Of course, the majority of humans now live in urban areas, and see little or nothing of the night sky at all, whether northern or southern. Perhaps I'm taking this a step too far, but would it be possible that we'll see a continuing decline in interest and support for astronomy and space technology as more and more voters and influential people grow up and live their lives without ever really seeing the skies?

Even so, you'd expect the proportion by any random factor X to be the same as in the general population.

This includes all immigration. I was specifically talking about skilled immigration.

You can't be sure, but you can give them a significant head start in form of a good education and a solid starting capital, which helps a great deal. Ultimately, it's a lot like stock market investments... you can go for low-risk and low-yield, or you can go for high-risk and high-yield. Both are viable strategies.

(And, of course, you can always go high-risk for yourself, cash in on that if your bet pays, then move to some other place to spend that money. And getting a citizenship in a first-world country makes it much easier - it's easy for an American citizen to move to e.g. Canada.)

In any case, yes, there are many choices, and people do choose differently. I and many of my friends picked US for all the reasons that I've described; I lived in Canada, as well. I have friends who have settled in Canada, and other friends who had Canadian permanent residence, but moved to US when they won the green card lottery. I also have some in Australia.

Bottom line is, to answer your original question: US is still a very popular destination for skilled immigration, enough so that it can certainly get more people coming in if it makes the process easier to avoid being out-competed by Canada and others.

By picking the shape and trajectory, we can have quite good accuracy on where to land the debris. Pick a piece of federal desert land and there you go.

Seriously, the scenario as I understand it is: we'd park an asteroid in a high orbit

Bad assumption right from the beginning. That's a terrible waste of energy. You mine an earth-crossing asteroid. Chunks mined off an earth-crossing asteroid can be put onto an earth-intersecting trajectory with only the tiniest of delta-V (you might have to wait a long time your payloads, but no problem there). The amount of delta-V is so low (dozens to hundreds of m/s) that you wouldn't even need to use a rocket, you could just kick it off with a railgun or similar. Then you don't brake it when it gets to earth - it brakes itself by crossing through Earth's atmosphere ("aerocapture"). There are various optional things one could do with the reentry chunks to assist, such as small rockets for trajectory adjustment en-route or small high-speed chutes to keep the asteroids from completely obliterating themselves on reentry / landing (no need for a soft landing, it's fine for them to hit moving at hundreds of meters per second). Both of these would be dwarfed orders of magnitude over by the mass of the return chunk.

All you, as a mining operation, need to do is get your operation up to the asteroid. You need to be able to mine off chunks, shaped appropriately for optimal reentry, and kick them off onto an ideal reentry trajectory toward your target impact zone - potentially with the various hardware systems described as above, but in the base case, not with anything at all. You need a source of power (solar, nuclear) for mining and to kick your chunks into their Earth-intercept trajectory. And of course you have to deal with a million and one details, starting with how to mine at all in microgravity and what targets would actually have commercially viable quantities of valuable minerals.

Which is why you send as optimal of a size and shape as possible. Note that asteroids normally come in randomly and have random shapes. Humans can have a huge impact on the behavior by choosing an optimal shape and trajectory. And, as mentioned, drogue chutes could be used to further reduce the free fall velocity - not for a gentle impact, simply to keep the velocity down to a level that it won't completely obliterate itself in the atmosphere or on impact.

Yeah, but experience with gigantic hypersonic parachutes is also rather limited.

Again, it's really doubtful that there's any show stoppers here. But there's a lot that needs to be done before you can bet a whole mission on these sort of things. There's many thousands of little details that could kill the crew if they go wrong, so the odds of any one doing so must be kept to the tiniest fraction of a percent.

Except that your terminal velocity on Mars is orders of magnitude higher than on Earth. Decelerate to subsonic then fall and you'll be back supersonic in no time.

I'm sure this is possible to do, but it absolutely requires more research and testing.

How exactly would that happen? Isn't ballistic capture's main drawback that it's slower than a Hohmann transfer?

Isn't leaving crews drifting in space longer increasing one of the main challenges of a mars mission - crew survival in transit?

Look, all this isn't remotely believable. You clearly compounded that account's massive spamming attempts by needlessly quoting obscenely huge chunks of his nonsense. [Rujiel, 2014-12-28]

Needlessly? How else should I debunk his baseless claim that I was "rude and insulting" when Jane/Lonny Eachus was actually just projecting his own obscene insults onto me? And if you have a better approach in mind, why not just suggest that better approach rather than repeatedly suggest that I kill myself?

Are they hiring you losers while still in high school these days? The bar for paid oil trolls sure is a low one--any stupid thing to prevent the discussion of the oil cartel's impunity. Do the world a favor and kill yourself. [Rujiel, 2014-11-20]

He's a paid shill and so are you--no amount of verbose whining on your part could hide the role of spamming you were playing in that thread. [Rujiel, 2014-12-28]

Once again, Rujiel accuses me of being a paid oil shill. But once again, why would the oil industry pay me to debunk the same baseless accusations they're helping to spread? I've been debunking misinformation about climate from Jane/Lonny Eachus and many others for 5 years now. Again, why would the oil industry pay me to do that?

... Save our collective unconscious from your fevered ego--kill yourself. your net sum contribution to society is at a negative. [Rujiel, 2014-11-26]

Really? Among other things, I've contributed open source software to estimate mass changes on the surface of the Earth using GRACE satellite data. Here's my dissertation which explains the methods. Does that count for anything, or should I kill myself?

Your response is akin to someone who has just spent the last hour rolling in his own shit and flinging it at passers-by, standing up all at once and asking the surrounding crowd what's wrong. You're seriously so bad at this. Even your employer would be better off if you killed yourself. [Rujiel, 2014-11-30]

I really don't understand why people like Jane/Lonny Eachus and Rujiel are filled with so much hatred. However, sociology research suggests that people are less likely to hurl abuse at people after seeing their faces. So here I am at JPL's open house explaining how our CO2 emissions are causing ice sheets to melt. And here's a clip from the Weather Channel where I explained (at 19m36s and 26m34s) how NASA measures these ice sheets from space.

Rujiel, now that you've seen my face, do you still hate me so much that you still think I should kill myself? Or would you like to retract those odious statements?

It costs more for the fuel to de-obit platinum safely than the value of platinum

Asteroids seem to deorbit pretty effectively on a fuel budget of zero.

Your return chunks of asteroid are their own ablative. Ideally you'd give them as optimal of a reentry shape and trajectory as possible, but you wouldn't brake them, you'd just aerocapture, and then give them just enough of a drogue chute that they don't disintegrate fully on impact.

And no Happy Hacking Pro. That's my go-to keyboard for any stationary use.

I do like the feel of the new chicklet Lenovo Thinkpads as well; I don't know why many people don't like them. Whoever decided on the layout, though (PrtSc between right-alt and ctrl?!) should be sent to the unemployment line as fast as possible.

Translation: "I am ignorant of what this term means to physicists, and I declare my ignorance trumps their knowledge."

Who the fuck cares about the hypothetical performance of the plane in some scenario that didn't come to be? What we have is a track record of A-10 performing a stellar job in the wars that have actually happened, from Iraq in 1991 onward. And with ISIS it looks like there will be more of that kind of thing in the future. Retiring a highly successful piece of military hardware when there's clear need for it now and in the future, and no suitable replacement, is just retarded.

This is a scientific paper being written for the author's peers, none of whom would ever misinterpret it. I've seen this issue come up in a couple of places where laypeople are confused by the language of physics.

This is not a problem with the language of physics: it is a problem with laypeople.

I'm all for clear scientific communication, but at the end of the day, communication is hard and worrying about how some random person on the 'Net might misinterpret a term you use every day in your professional work is just not a good use of anyone's precious attention.

When I write poetry I do so in a pretty technical way. If people don't appreciate that, sucks to be them, because they are not my audience. I'm the same way in scientific communication: I write for my peers, and everyone else does the same. Let the popular science authors do the translation. They need the work.

I had the same thought, but it turns out not to be the case. Given the model he's working with, the neutrinos will be as much above the speed of light as they would have been below it if they had the same real mass (0.3 eV or something like that.)

For ~10 MeV neutrinos this gives gamma absurdly close to unity, and it's as impossible to distinguish neutrinos traveling just over c from ones traveling at c from ones traveling just under c.

The paper actually mentions SN1987A and talks a bit about the time resolution required.