I’ve previously said that humanity has no viable alternative to Earth. Until I see a successful Biosphere-like experiment (building a sealed box and living in it, with only energy as input) I have no reason to doubt this. We simply do not know how to survive, long term, without Earth. Not even through entirely synthetic means — not even if we were willing to survive indefinitely on some manufactured nutrient-sludge.
If you don’t believe me, look at this page describing the nutrient cycling on the International Space Station. Below is a from that page. See the labels, ‘overboard venting’? That’s matter being lost to space that will need to be replaced eventually. Also, many of the processes depicted require ingredients and generate wastes that are not explicitly depicted. I don’t think any space mission has generated its own food, for example. We don’t know how to plant people inside bottle gardens.
So my political position is that space colonization ([hu]manned space exploration) is not a priority for our long-term survival: our first priority should be to learn how to live in a sealed box indefinitely, like a human bottle garden. This will mean we understand how the Earth sustains us, using (mostly) sunlight as a fuel source. Only then should we consider living on Mars or anywhere else. Many people disagree with me, some who are very smart, like astrophysicist Stephen Hawking:
“We are entering an increasingly dangerous period of our history…Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill. But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million…Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space.” [source]
Colonizing one of our neighboring planets offers one of those ‘living in a sealed box’ scenarios. As I said, nobody knows how to do that, even if we wanted to. But once we figure that out, a planet like Mars is available to let us live in sealed boxes while we attempt to manufacture an atmosphere (probably over hundreds of years). I call that the most-likely-space-colonization scenario. It would be like living on the space station, but with gravity, and sunrises. If we tried to do it today, and we didn’t routinely ship supplies from Earth, the colony would simply fail.
So maybe we should colonize some other planet, one with air, water, and dietary minerals. We’re light-years away from the closest extrasolar planet (about 15 light-years, or 141 trillion kilometers). So a spaceship traveling at the speed-of-light would get there in 15 years; at 600 mph (something like airplane-speed) it would take 168 million years. We need Star Trek-grade spaceships to travel that far in a reasonable time.
Long-term space travel is another one of those ‘living in a sealed box’ scenarios. Using more Star Trek source material (Aliens, actually), the space colonialists would likely hibernate or be frozen (in their underwear). But that’s science fiction; we can’t immortalize ourselves with a deep freeze. We don’t know how to cryogenically preserve people and to thaw them correctly. We cannot launch our flash-frozen colonialists into a brave new bottle garden. But I think the freeze/thaw technology is a lower hanging fruit than Star Trek‘s ‘warp drive’ allowing faster-than-light travel.
Under the theory of ‘general relativity,’ faster-than-light travel is impossible, and material objects cannot travel at the speed of light. But the (very successful) theory of ‘quantum dynamics’ is widely known to contradict general relativity, meaning one or both of the theories will eventually be replaced by a better one. All this “was Einstein wrong” hullabaloo you’re seeing in the media reflects the ongoing efforts of scientists to test the predictions of general relativity (and the media’s persistent tendency to recast genuine scientific progress as a pissing contest).
Stephen Hawking is famous for his proposals on ways to make these two foundational theories complement each other, so maybe he’s making a bet that people will figure out how to overcome our current limitations. Hawking is one of the people actually smart enough to place odds on the chances of developing faster-than-light space travel in the next 1000 years. But Hawking is wrong when he says that humanity should evacuate the Earth to avoid a disaster. It would perhaps be comforting to know that, should an asteroid destroy Earthbound humanity, that the Martian humans would soldier on. But for now, a Martian colony would not be able to self-sustain, not before we now how to self-sustain on Earth.
So it would be great for us to build an enormous Martian bottle garden, and to lurk in it while we build an oxygen atmosphere on Mars. Maybe Mars would be colonized by nice people who cooperate and harmonize (all the mean people get left behind). Maybe Martian people would somehow overcome the “selfish and aggressive instincts” that Steven Hawking invokes to justify abandoning Earth. But I wonder why Steven Hawking wants us to lurk in a Martian bottle garden so much.
I do think he’s right when he says humanity is in increasingly dangerous times. When people take seriously the notion of jettisoning the Earth, these are dangerous times indeed.
Ryan MB Hoffman has a B.Sc. in Biochemistry from Queen’s University in Kingston, Ontario, and a Ph.D. in Biochemistry from the University of Alberta in Edmonton, Alberta. He is mostly interested in how protein molecules fluctuate throughout their functional processes. During his doctoral work he studied troponin, which is a switch that regulates striated muscle contraction. He works as a post-doctoral scholar at the University of California, San Diego, at the Center for Theoretical Biological Physics. He is active with the Intrinsically Disordered Proteins subgroup of the Biophysical Society. Ryan likes to remind people that his contributions to TRN are performed entirely using his personal resources.