PB666

No but the crust is an insulative layer, radiothermal is about half and its actually not that good. Given the surface area of the crust its not that good of a source, heat in most places is rapdidly depleted once you start circulating water over it, the sun dumps far more energy on the earth than is released as heat from the core, so its better to get energy from the sun and its indirect than look to the earths mantle for energy. Of the already there stuff, small hydro is the way to go. There are places, like iceland and Japan where geothermal is already in use and the energy bubbles up anyway, but drilling a 10 mile deep hole in Denver prospecting for hot water is probably not going to payoff, and you may end up contaminating ground water with heavy metals. BTW if you really want geothermal, just neogeothermal, take the nuclear waste bury around a corrosion resistent piping system in some place were ground water is trapped, like the upper high plains, and use your decaying over 29000 years isotopes tobgenerate the steam you want. The brits have already declared there is an endless supply of energy in the waste, its only a manner of finding a safe way to extract it.

But think about this, global warming will heat the earths crust, if we are any good at geo thermal we will cool some of the deeper convections, this would increase siesmic activites in some places. There are some places where it likely to have little effect, such as lake yellowstone. Btw there simply is not that much energy/sec being built up in the earth, which has a dynamo we need for our survival, so its best not to drill too many hokes and start transferring energy up. Small hydroelectric is a better choice.

Yeah, but turbofan AC are not really designed to run clean well at 250kts MSL. The heavies tend to barrel up to the <FL100 speed limit until they supercede 10k and speed up past 290 kts IAS. The engines are burning hot air at that altitude, they lean out alot as they climb, they are producing less thrust as they climb past 180 but burning much less fuel. The worst example was the concorde, Not a turbofan but it is barely off the runway at 200 kts with afterburners and is suffering to get past fl100 at 250 kts, but get a little more air under the wings and cool it down a bit and its acceleration all but doubles. That poor ac was an accident waiting to happen it really needed a 4nm runway for abort takeoff at v rot. Of course there are not too many good reasons to make a tight bank turn at FL600 at mach 2.0

This thread precedes the new thread by more than a month, the reason the posts were addede here is that the articles both mention the possible influence of a much larger object. That thread should be merged into this one.

huh? hows that?

Two links were added to the Nemesis thread this morning, guess they were missed anyway. Careful read indicates that the eccentricity of its orbit may not be known for a year.

Nuke the moon! Take a bunch of legos and launch them into Equitorial, bydef, GSO. You can even sort them according to color and have collored rings. That, of course, would not cause any problems with satellites :^). Better yet skim all the plastic fragments in the north pacific gyre, put them into GSO. Aliens from all over the galaxy will be impressed with ou solution to consumeristic household waste.

Thats a feature, then you don't have to waste any energy to get back in orbit. Well if indeed phobos is already starting to fall apart then rather shortly we can expect bolloids torn off the surface to start striking the moon causing all kind of unpredictable impactors. BTW, mars poles shift down to almost flat, so placing colonies at the poles is not a defense. Colony placement would have to move from time to time. Colonizing Mars does not apoear to be wise.

http://news.sciencemag.org/space/2015/11/astronomers-spot-most-distant-object-solar-system-could-point-other-rogue-planets New article on the matter, new planetoid has been discovered with quirky orbit that cannot be defined for a year or so. Another link: http://www.bbc.com/news/science-environment-34787422

Well you almost got there, but you could have explained precisely why phobos is spiralling inward and the moon is spiraling outward.

thanks, it did seem like to coincidentally soon. At what point does phobos start disrupting objects on the surface such as landslides and rock falls? or Not.

https://earthsky.org/space/mars-moon-phobos-slowly-falling-apart .02 meter per year at a distance 6000 km means that in 300,000,000 [corrected] years mars and phobos will collide. Make a long story short. I'm relatively certain it will make more than a poof of dust.[at least on phobos] Mars, colony, not so wise. Ok, so the question of course is how.

True because of what level flight near coffin corner requires. At that alt the IAS is near the minimum in trim flight to support the craft, the engines cannot produce much more thrust, they are often close to the N1 limit. Increasing flap would certainly allow a slower craft but dramatically increase drag, which a slower craft has less engine output, which means stall is more likely. The point though is that at FL400 and 500kts Flight control is heavily restricted by a performance application. If there was a runway at 39,000 feet the craft could not land because a precision turn would be impossible, it could not make a proceedure descent 6nm out. and it would hit the runway at 52 fps. dare say the wheels would prolly explode if the a/c flared in time. There are craft that could do this, not commercial, but have alot more wing and thus fly much more slowly I should also make the point in that increasing the crossectional curvature of the wing does not increase lift indefinitely, on many commercial craft the last one or two flap settings do little more than increase drag and make it somewhat easiler to stop a heavy load. The V-land is set pretty much by weight and assumes that the optimal flap is engaged.

https://en.wikipedia.org/wiki/Solid_oxygen#Red_oxygen. The octomer of oxygen is stable at advanced pressure, highly compact. The problem is storage and conversion back to O2.

1000s of years perhaps.

http://phys.org/news/2015-11-doomed-quasar-powerful-explosion.html Another example of stars headed toward an explosive end.

Down here we call those tornados and hurricanes. Given that most aircraft do not fly over the speed of sound.. Some points. Flight control. Simple example, you have a 747 at FL400 and you want to turn in a circle, you are roughly talking about 25km in a 30 bank turn. Why, 747 in level flight has one of the best glide characteristics do to its wing shape, it can almost approach the speed of sound, but it can't turn worth much at 400. momentum, it GS is near 500 kts. IAS is in the upper 200s kts. It can slow down however at flight configuration it would stall, and fall. So just before landing, say 20 km aircraft are expected to make 30 bank turns changing about 30 degrees. So as the 747 descends it begine to lower flaps, this makes the wing much less able to glide at high speed but much more capable of flying at lower speed. Flaps increase the differential distance air has to travel over the top of the wing. This increases lift, but in a turn it also increases the change of angle per volume of air traveled through, because turnig is steered from the tail and produce from the wings. As a result the plane can turn full circle over a few kilometers. Landing. Most planes could survive a landing withou flaring, but not at flight level speed, 170kts and traveling 1000 feet per 3 nauticle miles they are traveling downward at 17 feet per second. Contact the insurance company afterward. If the craft was traveling at flight level configuration, that would be 265kts, thats 26kts -verticle and you have airframe collapse on the runway as well as a wreckage that flies off the runway. Flaps are responsible for flight control at low speed, they allow the AC a nose level on approach an a tiny flare puts the front gear just a little bit off the runway so that a moment after wheels down the thrust diverters can be deployed. So to correct these. The shape of the wing is adjusted during the flight to make it more or less like a plane for the purpose of flight control. If you need lift at low speed bernoulli is your friend, if you need efficiency at high speed low profile into the angle of attack is your friend. if you want to turn fast lots of control surfaces are going to need to be deployed.

You expect there to be fatalities in the industry but not in the consumers. In china they estimate now that coal and cigarettes combined will kill half the male population. Coal is beyond anecdote, its simply bad. Worst btu production per carbon atom highest level of particulate production highest level of heavy metal contamination Biggest effector of pan evaporation rates (drought causing) therfore crop reducing. I should add i also knew someone who died from an explosion caused by a natural gas leak. The last people to actually die from nuclear power related death was 1963 prompt critical accident in the US. There is really no comparison, coal is a legacy fuel, the sooner it is abandoned the better off humanity will be.

I don't know anyone who has died from radioactivity, solar panels or windmills. I do know someone who died from earing fish that had too much mercury, and i do know people who died as a result of working in the oil and gas industry. I don't know of any dead bats or birds, but i do know that the local parks and wildlife folks confiscate billfish that they suspect carry dangerous levels of mercury. Since i eat alot of fish and very well aware of local mercury levels in fish, i have a certain opinion about coal that just about any self-respecting fisheries biologist would have. Coal is bad stuff, but lignite coal is the bad of bad stuff. You can put all the PR day and night and tell me how great coal is and how its not as bad as people say. The only thing i would think is the four letter title of a three dog night song.

http://www.techtimes.com/articles/103662/20151108/hubble-gazes-into-the-heart-of-the-milky-way-to-gather-clues-about-its-early-history.htm They have uncovered 70 white dwarf stars which may have been some of the first stars in the galaxy. Several problems i have, first in our little comoving space, more than likely thise first stars blew themselves to nothing. i don't know if any galaxy on the visible horizon (13.7 billion years ago) with 100,000 stars as early. These are prolly stars that formed after the earliest generation of stars had blown themselves to bits.

Given that it will be 2016 before this back end is fitted to the capsule, then thevfittings and back end will undergo more design so . . . . . for the unmanned test flight.

Seriously, and you started a poll also. There are a half a dozen past threads this could have gone under. The general consensus, in a nutshell is no.

This from the beeb......... http://www.bbc.com/news/science-environment-34767799 Back end.

Well, if humans were to completely vanish the environment would do remarkably well, of course extinct soecies would not bounce back, and a few more would probably go extinct because of momentum effects and xenobiotic wildlife (invasive species and the like). There would also be legacy issues like waterways, canals, dams, jetties, highways, and of course there would be waste piles that would create issues. The problem is that CO2 levels are so high now, that when they begin to falll, they will drop so quckly that the earth would slam right into a glacial maximum of unseen proportion. We don't need to get rid of all CO2, just enough to bring the earth to 1980 levels. Having said that the earth is in deep doo-doo and coal burning is the primary cause. We can point the finger at china, but if we consider cummulative usage the west has the lions share. #1 problem is overpopulation - india, indonesia, pakistan, ...........deforestation, conflict zones #2 unmodulated industrialization - china, india #3 overconsumption - west The biggest victims of climate change will be in the top ranks, and these groups are least equipped to understand why. Developed countries have a certain immunity as a whole (california might be exceptional), because they typically do not live on the margin, and climate changes effects will be seen in highly irradic food prices, followed by highly disruptive weather patterns. Superstorms and superdroughts will become the norm. Solar panels raising changing weather patterns in the desert is not so harmful. Lower pan evaporation rates due to coal in the indian and northern pacific oceans is devastating. So yeah, massive government intervention in the biggest increased emitters, those who don't want to change is were alot of work needs to be done. I think the best solution is some hefty lawsuits in the international court for some of the concurrent violators, like indonesia. Just to tag this on: http://www.bbc.com/news/science-environment-34763036

http://www.bbc.co.uk/newsbeat/article/34733248/nasa-wants-people-to-apply-to-be-astronauts