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That's not a solution for multiple reasons. First off, if it did raise money (which it wouldn't), what would justify sending those monies to space exploration? It's a non sequitur. Secondly, it wouldn't raise money. Getting rid of the tobacco industry is a money-loser as far as governments are concerned. Tobacco is heavily taxed at multiple waypoints from the crop to the final product. That final product is so heavily taxed that smokers are a net financial benefit to society rather than a burden. Smokers die young. They pay taxes and then collect minimal retirement because their stupid habit killed them before they could collect much of anything. Drinking, maybe. Drinkers tend to have a problem with gainful employment when they are below retirement age and also have a habit of dying slow, expensive deaths. However, getting rid of the alcohol industry wouldn't work either. We've tried that experiment before. All that that accomplished was to give organized crime a place to flourish.

The cost, for starters. Six billion? That's just ridiculous. The recently launched Mars Science Laboratory cost $2.5 billion. Even Mars Direct is five times the cost, and Mars Direct is ludicrously low and overly optimistic in its cost estimation. It's easy to come up with a low price tag if you sweep all the new technology development under the rug, if you assume that untested technologies will work the very first try, if you ignore the two steps forward / one step back nature of developing new technologies, and if you use these untested technologies on humans right off the bat. Another problem is the suicidal nature of the mission. Astronauts and cosmonauts are psychologically rock solid. Candidates must pass a number of psychological tests; even their ancestry is investigated for psychological problems. This is a suicide mission. The kinds of people who would volunteer for such a mission are exactly the kind of people who would go nuts in a very bad way on an extended mission. This isn't just an extended mission. It's permanent. Yet another problem are all of the untested technologies. Cost is just one part of this problem. There's also a does it work / can it work issue. There are so many things we do not know how to do. A partial list: We do not know how to grow in isolation all the things needed to sustain human life. We can't even do it on the Earth. Experiments here on the Earth are a history of one failure after another. The only way to do it on Mars involves a magic wand. We do not know how to perform aerocapture with the Martian atmosphere. Aerobraking has been used, but that takes a long time and also uses extra propellant compared to aerocapture. All of the low cost missions to Mars just assume aerocapture will work as a way to reduce mission cost. We do not know how to do pinpoint landing on Mars. Multiple landers must land in extremely close proximity to one another to make them useful. The Mars Science Laboratory (which hasn't landed yet) is supposed to improve our pinpoint landing skills to within 20 kilometers. That's not good enough for multiple landers that need to support humans. A factor of ten improvement is pushing it. We do not know how to do the mining and refining needed to support human life on Mars. It's easy to say that the technology exists for extracting oxygen from CO2 via the Sabatier process. There's a problem here: Nobody has built a Sabatier reactor for use on Mars. You can't just say that the technology has been used elsewhere. Things don't work that way. The US and Russia have learned that lesson many times over. That's why they are so conservative when it comes to new technologies. One final problem is the reliance on nuclear technology. The nuclear industry was moribund prior to March 2011. Post Fukushima, it is pretty much dead. Society for the most part does not understand nuclear technology other than that it makes us glow in the dark. The kinds of protests NASA saw when it launched RTGs with the Cassini mission are nothing compared to what would happen were some space agency to launch a nuclear reactor. There's a world of difference between what is achievable technologically and what is achievable politically. Right now, and for at least the next decade, using any nuclear technology beyond a radioisotope generator in space is a dead proposition.

Silly, nonsensical steps. Science fiction can be fun to read, but just because it's fun to read doesn't make it reality. This concept is divorced from reality in every way. It's not even good science fiction. It's just nonsense.

That, plus other powers public and private. There are lots of organizations these days besides governments that have the resources to poke way too deep into my private life. Privacy is one of the few matters where Libertarians and I agree. Here in the US, Libertarians generally evince right wing attitudes but diverge markedly from the right when it comes to government intrusiveness. This suggests that privacy is neither left wing nor right wing. That's looking at things too one dimensionally. Privacy is a more of a big government / small government issue, which is a bit orthogonal to the prototypical left / right divide. Another possible explanation of the apparent difference between Europe and the US is which side is dominant. It is those in the minority who have the most to fear from governmental intrusiveness. As the right has been dominant in the US, but it's the other way around in Europe, it makes some sense that privacy would be a right wing concern in Europe but a left wing concern in the US. That said, at least here in the US, it is the left that has advocated for privacy rights for as long as I can remember, even in the 1960s to 1980s when the Democrats were the dominant party.

Let me see: four times five is twelve, and four times six is thirteen, and four times seven is -- oh dear! I shall never get to twenty at that rate! Ask nonsense questions and you should expect nonsense answers. Your concept of a "Universal Time Unit" explicitly assumes something GR says cannot exist. There is no such thing as a global reference frame or a universal time standard.

The Hechee used black holes as a hideaway from the Assassins (or the Foe or the Kugel). It is the latter who were the bad guys, not the Hechee. The Assassins were the ones who were killing off intelligent species willy nilly and who were adding energy to the universe in the form of kugelblitzes to make the universe collapse in a Big Crunch and re-emerge without all of that stupid mass. Yeah, yeah, silly sci fi. More silly sci fi! Cool! It's better than all that fantasy nonsense that pervades the science fiction section of book stores today. I've read a one or two of his books, but none of that series. I have a plane flight tomorrow. Sounds like a good thing to grab for the flight.

Come on. Please do a tiny, tiny bit of research before you post your musings. Privacy rights are, for the most part, a left wing concern. Organizations that advocate for privacy rights include NARAL, NOW, the ACLU, the EFF, LGBT advocacy groups. These are all left wing concerns. From the right you're more likely to get statements like "The only people who have things to hide are criminals." and "There is no such thing as a right to privacy in the US constitution."

Baez isn't. You are.

Fredrik Pohl, Hechee Rendezvous? In any case, what you are talking about is called a kugelblitz, which is the German term for ball lightning. A bucket full of photons (a closed bucket with perfect mirrors for sides, top, and bottom) weighs more than does the empty bucket. Put enough photons in the bucket and it will form a black hole. One way of looking at it: It's energy rather than mass that gravitates in general relativity.

That's a bit wasteful. There are, depending on who's counting / what is being counted somewhere between half a million to tens of millions of words in the English language. In any case, it's a lot, lot less than 4 billion. In other words, the numbering scheme will easily fit in a 32 bit word. Your value for "school" does not, and "school" is not a particularly long word. The correct answer is Klaynos'. Google the term "hashing".

Short answer: In general relativity it is energy rather than mass that gravitates in general relativity. Better said: It is energy, momentum, stress and pressure that gravitate in GR. It's called the stress-energy tensor. Mass gravitates because mass is one kind of energy. Light gravitates because it is another kind of energy. Note that mass is a somewhat ambiguous term in special relativity, and even more ambiguous in general relativity. There are several other threads on this topic right here at this site, and even more discussions elsewhere. Here are few things almost everyone agrees on (there are always nuts who won't agree to anything): The intrinsic mass of a single photon is identically zero. Light is affected by gravity. Light gravitates.

So what's this post #26, then? Follow your own advice in post #20: Let it go. I too don't want to get into ontology/etymology wars. They're silly and useless for the most part.

Venus and Mercury. I had a longer post that talked about how both the Sagnac and Shapiro effects exemplify that the local constancy of the speed of light is not global but decided to keep that post short and simple instead.

Nope. granpa is correct. The speed of light is locally equal to c. Using the words global and general relativity in the same sentence doesn't make sense. Look to special relativity first. Note that one of the postulates of special relativity is that the speed of light is the same to all inertial observers. Why the qualification? The answer is simple: The speed of light is not constant to non-inertial observers. This concept carries over to general relativity with one huge caveat. Inertial frames are global in special relativity, but they are local in general relativity.

What one chooses to be axiomatic and what one chooses to be derived is a bit arbitrary. Example: the axiom of choice, Zermelo's well-ordering theorem, and Zorn's lemma are equivalent to one another. Assume any one and you can derive the other two. Another example, this time in physics: Lorentz ether theory (LET) and special relativity are mathematically equivalent. The two differ only in their axioms. So which to choose? In the case of ZFC, it's rather arbitrary. In the case of LET vs SR, the axioms of special relativity are simple while for LET it's more a question of WTF.

It's just a parameter. Perhaps it would help if you rewrote it so that [imath]\vec{OA} = x\hat i[/imath] and you solve for x rather than λ. In the end it doesn't matter what you call it. Note that your graph is incorrect. There is no y component in the point A. The coordinates of the point A are (λ, 0).

No, it's not. It's not even close. We have ideas on paper. The path from an idea on paper, Technology Readiness Level 1, to a system that has been successfully deployed and used, TRL 9, can be long and torturous, and oftentimes falters indefinitely. There are lots and lots of concepts that linger at TRL 1 to 3 indefinitely. NASA and the DoD support conferences dedicated to technologies at a perpetually low readiness level in the hope that some of them will advance. Occasionally NASA or the DoD spend inordinate amounts of monies on low TRL items, but this has almost always been a huge mistake. A single stage to orbit vehicle and a nuclear powered airplane are just a couple of examples of such mistakes. These mistakes were part of what drove NASA and the DoD to develop the concept of technology readiness. Terraforming is at TRL 1, and it will stay at TRL 1 for a long, long time.

Yes, it is. Photons are a subject of quantum mechanics, not relativity. Both special and general relativity are classical (non-quantum) theories. One can legitimately talk about photons in the context of special relativity because quantum electrodynamics has bridged the gap between special relativity and quantum mechanics. Talking about photons in the context of general relativity is not quite so legitimate because there is no theory (yet) that bridges general relativity and quantum mechanics.

It's bad science reporting bouncing around from one media outlet to another with no one checking the facts. This story is all over the media (just search for it at news.google.com). Fox is just late in the copying game here. The first problem is that of a ballistic trajectory with quadratic drag, [imath]\ddot{\vec x} = -\kappa ||\dot{\vec x}||\, \dot{\vec x} + \vec g[/imath]. This is known not to have a closed form solution in the elementary functions. Just because a problem doesn't have a closed form solution doesn't mean it isn't solvable. Kepler's problem (the elliptical orbit of a planet) does not have a closed form solution. Most real-world problems don't have a closed form solution. This particular problem has been solved over and over again. Calculating ballistic trajectories was one of the key factors that motivated the development of digital computers in the 1940s. The student claimed to have found "the first fully analytic solution of a long unsolved problem." He didn't. He instead expressed the solution as a ratio of infinite series. That's a variation on a standard freshman calculus trick: Turn everything into an infinite series. Someone should have told this student that an infinite series representation doesn't count as an analytic solution. Someone should have told the news media not to add even more hyperbole to the story.

Space is not going to solve that problem for a number of reasons. One is that we do not now have either the technology to terraform Mars or the technology to move massive numbers of people from Earth to Mars. Terraforming Mars and getting large numbers of people into space are problems for our children's children's children to solve. Compare to the population problem: We collectively are having too many children right now. We need to solve this problem soon, not 100 years from now. Another is the demographics of the overpopulation problem. Overpopulation is not a problem in Western Europe or in Russia or in Japan. If anything, these nations have the reverse problem. Their birth rate is less than that needed to sustain the population. Overpopulation is not a problem in the US or Canada. They still have plenty of room for growth. Overpopulation is a lessening problem in China as well. Except for India, overpopulation is not a concern amongst any the spacefaring nations. The overpopulation problem is a problem of the developing and underdeveloped world. Those nations do not have the resources to develop space technologies. Many of them barely have the resources to build roads, let alone spaceships. Finally, the billions of humans that exist now have the breeding capacity to overwhelm even the most aggressive of space technologies. We could even outbreed that magical portal I mentioned in my prior post. Space technology is not a way to address our current overpopulation problem. Far in the future, it will perhaps be a way to address our underpopulation problem. That there are seven billion of us humans is a problem. It is far too small a number.

Unless you have a magical portal that opens up onto some alternate unpeopled Earth, going into space is not a solution to the overpopulation problem. The human population is currently growing by 78 million people per year. Suppose we advance our spaceship technology to such an extent that one spaceship can carry 1,000 people. We would to have over 200 launches per day to offset that growth of 78 million people per year. That assumes there is somewhere in space to put those 78 million people. The Earth's overpopulation problem must be solved right here on Earth.

What is the attraction for terraforming? It is too far in the future. Want some laughs? Dig up some Popular Science or Popular Mechanics magazines from the 1950s where they try to predict fifty years into the future. They got almost everything wrong. Trying to predict 100 years or more into the future now is even more of a laughable endeavor. The world is changing at an even faster pace now than it was in the 1950s. It is fraught with political peril. Politicians have a hard time committing to anything long-term. This is a very long-term project. It is fraught with economic peril. Terraforming would be a massively expensive venture. Once started, it would have to be followed through to completion without interruption. A multi-year hiatus due to some future economic collapse could easily set the project back to step one. It is fraught with ecological peril on Earth. What if life is discovered on Mars? This is a huge uncertainty, and a huge risk. Kim Stanley Robinson's Red Mars faction is somewhat real right now, and would become very real should life be discovered on Mars. It is fraught with ecological peril on Mars. The focus of most terraforming articles is on the physics and chemistry. The messy biological issues are just hand-waved away. Ask a biologist for their opinions on the viability of those proposed terraforming efforts. It isn't scalable. Instead it's an all or nothing kind of venture. Habitats are scalable. Exploiting asteroids is scalable. Terraforming is counterproductive to the goal of a permanent human presence in space, at least for the foreseeable future. Terraforming is a project for two or more generations into the future. Leave that problem to them. Our problem now is to get a start on that permanent human presence in space so that the people two or more generations in the future have a chance at that. That's assuming that our successors two or three generations into the future will even want to terraform another planet. Why go back down into a deep gravity well once we've learned how to reliably and safely get out of one on a regular basis?

Double negatives. Triple negatives. We have to be taught that a double negative is a positive. In many languages, English included, a double negative strengthens rather than negates the first negation. A triple negative adds even stronger emphasis. A fictional snippet of a conversation in a Texas bar, to illustrate my point: "Well I ain't never used no toothbrush!" exclaimed the gap-toothed cowboy. "So is that why you're missing those teeth?" "Heck no. I lost this'n in a flight, and that'n, I ate some chili with beans, only one of them beans was a rock. From then on, I swear by the adage 'real chili ain't got no beans!'."

In this case you can. The Moon is very important for stabilizing the Earth's orientation. Mars has undergone, and will continue to undergo, huge swings in its obliquity. Venus also went through a chaotic phase in the past, but it's current configuration is stable.

And another, Fermilab this time. http://www.fnal.gov/pub/inquiring/matter/madeof/index.html. Here's an image from that Fermilab page.