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Science (non-SETI) :
A thought about space travel
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Author | Message |
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Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
Some clear nights when I sit outside looking up at the stars I can't help but wonder if God or nature or whatever you want to call it hasn't played some cosmic practical joke on humanity. Making us just smart enough to figure out what space is and how big the universe is but not smart enough to even get to the nearest star with planets. At least not in a time frame that would allow an individual to go there and then return home to tell others about the trip. How cruel is that knowledge? It's like putting a banana split in front of a hungry child and placing an inpenitrable barrier between them. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
My question is different: is there life somewhere in this vast universe? And can we connect to it using some kind of signal? If we were the only life form in the universe, that would be a practical joke. Maybe an answer to your question could be found in a book by an Italian astronomer, Paolo Maffei, titled "Al di la' della Luna" and translated in English by another astronomer, Father Daniel O'Connell,SJ, as "Beyond the Moon" and published by MIT Press. The book was written after Apollo 11 when many people thought we had conquered space. But the Moon is only our backyard. Tullio |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
I have no doubt that life exists all over this galaxy and by extension all over the universe. And probably some of that life is way smarter than we are. But unless there is a way around the speed of light even communicating with any of them would have such a delay involved that two way communication would be of little value other than knowing they are there. Can you imagine sending a message that the aliens might receive 50 years later, then they would have to analyse our message, determine whether or not they want to reply and then compose a reply and 50 years later we get an answer. But the original senders are long dead and who knows what governments would exist at that point. Maybe no one would remember the message we sent so our experts would have to analyse the message and decide whether to respond....yada yada yada. And that case involves a star fairly close by. |
Michael Watson Send message Joined: 7 Feb 08 Posts: 1385 Credit: 2,098,506 RAC: 5 |
It could be that in more advanced civilizations than ours, both governments and individuals are much longer-lived. 100 years between the sending of a radio message and receiving a reply might seem trivial to them. It's also possible that there are useful exceptions to the light speed barrier, both in communications and space travel. Artificial warping of the the space time metric and something analogous to quantum tunneling on a much larger scale have been given serious speculative consideration among scientists. Recall that Dr. Carl Sagan used something of the latter sort in his novel Contact, after consulting with a top physicist about a reasonable possibility for a faster-than-light space travel scenario. |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
I grew up in the 1960s watching Star Trek, 2001 A Space Odessy, Star Wars and anything else involving space travel and I would love to find out that there is a practical and workable way to get around the speed of light before I die, but the longer I live the more I doubt it. In 1972 when I was a senior in college I wrote a term paper reporting on progress with mastering fusion for power generation and the concensus then was that the world would be running on fusion reactors within 20 years. Next year will be 40 years and there isn't even one continuously working fusion reactor. I imagine that some of the techniques described in various Sci Fi stories will eventually show more than a little promise but the science just isn't there yet. So I still sit outside at night looking at the stars and go there only in my imagination and dreams. Bob DeWoody My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events. |
Akio Send message Joined: 18 May 11 Posts: 375 Credit: 32,129,242 RAC: 0 |
But as we are not sending out any signals or messages, how would they know we are here? What about all of our transmissions that occur on earth and transferred too/from the satellites? Don't some of those signals travel away from Earth that could be detected by other beings? |
Allie in Vancouver Send message Joined: 16 Mar 07 Posts: 3949 Credit: 1,604,668 RAC: 0 |
But unless there is a way around the speed of light even communicating with any of them would have such a delay involved that two way communication would be of little value other than knowing they are there. I've often wondered about that myself: here we are listening for something we don't produce ourselves. A certain sense of tongue-in-cheek irony is needed to be a seti cruncher. RE. Speed of light. True, that is a barrier but remember, the faster you go the slower time passes so it is possible to travel a tiny bit slower than light and have time pass so slowly that thousands of years of travel will have the ship and crew only age a few months. There are a few technical and engineering problems to be solved first, tho. :P |
OzzFan Send message Joined: 9 Apr 02 Posts: 15691 Credit: 84,761,841 RAC: 28 |
RE. Speed of light. True, that is a barrier but remember, the faster you go the slower time passes so it is possible to travel a tiny bit slower than light and have time pass so slowly that thousands of years of travel will have the ship and crew only age a few months. There are a few technical and engineering problems to be solved first, tho. :P Can be a major problem if you agree to a diplomatic mission across the galaxy. Those who invited you won't even be alive anymore by the time you get there. ;) Even Master Yoda's race only lived to an average of 800 years. |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
But unless there is a way around the speed of light even communicating with any of them would have such a delay involved that two way communication would be of little value other than knowing they are there. Yes but of what good would that be for two way travel across the galaxy. By the time you got back to earth it would be possible that mankind would have wiped himself out. My observations are based on the need for two way travel, there and back. No investor is going to finance a space ship that if and when it returned everyone who invested in the trip was long dead. Bob DeWoody My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events. |
Michael Watson Send message Joined: 7 Feb 08 Posts: 1385 Credit: 2,098,506 RAC: 5 |
The concern that all stellar civilizations are listening, none talking, probably isn't as big a problem as it might seem. It would be possible for an only modestly advanced civilization to detect even our incidental radio emissions, if they wanted to. Dr. Frank Drake has written about how this could be done. It involves using our Sun as an immense gravitational lens. Starting some 550 astronomical units from the Sun, there are an infinite number of focal points, he says. He thinks 1000 AU (~9.3 billion miles out) would be ideal; avoiding interference from the solar atmosphere. A small receiver at that distance, aimed at the Sun, could intercept transmissions from all over a substantial portion of the galaxy. Michael |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
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Jason Safoutin Send message Joined: 8 Sep 05 Posts: 1386 Credit: 200,389 RAC: 0 |
But unless there is a way around the speed of light even communicating with any of them would have such a delay involved that two way communication would be of little value other than knowing they are there. We send out signals every second of everyday with every TV broadcast, radio show, when we talk on cell phones or walkie talkies. Granted they aren't beamed into space so aliens to intercept, but they do go into space. The signal(s), like all signals, weakens and degrades over time. In terms of us or aliens sending a message, unless A signal is in constant transmission 24 hours a day, 7 days a week, in specific directions, we will one receive bursts of a signal. You also have to account for other interference and so on. If any aliens are as intelligent as we are, or not so much, or even maybe smarter, I wouldn't see why some of them wouldn't be listening if they have the capability to do so, or travel at warp speed, light speed or whatever fancy name you want to give it. Time is of the essence. We as humans must be patient and not lose the hopes of finding something. If we do, even for a second, then that one second could be the key that we have been looking for. "By faith we understand that the universe was formed at God's command, so that what is seen was not made out of what was visible". Hebrews 11.3 |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
To my mind the only hindrance is the inability to protect from cosmic rays--we would wait for favorable orbital alignments and could possibly make the journey in 6 months transit time. I would think that 20 years would be enough to accomplish this--given the commitment and the funding--but a solution for the cosmic ray problem must also be found. |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
My intuition (hope I am wrong) is that there will not be any planets suitable for the delicate balance required for the development of a contemporaneous, advanced civilization. I am not sure that our spurious emissions could be detected at this distance anyway. Since we are not beaming (to my knowledge) a "we are here" message; the chances are slimmer than necessary that anyone will hear us. |
zoom3+1=4 Send message Joined: 30 Nov 03 Posts: 65757 Credit: 55,293,173 RAC: 49 |
As Commander Adama said to Starbuck: JUMP What is needed is a Jump Drive(FTL), so far most searches online for even theoretical info on this result in a lot of junk fiction and not much else, that or I'm using the wrong search words. Of course finding a working model in orbit or on some moon or asteroid would be a lucky break. The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's |
Allie in Vancouver Send message Joined: 16 Mar 07 Posts: 3949 Credit: 1,604,668 RAC: 0 |
As Commander Adama said to Starbuck: JUMP Would be nice if it were possible but I think that the idea of having a bunch of machinery in the trunk (that is, a self contained, FTL system) is almost certainly not happening. Things like black holes and worm holes and such involve physics that no one really understands and so almost anything can be theorized. That doesn't mean it is possible tho. My personal feelings that FTL is not ever going to be a possibility. But old school, Einstein type space exploration has it's appeal. Sure, traveling to the stars via sub-light ships would be a one-way trip but there would still be no shortage of volunteers (myself included!) Remember, most of the European settlers that came to North America a couple hundred years ago knew when they left that there was no going back and that they would never see their homelands, their friends and their families again. Still, they went, as so will humans in the future. Pure mathematics is, in its way, the poetry of logical ideas. Albert Einstein |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
K, The problem would be in knowing where you were going. It would be more exciting if we could find a habitable planet within 10 light years or even 20 or so. I have stated elsewhere that I have little confidence that we will ever find another "Earth". We are probably talking multi-generational trips here even if we could get up to 10% of the speed of light and find a planet near Proxima Centuri. Another thought might be a self sustaining ship with breeder reactor, garden plots, animal farm that would just wander and exist for many generations. For now I would just like to know how we could survive cosmic rays for even a trip to mars. |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
I have begun to think that the cosmic ray/radiation issue is why we haven't sent humans beyond LEO since the moon missions. We got real lucky back then that there were no CME's directed toward the earth and the moon. We would have had three fried astronauts. Bob DeWoody My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events. |
Allie in Vancouver Send message Joined: 16 Mar 07 Posts: 3949 Credit: 1,604,668 RAC: 0 |
Bearing in mind that this is all pie-in-the-sky dreaming we are doing here, there are ways around the cosmic ray problem. A ship with central passenger carrying section, radiating out from the centre booms a thousand or more kilometers long at the ends of which magnetic field generators. They produce fields strong enough to deflect cosmic rays away from the central part but are far enough away to protect core from harmful effects of the magnetic fields. And I do think that it is far to early to conclude that there are no earth-like planets in the stellar neighbourhood. Each year comes reports of more and more planets. Current technology limits the combination of closeness to a star and smallness of a planet. I doubt that present technology would be able to pick out Earth from a distance of 100 l-y so it is more a lack of ability than a lack of existence. Also, I don't think that, given a bit of time (not in our life times, but a few centuries) that speeds well beyond 10% of c are possible. I would tend to think that 90 to 95 % c would be a more likely upper practical limit. I reiterate: this is all pie-in-the-sky guessing, and none of us will live to see it happen. But our grand kids or great grand kids? That's another thing entirely. Pure mathematics is, in its way, the poetry of logical ideas. Albert Einstein |
zoom3+1=4 Send message Joined: 30 Nov 03 Posts: 65757 Credit: 55,293,173 RAC: 49 |
Of course finding Earth type planets is holy grail of planet hunters, but this would if it were real and not fictional be truly amazing, Immense indeed, if It were even possible. Population size there would truly be ignorable. Ringworld [extended version] YouTube The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's |
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