Archive for December, 2008

Season Reason

So it’s Christmas time. As you unwrap your presents, eat your Christmas ham, and revel in the good tidings and fun of the holidays, make sure to take time out to remember where it all comes from:

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Sometimes Being So Smart is a Drag

I’ve been busy playing this online game called EVE Online. It’s basically a massive online space simulation game in which you can do a number of things.  You can mine resources, refine them, make items to sell in-game or use yourself, fight NPCs or PCs (that is, computer controlled characters and other real human players), any and all at the same time.

But being the smart guy that I am I like to ask questions and figure things out. For example: what is the best way to make in-game money? The economy is almost exclusively player-driven. When you sell an item, it is because some other player somewhere in the world has put out a buy order. When you purchase an item, it is because someone else has put it on the market. It takes a bit of mathmatics but I figured out that the best way to make the most money was to go out, mine a certain type of ore (called Dense Veldspar, which is entirely common throughout the game’s universe) and sell it.

Then do it again. And again. And again. You might use the money you get to purchase better ships and mining equipment so you can mine larger quantities exponential growth. But in the end it’s just going out, mining asteroids, and selling the results.

The game now seems incredibly boring. I can go out and keep mining sure, but to what end? It’s not like the money I earn in-game can be transferred to the real world. There are other things I can do, like combat, but that appeals less to me than mining and manufacturing. My own sheer brilliance has reduced a complex game to a simple equation: mining = wealth. Wealth that is ultimately worthless.

Oh well.

Xtreme Koolz Comix Distributron

I love the web comic XKCD (which actually doesn’t stand for the title of this post or anything for that matter). It sometimes deals with computer stuff, which I’m generally clueless about, but also brilliantly combining bizarre and arcane mathematical and physical theory (all of which is accurate) with everyday life. For example, check out today’s comic. This site is where I got a couple of comic images that was on The Other Blog.

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Alien Civilizations III: Travel

An alien civilization is likely to have developed billions of years ago. They would have swiftly progressed through the technological invention stage, and long ago reached the point where they could do all the things they wanted, bound only by the laws of physics (they couldn’t, for example, create matter and energy out of nothing).

So what would they do for all those billions of years? Most likely, they’ll begin to spread out. Staying on one planet, or even in one planetary system, is more or less suicide. There are innumerable catastrophies that can befall such a multi-planet but single-system species: supernovae, gamma ray bursts, war, and eventually the death of their star itself. A species that has been able to survive the evolutionary process would have survival instincts and desires hard-wired into their brains (or whatever thinking organ they have… if they have organs…). And, they are very very smart, even smarter than us. It seems overwhelmingly likely that they would take to the stars.

Interstellar travel is slow and it is hard. Even at the speed of light–the absolute fastest it is possible to go–travel across the galaxy takes tens of thousands of years. And getting even close to that speed takes enormous amounts of energy.

But wait…tens of thousands of years? The species we’re dealing with is billions of years old. From that perspective, interstellar travel is actually pretty fast. In fact, even using concievable methods of starship propulsion, the time to cross the entire galaxy is measured in only millions of years. Here is a table detailing various engine types both real and theoretical (though all physcially possible) and their performances:

 

H2 – O2

Ion

VASIMR

H3–D Fusion

Antimatter

Exhaust Velocity (km/s)

4.5

88

294

7,480

100,000

Max. Speed (km/s)*

20**

183

610

15,500

104,000***

Time to Alpha Centauri (4.36 ly)

65,350 y

7,140 y

2,140 y

84.3 y

12.6 y

100 ly

1.50 mil y

164,000 y

49,100 y

1,930 y

288 y

1000 ly

150 mil y

1.64 mil y

491,000 y

19,300 y

2,880 y

Galactic Core (26,000 ly)

390 mil y

42.6 mil y

12.8 mil y

503,000 y

74,900 y

Across Galaxy (100,000 ly)

1.50 bil y

164 mil y

49.1 mil y

1.93 mil y

288,000 y

Andromeda Galaxy (2,400,000 ly)

36.0 bil y

3.93 bil y

1.18 bil y

46.4 mil y

6.92 mil y

*Max. Speed is figured by assuming a staged rocket with an overall mass ratio of 64, and assuming the probe will stop at its destination. If the mission is just a fly-by, the maximum speed would be twice as high.

**Because hydrogen-oxygen rockets tend to be very slow, any probe would likely also utilize gravitational boosts by flying near the outer planets, increasing its speed while not using any propellant. Other engines could also utilize this, but the amount added is very small compared to the overall speed.

***It is likely impossible to have an staged antimatter rocket with a mass ratio of 64, since antimatter tends to annihilate when it touches normal matter. An antimatter fuel tank would have to be arranged to keep the antimatter suspended completely away from the rest of the normal-matter rocket This figure is based on a mass ratio of 8 (that is, three stages, each consisting of a mass ratio of 2).

As you can see, even today’s hydrogen-oxygen rocket technology is more than sufficient for crossing (and thus colonizing) the galaxy in the given. Keeping a ship working for a billion years is definitely a challenge, but if aliens have billions of years to work on the problem, they’d probably be using antimatter rockets and know how to keep them operational for the several hundred thousand years necessary.

But why would they come here? Our solar system is just one in two hundred billion. There must be many interesting locations to explore. The odds that they would choose ours are literally billions to one.

But it is more useful to see the galaxy from the alien’s perspective (which is actually not very different from our own). We live in one tiny patch of space and want to know as much about the rest of the galaxy as possible. Sending probes to stars one at a time is very inefficient. The mathematician John von Neumann showed that by using self-replicating robotic probes, one can create a vast number of interstellar probes for very little cost (you only have to pay for the first one). These probes would utilize the resources found in other solar systems to make copies of themselves, then send the copies off to the next star system. The aliens wouldn’t just colonize a few stars, they would colonize all the stars.

More likely, it would be desirable to make all the probes in your own star system using the resources available then launch them all at once. This is better because A) you avoid two robotic probes heading to the same star system B) you avoid the problem of a probe coming upon a system that has no resources and so can’t make a copy of itself and C) you can better control the self-replication process, avoid any accidents.

Such robots would then explore their respective targets and likely continue observing over a period of millions of years (assuming advanced self-repair capabilities). Perhaps they might even set up colonies if any of their creators wished to relocate there, or even begin terraforming any suitable planets.

The implication is obvious, if aliens have evolved at some point, they’re probes should already be here in our solar system. We have never found such alien artifacts, but the solar system is a largely unexplored place. The most likely place to find such artifacts are in a place where resources are plentiful and easy to get at. That is not the Earth, or the Moon, or any planet at all. They would likely reside in the asteroid belt, where there are vast resources, out of deep gravity wells, and close enough to the sun to provide a constant power source. The Kuiper Belt, farther out, has even more resources, and the probes might use on-board fusion plants for power instead of the Sun.

Maybe they’re out there right now. If so, there’s no use trying to signal them. Assuming they’re still active, they know all about us and aren’t talking anyway. There are hundreds of millions of asteroids out there and the only way to find them, perhaps, would be to send out our own von Neumann probes to scour the solar system.

Next Chapter: Survival

Thou Shalt Steal

I’m not sure exactly what to make of this. An athiest organization put up a sign attacking religious thought, which was then subsequently stolen, presumably by someone who disagreed with the message, and so who was almost certainly religious. Isn’t there some sort of religious rule against stealing. I mean, I know the Bible is big book, but I’m sure I saw that in there some place.

Of course, the sign itself is a little insensitive. One of the lines on there reading, “Religion is but a myth and a superstition that hardens hearts and enslaves minds”. I’m always trying to come up with ways to promote disbelief in god(s) while still being positive and respectful for other people’s beliefs, but it’s hard to do. Atheism is just a simple negation of single claim, nothing more. It’s hard to be encouraging when speaking against a belief that someone has made the core of their life.

Alien Civilizations II: Time

The first notion that we need to contend with is the enormous span of time that has come before human civilization. Human civilization has been around, at most, for around 10,000 years. The human species, homo sapiens, has been around for around 200,000 years. These are very long periods of time, but are insignificant when compared to the fact that the Earth itself is 4.6 billion years old. The universe is about three times older, clocking 13.7 billion years so far.

For all of Earth’s existence, the human species have only been walking around on it for 0.004% of the time. Yet in that tiny tiny sliver of time, be have ascended from mere animals into a global technological civilization. In fact the vast majority of this progress has only taken place within the past few centuries.

It is reasonable to believe alien civilizations will follow a similar pattern. Very soon after evolving, an alien civilization will develop technology and likely head for the stars. The thing to remember is that the point in time when this alien civilization evolves is essentially random. If you pick a random point anywhere during the history of the universe, you will likely end up picking a point billions of years in the past. In fact, the odds are greater than 99% that you will pick a point further than 100 million years in the past. If aliens have evolved on some other planet at some point, they have already vastly surpassed our capabilities, assuming they don’t destroy themselves in the process.

Next Chapter: Travel

Alien Civilizations I: Prologue

Fitting in with my interest in the future is my interest in extraterrestrial life. Life is a very unique form of matter. It is a self-perpetuating, self-contained chemical system which can adapt and change the environment around it. Yet all we know is a single example. All life on Earth is essentially identical. The chemical make-up and operations of all known living things are very similar. Any cell in your body can “read” the DNA of any other organism. This is because all life on Earth is descended from a single cell, way in the past, shortly after the formation of the Earth itself.

But alien life is completely foreign. It evolved in a completely different environment, using the building blocks it had on hand. It may be so unlike anything seen before on Earth we may not immediately recognize it as being alive.

The most interesting aspect of extraterrestrial life I find is the possibility of extraterrestrial intelligence, the idea that life elsewhere has evolved another intelligent species completely independently. It is, of course, immediately obvious that such an ability is possible: we are here. Nature very rarely, if ever, produces some phenomenon only once.

Thinking about alien intelligence is very much like thinking about how our species will develop in the future. The only difference (besides the fact that they are alien), is that aliens will very likely have had a multi-billion year head-start. That is, anything I predict human civilization will develop, aliens have likely already done. We just need to find them.

Next Chapter: Time