decades/centuries, none has made it on the watch lists for a longer time.

I don't think so. If i did, it would be irrelevant. But we may be able to find more (indirect) once a new telescope generation is in service :-)

Former PPL, looong ago. Motor and Glider.

Probably should better have studied engineering. More hardware, less reasoning ... ;-)

C is punk rock. But C++ has its appeal ... I can't tell how often i was bitten by C++ ... :-) (only hobby)

SETI critic and pessimist speaking: First, nothing was found until now, only every now and there is something promising and then "oh, no, nevermind". Seti needs money to keep its activities up, imo that is why it pops up every now and then. Searching for ET isn't exactly natural science. It assumes the existence, which in itself is not a valid null hypothesis because it is not falsifiable. It leads to wild guesses about UFOs, aliens taking our women, and such. Read and view with some salt and a smile :-) Edit: otoh: it can be an expensive way of signaling when the lunch is ready: https://arxiv.org/abs/1504.02165 , but the mentioned FRBs are subject to serious work, of course.