Monday, August 25, 2008

Threats to our Future

This post contains a list of what I consider to be the most serious threats to the future of humanity, as of today. It should be considered an incomplete and open-ended list; I'm certain that each of us can think of additional threats.

Note that I'm not considering threats to our civilization and/or way of life. There are many more of those. Rather, I want to limit this discussion to threats that can end all human life.

There are four main categories in two dimensions: the first dimension is simply natural disasters or man-made ones. The second dimension is things we can control versus things we can't. There may not be any entries in the list for "man made disasters we can't control", so perhaps we should qualify that as things we can't fix.

1) Natural Disasters we can't control/fix:

  • Nearby supernova or gamma ray burst or passing black hole: Nothing we can do about any of these, so don't worry about them.
  • Super Flare from the Sun: Our sun won't go nova or expand into a red giant for billions of years, but there is a possibility that it could have a major hiccup and blast the Earth with searing heat or sterilizing levels of radiation. Sea life would survive, as would any people lucky enough to be in submarines. It's too bad those tend to be men only; we also need women to save the species. Solution: co-ed submarine crews.
  • Large Igneous Event: These have caused mass extinctions in the past, and might in the future. Not much we can do here, either, as long as we all live on the surface of the Earth.

2) Natural Disasters we can control/fix:

  • Snowball Earth: At least twice in the Earth's history we have had global cooling so extreme that the oceans have completely frozen over, causing the loss of all surface life, and likely the loss of all oxygen. The solution is simple: Global Warming.
  • Comet or Asteroid Impact: There are millions of comets and asteroids large enough to destroy all human life, possibly all life period on the face of the Earth. Some of these will eventually strike the Earth; this is inevitable unless we take active steps to prevent such a catastrophe. We may have years or millennia before the big one hits, but we may not have enough advance notice to do something about it, unless we start building the infrastructure now. We need a very well-funded Space Watch program to find these objects years before they might obliterate us, and given enough advance notice, current technologies are likely to prove sufficient to avert disaster.

3) Man-made disasters we can't control/fix: (these are things that we create, but have no effective control over, and no natural defenses against)

  • Experiments gone wrong: While I'm a firm believer that nothing will go wrong when the LHC begins operation, I can't guarantee that all scientific experiments will have a similar result. If we knew the results in advance, we wouldn't need to perform the experiment now, would we? For example, if someone managed to create a nanometer-diameter black hole and drop it into the Earth, it would eat away at our planet and grow until it consumed the entire planet -- and there's not a damn thing we could do about it, even if we had hundreds or thousands of years before the disastrous end.

4) Man-made disasters we can control/fix.

  • Nanotech gone bad: While it may be remotely possible to create a self-replicating nanite that will reproduce until all possible resources are consumed, burying humanity in 3 feet of gray goo,this is so difficult that I'm not worried about it. We can't create a reasonably self-powered machine that could live off of the environment at present. We cannot build a complex small machine that can self-replicate. Or even a big machine. In any case, this problem is well described, and guidelines exist to insure that any replicating machine will have limits built into it (such as a critical and rare raw material).
  • Strong, malevolent AI (see The (likely coming) Technological Singularity) poses a very real threat, but one which may be difficult to realize, and one that we could choose to avoid by limiting computers to sub-human intelligence. Even if such an AI existed, there is a possibility of negotiation and co-existence so long as its intelligence and capabilities remain within the grasp of human understanding. But once we have made a machine significantly more intelligent than any human, we risk losing control. We will become the pets, to be neutered and/or put down at the convenience of the AI.
  • Biotech Terrorism: To me, this is the thing to worry about. It is completely within the realm of possibilities that a small group, even an individual, could tailor a virus or bacterium to create an airborne disease of unparalleled lethality, one that was immune to our natural defenses, one that could wipe us all out. My friend Jeff Carlson has written an excellent  techno-thriller (Plague Year) about an engineered viral organism that kills nearly all warm-blooded life on Earth, and the most unbelievable part is that it was designed with a weakness that could be exploited such that we might survive. What if those designers had made a mistake and the self-destruct mechanism failed? Or the bug evolved and the mechanism failed due to a minor mutation?

Did you note the traditional really big things that I don't think threaten humanity?

  • Nuclear War (and the threatened Nuclear Winter): Contrary to the hype we've all heard, we do not have enough nuclear weapons to destroy humanity, or even to create a nuclear winter. Many natural disasters release much more energy or release much more pollution. Yes, we do have the capability of destroying civilization as we know it, and even of killing more than 90% of humanity. But some of us will survive, live on, and rebuild civilization. An all-out nuclear war would merely set us back a few thousand years.
  • Global Warming: Warming up the Earth by 5 or 10 degrees would eventually melt the ice caps, raise the oceans by 200+ feet, drown coastal cities, states, even entire nations. It would radically disrupt the ecology, and hundreds or thousands of species would face extinction. The expense of dealing with such a catastrophe greatly exceeds trillions of dollars. But in the big picture, this is an inconvenience, a forced change. Human casualties would be in the noise range, likely fewer than the toll from malaria.
  • Overpopulation: Another serious problem, overpopulation has well-known natural controls: starvation and disease. Once half of everyone is dead, we no longer have a problem. Works for lemmings, too. The species survives. Note that the opposite problem, underpopulation, is much more serious (if it happens), because it is difficult to recover from the loss of genetic diversity. We'll lose some big cats (such as cheetahs) because they have insufficient genetic diversity to survive a nasty disease.

Please, propose your own threat to the future of humanity.

Thursday, August 14, 2008

Capturing Apophis

Past blog posts of mine have described many aspects of the expansion of human civilization into space.

Today I'd like to focus on the orbital mechanics of capturing an asteroid, specifically 99942 Apophis (aka 2004 MN4).

Apophis is the near-earth asteroid that made the headlines in 2004 because of it's feared potential impact on Earth on Friday, April 13, 2029. Additional observations revealed that Apophis will miss by a hair (passing closer to earth than our geosynchronous satellites), but its orbit will be changed by that close approach such that there is a small chance of an Earth impact on April 15, 2036.

Apophis is a small asteroid, only about 300 meters in diameter (approximately 1,000 feet). This is too small to create an ELE (Extinction Level Event, to borrow a phrase from the movie Deep Impact), but it could devastate an area the size of Connecticut, or strike the ocean creating tsunamis that would kill millions of people and destroy trillions of dollars worth of property. Note that if we do nothing, Apophis will almost certainly strike the Earth some day, although perhaps not for thousands of years. We must take steps to prevent that catastrophe.

Luckily, one method of preventing a future Earth impact is to place the asteroid into Earth orbit, from which a future Earth impact is impossible. The near-Earth pass will result in a gravitational slingshot, changing its orbit.

As it passes near us in 2029, Apophis will be moving approximately 5 km/s slower than the Earth in its orbit around the sun, dropping in toward the orbit of Venus (and ignoring, for the moment, the additional speed it will gain dropping into our gravity well). If we do nothing, the near-miss will speed up Apophis by a few km/s, turning it from an Aten Asteroid (a near-Earth asteroid whose orbit is primarily inside of the Earth's) into an Apollo Asteroid (one whose orbit is close to the Earth's orbit, at least on average).

My own rough calculations indicate that if we speed up Apophis by a relatively small amount, such that it passes even closer to the Earth, then it will gain even more speed from its slingshot around our planet. A deflection into an orbit nearly co-circular with the Earth's will also speed it up to approximately Earth's orbital speed (a 5 km/s velocity increase is needed--well within the range of possibilities). Apophis only needs to reach closest approach about 500 seconds earlier than on the current orbit, still passing 10,000 kilometers above the Earth's surface.

It will have too much speed (due to the earth's gravity well) and will speed away (and outward), but will return to the vicinity of the Earth with a low enough speed that another slingshot around the moon will drop Apophis into Earth orbit. As a result of these two slingshot maneuvers, Apophis will have an orbit whose apogee is near the moon, and whose perigee (closest approach) can be tuned by small adjustments in its orbit before it performs the Lunar slingshot.

Over time, some additional velocity should be removed (by ion thrusters or other propulsion methods) so that its orbit is entirely within the moon's orbit, or some other permanently stable orbit. We don't want it crashing into the moon, either. Apophis is a far too valuable resource to waste.

I'm confident that the orbital changes needed to capture Apophis are within current technology capabilities, although more detailed analysis is certainly needed. And this is an opportunity that should not be missed: a billion dollar mission to capture Apophis will result in a trillion dollar resource in high-Earth orbit, and avoid a trillion dollar catastrophe at the same time.

Apophis masses perhaps 50,000,000 tons. While the largest percentage is oxygen, approximately 20% is metals (primarily iron). It contains large amounts of magnesium and aluminum, and significant quantities of hydrogen (think millions of tons of water). It contains more than enough silicon to build all of the power satellites we'll ever need.

Who could pass that up? If not NASA and the U.S. government, then perhaps the Chinese, or Dubai. Or even private enterprise; this project is well within the funding capabilities of large corporations or even a few individuals. Perhaps Bill Gates would like to have a private moon around the Earth. Or the Disney corporation (I'm thinking Disneymoon), or Hyatt Hotels (I'd love to stay at the Apophis Hyatt some day).

Any takers?

Tuesday, August 5, 2008

The Future of Sex

Yes, there will be sex in the future. You weren't worried about that, were you?

But will technology affect our enjoyment of sex? Will it be like in Demolition Man, where the sex act avoids physical contact and the exchange of body fluids? Or will it be like in (name the movie) where virtual sex is rampant and some people orgasm to death?

Sex toys are one area Moore's Law hasn't affected, but some day that will change in a huge way.

A realistic virtual reality simulation allowing people to experience sex with others (real or imagined) would be worth billions.

While porn would be the early adapter of "feelies", they would change the way all movies are made and presented.

What about virtual sex between virtual people? If our brains are uploaded into computers, I'll bet that someone figures out how to implement virtual sex that is largely indistinguishable from the real thing (at least to the participants).

Or is it truly the same? How will virtual self-representations affect virtual sex? Many people in gaming choose avatars not related to their physical appearance. That might be even more true when it comes to sex play. I'm sure that ED won't be an issue, nor will premature ejaculation. Or size. (Never mind. I was just told that size doesn't matter).

How about sex in space? In space, no one can hear you scream. (No, wrong movie.) In orbit or other zero-gravity environments, sex would be more difficult, a challenge. As I point out in Apophis 2029, while possible, sex in free-fall is awkward and likely tiring. It's still worth the effort, I'm sure, but it is different. Straps, hand-holds, and surfaces to thrust against would be important. Vital, even.

So, yes, I believe there will be sex in the future. Hopefully it will be between between consenting adults, and at least occasionally result in children. After all, if we stop having children (see The Purpose of Life), soon there would be no more sex in our future.

Saturday, August 2, 2008

Animals in Space

In the long run, the animals whose populations grow will be those that either prove themselves valuable to humans or that prove hard to eliminate. In a resource-starved highly over-populated Earth, the choice of who survives--human or animal--is likely to be won by the human (ignoring the impact of sub-species such as attorneys).

The animals we take with us as our civilization expands into the cosmos are likely to be numerous. Those limited to a meager existence in zoos and parks can't be viewed as successful, but at least their lives will be in a rather pleasant captivity. Modern zoos are more like a Hyatt Regency than Alcatraz for their occupants.

Humans will likely keep our pets, the dogs and cats that provide us with love and companionship. Cats seem especially suited to a life in zero gravity--I have no problem imaging cats thriving in such an environment. Dogs, to me, seem to need gravity for happiness (running, jumping) but they'll adapt, I'm sure.

The other animals we take with us are those domesticated ones that taste good. We are, after all, omnivorous, and no amount of processing is likely to give an algae cake the taste and texture of a steak. I could be wrong, and there is a huge efficiency drop if we choose to eat animals instead of plants, but it seems that in a wealthy society, we'll find a way to raise cattle for meat and milk, chickens for meat and eggs, pigs for bacon and ham.

Better (more efficient) choices exist for meat animals; goats produce much more milk per pound of food consumed, rabbits much more meat. Chickens are quite efficient as-is. But you can't prepare a prime rib from rabbit. Still, these choices are likely to be early winners, in some cases because they eat different parts of the plant than we humans.

Seafood will likely be available, also. We already raise salmon, catfish, and other seafood in farms. These are likely to do quite well in space, at least as long as we can find and utilize large volumes of water (I like comets). We'll miss many foods from the top of the food chain (such as tuna, swordfish and the like), but varieties of others are likely to be plentiful, possibly even critters such as shrimp and lobster.

My question for today is, how many animals will succeed against our will (such as mice, or pigeons, or ants, or roaches)? Or what others must we bring along because they are a necessary part of the ecology? For example, must we use bees for pollination? Earthworms to churn the soil?

Here's a scary thought: What if there is some pest whose presence is necessary for long-term health, such as the mosquito? Some of them can't reproduce unless they've consumed human blood, but has any human ever reproduced before being bitten by a mosquito?