How could Extra Terrestrials do it?

[Entrails Konfetti]

Travel through space, to our shit-hole.
There is a speed limit, that of light-- if you go at the speed of light, or faster than it, you turn into gamma rays. How can these rays be recombined into the humanoid and mechanical forms?

Also, say these aliens travel through our atmosphere, is it possible they are travel so fast we cannot see them nor detect them with radar?

[Luís Henrique]

Travel through space, to our shit-hole.
There is a speed limit, that of light-- if you go at the speed of light, or faster than it, you turn into gamma rays. How can these rays be recombined into the humanoid and mechanical forms?

You can't go faster than light, even if you have turned into gamma rays. Indeed, gamma rays are light, and they travel at light speed. I fear that if you turn into gamma rays, there is no way you can be recombined into organised matter again. Any information encoded in your material form would be permanently lost.


Also, say these aliens travel through our atmosphere, is it possible they are travel so fast we cannot see them nor detect them with radar?

If they traveled that fast, attrition with our atmosphere would make them, or their trail, visible to us, just like meteorites. They would also quite probably be killed in the process.

Luís Henrique

[mikelepore]

Seems that Entrails Konfetti read that, if a particle meets its antimatter version, like electron and positron, they are annihilated and replaced with two photons. True, but this won't provide us with a new mode of transportation. They're just annihilated. And if you did this with a large sample of matter, energy equivalent to thousands of H-bombs would be radiated spherically.

[mikelepore]

If travelers have a way to accelerate continuously, they might get close enough to the speed of light so that a short time would pass for them during an interstellar trip, although a long time would have passed on their home planet.

[ÑóẊîöʼn]

If travelers have a way to accelerate continuously, they might get close enough to the speed of light so that a short time would pass for them during an interstellar trip, although a long time would have passed on their home planet.

This is perhaps the best scenario for interstellar travel... unfortunately, it comes at an enormous cost of energy - as an object with real rest mass (such as a starship) approaches the speed of light, it's mass increases.

So in order for the time dilation effect to be truly useful to the crew, one would have to find an energy source of extremely high density. The only thing I can think off that has anything remotely to do with physics as we know it that could possibly power such a vessel is total matter-to-energy conversion - the total energy content of matter is very high, but unlocking that energy is an unknown at this point, although it doesn't violate any known physical laws.

[Entrails Konfetti]

As pertaining to Earth, these beings cannot be from our gallaxy (or whats known about the Milky Way), which causes the problem of time. The starcraft would have to be like a space center of multi-generations, or of beings that have a very long life.

[mikelepore]

I don't understand your first sentence. This galaxy doesn't cause any problem with time.

[razboz]

since anyway this is speculation, why limit yourselves to humanoid, or beings that use human scales of time. for example a being composed of millions of single-celled organisms probably would have no conception of mortality and as such would probably not see time as being "limited" in any way other than it's own use of resources and metabolic activity. as such it could embark on space voyages exceding by several millions of years our own standards for acceptably long time. or beings made entirely of light. They could move at the maximum speed permisible within the regular laws of physics. they could even get to earth and enter our atmosphere totally undetected by us.
Hell, i've heard the possibility voiced that extraterrestrial inteligent beings could be composed of millions of planets and stars which function as cells in a regular organism.

[Entrails Konfetti]

I don't understand your first sentence. This galaxy doesn't cause any problem with time.

It does because, we cannot travel out of our galaxy, time would be a problem. Everything out of our galaxy is over 100lys away.

[lithium]

100 light-years isn't that far, in astronomical terms. The Milky Way itself is around 100,000 light-years in diameter.

As has been pointed out there are issues with travelling at near light-speed. Although one interesting effect, as an aside, is how long a journey lasts for a photon. If I take a torch and shine it in some direction, I will observe the beam moving away from me at the speed of light. However, if I was one of those photons, I would reach my destination instantaneously. One of the other joys of special relativity: length contraction.

[Entrails Konfetti]

If we were to travel at light speed, 100ly is far!

[Leo]

How could Extra Terrestrials do it? Travel through space, to our shit-hole.

This ain't gonna sound fun but they either have to live unbelievably long lives or have to be living in a space ship.

Of course, it's not that it never happened: http://www.terrybisson.com/meat.html

[black magick hustla]

i have faith in the posadistas.

[ÑóẊîöʼn]

As pertaining to Earth, these beings cannot be from our gallaxy (or whats known about the Milky Way), which causes the problem of time.Why can't such beings come from our own galaxy? Their are hundreds of billions of stars in the Milky Way and as such I hardly think life-bearing planets are a fluke.


The starcraft would have to be like a space center of multi-generations, or of beings that have a very long life.Or they could be in suspended animation. (http://orbitalvector.com/Interstellar%20Flight/Sleeper%20Ships/Sleeper%20Ships.htm) Or not even born yet. (http://orbitalvector.com/Interstellar%20Flight/Seed%20Ships/Seed%20Ships.htm)

But even if they were travelling within the Milky Way, barring wormholes or some kind of FTL they would have to use such measures anyway.

[Leo]

i have faith in the posadistas.

Ahahahahahahaha yeah dude totally that's the most astonishing thing ever!

[mikelepore]

because, we cannot travel out of our galaxy, time would be a problem.

Right, I got confused because I thought you said the extraterrestrials cannot be from within our galaxy. So I went, huh?, being closer wouldn't add more problems than being further does.

As to your 100 LY, you want to add some zeroes. 100,000 LY is about the diameter of our galaxy, and we're about two-thirds of the way from the center to the rim. Then it's millions of LY's to get around the few dozens of galaxies in the Local Group.

[Entrails Konfetti]

Of course, it's not that it never happened: http://www.terrybisson.com/meat.html

Which makes me wonder if beef can be ingested at the speed of light.


Why can't such beings come from our own galaxy? Their are hundreds of billions of stars in the Milky Way and as such I hardly think life-bearing planets are a fluke.

In theory it's possible, but the stars in our skies aren't confirmed to have other planets surrounding them.

Though I wouldn't be surprised if Europa has some sort of uni-cellular aquatic life living on it (I would be surprised about multi-cellular life), or that other galaxies contain life.


Or they could be in suspended animation. (http://orbitalvector.com/Interstellar%20Flight/Sleeper%20Ships/Sleeper%20Ships.htm) Or not even born yet. (http://orbitalvector.com/Interstellar%20Flight/Seed%20Ships/Seed%20Ships.htm)

How do we know this stuff isn't like the Lightsaber-- how impossible it is for photons to terminate after 4 feet without anything blocking their path, aswell as for photons to cut through all matter.


But even if they were travelling within the Milky Way, barring wormholes or some kind of FTL they would have to use such measures anyway.

In theory anyhow. Wouldn't wormholes suggest that the universe has a shape?

[Luís Henrique]

Are you trying to write a sci-fy story?

Luís Henrique

[Entrails Konfetti]

Haha, no.

I just think it would be really sweet if there were sentient-beings on other planets.
Plus I'm taking intro to astronomy at my community college.

I think my instructor is an Alien, he's weird, and tries to ascertain that there isn't any life in our galaxy, and that interstellar travel is impossible.

[RNK]

Keep in mind that quantum theory is theory.

Einstein and Stephen Hawking's theories have never been tested conventionally; like many facets of science they are but educated guesses for which counter-arguements have not been created. Our knowledge of science is piss-poor compared to the amount of knowledge to be had. We don't know that speeds faster than light are possible; we only know that according to the leading theory on the matter it isn't.

[RebelDog]

I have my doubts whether humans or any other advanced biological life would travel vast distances in space. I think it would be more sensible to send robots. I think this Star-Trek style idea of hundreds of people going around exploring on a huge ship is unrealistic. Why send humans when robots can do a better job at a fraction of the cost and without risk to life. I actually think the days of human space flight are numbered right now.

[Plagueround]

I would think if an alien species were to explore the galaxy they would do so with probes first...as you said, it's cost effective and less risky, not to mention that we don't have the technology available to send people very far into space as of yet, who knows if another species would? Then again, perhaps we shouldn't assume other lifeforms would think like we do. Maybe they would have good reason to explore space themselves. ;)

[ManyAntsDefeatSpiders]

I thought the question 'How could Extra Terrestrials do it?' was asking something entirely different. :blushing:

[Awful Reality]

Seems that Entrails Konfetti read that, if a particle meets its antimatter version, like electron and positron, they are annihilated and replaced with two photons. True, but this won't provide us with a new mode of transportation. They're just annihilated. And if you did this with a large sample of matter, energy equivalent to thousands of H-bombs would be radiated spherically.

We know almost nothing about antimatter today. When atomic power was first conceived, it was considered to be only of military applications.


I thought the question 'How could Extra Terrestrials do it?' was asking something entirely different. :blushing:

:lol:

[ÑóẊîöʼn]

Where the fuck did my reply go to? :cursing:


Keep in mind that quantum theory is theory.

Gravity is also "only a theory". :rolleyes:


Einstein and Stephen Hawking's theories have never been tested conventionally; like many facets of science they are but educated guesses for which counter-arguements have not been created.Relativity and quantum mechanics have been experimentally verified. Otherwise, GPS satellites wouldn't have to compensate for relativistic effects and your computer wouldn't work.


Our knowledge of science is piss-poor compared to the amount of knowledge to be had. We don't know that speeds faster than light are possible; we only know that according to the leading theory on the matter it isn't.And until somebody comes up with a verifiable theory to the contrary, faster than light travel will remain impossible.

Of course, that doesn't mean that there aren't ways of "cheating" relativity... but none have been experimentally proven yet.


I have my doubts whether humans or any other advanced biological life would travel vast distances in space.

Why?


I think it would be more sensible to send robots.In the initial stages it probably would be... but merely sending out robots won't ensure the survival of our species.


I think this Star-Trek style idea of hundreds of people going around exploring on a huge ship is unrealistic.Well, that rather depends on what form of interstellar travel turns out to be practical. A number of proposed methods include:

1. "Generation ships" massive vessels carrying viable breeding communities - on the centuries-long trip, people are born, have kids, work, play, and die of old age. A variant of this is the "Cross-generation Ship" (http://en.wikipedia.org/wiki/Cross_generation_ship)

2. The "Seed Ship" concept to which I linked to earlier. Typically containing millions of preserved fertilised eggs, artificial wombs to grow them in, robotic surrogate parents and a master computer. Some Seed Ship concepts also include the preserved seeds of plants and trees as well as the fertilised eggs of various animal species, so that a human-friendly biosphere can be built at the destination.

3. Perhaps a more extreme version of the previous is to "digitise" the whole crew, whereby the ship's computer runs detailed simulations of the crew members on the journey and places them into artificial bodies at the destination.

4. "Sleeper Ships" hold all or most of the crew in some kind of suspended animation during the journey, reducing the amount of resources needed sustain the crew. Some concepts postulate a handful of crew members being woken up on a shift basis to ensure the smooth running of the ship.

5. Perhaps some way can be found to massively slow down human metabolism and perception, perhaps to 1/1000th of normal speed. So on a ship travelling at 10% to Alpha Centauri, the trip only seems to take a few weeks to the slowed-down crew.

6. Another way of getting round the fact that a typical interstellar journey is likely to take decades if not centuries, is to extend the natural lifespan so that such long journeys take out a much smaller chunk of one's life. In this case, long insterstellar journeys become more of a problem of boredom than enything else.

One of these methods, some of them, or perhaps a combination of them may turn out to be useful to potential interstellar travellers. Some of them require a minimal crew, others require crews of thousands if not millions.


Why send humans when robots can do a better job at a fraction of the cost and without risk to life.Because robots aren't humans, unless you gift them with human consciousness, in which case if you're going to do that you might as well send humans in some form or another.

And besides, sooner or later we have to send some of our kind out of the solar system - it's not going to be a cosy, inhabitable place to live for long, cosmologically speaking.

Although, humans spreading to other stars might happen by accident (http://orbitalvector.com/Interstellar%20Flight/Stepping%20Stone/Stepping%20Stone.htm):


In most scenarios of interstellar colonization, immense ships of one design or another leave one life-bearing world in the inner system of a star, fly through the void, then brake around another life-bearing world in the inner system of another star. The old assumption was that the outer reaches of a star system, being cold, lifeless, and only sparsely populated with material resources, wasn’t worth the bother.
However, discoveries in the past decade has shown that the outer reaches of a star system may reach much farther, and contain much more in it, than previously thought.
First of all, there’s the Kuiper Belt, which extends from the orbit of Neptune to at least 50 AUs (about 7 billion kilometers) out from the sun in more or less the same orbital plane as the planets. It is estimated that at least 70,000 cometary objects with diameters larger than 100 kilometers exist in this Belt, all primordial remnants from the accretion disk that originally formed the solar system. Pluto, its moon Charon, and a large object near Saturn’s orbit called Chiron are all thought to be unusually large Kuiper Belt objects.
There’s also the Oort Cloud, an even larger and more widely dispersed collection of cometary objects that forms a rough sphere around the solar system, starting roughly from where the Kuiper Belt ends. Comprised of an estimated trillion significantly sized objects, the Oort Cloud is thought to extend to at least 50,000 AUs from the sun, though some estimates put the outer boundary at 2 light years or more. The total mass of all the comets in the cloud are thought to exceed 40 times the mass of Earth, though individual objects may be tens of millions of kilometers apart.
Rogue planets, worlds either ejected from their home star systems or ones that formed along side stars in interstellar nurseries but were never bound to them, are now thought to be far more numerous than previously thought. As are Brown Dwarves, objects too big to be a planet but too small to ignite into a star, which have masses between 15 and 80 times that of Jupiter. Both types of objects are now considered to be more numerous than mainstream stars, and litter the vast interstellar depths.
The Sun itself is thought by some astronomers to have a distant near-interstellar companion that may either be a rogue planet or a brown dwarf. Named Nemesis, it is theorized to have an orbital period measured in the millions of years, periodically sweeping through the Oort Cloud to send comets raining into the inner system, causing mass extinctions such as the one that wiped out the dinosaurs.
The Stepping Stone strategy for colonization takes advantage of all these various objects to very slowly build a ‘step ladder’ out of one solar system and into another. Using both passive astronomical techniques and powerful active radar arrays, most of the major objects in the Kuiper Belt, Oort Cloud, and nearby interstellar space are found and their orbits plotted. One first builds bases and/or colonies on the outer planets to use for building and refueling outbound ships using fission, fusion, antimatter or simple lightsail drives. Then one moves into the Kuiper Belt, mining the objects there for fuel and hollowing out larger comets to use for bases and colonies. One repeats the process once again for the Oort Cloud, then again for any significant objects that may exist in interstellar space.
Once a human presence is established on an interstellar brown dwarf or rogue planet or lonely comet, the process is reversed in a nearby system, moving inward from the interstellar way station to the new system’s Oort Cloud, then to its Kuiper Belt, to its outer planets, and finally to its inner system. If a conveniently-placed interstellar object is absent, a comet can be towed or boosted into place or built up using cyclers.
Needless to say, this is an extremely gradual, multi-generational process. In fact, some think it may not even be done intentionally. As humanity moves out into the solar system, the inner worlds may fill up within a millennium, forcing some elements of its population ever outward looking for new resources and living space.



I actually think the days of human space flight are numbered right now.

If that is indeed the case, then the days of the human species are numbered. :( did you know that 99% of all species that ever lived on the Earth are now extinct? Just how friendly do you think this planet, this solar system, hell even this universe is?

We have two choices - spread out into the universe (and if possible, colonise other universes) or become extinct like almost every other species that lingered too long on this planet.

[Schrödinger's Cat]

Remember: even the big bang theory has been open to alternative criticisms in the past year pertaining to an infinite life cycle (http://www.princeton.edu/pr/pwb/02/0506/0506-cyclicuniverse.htm). I personally think of it as supplementary idea (and devastating to Abrahamic faiths), but regardless - criticizing Hawkins and Einstein isn't absurd.

Assuming FTL (faster than light) travel is implausible, interstellar travel would probably necessitate a Lorentzian wormhole (http://en.wikipedia.org/wiki/Wormhole). Reassembling one's person (including memory) through a teleportation device doesn't seem feasible to me. You would probably have to destroy the original organism and instantaneously create a new one with the stored information. Dan Simmons speculates about this idea in his fictional masterpiece, Hyperion. It's wonderful for anything in the "short" realm (Tokyo to Rome), but you would still need to find a way to transport information faster than light.

There's also the problem of cause leading to effect. If something can travel faster than light, you should be able to go back in time. Some scientists have made the claim (http://news.bbc.co.uk/2/hi/science/nature/781199.stm) that they sped up C, but in terms of scientific credibility their results are still dubious.

I can't speak on behalf of ET, but I presume transport like this will not occur for hundreds of years. Planetary and solar colonialization will probably be an 'immediate' consequence of space tourism, or an arms race.

[RebelDog]

Me: I have my doubts whether humans or any other advanced biological life would travel vast distances in space.

NoXion

Why?Because as I have said it would be easier, safer and cheaper to send robots. By the time we are likely to be advanced enough to travel meaningfully in space robots will have become more intelligent than humans. Where the reason for the voyage is exploration to find habitable planets or exploitable resources, it would be more sensible because we would have to send many probes to many places for long periods of time. Human space travelers would increase the cost of and thus reduce the possibility of success. It might be that just robots travel in space, or a mixture of humans and robots but I do not see the sense in sending humans vast distances in space when robots could do a better job. Of course, once habitable planets/resources were located then humans could travel there. It might be that biological life will give way to technological life in any case and the robots no longer need humans in any way and think for themselves but that of course is a controversial idea and may never take place.


Because robots aren't humans, unless you gift them with human consciousness, in which case if you're going to do that you might as well send humans in some form or another.

And besides, sooner or later we have to send some of our kind out of the solar system - it's not going to be a cosy, inhabitable place to live for long, cosmologically speaking.Obviously I talk of sending robots for the benefit of the human race and not to replace them. I think the earth is good for a long while yet, that is if we can emerge from the other side of global warming, but that would get us before we can escape to another planet.


If that is indeed the case, then the days of the human species are numbered. :( did you know that 99% of all species that ever lived on the Earth are now extinct? Just how friendly do you think this planet, this solar system, hell even this universe is?

We have two choices - spread out into the universe (and if possible, colonise other universes) or become extinct like almost every other species that lingered too long on this planet.No other species has ever been able to exploit nature like the human race and we get more powerful as time goes on. Once class society has gone the last great dialectical contradiction will be between the human race and nature and hopefully it will go on for billions of years.

[ÑóẊîöʼn]

Because as I have said it would be easier, safer and cheaper to send robots. By the time we are likely to be advanced enough to travel meaningfully in space robots will have become more intelligent than humans.

I see you have a functioning crystal ball... What makes you think advanced artificial intelligence is more easily achievable than better rocket engines?

I mean, we actually have rocket engines and a decent idea of how to support humans in the airless vacuum of space, but we don't yet have an inkling of how to create an artificial intelligence smarter than a simple insect.


Where the reason for the voyage is exploration to find habitable planets or exploitable resources, it would be more sensible because we would have to send many probes to many places for long periods of time. Human space travelers would increase the cost of and thus reduce the possibility of success.No, that doesn't follow at all. The success of a given mission in space is independant of it's cost. It was costly to send men to the Moon but only one of the missions (Apollo 13) was a failure, and even then no lives were lost.


It might be that just robots travel in space, or a mixture of humans and robots but I do not see the sense in sending humans vast distances in space when robots could do a better job.Because you can't actually colonise other star systems without sending humans in some form or another.


Of course, once habitable planets/resources were located then humans could travel there. It might be that biological life will give way to technological life in any case and the robots no longer need humans in any way and think for themselves but that of course is a controversial idea and may never take place.As a transhumanist I think it is in the interests of the human species for expeditions into the great unknown to not be composed of wholly biological or robotic crew.


Once class society has gone the last great dialectical contradiction will be between the human race and nature and hopefully it will go on for billions of years.There is no "dialectical contradiction" - dialectics is mystical rubbish dressed up (sometimes) to look like materialist reasoning. Nature provides both obstacles and assistance to human development, the universe is not in black and white "contradictions" but in shades of grey.

[RebelDog]

I see you have a functioning crystal ball... What makes you think advanced artificial intelligence is more easily achievable than better rocket engines?

I mean, we actually have rocket engines and a decent idea of how to support humans in the airless vacuum of space, but we don't yet have an inkling of how to create an artificial intelligence smarter than a simple insect.
I don't have a crystal ball, like you I have an opinion.
Rocket engines are fine for very localised space travel, ie the Moon and possibly Mars but surely for anything meaningful like searching for other habitable planets across vast distances they are completely obsolete. Powered space flight needs to make a jump forward from the sixties.

Where robots are concerned their intelligence and worth to humans is rapidly increasing.


No, that doesn't follow at all. The success of a given mission in space is independant of it's cost. It was costly to send men to the Moon but only one of the missions (Apollo 13) was a failure, and even then no lives were lost.
I'm calculating that sending advanced probes or intelligent robots would reduce the cost overall due to the fact they do not need lots of resources to function and would not need to be rescued if they came in to trouble.
The chances of finding what we need in space could be increased by sending more robots/probes than less human missions.

The moon missions were different, we basically knew what to expect and also the moon is very close and easy to get to. Exploring the galaxy and beyond is a whole different kettle of fish.


Because you can't actually colonise other star systems without sending humans in some form or another.We have to first find something to colonise and robots can fulfill that function. I have no great aversion to human space travel per-se, I believe we should be pragmatic and use technology and resources efficiently and sensibly. I just think that in this stage of human space exploration manned space flights are going to be few and far between because they are actually unnecessary.

[ÑóẊîöʼn]

I don't have a crystal ball, like you I have an opinion.
Rocket engines are fine for very localised space travel, ie the Moon and possibly Mars but surely for anything meaningful like searching for other habitable planets across vast distances they are completely obsolete. Powered space flight needs to make a jump forward from the sixties.We have plenty of propulsion technologies that we can develop in order to make a first step out of our own solar system. We just need to implement them.

Project Orion (http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29) offered us a chance to develop a heavy-lift launch vehicle as well as a more powerful propulsion system. Should the Partial Test Ban Treaty of 1963 ever be lifted then without a doubt this avenue will be explored. This (http://orbitalvector.com/Deep%20Space%20Propulsion/Nuclear%20Pulse%20Drives/Nuclear%20Pulse%20Drives.htm) page has more details on similar propulsion schemes including links to further pages.

Plasma Rockets (http://orbitalvector.com/Deep%20Space%20Propulsion/Plasma%20Rockets/Plasma%20Rockets.htm) such as the Magnetoplasmadynamic Thruster and the VASIMR (http://en.wikipedia.org/wiki/Variable_specific_impulse_magnetoplasma_rocket) are being researched by NASA; this includes Ion Drives and Hall Thrusters which are already a proven technology.

We've actually created antimatter in particle accelerators. This raises the distinct possibility of Antimatter Rockets (http://orbitalvector.com/Deep%20Space%20Propulsion/Antimatter%20Rockets/Antimatter%20Rockets.htm), especially those designs which use a minimal amount of antimatter such as the ICAN micro fusion/fission propulsion scheme being studied by the Pennsylvania State University and is being soncidered for a future Mars mission.

Of course, if all else fails we have trusty fission rockets such as the Gas Core (http://en.wikipedia.org/wiki/Gas_core_reactor_rocket) or Nuclear Thermal (http://en.wikipedia.org/wiki/Nuclear_thermal_rocket) engines. Or Mass Drivers (http://en.wikipedia.org/wiki/Mass_Driver#Spacecraft-based_mass_drivers).

There are loads more engine designs and schema on this page (http://www.projectrho.com/rocket/rocket3c2.html).

Now tell me, what potential advances are there in the field of artificial intelligence? Is there anything as potentially feasible as the aforementioned technologies?

I contend that the problem of crossing interstellar distances is less of an obstacle than developing a fully-fledged AI.


Where robots are concerned their intelligence and worth to humans is rapidly increasing. I think you are confusing processing speed with intelligence. It is true that computers are getting faster every year, but we have yet to create anything that could sensibly be called sentient let alone sapient.

And some kind of autonomy will be absolutely essential for any robotic probe sent out of our solar system - the signal delays at such distances will make anything resembling remote control practically impossible.


I'm calculating that sending advanced probes or intelligent robots would reduce the cost overall due to the fact they do not need lots of resources to function and would not need to be rescued if they came in to trouble.Judging by your previous comment and this one, you clearly underestimate the true scale of an interstellar mission. If an interstellar mission gets into trouble, the odds are they will be millions of kilometres from Earth and far from any possible help that we could render to them. An insterstellar vessel would be designed to be completely self-reliant and to be able to deal with any and all foreseeable emergencies.


The chances of finding what we need in space could be increased by sending more robots/probes than less human missions.Scouting is fine, but you seem to be assuming that interstellar colonisation is out of the question (comments like "I have my doubts whether humans or any other advanced biological life would travel vast distances in space" and "I actually think the days of human space flight are numbered right now" lend weight to my suspicions).

In any case, the more humans we send into space, the more experience we will have in actually living in such conditions.


The moon missions were different, we basically knew what to expect and also the moon is very close and easy to get to. Exploring the galaxy and beyond is a whole different kettle of fish.We know what to expect when it comes to interstellar space, and our initial exploration of our own solar system will teach us how to best get around the planetary systems of other suns. It's not like we're completely ignorant of what's out there - it is the same universe after all, with the same physical laws and such.


I have no great aversion to human space travel per-se, I believe we should be pragmatic and use technology and resources efficiently and sensibly.This is exactly the same language the stay-at-homes who would have us go nowhere would use. Who defines what "pragmatic" and "sensible" use of technology and resources is and why should we listen to them?


I just think that in this stage of human space exploration manned space flights are going to be few and far between because they are actually unnecessary.They are the furthest thing possible from unnecessary! We need as much data and practical experience in living, working and playing in space as we can possibly get. The sooner we get to getting off this planet for good the better.

[Peacekeeper]

Well, that rather depends on what form of interstellar travel turns out to be practical. A number of proposed methods include:

1. "Generation ships" massive vessels carrying viable breeding communities - on the centuries-long trip, people are born, have kids, work, play, and die of old age. A variant of this is the "Cross-generation Ship" (http://en.wikipedia.org/wiki/Cross_generation_ship)

2. The "Seed Ship" concept to which I linked to earlier. Typically containing millions of preserved fertilised eggs, artificial wombs to grow them in, robotic surrogate parents and a master computer. Some Seed Ship concepts also include the preserved seeds of plants and trees as well as the fertilised eggs of various animal species, so that a human-friendly biosphere can be built at the destination.

3. Perhaps a more extreme version of the previous is to "digitise" the whole crew, whereby the ship's computer runs detailed simulations of the crew members on the journey and places them into artificial bodies at the destination.

4. "Sleeper Ships" hold all or most of the crew in some kind of suspended animation during the journey, reducing the amount of resources needed sustain the crew. Some concepts postulate a handful of crew members being woken up on a shift basis to ensure the smooth running of the ship.

5. Perhaps some way can be found to massively slow down human metabolism and perception, perhaps to 1/1000th of normal speed. So on a ship travelling at 10% to Alpha Centauri, the trip only seems to take a few weeks to the slowed-down crew.

6. Another way of getting round the fact that a typical interstellar journey is likely to take decades if not centuries, is to extend the natural lifespan so that such long journeys take out a much smaller chunk of one's life. In this case, long insterstellar journeys become more of a problem of boredom than enything else.

I learned about these during my childhood of reading hard science fiction.
That being said, a Generation Ship would be the easiest to organize at this point in time. :)

[Dr Mindbender]

Travel through space, to our shit-hole.
There is a speed limit, that of light-- if you go at the speed of light, or faster than it, you turn into gamma rays. How can these rays be recombined into the humanoid and mechanical forms?

Also, say these aliens travel through our atmosphere, is it possible they are travel so fast we cannot see them nor detect them with radar?

It may be impossible to travel faster than the speed of light, however the wormhole (http://en.wikipedia.org/wiki/Wormhole)theory is yet to be disproven.

Also, there is the option of cryogenics.