Prior to space flight we, in our ignorance, had created myths regarding our moon and nearest planets and today we are creating myths and fantasies about deep space. We envisage other races, mostly human in form and oddly enough most speaking English. We fantasize about traveling to other star systems as easily as one might travel across town to visit a friend.
Yet, just as our myths of Amazon women on the moon were dispelled when we first landed there our myths about other species among the stars and traveling about the galaxy in the blink of an eye will be dispelled. In fact, with remarkable advances in astronomy and our ever increasing knowledge of the laws of physics and the limitations of nature we can dispel many of these fantasies now.
By our most conservative estimates to date we can surmise that there are millions of planets circling the stars of our galaxy. The Kepler mission to detect planets surrounding about 100,000 stars in the constellation Cygnus has, in only few months of operation provided us with 1,235 possible planet candidates to add to the 552 extra-solar planets we have already confirmed exist. Given that Kepler is only looking at .25% of the sky we can extrapolate that number to 494,000 planets. And Kepler can only detect planets that cross in front of their parent star so that small number swells to millions if we consider planets orbiting at a different plane than edge on to us.
Even with these discoveries of extra-solar planets the nearest earth-like, that is rocky, planet we can find in a Goldilocks zone (not too hot and not too cold) is 20.3 light years away. Gliese 581 g may theoretically be suitable for life although the planet is over 3 times the mass of Earth.
A few years ago a message was sent to that star system by radio astronomers. Let’s speculate that we get an answer back from an intelligent civilization. We would receive a response 40 years later. It would be a little difficult to carry on a conversation, even at the speed of light. So could we possibly travel to Gliese 581 g?
The British Interplanetary Society speculated on sending a 450 tonne unmanned payload to Barnard’s star which lays only 6 Lys away. They calculated that a vast spacecraft 190 meters in length weighing about 50,000 tonnes and powered by internal confinement fusion could reach a velocity of about 12% c and reach Barnard’s star in about 46 years. It wasn’t designed to decelerate and be put into orbit so double that time if you want your payload to stay there. So an unmanned scientific mission to Barnards’ star would take about 92 years. The same vessel traveling to Gliese 581 g would take 307 years.
If we were to send a manned vessel it would have to have to be a generational ship where people would be born, live, and die for many generations before it reached its destination so it would have to be orders of magnitude larger and therefore requiring much more fuel and would take instead of 307 years perhaps tens of thousands of years to reach only the nearest earth like planet.
The cold hard reality is that one cannot propel any appreciable quantity of matter anywhere near the speed of light so a visit to any nearby star is absolutely out of the question not only with the crude technologies we have now but with near-future technologies like internal confinement fusion.
But what about such exotic notions like warping space, anti-matter engines, worm holes etc.? These are pure fantasy, just like Vulcan mind melds. The only thing we know of that can warp space is matter, and gravity is so weak just consider this: Every time you lift your arm you are defeating the gravitational pull of the entire planet. That’s how week our own massive planet warps the space around it.
Worm holes exist only as speculative mind games of cosmologists and even if they did exist to “enter” one would crush you and your ship to an infinitesimal size.
No, traveling to the stars will have to be left to our far distant offspring who would be living in vast vessels probably not too dissimilar to science fiction’s Babylon 5 space station. It would roam interstellar space taking tens of thousands of years to visit even the closest of stars. Once there they might colonize any habitable planets or even terraform what uninhabitable planets that may be there. More likely still is that they would not see the necessity of leaving their space station home.I do not envisage humanity leaving our solar system for countless thousands of generations to come.
I don’t consider this a pessimistic view. I consider it a practical view given what we know of the laws of physics. If our knowledge of these laws change it will have to be an entire paradigm shift in thinking which is not out of the realm of our imagination but to speculate that our current knowledge of physics is far off the reality mark and that the true nature of the universe has yet to be discovered and such a discovery would allow us to travel to other planets as easy as thinking about it is without merit. There is nothing to suggest that we can warp space or exceed the speed of light. There is nothing to suggest that what we know about the laws of physics is so incorrect that the fantasies of a show like Star Trek can be realized.
What we can do however is something that may give us a vicarious trip to other worlds and possible extra-terrestrial civilizations. Given the current rate of astronomical invention and discovery even using known laws of physics we should soon be able to image the thousands of planets that exist near us in space and although it may be tediously slow to communicate with any intelligent life we may find out there, an exchange of information with extra-terrestrials may be possible, if and when we find them and if they consider it in their best interest to tell us about themselves.
A more reasonable approach to off-earth colonization won’t involve travelling by the fictional “soliton waves” of Star Trek: The Next Generation or by focusing thought though some kind of lens, it will involve propellants that don’t defy reason and logic.
Chemical rockets can get us to the moon and I have no doubt that within a reasonable amount of time, say 200 hundred years or, so we may have a sizeable permanent habitat there. But I don’t think that what is going to drive colonizing the moon will be government or resource mining, it will be tourism.
To date there have already been 7 space tourists including one Canadian, Guy Laliberte, the CEO of Cirque du Soleil. Each has paid as much as $35 million to ride about the International Space Station as a guest of Russia.
It will be people like these who will bankroll a space tourism industry which will see routine sub-orbital flights for people wishing to experience free-fall, space station hotels for extended stays and a chance to get into the 100 mile high club and eventually hotels on the moon. The money these tourists pay for such adventures will allow offshoot industries to help build and maintain the space stations and the moon habitats and these off shoot industries will have to house the workers and support staff. The moon’s first permanent settlements may start out resembling any small adventure tourist destination here on Earth.
Following such small steps we may find the mega rich willing to fund tourism to Mars although such a technical undertaking may take several hundreds of years to get to the level where it can be done routinely.
Aside from the moon and Mars I believe that there are no other destinations in our solar system which merit any form of permanent habitat primarily due to the extremely hostile nature of every other planet and moon.
This being said I do think that the majority of off-world colonization will be in space stations which may be set up in orbit around the other planets and their moons.
Practically speaking I see the colonization of our own solar system happening, yes, but happening very slowly, perhaps taking several thousands of years.
In the far distant future we may one day terraform Mars, making an atmosphere thick enough to live in without a space suit and perhaps even breathe without an oxygen mask. This process will, from my understanding. take tens of thousands of years but I believe it most likely will be done.
Any such grand adventures will only occur with private industry running the show and government protecting their right to do so. But eventually we will have two planets to call home and several, perhaps hundreds or thousands of enormous self-sustaining space stations orbiting every celestial body in the solar system and some even venturing out into deep space to slowly and gradually add to an ever expanding sphere of humanity.
(Originally broadcast on Just Right #201, May 26, 2011)