There’s a brilliant Outer Limits ep where a nuclear war on Earth is allowed to go through, because the leadership thinks they can escape to space & survive.
whistles
The guy who thought of that is SMART. Either that, or he got piss drunk one night and scribbled some crap on a napkin. I think this crosses the barrier where they are one in the same.
I bet if he put 1/10th as much energy into discovering new farming technologies that increase yield in arid terrain, he’d say something that actually mattered to someone.
The former. He’s very smart. About as smart as it gets, by all accounts; certainly a hell of a lot smarter than me. I kind of like the fact that Kip Thorne does what he does. He actually dreampt up his wormhole contraption to help out Carl Sagan, who was writing Contact, which involves wormhole travel. Thorne surprised himself by discovering that, as long as you’ve got the exotic matter, General Relativity allows traversable wormholes. Even weirder, you can put one end of the wormhole on a spaceship, rocket off at close to the speed of light, and make a time machine out of it.
Then along came Stephen Hawking, who pointed out that such a new path through space allows photons to traverse the wormhole and meet up with themselves in a closed-loop through spacetime. Hence, you get “feedback” and immolation.
This may all seem like a total waste of time, but what these guys are doing is taking Einstein’s equations and pushing them as far as they can be pushed without violating basic laws. You may know that at one time Schwartzchild’s proposal of a star that collapses on itself was seen as a mathematical curiosity; but later on people figured out that these collapsed masses could actually be formed in nature, and pretty soon you’ve got black hole research, which thus far goes a long way towards explaining some highly energetic phenomena we have since observed. In tinkering with wormholes, Thorne may be opening up other avenues of exploration of natural phenomena people haven’t even thought of yet.
Again, though, one thing many people conjecture is that because it’s theoretically possible to make wormholes and warp drives (as long as you’ve got the negative mass/energy in sufficient amounts, and you can manipulate it) within the framework of General Relativity, GR can’t be the whole story, because these contraptions allow us to do things that are sheer nonsense, as far as we know. This is pretty interesting in itself.
Hm. Can us people with IQs under 200 rent him for a weekend? There’s lots of cool stuff we could actually use now that needs to be invented. 
Are you advocating that pure research should be dropped in favour of applied science? I find that very short-sighted.
I don’t think 1/10th of his energy is too much to ask for for those of us starving to death while he’s working on theoretical equations. O_o
Do you know anything about the guy, and what activities he is involved in? Do you have an objection to all frivolous thoughts and musings?
Nope. Do you know his middle name and penis size?
If I did that, I wouldn’t be posting on this message board, now would I?
I’m guessing building artificial hearts or fusion reactors or whatever aren’t your average theoretical physicists’ passion, or even area of special talent. Werner Heisenberg singlehandedly reinvented matrix mathematics to come up with the first rigorous (and completely correct) description of quantum mechanics, making the first observation of noncommutative mathematics in natural phenomena. He then went on to discover the Uncertainty Principle. You’re talking about a guy with brains out the wazoo, but when it came to building an atomic bomb, he turned out to be a rotten engineer. Reportedly he got the critical mass of uranium estimate off by about a factor of 100, concluding that building a fission bomb was impractical (Heisenberg later claimed he meant to do this, but the facts speak otherwise; for instance, he nearly killed himself and a few other folks building a reactor, not knowing how close he was to achieving a sustainable reaction, meltdown, and blasting himself with radiation in the process). So how is it a guy can invent matrix mechanics from scratch, one of the all-time towering achievements of physics, yet royally screws up his work on fission? Again, engineering wasn’t his talent, it seems. Or maybe, as he claimed, deep down he didn’t want to succeed. Whatever the explanation, I think it’s best to let these geniuses do what they will with their talents. We are almost guaranteed to benefit in some way, I think, even if we can’t predict immediately how. History supports this approach in a big, big way.
Cite!
I agree that we eventually (with technology we can’t even imagine now) will colonise the universe, but rockets aren’t the way to do it. Right now, just to get a small payload into orbit requires a) producing a tremendous amount of fuel b) burning it all up. And the sad thing about rockets is that most of the fuel you burn up is used just to carry the fuel!
Nah, but we’ll think of a better way… eventually.
Wrong. It’s an empirical claim that has not entirely been “proved.” I think I saw on SD (Cecil column?) a column in which the question of units and constants is discussed. Could it be E = 1.2mc[sup]2[/sup]? Yes, it could, but Einstein’s equation is so elegant and neat that it has stuck.
No reaction in the universe comes even close to turning matter 100% into energy, so it’s essentially an unprovable claim. I think even solar fusion is only a few percent efficient, IIRC.
And what does this have to do with space travel, anyway? The equation has nothing directly to do with whether faster-than-light travel is possible. I agree that it is probably impossible through acceleration alone, but I can’t see why it would be impossible if we could manipulate space directly (with plenty of caveats about the dangers of such technology).
Dunno, pick one. Whose to say what is, or what is not, ultimately possible? Certainly not you thinking that a law is unnavoidable or inviolate.
Never been in a large airport like they have in Hong Kong have you? Maybe find a box canyon and use a roof that is inflated by the pressure of the atmosphere created inside it. Or maybe live underground. Lots of things are possible.
Again, how is that working for you so far? All that foreign aid actually doing something other than making more starving people? (Please note that my main job function is to train Nationals to eventually replace me and be competative in the modern world and that is the one part of my job I really like doing. So, I am actually walking your talk, so to speak. I’m all for teaching a man to fish other than just giving him one.)
You object to a genius working on things that aren’t practical yet how many people build monuments to imaginary beings with money that could be far better spent elsewhere on more ‘practical’ things? How many people are against same sex marriages because of these same foolish beliefs? How many against birth control? Yep, that would be only a ‘few’ people. Get real.
I don’t think this is right at all. Combining an electron with a positron converts them both to energy, which can be measured. Since we know the rest masses of these particles, and can detect the gama ray photons pruduced by such a reaction, I think the equation can and has been tested, in this way and a variety of other ways. I don’t think E=mc^2 has any doubt associated with it. There are also a number of mathematical proofs that are derived from the theory of special relativity, which itself has proven to be totally accurate in its predictions.
Here’s another proof:
I am not a relativity doubter. I probably overreached here, but my point was that E=mc^2 is an empirical claim, not merely a logical or mathematical truth.
Pretty irrelvent to the debate though. My bad.
That’s like saying that the Pythagorean Theorem is an empirical claim rather than a logical truth, but such is not the case. You can observe that the PT is in fact true, but its truth is not derived by observation. In the case of Special Relativity, Einstein began with 2 axioms: (1) “the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good”, and (2) “'principle of constant velocity of light in vacuo.” (Einstein, 1905) He then used the Lorentz Transformations to deduce, among other things, E=mc[sup]2[/sup]. The fact is that the empirical observations seem contradictory, since observations of motion at variant velocities might contradict. It is only the logic of the theory that reconciles those contradictions. Incidentally, the Pythagorean Theorem figured prominently in Einstein’s thought processes since he realized that its truth actually is caused by the spherical shape of matter.
An H-bomb is a pretty efficient way of turning a little mass into a lot of energy. The problem is: what exactly do you do with all this energy? In space, a nuclear explosion is actually just a very very bright light - it has little propulsive ability - and the same would be true of antimatter annihilation, which would merely be more efficient.
Now if you had a large plate coated in something which expanded when heated, this could provide the actual propulsion. Hey presto, we have orion spacecraft.
These are perfectly theoretically possible with today’s technology: A craft built in space containing a million nukes could feasibly reach 0.1c (a tenth of light-speed) within a few months, thus reaching Alpha Centauri in 45 years. “Tomorrow’s” technology might bring us further towards lightspeed, perhaps allowing us to get anywhere in this map in a lifetime (250 years), assuming some slowing down of the aging process or time dilation effects (which only become significant past 0.95c).
Further? Ever? I think not. We may talk of warp space or wormholes, but the energies and forces inherent in these things are simply unimaginable. It would be fairer to ask: Will we ever build a spaceship which can fly through the sun?
We had better hope that somewhere on that map is a habitable planet. For What It’s Worth, SETI tells us that nobody on the map is transmitting anything.
You don’t get the “giant leaps for mankind” without the baby steps, folks.
Forget the stuff in this thread about FTL travel. We’ve got a hell of a long way to go before that’s even an issue.
The idea that we will be able to force the poor Earth to continue to support our exponentially increasing population is a madman’s dream. While maximizing the efficiency of our resources here and providing universal access to them are essential goals, we need a Plan B for when we reach our inevitable limits: to spread out. Our future lies upward.
But there is not one god-damned point in perfecting the technology to travel between the stars if you have no idea what to do once you get there. If you don’t know how to survive on a planet that isn’t Earth, you have no business trying to get to any that might exist elsewhere in the galaxy. A race that stupid would deserve to die out.
The baby step to take before that is to show that you can create a thriving colony on another planet. If you’re smart, you begin that process by beginning your colonization efforts on a planet or body that’s fairly close. for Earth, that gives you three options: the Moon, Venus, or Mars, in order of distance.
Moon
Advantages: proximity, frequently-opening launch window, familiarity (we’ve been there a little), minerals similar to Earth’s, trace amounts of water in the soil.
Disadvantages: Very low gravity, the extended long-term effects of which are not understood AT ALL. Light/Dark periods not anything like Earth. No atmosphere, for either breathing or protection from solar and cosmic radiation. No organic matter; all food will have to be imported, or some means of agriculture will have to be developed. If the agriculture can be developed in a way that transforms the lunar environment into something which can sustain it (terraforming, which we currently have no idea how to do), so much the better.
Conclusion: Lunar colonization would be very difficult. An early lunar colony would have to completely sustain itself apart from its environment while terraforming experiments succeeded or not. Our only attempt at a self-sustaining artificial biome (Biosphere 2) was a complete disaster. Unless this model could be improved upon, everything would have to be imported from Earth, which would be astoundingly expensive.
That said, Lunar colonization could be beneficial to further space travel. If industry could somehow be created there, the water in the soil could be turned into rocket fuel, the mineral resources could be used to fashion rocket parts, and the lower gravity turned into an advantage by providing lower cost launches.
If this path is to be pursued, we need to first determine conclusively that no life exists on the Moon already. Then we should focus our current efforts on generating a lunar-friendly factory. We also need long-term studies on the effect of low gravity on human physiology, particularly on children born in such an environment. Lots and lots of unknowns there.
Venus
Advantages: Proximity, with a launch window that opens roughly annually.
Disadvatages: Lead-melting (900 degree) surface temperatures. Crushing (90 times earth pressure), sulfuric-acid-laced atmosphere. long, retrograde rotational period and creates bizarre (by mid-latitude Earth standards) light/dark periods.
Conclusion: The life-span of our current technology in the Venutian environment is measured in minutes. There can be no colonization of the planet for the forseeable future.
Mars
Advantages: light-dark periods almost identical to earth. Evidence of former surface water leads to possibility that careful human use could return it. Water exists in the soil and has been shown to be obtainable by heating. Thin atmosphere with CO2 predominating, which could possibly be used in agricultural terraforming.
Disadvantages: Distance (6 months by current rocket technology) and infrequent opening of launch window (roughly every two years). Increasing signs of life-sustaining properties leads to higher possibilities that life is extant, which could prove detrimental to human quality of life. Cold surface temperatures (a hot summer afternoon is -20 Farenheit). Low gravity. Eccentricity of orbit is high for the solar system. Receives only 1/4 of the sunlight that earth receives.
Conclusions: Mars presents the most promising colonization possibility. However, there are a number of hurdles.
The infrequent launch window can not be changed by advances in rocket technology. Shortening the trip there (thereby minimizing the astronauts’ exposure to microgravity) simply lengthens the time one must survive in the freezing, low-gravity environment of Mars.
The baby step we must take before we strand some colonists there until a rescue mission could be launched two years later, is to find out if we can support ANYONE in low gravity for that long. This involves putting an astronaut in space for six months, low gravity for a year, and microgravity for six more months. No one has ever spent anything like this amount of time in these environments, not to mention the isolation involved.
The baby step before that is to simulate a proposed Martian colony on the Moon, where rescue is much easier. A step before this is a sample-return mission that brings Martian soil back to the moon for a series of two-year Biosphere experiments. The first sample-return mission from Mars, which will simply demonstrate that we can successfully bring ANYTHING back at all, never mind enough for Lunar agricultural experiments, is scheduled for no earlier than 2014.
The other prior step, is to have as full knowledge as we can of the long-term effects of low-gravity on the human body. The most cost-effective way of getting a jump-start on this research in the US is to ensure that the Centrifuge Accomodation Module of the ISS becomes a reality. It was to have launched in 2006, was pushed back to 2008 at least, and is currently listed as having its launch date “under review”.
We must also commit to creating the next generation of re-usable spacecraft, scrapping the current fleet of aging shuttles. The ISS’s Crew Return Vehicle, scrapped by the Bush administration in 2001, was to have provided the technology direction for this, in addition to allowing more efficient use of the station by 7 crew members (we can only provide escape accommodations for 3 right now). The idea that, during a time when some clown in the Mojave can land from space at a spot of his choosing, NASA will return to sending the fleet out into the Pacific to scour the seas for a dropped capsule are patently ridiculous.
No, you’re wrong. The fact that the speed of light is constant in a vaccum must be derived from observation. The Lorentz Transformations are derived from observation. E = mc^2 requires observations to back it up.
The Pythagorean Theorum does not. There’s the difference.
OK, look at it this way.
We went to the moon. Big whoop. The problem was, we went to the moon before we had a reason to go there. We went, stuck a flag in it, collected some rocks, came home, and forgot about it for 40 years. I don’t want a Mars mission to do the same thing.
There are many, many more “baby steps” than you list, if you want to do more than go collect rocks. You have to do all kinds of science on sustainable living, for instance. That is why I said that you would be wiser to invest your research into terraforming (or rather, the general field of engineering terrain, growing crops, recycling waste, etc). IMHO, a perfect testbed for this kind of stuff is, for example, the increasing desertification of sub-Sahara Africa and Central Asia. If you can figure out ways to reverse those situations, you’re doing a lot of rea-world research on what it will take to start any kind of farming on Mars.
The colonization of space, as we have mentioned, will NOT be an elite group of the smartest scientists. It will be farmers and workers. The key technologies will not be a new solid-state rocket engine or something made of astrophysics. They will be in biology and ecology and farming and such.
No, actually, you’re wrong. Light’s speed pops naturally out of Maxwell’s equations. Since the constant Maxwell derived closely fit the known speed of light, Maxwell was able to deduce that electromagnetic waves were light. The great mystery at the time was that nothing about the system seemed to change this constant; it was not dependent on any frame of reference, be it stationary or moving, which was the reason Michelson and Morley did their experiment in the first place; because what the equations said about light flew in the face of known kinematics and the apparent truth of the Galilean transformations. If one took Maxwell’s equations to be true (which they were), the Michelson-Morley experiment would be unnecessary. One could derive the Lorentz transformations from the simple fact that c does not depend on a frame of reference.