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Author Topic:   Interstellar Travel - Possibilities and Human Physiology
Sarawak
Member (Idle past 5564 days)
Posts: 47
Joined: 03-07-2009


Message 31 of 63 (504173)
03-24-2009 10:40 PM
Reply to: Message 30 by Taq
03-24-2009 10:24 PM


Re: DNA
It's everything. History, environment, language, society, and oh yes, DNA.
Perhaps a way to bridge the gap between the home planet and a freshly seeded population of humans would be anthropomorphic androids trained to raise a new human generation and a vast library containing art, history, primers on human society, etc.
Humans are quite adaptable and I see no reason why new populations need be carbon copies of Earth's. Indeed, new planets would probably demand differences. Do you mean copying, or just borrowing things that would apply to a new planet? Evolution would soon take care of that anyway.

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kuresu
Member (Idle past 2599 days)
Posts: 2544
From: boulder, colorado
Joined: 03-24-2006


Message 32 of 63 (504188)
03-25-2009 3:45 AM
Reply to: Message 26 by Sarawak
03-24-2009 8:58 PM


Re: Slingshot
what's the escape velocity of the target system?
The only things with enough gravity I'm aware of to actually capture something going .5C is a black hole. Maybe a pulsar or some other neutron star, and that's only because we won't be traveling at the speed of light.
Not exactly our target system, is it?

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DevilsAdvocate
Member (Idle past 3187 days)
Posts: 1548
Joined: 06-05-2008


Message 33 of 63 (504202)
03-25-2009 7:46 AM
Reply to: Message 26 by Sarawak
03-24-2009 8:58 PM


Re: Slingshot
Sarawak writes:
Myself writes:
This is conceptually plausable according to the laws of physics I suppose. However, the problem I see with this is more of an issue with human intolerance to high g-forces. How can we go from near c speeds (or even 0.5 c) to 0 without creating insanely high g-forces? I would imagine that even to get captured by a solar system's gravity and be swung aroung to reduce it's velocity (like a comet captured by the sun) would still entail high g-force. Any one have a solution to this problem?
Multiple passes.
Hmm, I have to agree with Kuresu, proceeding at or near light speed to decelerate to orbit a star system would require the gravity well of a black hole or a neutron/quark star.
The reason is this, EM energy only bends around stellar gravity wells and only black holes can actually trap matter/energy proceeding at this speed. Therefore when a near light speed ship approaches a star system it would only hyperbolically bend around it (the amount of bending would be a result of how big the gravity well of the star is) to a slightly different course but could not trap it. Something else would have to be used to tap off its near light velocity to a lower velocity before it could be trapped by the gravity of a stellar system.
Edited by DevilsAdvocate, : No reason given.

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Dr. Carl Sagan

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DevilsAdvocate
Member (Idle past 3187 days)
Posts: 1548
Joined: 06-05-2008


Message 34 of 63 (504204)
03-25-2009 7:51 AM
Reply to: Message 29 by Taq
03-24-2009 10:18 PM


Re: Slingshot
For constant g forces above 1xg we can take a cue from nature, specifically the womb. If you submerge the passengers in water they experience much lower g loads.
True, the g-loads will be less but even at extreme g-pressures, water has a limit to how much it can be compressed and would result in pressures amounting to a brick wall. The only other way I can see around this is some type of stasis field holding a human body (perhaps in hibernation) which would allow for a cushioning affect of these high g-forces.
Just my thoughts.

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Dr. Carl Sagan

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Sarawak
Member (Idle past 5564 days)
Posts: 47
Joined: 03-07-2009


Message 35 of 63 (504220)
03-25-2009 11:46 AM


I was only looking at the reverse slingshot as a means of requiring less fuel for deceleration. If it is not feasible then I need to find something else. It's also why I asked about "space friction", pondering whether that might help in deceleration, or require extra fuel to support a constant velocity. I admit to being out of my biological playing field with these musings.

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Taq
Member
Posts: 10158
Joined: 03-06-2009
Member Rating: 4.4


Message 36 of 63 (504252)
03-25-2009 6:52 PM
Reply to: Message 35 by Sarawak
03-25-2009 11:46 AM


I was only looking at the reverse slingshot as a means of requiring less fuel for deceleration.
It would work, but the savings would be pretty small assuming that you are slowing down from relativistic speeds. It works great for our satellites that are crawling through the solar system, but they aren't going that fast.

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Sarawak
Member (Idle past 5564 days)
Posts: 47
Joined: 03-07-2009


Message 37 of 63 (504253)
03-25-2009 7:03 PM
Reply to: Message 36 by Taq
03-25-2009 6:52 PM


What's the fastest speed any of our space junk has attained?

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shalamabobbi
Member (Idle past 2935 days)
Posts: 397
Joined: 01-10-2009


Message 38 of 63 (504254)
03-25-2009 7:13 PM
Reply to: Message 37 by Sarawak
03-25-2009 7:03 PM


Sarawak writes:
What's the fastest speed any of our space junk has attained?
quote:
We have previously written about two vehicles called Helios launched to study the Sun during the 1970s. Both of these probes attained maximum speeds of around 150,000 mph (250,000 km/h) at closest approach to the Sun in their highly elliptical orbits. Helios 2 was slightly faster than its twin craft, and this probe still holds the speed record as not only the fastest spacecraft but also the fastest manmade object in history.
reference

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Sarawak
Member (Idle past 5564 days)
Posts: 47
Joined: 03-07-2009


Message 39 of 63 (504260)
03-25-2009 11:28 PM


Shalamabobbi
We have previously written about two vehicles called Helios launched to study the Sun during the 1970s. Both of these probes attained maximum speeds of around 150,000 mph (250,000 km/h) at closest approach to the Sun in their highly elliptical orbits. Helios 2 was slightly faster than its twin craft, and this probe still holds the speed record as not only the fastest spacecraft but also the fastest manmade object in history.
So we'd have to do 1000x to make star hopping viable (about 0.2c). 100X I can see, but technology may get us there. I am optimistic. 25 years is not too much to ask of a ship and crew. Where do I sign up?

  
alaninnont
Member (Idle past 5523 days)
Posts: 107
Joined: 02-27-2009


Message 40 of 63 (504311)
03-26-2009 8:46 PM


I have serious doubts in our ability to colonize other planets. To colonize a planet we would need a large portion of the conditions we have on earth. Attempts at long term stays in sealed biospheres here on earth have failed. We are a relatively fragile species with specific needs in temperature, atmosphere, nutrition, pressure, radiation, emotional support, and G force. Even if we found a planet with many of earth's conditions, an absence of an important nutrient could easily result in failure. If you take a look at our population growth curve and pollution production trends, you will see that they are not sustainable in the long term. I think we will run out of resources or poison ourselves with our own waste before we develop the technologies for getting to habitable planets.
I could see the possibility of creating a space ship that spins to create centripital force simulating gravity for long term travel but the vastness of space makes the colonization of a planet a formidable task.
The other reason for my doubt is the absence of aliens. Other parts of the universe are far older than we are and if life exists elsewhere then they theoretically should have advanced to have the technology for space travel and life detection systems but the reports of alien sightings on earth do not seem credible as yet. It may be that we are alone.
I see our best hope in space travel as learning how to warp space-time. The other possibility is traveling through other dimensions. According to the string theory, there are ten or eleven dimensions. We detect only three space and one space-time but it is possible that the others were shrivelled up during the big bang. If we could find the others, a small distance in another dimension could be a huge distance in ours and allow us to travel to other parts of the universe. This is bordering on fringe.

Replies to this message:
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RAZD
Member (Idle past 1491 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 41 of 63 (504312)
03-26-2009 9:21 PM
Reply to: Message 40 by alaninnont
03-26-2009 8:46 PM


I have serious doubts in our ability to colonize other planets.
I would think that developing ways and means to exist in space, whether in large stations or by genetic modifications or both would be more practical than colonizing a planet.
(1) there's more of it
(2) resources are available
(3) planets are "naturally occurring" space stations
Once so developed, the need to colonize would be moot, although it may still be necessary to pick up certain resources. Certainly an animal that can naturally hibernate or form a spore would have an advantage in adapting to space travel.
At first thought it would seem that solar sails would work best near stars, with the force dropping off as the square of the distance -- however this is similar to gravity, so they can provide constant net acceleration (and deceleration at the other end).
Another typical science fiction engine is a ram jet that collects interstellar atoms through magnetic fields which also protect the ship from radiation and then uses fusion to create an ion jet. Problem is getting the fusion to work.
Enjoy.
Edited by RAZD, : nat

we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


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This message is a reply to:
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Replies to this message:
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DevilsAdvocate
Member (Idle past 3187 days)
Posts: 1548
Joined: 06-05-2008


Message 42 of 63 (504314)
03-26-2009 11:51 PM
Reply to: Message 40 by alaninnont
03-26-2009 8:46 PM


According to the string theory, there are ten or eleven dimensions. We detect only three space and one space-time but it is possible that the others were shrivelled up during the big bang. If we could find the others, a small distance in another dimension could be a huge distance in ours and allow us to travel to other parts of the universe. This is bordering on fringe.
Problem is, I believe that string theorists predict these other dimensions (outside the four dimensions of spacetime) like you said have been reduced in size tremendously during the big bang, in fact reduced in size to planks lengh aka the size of a string. Therefore, I don't think we would be able to travel in these dimensions without drastically changing our physical properties to suite i.e. turn humans (or any thing else we send to travel through these other dimensions) into pure energy. The other issue is the amount of energy required to do this would be on a cosmic scale even exceeding the energy of our sun.
So in actuallity this proposal is as prone to failure if not more so than attempting to explore and colonize extrasolar systems imho. That doesn't mean we shouldn't try thought. Just being Devil's Advocate, no pun intended

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.
Dr. Carl Sagan

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Sarawak
Member (Idle past 5564 days)
Posts: 47
Joined: 03-07-2009


Message 43 of 63 (504339)
03-27-2009 9:55 AM
Reply to: Message 40 by alaninnont
03-26-2009 8:46 PM


alaninnont said:
I have serious doubts in our ability to colonize other planets. To colonize a planet we would need a large portion of the conditions we have on earth. Attempts at long term stays in sealed biospheres here on earth have failed. We are a relatively fragile species with specific needs in temperature, atmosphere, nutrition, pressure, radiation, emotional support, and G force. Even if we found a planet with many of earth's conditions, an absence of an important nutrient could easily result in failure. If you take a look at our population growth curve and pollution production trends, you will see that they are not sustainable in the long term. I think we will run out of resources or poison ourselves with our own waste before we develop the technologies for getting to habitable planets.
I could see the possibility of creating a space ship that spins to create centripital force simulating gravity for long term travel but the vastness of space makes the colonization of a planet a formidable task.
The other reason for my doubt is the absence of aliens.......
I am sorry you have such a low opinion of your species. I am much more optimistic, but, yes, need may drive the necessary invention.
You have evidence for the absence of aliens? The absence of evidence is not evidence of absence. After all they would face the same problems that we have and may be a long way off.

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Blue Jay
Member (Idle past 2784 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 44 of 63 (504344)
03-27-2009 11:03 AM
Reply to: Message 28 by Straggler
03-24-2009 9:35 PM


Re: Calling Bluejay!!!
Hi, Straggler.
Sorry about the delay.
Straggler writes:
Isn't Bluejay an SF writer............?
How bout it Bluejay?
Yes.
Most of the stuff in this thread is beyond me, though: I'm no physicist or engineer. I focus on biology and evolution, and just assume things like wormholes and starships in order to make other worlds possible to explore.
And, I actually have written stuff similar to what you're talking about. I wrote about an automated system that is designed to generate new biospheres on habitable planets. Some industrialists used an automated system to terraform a remote, Earth-like planet with a "DNA ark" and declare that world a "nature sanctuary" in order to placate politically-powerful conservationists.
-----
It's fun to write about stuff like that in SF, but you always have to wonder whether the interest would ever exist to do it in real life. The conservation idea I came up with is probably not very practical, and probably wouldn't be satisfying to anybody in the real world, so it isn't very likely that people would buy into it.
Of course, you could always find some free-thinkers and misfits who would be interested in stuff like that, and, if any of them had financial or political connections (as in my story), they could make it happen.
-----
Straggler writes:
Simply transferring the biology of humanity to another far off place would, I think, not necessarily result in anything that particularly resembled humanity in so many ways that we take for granted.
I think a more pressing difficulty would be designing functional people with an automated system. Would the people be grown in artificial wombs and raised through childhood by the robots? Or, would they be built as adults? If the latter, could they be taught everything they need to know in order to build a functional---and advanced---society in a timely fashion?
Maybe you'd have to design the babies to be precocial, so they can walk and find food (which the robots could grow or produce) on their own from birth. Perhaps the robots could also construct complex environments designed to help the children mature into functional adults. At any rate, whatever culture evolves from this would clearly be very alien.
Of course, none of this happens unless society is willing to allow genetic engineering (designer babies is what this amounts to) and has a non-biological view of humanity.
-----
Maybe someday I’ll write up a thread to explain some of my SF concepts (a lot of it is quite applicable to EvC). Probably not anytime soon, though: I’m about to start a brutal field season.

-Bluejay/Mantis/Thylacosmilus
Darwin loves you.

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alaninnont
Member (Idle past 5523 days)
Posts: 107
Joined: 02-27-2009


Message 45 of 63 (504363)
03-27-2009 5:36 PM
Reply to: Message 41 by RAZD
03-26-2009 9:21 PM


I would think that developing ways and means to exist in space, whether in large stations or by genetic modifications or both would be more practical than colonizing a planet.
(1) there's more of it
(2) resources are available
(3) planets are "naturally occurring" space stations
Once so developed, the need to colonize would be moot, although it may still be necessary to pick up certain resources. Certainly an animal that can naturally hibernate or form a spore would have an advantage in adapting to space travel.
I agree. We would probably have to use centripital force to simulate gravity since artificial gravity doesn't seem to be anywhere near possible in the foreseeable future. The problem would be in the resources. I could see how a space station once built could be self sustaining but it would take an incredible amount of resources to build and people on earth are doing a good job of using up the resources we have. For a space station to build another space station would require a vast amount of raw materials which we would have to get from somewhere. If they aren't available from earth, the space station personel would have to find another moon, asteroid, planet, etc. with all the right resources and set up mining and processing facilities. It is possible but we would need some pretty incredible advances in technology to pull it off.

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