So I just skimmed through those links... And it's old news. All of it. Ground based lasers for propulsion may be possible. I know it has already been tested to some extent. The problem is the incredible amount of energy required to move an object. As for the particle sail... perhaps you didn't read. It failed. I read an article on that a few months ago. In any case, these methods of propulsion are not sufficient for interstellar travel. The laser approach would only provide movement in one direction. How would you turn? What happens when you slow down? I would like to point out that any deviation from the axis along which a laser would propel, would detract from magnitude of forward velocity. To the best of my knowledge, no one has developed any means of significant increasing the speed at which we can travel through space.
USAFHokie80 wrote:Chumly wrote:USAFHokie80 wrote:
I do not agree with your idea of "multi-generational" travel. It *IS* beyond our abilities. Suppose we need to travel 40 ly. Now, even at the speed of light, 40 yrs is near two "generations." Now, factor in the fact that we travel at such a trivial speed... now you're looking at hundreds if not thousands of generations. Do you know of a technology that can supply food, water, let alone, oxygen, for that many people for that long a period? I can't think of any.
I'll try to read up on those links you posted... However, my "generic critique" is still valid, generic or not. Can you mention any sort of technology that would allow us to provide oxygen, food/water to a crew for several thousand years? If you can't, then your argument is failed. You can't say "it is possible with today's technology" unless you can cite such technology.
Sure can! A honking big self-sustaining biosphere with nuclear energy as it's source. Again what part of technology as I have defined it would disallow it? None that I know of. Also please read Dr. Robert Forward, Dr. Geoffery A. Landis as per your "several thousand years" perspective.
Ladies! It should be remembered that the most I have accepted is that as per Dr. Robert Forward "Make no mistake - interstellar travel will always be difficult and expensive. But it can no longer be considered impossible."
USAFHokie80 wrote:So I just skimmed through those links... And it's old news. All of it. Ground based lasers for propulsion may be possible. I know it has already been tested to some extent. The problem is the incredible amount of energy required to move an object. As for the particle sail... perhaps you didn't read. It failed. I read an article on that a few months ago. In any case, these methods of propulsion are not sufficient for interstellar travel. The laser approach would only provide movement in one direction. How would you turn? What happens when you slow down? I would like to point out that any deviation from the axis along which a laser would propel, would detract from magnitude of forward velocity. To the best of my knowledge, no one has developed any means of significant increasing the speed at which we can travel through space.
Forget ground based lasers go for based and solar powered. As to deceleration I am not sure, perhaps they could carry a big enough ion drive.
USAFHokie80 wrote:Chumly wrote:USAFHokie80 wrote:Chumly wrote:USAFHokie80 wrote:I DO think there are other intelligent lifeforms out there...
Have you reviewed The Fermi Paradox & The Drake equation? If so on what do you base your assertion that "there are other intelligent lifeforms out there"?
Actually, I missed those. However, the reason I think there are other lifeforms is that in all the vastness of space, with all its millions or billions or trillions of planets and systems, I cannot believe that we are the singular existance of intelligent, or otherwise, life.
It (at the very least superficially) seems quite reasonable to believe that there is some life somewhere (perhaps a lot of life in a lot a places), however as far as technologically advanced intelligent life goes unless / until you review the Fermi Paradox & The Drake equation and make your arguments from a substantive perspective, I cannot add more about the technologically advanced intelligent life argument pros & cons as I would simply be quoting from sources already available to you.
However, to have further dialogue on the existence of lower life forms that have not / did not develop into technologically advanced intelligent life would mean you would need to present argument as to why this has not happened, any where at anytime, as least as per SETI / Fermi Paradox & The Drake equation. This you have not done.
Remember, evolution suggests that intelligent life is one it's potential results and it would be rather impossible to argue that no lower life from anywhere at anytime has ever evolved into technologically advanced intelligent life. Admittedly it is difficult to know with any certainty whether technologically advanced intelligent life is a common byproduct of the evolutionary process, but since you have argued for the huge potential of the universe (and I agree), you would need to explain why none of the lower life forms appear to have evolved into technologically advanced intelligent life as per as least as per SETI / Fermi Paradox & The Drake equation. (kind'a repeating myself a bit)
Understand there are many arguments and speculations one can make as to why lower life forms would not evolve into technologically advanced intelligent life and I am not biasing myself in any one direction and am quite open to discussing any you feel have merit.
You apparently misread what I typed. It says "intelligent, or otherwise" as I make absolutely no speculation as to what life on other planets would be.
I got that about the "intelligent, or otherwise". I am simply having a dialogue, and expressing some perspectives and asking you some questions along the way. Where exactly is the misreading on my part?
Booorrrrrriiiiiinnnnnngggggg
Tell me you are a rabid space dog from Sirius (the Dog Star).
For the record, Apollo 10 has the record for being the fastest manned vehicle ever built at 11.08kms. How, given that the speed of light is 299,792.458kms, that makes Apollo's record speed a whopping 0.00369589% c. That means, it would take us about 270.57 years to travel ONE lightyear.
USAFHokie80,
wellcome to able2know.com, it's fun.
Quote:Geoffery A. Landis, of NASA's Glenn Research Center, predicts the first star trek aboard a laser-powered sail ship could begin within 50 years as new methods of space travel put interstellar flight within the grasp of our grandchildren.
"I think that ultimately we're going to do it, it's just a question of when and who," Landis told SPACE.com. "Interstellar travel, actually colonizing space and terraforming a planet, this is the exploration that everybody seems to want to do."
Traditional means of space travel are too slow to push humans out of the solar system. Instead, Landis envisions ships with vast sails, propelled by laser light to about 10 percent the speed of light. Such a craft could make the 4.3 light-year trip to Alpha Centauri, the nearest star system, in about 43 years, though slowing down would be a problem. Stopping could take up to 100 years.
Chumly wrote:USAFHokie80 wrote:Chumly wrote:USAFHokie80 wrote:
I do not agree with your idea of "multi-generational" travel. It *IS* beyond our abilities. Suppose we need to travel 40 ly. Now, even at the speed of light, 40 yrs is near two "generations." Now, factor in the fact that we travel at such a trivial speed... now you're looking at hundreds if not thousands of generations. Do you know of a technology that can supply food, water, let alone, oxygen, for that many people for that long a period? I can't think of any.
I'll try to read up on those links you posted... However, my "generic critique" is still valid, generic or not. Can you mention any sort of technology that would allow us to provide oxygen, food/water to a crew for several thousand years? If you can't, then your argument is failed. You can't say "it is possible with today's technology" unless you can cite such technology.
Sure can! A honking big self-sustaining biosphere with nuclear energy as it's source. Again what part of technology as I have defined it would disallow it? None that I know of. Also please read Dr. Robert Forward, Dr. Geoffery A. Landis as per your "several thousand years" perspective.
Do you have any idea how nuclear power is generated? It is not a self-sustaining process. You have to provide FUEL. So how are you going to stuff, say 6000 years of uranium/plutonium and the control rod materials into your biosphere?
Aww come on Setanta. The subject doesn't even remotely interest you?
Besides, I think it may well be because of resources that we eventually venture off into the vastness of space. Economics has always been a huge drive for mankind to risk great dangers and travel large distances, after all.
As for aliens living in harmony, yet bent on destruction... Well, Xenophobia could well be a motivation. Something in the likes off: "I don't really like Qúxxxi and Qikki living next to me, but these pinkish hideuosu looking creatures called huumaaans are so hideous and incomprehensible, I'd ask Qúxxxi and Qikki for help to exterminate them every time."
I think the Fermi paradox is flawed, in that it fails to account with :
a) human scepticism... Even if we find 'proof' of alien life, would we believe we have found so?
b) luck. I am no scientist at all, but with all the almost unimaginable distances involved in spacetravel, how EASY would it be for us to aim only 0,000001 degrees offcentre from some planet, and thus miss it by barely more then a couple of million kilometres?
Najmelliw
What bores me are the happy horseshit speculations on how we are going to do what we have no reason to believe human societies are likely to do in the foreseeable future.
USAFHokie80 wrote:Chumly wrote:USAFHokie80 wrote:Chumly wrote:USAFHokie80 wrote:
I do not agree with your idea of "multi-generational" travel. It *IS* beyond our abilities. Suppose we need to travel 40 ly. Now, even at the speed of light, 40 yrs is near two "generations." Now, factor in the fact that we travel at such a trivial speed... now you're looking at hundreds if not thousands of generations. Do you know of a technology that can supply food, water, let alone, oxygen, for that many people for that long a period? I can't think of any.
I'll try to read up on those links you posted... However, my "generic critique" is still valid, generic or not. Can you mention any sort of technology that would allow us to provide oxygen, food/water to a crew for several thousand years? If you can't, then your argument is failed. You can't say "it is possible with today's technology" unless you can cite such technology.
Sure can! A honking big self-sustaining biosphere with nuclear energy as it's source. Again what part of technology as I have defined it would disallow it? None that I know of. Also please read Dr. Robert Forward, Dr. Geoffery A. Landis as per your "several thousand years" perspective.
Do you have any idea how nuclear power is generated? It is not a self-sustaining process. You have to provide FUEL. So how are you going to stuff, say 6000 years of uranium/plutonium and the control rod materials into your biosphere?
Your timeline of 6,000 years is silly as per potential average speeds.
Chumly wrote:USAFHokie80,
wellcome to able2know.com, it's fun.
Quote:Geoffery A. Landis, of NASA's Glenn Research Center, predicts the first star trek aboard a laser-powered sail ship could begin within 50 years as new methods of space travel put interstellar flight within the grasp of our grandchildren.
"I think that ultimately we're going to do it, it's just a question of when and who," Landis told SPACE.com. "Interstellar travel, actually colonizing space and terraforming a planet, this is the exploration that everybody seems to want to do."
Traditional means of space travel are too slow to push humans out of the solar system. Instead, Landis envisions ships with vast sails, propelled by laser light to about 10 percent the speed of light. Such a craft could make the 4.3 light-year trip to Alpha Centauri, the nearest star system, in about 43 years, though slowing down would be a problem. Stopping could take up to 100 years.
So, according to thermodymanics, energy cannot be created not destroyed, only transferred. So, suppose you have a craft of x mass. The problem is that we need to generate enough energy to get that mass moving. Usually, we do this with rockets. I'm not terribly sure the output in watts/joules the rockets produce, but if a laser were to be used, it would need to generate many times that power. Given that Apollo 10 was only travelling at 0.0037% (i rounded up) the speed of light, that laser would need to produce 2700 times as much power to get us to that 10% mark. Just where are we supposed to get that much power?
Hmm.
It may be unlikely indeed, but I imagine everybody scoffed at the idea of Columbus having any luck with his expedition as well. That too took a lot of resources and a great deal of faith and luck to pull off, but with the discovery of America, unforeseen and unimaginable consequences came to pass for every civilization on the planet (barring Australia, perhaps).
Naj
Columbus had an exterior, "inexhaustible" energy source--the wind. He only needed supplies for about three months, and had a good deal more than that in his holds. The analogy does not work.
najmelliw wrote:I think the Fermi paradox is flawed, in that it fails to account with:
a) human scepticism... Even if we find 'proof' of alien life, would we believe we have found so?
Yes I believe many would accept verifiable scientific evidence via electromagnetic radiation, the premise Fermi/Drake is not intended to account for disbelief in the face of fact.
najmelliw wrote:b) luck. I am no scientist at all, but with all the almost unimaginable distances involved in spacetravel, how EASY would it be for us to aim only 0,000001 degrees offcentre from some planet, and thus miss it by barely more then a couple of million kilometres?
Such travel would not be the equivalent of shooting a bullet and ongoing course corrections would be the norm.
USAFHokie80 wrote:Chumly wrote:USAFHokie80,
wellcome to able2know.com, it's fun.
Quote:Geoffery A. Landis, of NASA's Glenn Research Center, predicts the first star trek aboard a laser-powered sail ship could begin within 50 years as new methods of space travel put interstellar flight within the grasp of our grandchildren.
"I think that ultimately we're going to do it, it's just a question of when and who," Landis told SPACE.com. "Interstellar travel, actually colonizing space and terraforming a planet, this is the exploration that everybody seems to want to do."
Traditional means of space travel are too slow to push humans out of the solar system. Instead, Landis envisions ships with vast sails, propelled by laser light to about 10 percent the speed of light. Such a craft could make the 4.3 light-year trip to Alpha Centauri, the nearest star system, in about 43 years, though slowing down would be a problem. Stopping could take up to 100 years.
So, according to thermodymanics, energy cannot be created not destroyed, only transferred. So, suppose you have a craft of x mass. The problem is that we need to generate enough energy to get that mass moving. Usually, we do this with rockets. I'm not terribly sure the output in watts/joules the rockets produce, but if a laser were to be used, it would need to generate many times that power. Given that Apollo 10 was only travelling at 0.0037% (i rounded up) the speed of light, that laser would need to produce 2700 times as much power to get us to that 10% mark. Just where are we supposed to get that much power?
From the sun via space based lasers as I already posted.
Up to a certain extent (the wind was a fickle energy source at best) . You're objections are valid, of course. Technically speaking, Columbus' voyage was far more feasible then space travel.
But no one believed in his succes (apart from himself) when he started out, and, the results no one could foresee.
A proper analogy cannot be found in earth history, but I would like to attend that the society of today, while in general I am exceedingly pessimistic about it, is far more research oriented than ever before.
Naj
Quote:If we had the same amount of chemical propellant, it would provide only one tenth as much velocity increment.
What is ion propulsion?
Deep Space 1 sets record with ion propulsion system
It's important to note that it's not the amount of power at any small time period but the amount or power over mission time, hence rockets are not a good example but lasers are, as is possibly ion drive at least for light unmanned craft.
Note I am not suggesting ion drive for manned missions, except possibly for deceleration.
