I remember seeing starving Ethiopian kids on TV when I was a kid, and it left me deeply shaken up. But over the years, I realized that you saw all kinds of things on TV- GI Joe and Transformers and the Enterprise and the Millennium Falcon and exploding coyotes, and the little Ethiopian kid with the distended belly sort of entered that realm. One more image on TV and you can just change the channel.

And then travelling in Africa I saw a starving kid, face to face. Me looking at him, and him looking back. And I realized, that's not fake. That's not TV. I can't just change the channel and make him go away. And he can't just change the channel and make all this stuff go away. This is his reality, and it fucking sucks, and this is the reality of millions and millions of people.

One of the tropes in science fiction is the Bubble City. The residents of the Bubble City live in their cozy, clean, climate controlled little domed city and have wealth and peace and long happy lives. And meanwhile, outside live the savages, with their poor, dirty, and violent little lives, and the people in the Bubble City don't think much about them or worry about them. What I saw for the first time is that this isn't science fiction. This describes the world we live in. The developed world is a bubble, but until you step foot outside, you don't even know it.

I think that this is probably a bit overly optimistic. The difference between the U.S. and some failed state isn't merely a difference in the level of wealth. It's a whole series of things- an effective security apparatus, infrastructure, a court system, trustworthy, responsive, and effective government administration, education and literacy, a free press, a fair market system with companies and finance, a national identity, tolerance of different people and ideas, and a culture that buys into and believes in these things as realistic and important goals. The wealth and prosperity of the United States are built on a culture, ideals, markets and governments that go back hundreds of years, to the Colonies, to England, to Renaissance Italy, to Rome, to Jesus, to the Greeks.

Wealth isn't just the condition of not being poor, it's about creating a productive and fair society. Like they say, give a man a fish and he eats for a day, teach a man to fish and feed him the rest of his life. The issue is that being a good fisherman is *hard*. It takes a work ethic and discipline, piloting, engineering, and navigational skills, management skills, and learning how to actually catch fish. It takes years.

Poverty has a lot of causes. If you cut your potential labor force in half by keeping women unemployed, if government officials steal from the people with bribes, if there's a lack of education so you can't hire skilled workers, if business can't operate because of a corrupt judiciary, if you can't move goods to market because there are no roads, if you're sick with malaria and can't work, if the army is weak and violence flourishes, if you can't get a small business loan... these are problems that make going to the moon look pretty straightforward. I'm not saying we shouldn't try. As Kennedy said about the moon, we're not going there because it's easy, but because it's hard. But we need to be realistic about how hard it's going to be.

Yes, Elon Musk's rockets will be funded by all those privately funded space stations, privately funded spy satellites, and privately funded missions to Mars.

The cost of the International Space Station was $150 billion, and a crewed Mars mission- sending a crew to Mars, landing them, bringing them back- is an order of magnitude more complicated. I'm guessing it would cost on the order of 500 billion or a trillion dollars. The issue is, that money has to come from somewhere. That's a trillion dollars that's can't be spent on other things. Economic development, medical treatments, flood and famine relief, scientific and medical research, etc. So we have a choice. We can spend hundreds of billions or trillions of dollars on the possibility that the human race will face some crisis in the far future. Or we can spend that money on solving the very real problems that people are facing today, right now, as we discuss this. Unemployment, poverty, starvation, disease, lack of education, lack of opportunities for women. I'm not saying that we cannot do anything else until we solve all those problems. But for all the talk about The Good of the Species and Preserving the Species, space nutters seem remarkably unconcerned by the idea that there are people right here on Earth who could use some help, and last time I checked the species was composed of these people. And if you space nutters are really so goddamn concerned about saving the species, maybe you'd be more interested in helping them out. If half the planet wasn't uneducated and living in poverty, maybe we'd have a lot more economic and intellectual resources at building that Space Ark or Warp Gate or Hyperdrive or whatever it will take to get into space. I'm skeptical about the possibility of setting up space colonies, but if it does happen, I think Bill Gates' work on malaria in Africa will probably end up doing a lot more to help get us there than Elon Musk's rockets.

The "we've got to get off of this rock!!!" argument is nonsensical when you consider that the Earth is currently the most habitable place within several light-years and it's been that way for at least the past 3.5 *billion* years. Just over the past 550 million years we've seen severe ice ages, runaway greenhouse warming, an asteroid impact, several massive volcanic eruptions... these events were severe enough to devastate the biosphere and wipe out most of the species on the planet, but in each case some of them survived (otherwise we wouldn't be here). It's been able to sustain complex life for at least half a billion years. Even after the Chicxulub asteroid impact, it's still got a breathable atmosphere, radiation shielding, normal gravity, liquid water, etc., none of which are the case on Mars (all you'd need to survive would be stocks of food, warm clothes, and fuel to last out the impact winter). And even before 550 million years ago, when there's too little oxygen for complex life, it's still a better option than Mars (you'd need supplemental oxygen like on Everest but otherwise it'd be habitable). You would have to do a lot to the Earth to make it less habitable than space or Mars; even with a full-out nuclear war, you've got the Strangelove option.

Looking backwards, Earth has been habitable for a very long time, it's likely to remain so for tens of millions of years more- far longer than our species can be expected to last. Looking forwards, there's no realistic scenario in which space colonies make sense:

Let's assume that we do develop the technology to live on hostile environments such as Mars, asteroids, etc. Wouldn't this exact same technology also allow us to cope with whatever hostile environmental conditions might develop on Earth?

Let's assume that we develop the ability to terraform Mars to make it habitable. Wouldn't this exact same technology allow us to terraform Earth to correct whatever hostile conditions might emerge here?

Let's assume that nuclear war or other environmental issues threaten us as a species. Wouldn't it be a lot easier and more realistic to prevent these things from happening in the first place than build some fleet of Space Arks to escape them once they've already happened?

Let's assume again we're so suicidal that we're in danger of wiping ourselves out due to nuclear war or environmental damage. Doesn't this undermine the whole All Your Eggs in One Basket argument? I mean, the idea is that some freak event might wipe out one of your baskets, but not ALL of them. But that assumes these are independent events. If people on Earth are stupid and suicidal enough to wipe themselves out, that's not a problem with the Earth, it's a problem with the *species*. EVERY human population will have those same suicidal tendencies. It's false redundancy because all your backup systems share the exact same fatal flaw.

Because the lookup table would have to have ~ 10^46 entries.

I run a personal mail server and know I know just enough to know that I have vast chasms of ignorance about mail and network rules/firewalls.

Wouldn't it be easier to filter outbound packets destined for Gmail's SMTP servers and prevent Chinese email users from sending email to Gmail users? (This is an honest question.)

Actually, proto-humans migrated repeatedly out of Africa. Homo erectus, Homo antecessor, Homo neanderthalensis, and finally two waves of Homo sapiens moved out of Africa and into Eurasia. North America was colonized repeatedly by Homo sapiens, by the Amerindian, Navajo-Dene, and Inuit peoples. Migration probably is in the genes. Lineages that become widespread are harder to wipe out as a result of drought, famine, climate change, etc. so lineages with some innate tendency to disperse probably tend to survive. But it's kind of a moot point. The places they went to already had atmospheres, normal gravity, ambient temperatures, radiation shielding, abundant game and edible plants. Mars has none of that. It was simple enough to move out of Africa that a cave-man could do it, literally. It doesn't follow that because humans could and did repeatedly move from continent to continent that it's a good idea to try to colonize a cold, barren, airless wasteland millions of miles away.

It's a bullshit argument. The problem is that a robotic mission is going to cost on the order of 1% of a human mission to do the same thing. If there's a risk of the lander failing, the cheapest and easiest solution is to create two or three separate robotic probes which minimizes the chance of failure. Obviously a 100 billion dollar manned mission will be more capable than a 1 billion dollar robotic mission. But a 100 billion dollar robotic mission would be vastly more capable than a comparably expensive manned mission.

I keep hearing this argument, in fact I've been hearing it for around 20 years. And during that time, we've spent hundreds of billions of dollars on NASA. So it's about time to ask... where is all this spin-off technology we've been promised for the past 20 years? Most of the major innovations we've seen are either military (GPS, internet) or commercial (cellular networks, smartphones). It's hard to point to a single transformative innovation to come out of NASA recently, and historically the military has done far more to spur technological innovation than NASA. I'm not arguing that building more F-35s is the best way to spur technological innovation, but it's worth taking a hard look at where our research dollars make the biggest difference, and I think it would be hard to show that NASA is the best way to do that.

The defense budget is 20% of the federal budget, which is around 1/5th. America's defense budget exceeds that of the next 10 largest defense budgets *combined*. The U.S. still has unquestioned air superiority in every conflict it enters, a fleet of aircraft carriers to project that air power, ballistic missile submarines that can rain down nuclear death at a moment's notice, a rapidly growing drone army to silently hunt our enemies from the skies, electronic intelligence and cyberwarfare capabilities to spy on the whole world, and critically, the network of ships, bases, and air transport to rapidly move troops and supplies to conflict points anywhere on the globe and project that military force... America is the only remaining global military power. No one else- not China, not Russia- has that ability to project power beyond their regional sphere of influence. It's not limitless power, as shown by Iraq, Afghanistan, or even Viet Nam, but it still makes the U.S. the only remaining superpower. And if anyone's hurting the U.S. military preparedness, it's not the left, it's the generals who push for expensive toys like the F-35 instead of focusing on problems like counterinsurgency warfare.

Free electron screening is well understood. It doesn't make LENR feasible.

Until there is a convincing and well controlled demonstration of paladium/deuterium LENR, or a plausible theoretical mechanism proposed, don't expect people to take it seriously.

Your objections are easily explained away as a false flag operation initiated by an individual or group.

What's with your attitude? As far as anyone can tell, you're the asshole for all your presumption.

In any case, I do signal before moving from the edge of a lane to the middle, and I do assess if it's OK to do so.

Also, where I live (California), drivers may only pass when there is three or more feet between a cyclist and a driver.

Why don't you take your sanctimoniousness someplace where it's warranted?

Where I live, as in many municipalities, motorists must yield to cyclists who may be avoiding hazards that motorists cannot see such as roadside debris, potholes, opening doors, etc.

Additionally, in major metropolitan areas, it's safer to yield to bicyclists who will pass through traffic once they've done taking the full lane as they need.

With regard to cycling safety: when I drive, I think like a bicyclist and when I bike, I think like a motorist.