I've always loved science fiction, but it wasn't until 2006 that I picked up "Revelation Space," the book that transformed me from a casual fan to a dreamer.
I was electrified -- here was an unblinking look at what the human race might look like more than 600 years from now, written by a former astrophysicist who has the writing chops of a gifted novelist. This was a story about water worlds enveloped in sentient biomasses that could absorb the neurological structures of beings swimming in its oceans. It was a story built on physicist Enrico Fermi's famous paradox -- that, given the sheer number of star systems in our galaxy, the Milky Way should be teeming with intelligent life, not the lonely, dark void we've observed all these years.
It was a story about sinister "artilects" of unknown provenance, of advanced civilizations that had transcended ordinary existence by escaping into pockets of folded space-time, of heavily modified human beings crossing the interstellar void aided by cryopreservation and relativistic time dilation. It was a story about astroarchaeologists digging up the remains of long-dead alien cultures, of biology fused with nanotechnology, and most of all the deep mysteries of the universe and the sense that literally anything can be out there.
"Revelation Space" is geneticist J.B.S. Haldane's famous quote incarnate: "The universe is not only stranger than we imagine, it is stranger than we can imagine."
And that's why, in a world where millions of people hang on every Twitter utterance and every Instagram selfie posted by a Kardashian, completely uninterested in the mind-blogging mysteries of the universe, we need people like Elon Musk.
Musk is a dreamer, too. While he made his money as a dotcom entrepreneur, his heart has always belonged to the allure of space exploration and humanity's destiny among the stars. He's the rare billionaire who would rather spend every last dime he has trying to push the human race off our home rock than kick back and spend the next few decades sailing a yacht.
That's why it pains me to say that Musk's recent announcement -- that he'll get humans to Mars within six years -- seems to come from Musk the dreamer, not Musk the shrewd businessman. There are simply too many challenges, too many unanswered questions.
The first question might seem too obvious to ask: Why Mars, and why not the moon? In all, there have been six manned missions to the moon. The last one, Apollo 17, was in 1972.
Musk says his ultimate goal is long-term habitation, the establishment of a permanent colony on Mars. There's no reason why that plan can't be modified for a test run on the moon, and there are good reasons to opt for our closest neighbor.
First, humanity has to learn to walk before it can run. A manned mission to Mars would take about eight months, according to NASA. By comparison, it took the Apollo crews about three days to reach the moon.
That's crucial because, if something goes wrong, there's hope for visitors or colonists on the moon. But if something goes wrong on Mars, it's a death sentence. "The Martian" may have made for good drama on a movie screen, but there's no way to "science the s--- out of" the unforgiving red planet, as Matt Damon's character famously declares in that movie.
If Musk wants to skip the moon and jump directly to Mars because the moon isn't sexy enough for this generation, he's making a big mistake, a mistake that will cost lives.
Then there are the practical challenges of sending people to Mars, which is completely different from sending unmanned probes and rovers. Elizabeth Lopatto, science editor of The Verge, points out that Musk minimizes problems like radiation and seems "wholly uninterested in food or habitat." He's much more interested in building a ship than he is in figuring out how people can survive the journey and eke out an existence on the red planet when they get there.
But, Lopatto argues, "those soft, messy biology problems Musk is ignoring are the critical problems, the ones that are truly difficult for long-term Mars living. A rocket explosion is the exception rather than the rule these days. But space is tough on the human body."
There are fundamental challenges to establishing a permanent colony that are much more difficult to tackle than the problem of getting to another planet. They range from the practical -- growing crops, addressing basic biological functions -- to concerns about psychology, social relationships in permanently tight quarters, and how the human body might respond to long-term existence in low gravity.
In an age when government space programs like NASA are critically underfunded and there's no international rivalry to fuel space exploration, people like Musk are critical to reminding the rest of us that there's a whole universe out there to explore, and the first step in that process is mastering our own backyard, the solar system.
Musk and his allies might get people to Mars, but it probably won't happen within six years.
That doesn't mean Musk's efforts will be wasted. If his vision gets even a few people to look away from the Kardashians and up into the sky at night, wondering what's out there, it'll be worth it.