Soylent Green got me thinking...

Last week I made the dubious decision to watch the classic film Soylent Green.  Unlike most science fiction, which becomes dated in a few years, Soylent Green has only become more relevant—and more urgent.  Sure, the hairstyles and film techniques are distinctly '70s, but the content of the film is more agonizingly prophetic than ever.

Set in the year 2022, Soylent Green (based on Harry Harrison's novel Make Room, Make Room) is about a futuristic world in which the squandering of Earth's resources, the burning of fossil fuels, uncontrolled overpopulation, destruction of the forests, pollution, and urban sprawl have turned the world into a living death.  Baked and stifled by the greenhouse effect, starving from lack of food, people have no privacy, no hope, no physical comfort, and no future.  The world is choking itself to death.

When I first saw Soylent Green in the 1990s, when it was over I rushed to the window, took a deep breath, and reassured myself that it wasn't real.  But last week I had the disconcerting feeling that it was coming true—all too quickly.

For those few who don't know how the movie ends, when Charlton Heston learns the terrible secret of the Soylent Corporation, he divulges to his boss:  "The oceans are dying."

That line struck a resonant chord for me.  Even today, the oceans are absorbing so much carbon dioxide from the burning of hydrocarbons that they are becoming acidic—thus killing the bacteria at the bottom of the food chain.  It doesn't take a genius to figure out the consequences.

Depressed, disheartened, and near panic, I comforted myself by watching another, more optimistic piece of science fiction:  Star Trek (specifically the 1967 episode "Amok Time").

Not for the first time it occurred to me that the two pieces of science fiction offer diametrically opposite visions of the future, and the critical difference between the two is—wait for it—space flight.

It's not far off the mark that we have a choice between those two futures.

The Earth now supports at least five times as many people as it can naturally sustain, and the number keeps rising.  Not only does population keep growing, but there is no serious attempt in any quarter to check that growth—on the contrary, our political, economic, and religious systems are based on continuous exponential growth.

Even without the global warming crisis, the world's supply of fossil fuels is being depleted.  Estimates vary as to how much is left, but no one can dispute that the supply is finite, and obviously a finite supply of anything will eventually depleted.  As we continue to use fossil fuels at an exponential rate, the existing supply—even if it's more than the total of what we've already used throughout the industrial age—cannot last much longer.

The United States has been remarkably fortunate in avoiding famine, but we're starting to see depletion in crops due to drought, wildfires, and storms.  But even as the United States remains relatively prosperous, other places in the world face widespread starvation.

In short, Earth has gotten too small for us.

So can space flight solve overpopulation?  Probably not.  Space launch costs are still prohibitively high for a mass migration from the Earth.  Even if, as many space enthusiasts hope, we build a space elevator, where would hordes of space migrants go?

The Moon and Mars are possibilities, but since neither is habitable, it will be a long, long time before enough space is available there to support large percentages of Earth's population—and in the meantime, Earth's population will continue to grow exponentially unless other steps are taken to mitigate it.  (What steps might those be?  Enforced birth control?  Mass executions?  Certainly not possibilities the public would embrace!)

However, although space flight cannot solve overpopulation, it can at least provide a relief valve.  If we establish a colony on the Moon, and eventually Mars—and as those worlds become more habitable as Earth becomes less habitable (more on that later)—at least there will be somewhere for people to go to escape the Earth.

But if we're killing the bacteria at the bottom of the food chain, isn't this all moot?  Aren't we all going to die anyway?  Isn't the nightmarish vision of Soylent Green bound to overtake and destroy us?

Well, as bleak as it can look sometimes, my answer is . . . nah.  Soylent Green is a worst-case scenario.  Humans are very good at causing crises, but we're equally good at solving them.  But once again, the solution could well be found in space technology.

One of the most frequent responses when space flight is criticized is to cite the many "spin-off" technologies—pacemakers, desktop PCs, smoke detectors, ergonomic beds, etc.  But perhaps the most vital "spin-off" technology will be the means to save the Earth.

The International Space Station is a closed system.  Everything must be recycled and reused.  The Environmental Control and Life Support System (ECLSS) turns the astronauts' breath into breathable oxygen, and their urine into potable water.  Though not exactly palatable for the squeamish, it's a science fiction aficionado's affirmation:  sci-fi was right again!

Although food still has to be delivered to the ISS by cargo ships, water and oxygen are regenerated.  There's no reason the same could not be done on Earth.

When (if?) we go to Mars, unless a breakthough in space propulsion shortens the trip to weeks instead of years (which is possible), some method of food recycling will have to be developed.  Just as urine is recycled into drinkable water, so feces could be recycled into food.  If you can stifle the gag reflex, just consider that this is exactly what nature does.  Animal waste fertilizes the soil, animals eat the plants, we kill and eat the animals.  Direct recycling of waste into food would be not only more direct, but actually more sanitary, because the threat of foodborne illnesses is eliminated.  The ethical quandary of having to kill to survive is also averted.

None of this is to say it's okay to go whole-hog and destroy the Earth's ecosystem because technology can solve our problems—first of all, we're not there yet, and secondly, the despoiling of our native world still has dire consequences even if we manage to pull ourselves from the brink of extinction.  If we're going to survive, perhaps it might be nice to survive in a pleasant world.

Which takes me back to the Moon and Mars.

Right now, there's nothing pleasant about either world.  A mere two days on the Moon convinced Alan Bean that he is delighted to live on so beautiful and crowded a planet as Earth.  The Moon is bombarded by fierce sunlight, micrometeoroids, and radiation.  Mars is a lethal boiling pot of ultraviolet rays and cosmic rays.  There's no oxygen, no free flowing water.

Any base on the Moon will have to be well shielded, most likely underground—or at the very least, coated with a thick layer of dust.  John Young, who commanded the historic Apollo 16 Moon landing mission, has a lot of interesting ideas on lunar colonization, which can be found in the audio commentary of the fine documentary The Wonder of It All www.amazon.com/The-Wonder-All-…

Science fiction writers have often talked about "terraforming."  Star Trek fans will immediately recall Project Genesis from Star Trek II: The Wrath of Khan.  In fact, terraforming is completely feasible, and doable with today's technology.  For details, I recommend Robert Zubrin's The Case For Mars www.amazon.com/The-CASE-MARS-R…

In short, the temperature of the Martian south pole would need to be raised a mere five degrees.  There are a number of ways of doing that, but the most practical would be to set up a mirror in space to reflect the sunlight onto the surface.  As the frozen carbon dioxide evaporates, it would cause a chain reaction—the more carbon dioxide is released into the atmosphere, the more infrared radiation from sunlight would be trapped by the greenhouse effect, which in turn would melt more of the polar ice.

If this sounds familiar, it's because it's exactly the same thing that's happening on Earth due to the burning of fossil fuels.

It's interesting that the same phenomenon that's destroying our planet will make Mars habitable.

Of course, giving Mars a thick, warm atmosphere is only the first step:  it would still be a poisonous atmosphere of deadly carbon dioxide; denitrifying bacteria would need to be added to the soil to slowly remove the oxidization that makes it impossible for anything to grow there—but it seems increasingly likely that there's water on Mars, which will save us a lot of trouble.

After that it's a matter of creating a biosphere.  Beginning with small greenhouses, Mars could be slowly modified into a lush, green world.

At our present level of technology, the terraforming of Mars would last a thousand years—but there will certainly be scientific advancements along the way which will speed up the process.

And the more we learn about terraforming other planets, the more we'll learn about terraforming our own.

There are some hopeful ideas about spraying reflective aerosols into Earth's atmosphere or setting up reflective surfaces at the poles or putting mirrors in space to reflect sunlight away from Earth, but those are band-aids, not cures.  We really need to, as politicians endlessly remind us, get off of fossil fuels—and hence the overwhelming opposition by the oil giants even to the existence of global warming, or at least that human activities have anything to do with it.

I won't get into the political debate here.  The science speaks for itself.  But are solar and wind power viable alternatives to fossil fuels?

As we approach the end of the fossil fuel age, we are more and more concerned about "clean" energy sources.  Nuclear power is widely embraced, though what will become of the highly toxic spent power rods is an issue that must be addressed by anyone thinking of the long-term.  Solar and wind power are today's hot topics, but both are afflicted by one critical flaw:  they are difficult to store for later use.  Wind farms collect most of their energy at night.  Solar panels obviously can only collect sunlight when the Sun is out.  Although numerous corporations and individuals are working on ways around that problem, the Moon offers something exciting:  microwave power.

The lunar poles are in perpetual sunlight.  A power station on the Moon could convert sunlight into microwaves and beam those microwaves to power stations on Earth.  Unlike sunlight, microwaves are not blocked out by clouds, and can easily be stores over long periods.  Such an approach would mean a redesign of our electrical grid, but that would not be a bad thing.

One of the methods for storing solar power is electrical energy storage, which would make use of the existing electrical grid.  Unfortunately, the electrical grid is extremely vulnerable; each electrical station must manually maintain a precise balance between supply and demand or there will be a power loss; and the grid is completely vulnerable to an electromagnetic pulse which could be triggered either by a small nuclear warhead exploded in the upper atmosphere or by a major solar storm—both of which are very real, perhaps imminent, possibilities.

A hardened electrical grid would, therefore, be yet another benefit of the permanent colonization of  the Moon.

Unfortunately, getting to the Moon is still difficult, expensive, and dangerous.  But there is a technology that could change all that, and in fact open up the Solar System.  That is the space elevator.

First proposed by Konstantin Tsiolkovsky in 1895, the space elevator has since been popularized in the works of Arthur C. Clarke, Charles Sheffield, Larry Niven, and numerous other science fiction writers, and so I need not describe it in too much detail.  Basically the space elevator would consist of a tether leading from a satellite in geosynchronous orbit all the way to the surface of the Earth.  An electrical elevator would climb up the tether, hauling cargo or people or both from Earth into space with no expenditure of fuel and at virtually no cost.

Today the space elevator is still in the theoretical stage, though carbon nanotubes and grapheme ribbons are contenders for suitably tensile and electrically conductive cables.  There are matters of physics to be overcome, but the one-time expense of building a space elevator would certainly be worth the benefit of permanently shedding the cost and danger of rocket launches—as much as a shame it would be to lose the coolness factor of a good, loud, old-fashioned rocket.

Astronaut Edgar Mitchell pointed out, "every measure of human activity is on an exponential growth curve.  And it doesn't take a genius to figure out that exponential growth can't continue indefinitely in a finite space."

Earth is a finite space—the Universe is not.

So space flight can be economical, it is certainly beneficial, and in the long run it is vital to the survival of the human race.  It's certainly a better picture than the bleak and horrifying images of Soylent Green.