Archive for the ‘Asimov’ Category

SciFi Round Nine: Portal

2013/01/06 4 comments

Portal and Portal 2 are a couple of the best computer games I’ve ever come across.  I heartily recommend them, especially if you like puzzles and snark.  The basic idea in both is that you’re playing as Chell, a woman trying to escape from a laboratory controlled by a homicidal AI.  To aid you in your escape… or scientific “testing”… you get a device that shoots portals onto walls in pairs.  If you go in one portal, you come out the other one.  Instant wormhole, just add portal gun.

As ever… here, there be spoilers.

This is a portal.  In the words of GLaDOS, speedy thing goes in, speedy thing comes out.

This is a portal. In the words of GLaDOS, speedy thing goes in, speedy thing comes out.  The setup above is nice for getting the person pictured to fall at terminal velocity and also break conservation of energy.

Portal Guns Break The Universe

The main physics-breaking part is the Portal Gun itself.  It turns out, Larry Niven wrote a very good essay a while ago, The Theory and Practice of Teleportation, which covers a lot of different ideas in great detail.  I’ll just hit a couple of the main points about Portal’s portals, and then move on.

The first issue is conversation of energy and momentum.  Put a portal on the ceiling, and one on the floor, so that when you go into the one of the floor, you fall out of the ceiling… into the portal on the floor… and this keeps going on indefinitely until something stops you, somehow.  The problem here is that you can now accumulate energy until you hit terminal velocity — and then you keep dumping more energy into all the noise and heat you’re making while going that fast.  You essentially get to move “up” in Earth’s potential for “free” when you go from floor to ceiling.  But all that energy has to go somewhere, and a quick estimate suggests that this would raise the temperature of a room by a few degrees Celsius per second… which would rapidly cook Chell.

The other problem is momentum.  Put both portals on the same wall.  Throw a ball into one portal, and it comes out of the other with momentum in the opposite direction, without transmitting that momentum into any other object.  Oops.

While portals you shoot are limited to light speed travel times, this does suggest a nice way of colonizing other planets.  Or sending stuff to other places in our own solar system.  I’ll leave the exact details to Niven’s essay, but it includes sending fuel through portals to break the rocket equation… but that’s if only if you have to have an artificial surface to shoot onto.  Otherwise… fire, carefully, and wait.

At least there’s an explanation for why all this high-speed portal-hopping doesn’t kill Chell.  In fact, this aspect bothered initial testers of the game so much that Valve added Long-Fall Boots.  These are specifically designed to perfectly kill the wearer’s inertia so that they don’t go splat on the landing, and also ensure that you land feet down.  Nifty, right?  Totally doesn’t violate physics…

All AI is a Crapshoot

This is GLaDOS.  She promises cake and grief counseling.  What you get is a portal gun and deadly neurotoxin...

This is GLaDOS. She promises cake and grief counseling. What you get is a portal gun and deadly neurotoxin…

Your main antagonist in the first game and the first segment of the second is GLaDOS (Genetic Lifeform and Disk Operating System).  As you play, it becomes increasingly clear that something is wrong with the AI.  This is even more clear after you get shunted from regular testing to the android live-fire test range.  And then it gets worse.

How hard is it to program a non-evil AI?  With a strong negative weight on harm to human lives?  And then, rather than simply cutting off its access to the deadly neurotoxin, they just stick a module on GLaDOS to keep it/her from releasing the deadly neurotoxin.  Oy.  Why can’t we downweight killing humans?  Or apply the Laws of Robotics?  That last link is interesting — turns out, there are some real-world guidelines for robot construction.  Obviously a robot?  Check.  Not designed to kill humans [by running them through deadly testing chambers for “science”]?  Fail.

The other antagonist you meet is Wheatley.  He’s friendly.  He’s helpful.  He’s also deliberately constructed to be a total moron (intended to keep GLaDOS in check) and undergoes an epic and hostile personality change when you replace GLaDOS with him.  Oops.  Nice job breaking it, hero.

Cave Johnson Failed Business Planning

As a matter of fast, OSHA came in in 1970, so this matches up with the timeline.  Otherwise, this poster is an epic lampshade.

As a matter of fast, OSHA came in in 1970, so this matches up with the timeline. Yes, this poster is an epic lampshade.

Once Wheatley turns on you in the second game, you get to explore the deeply buried history of Aperture Science.  Ignoring the problem of the absurdly deep mineshaft that’s storing everything, there’s a more serious problem:  Where is Cave Johnson, CEO of Aperture, getting all the money for this?

Millions for moon rocks to make surfaces for portals… which were originally intended to be better shower curtains.  Various other nasty things are tested by and on humans, with no regard for anybody’s safety.  Cave’s idea of science is building random crap and seeing what happens, which ranges from bouncy repulsion gel (intended as a diet product — the food bounces right out!  And does bad things to your stomach…) and things like turning people’s blood into gasoline.  Or making them into an army of mantis-men.  Among other problems too numerous to mention.  WHY HASN’T THE GOVERNMENT SHUT THESE PEOPLE DOWN ALREADY???  Then again, this is all delightfully lampshaded by various signs (such as the one above), and we never see what the exterior used to look like, back in the day.  It’s quite possible that there were protestors all the time outside the facility.  Maybe even a demonstration dedicated to the missing astronauts…

Meanwhile, the game does demonstrate the increasingly dire financial straights of the company.  Since they have trouble marketing their various deadly products.  For instance:  An ad for the long-fall boots.  If you’re bored, you can even try looking for the ad about using turrets for guarding babies.  It’s even worse.  This is not a good business plan… which explains the lack of funding, but I still wonder how they managed to get any funds in the first place.

Cave’s other major problem seems to be that he thinks of science as throwing together a bunch of random stuff, and then seeing what happens when some poor sucker tries to use it.  That’s not science.  That’s cruel and unusual.  And darkly hilarious for the player.

But anyway, Cave, you don’t know what science is.  And don’t get near my house with those combustible lemons.


SciFi Round Seven: Alpha Centauri

2012/10/25 10 comments

There’s a planet at Alpha Centauri.  And that’s just too cool not to follow up.  (For those of you who may want more technical information than the first link, the full Nature article is here… though it may take a subscription to see the whole thing.)

In honor of that discovery, let’s see how well some fictional accounts of Alpha Centauri stack up.  It’s a popular system to consider, since the stars at Alpha Centauri are the closest to Earth (other than Sol – aka “The Sun”) at a mere 4.4 light-years.  I’ll only be hitting a few examples, but oddly enough, Wikipedia has an extensive listing if you want to see them all…

Alpha Centauri Is More Than One Star

I was shocked to see this mentioned on the aforementioned Wikipedia page, but apparently some authors think that Alpha Centauri is only one star.  I have the good fortune to not have read any of these; I would have been very upset by them.

While not obvious to the naked eye (or authors from the northern hemisphere who don’t see it at all), Alpha Centauri is composed of two stars.  The larger, Alpha Centauri A, is a spectral type G2V, the same as the sun, has a slightly larger mass and slightly brighter.  Alpha Centauri B is type K2V, and is noticeably cooler and dimmer than the Sun, and has about 90% of the Sun’s mass.  The two stars are close enough in mass that the system’s center of mass is well between the two stars, not near the center of one or the other.  Their orbit is eccentric, with the distance between the two stars varying between roughly 10 and 50 AU.  For scale, that closest pass is about the distance between the Sun and Saturn.  There’s a nice animation of this, along with other information, which also shows an estimate for where the habitable zones of the stars may lie.

On top of the bright binary, there’s a third, even dimmer star called Proxima Centauri (or sometimes Alpha Centauri C).  It orbits around Alpha Centauri at a distance of about 15,000 AU.  Its spectral type is M5.5Ve — at a bit over a tenth of the Sun’s mass, it’s much dimmer, cooler, and redder than the Sun or Alpha Centauri AB.  The “e” means it’s an actively flaring star.  More on that later.

Moving In

Sometimes it’s only mentioned in passing, but fictionally speaking, Alpha Cen is a common waypoint or colonization target.  It gets mentioned as such, and occasionally featured, in such things as Star Trek, Lost in Space, Buck Rogers, Doctor Who… the list goes on.  A couple of books that mention or feature Alpha Centauri are The Songs of Distant Earth by Arthur C. Clark and Foundation and Earth by Isaac Asimov.  In the movie Avatar, the moon Pandora orbits a gas giant which in turn orbits Alpha Cen A.  Sending a colony ship there is a method of winning the game in Civilization, and it’s the name of the game Alpha Centauri.  Typically, these works imply or require the presence of at least one habitable planet orbiting either A or B.

The recently discovered planet is Alpha Centauri Bb.  It has a mass somewhat greater than Earth’s, and orbits Bb at a radius of 0.04 AU.  Despite the fact that B is dimmer than the Sun, that means this little planet is baked to a surface temperature of at least 1500 K (depending on its albedo and atmosphere).  That’s hot enough to melt silicate rocks, and is at least twice as hot as Venus (which averages 735 K).  Odds of anything living there are pretty slim.

Artist’s conception of Alpha Cen Bb, which really needs a better name, in orbit around Alpha Cen B. The color scale is logarithmic, with brightness ranging over a factor of many trillions. Alpha Cen B is ~100,000 times brighter than Alpha Cen A as seen from Bb, the Sun is not quite a billion times fainter than Alpha Cen A, and the galactic plane is fainter still.

Because Alpha Centauri is so close, there’s enough data to give good limits on what other planets could be in the system.  Anything habitable must be orbiting either A or B relatively closely in order to be warm enough and to avoid having its orbit perturbed too much by the other star — but not too closely.  The combination of these two requirements makes it difficult for a planet to stay in Alpha Cen A’s habitable zone — it’s likely to get scattered out by B.  This may be a problem for works that put the habitable planet around A, such as Foundation and Earth.  B, on the other hand, may have less trouble with this, since its habitable zone is closer in.

Planets far enough out to orbit outside the AB pair would be too cold.  C is an unlikely candidate — it’s so small that any planet close enough to be warm enough for life would be close enough to be seriously zapped by radiation from the flares, which would (probably) erode its atmosphere.

Back to Avatar.  The moon Pandora orbits a gas giant, which orbits A.  Even assuming it gets away with orbiting A, there’s another problem.  Despite some false alarms, current limits indicate that there are no gas giants or brown dwarfs anywhere close to A, B or C.  Pandora doesn’t exist.  (And who names their moon Pandora, anyway?  But we’ll cover Avatar another day.)

On the other hand, that leaves plenty of room for speculation — smaller, rocky, habitable planets are possible, and more plausible around B.  The stars in the system are also older than the Sun, which means there’s been plenty of time for life to develop…


If the aliens are the technologically primitive (no radio) Na’vi, it’s pretty obvious why we haven’t heard from them yet.  Or they could all be a hundred years dead.   On the other hand, if we’re talking about aliens like the fithp in Footfall (by Larry Niven and Jerry Pournelle), then we’ve got a problem.

Contact with aliens from Alpha Cen is another common theme, with technologically advanced aliens an option.  In Footfall, they’re in the form of an unusually plausible group of alien invaders.

There’s just one problem.  We’ve been putting out radio signals for over a century, and relatively strong ones for television broadcasts for over seventy years now.  Those signals, while usually not decipherable, are still detectable and clearly artificial for a sphere sixty or seventy light-years in radius and expanding.  If we ourselves were sitting at Alpha Centuari, with our current technology, we could unambiguously detect those radio signals and notice both Earth and the fact that it’s inhabited.

By the same token, if Earth with all its radio chatter were orbiting Alpha Cen B in the habitable zone… we’d have heard them by now.  At least one of the books listed in Wikipedia (Factory Humanity) seems to get this right — contact with aliens at Alpha Cen is established first via radio.  Why we didn’t hear the fithp before they decided to take a detour through our solar system isn’t clearly explained.  Maybe they’ve replaced all their radio tech with subspace transponders.

Either that, or they’ve seen us, and are deliberately hiding.  Just like the Martians.  Insert your conspiracy theory here.

Fantasy League Round 4: Economics and Fantasy Role-Playing Games

I keep talking about the importance of considering what technologies (in the broadest sense of the word ‘technique’) can do to a society when writing a story.  In many stories, the technology itself isn’t the purpose of the story that was being written.  Inception is a heist film – in some sense, the dreaming technology is less relevant than the interactions between Cobb and his memories of his wife, and his quest to return to his children and home even if that means assaulting Fischer.  This is the second of Asimov’s three kinds of science fiction: the technology is incidental to the adventure.
But what about role-playing and strategy games, where the techniques concerned are the main way that the players’ characters interact with the game world?  Here it is essential to consider how the technologies interact with one another, in the form of possible combinations of the rules.  Otherwise the game may end up essentially unplayable.  Most good games don’t have that severe of a problem, but considering all of the possible combinations of rules becomes very difficult for complicated games where the full description of the rules may be hundreds of pages long.  In particular, economics is very hard to do right.

Game Breaking

If the game developers and beta testers haven’t found and fixed all possible problematic combinations of rules, there will be exploits to take advantage of.  And given a large enough base of players, they will be found.  There are very long lists of such game-breaking techniques, but here I’ll focus on economic ones.

The economics of Dungeons and Dragons 3.5. Notice that a 10-foot ladder costs 5 copper pieces and a 10-foot pole costs 2 silver pieces = 20 copper pieces. So, buy ladders, take them apart, and quadruple your money. That works until the demand for ladders and poles changes and the prices adjust; but price elasticity isn’t included in the rules for the game.

In all of the versions of Dungeons and Dragons, there are exploits that allow relatively low-level characters to defeat any opponent.  The most notorious example is Pun-Pun, a level-1 starting character in DnD 3.5 that has arbitrarily high power.  But the exploits in DnD are easier than that.  The purchase price of a ten-foot ladder is less than the sale price of the two ten-foot poles and shorter rungs that it is made of.  A player can in theory drain all of the cash out of the local economy.

In the Dresden Files RPG, there is another simple exploit.  A lot of the competitive balancing in the game relies on high-powered magical characters being unable to use complicated technology, particularly computers and other electronics.  This is justified by the characters ‘magical energy’ damaging the electronics.  They are walking techbane.  But moving water is also established to block magical energy.  You can still use a cell phone, a GPS, a computer terminal, and all of the fancy gadgets in a modern hospital as long as either they or you are encased in a thin layer of circulating water.  Time to go shopping at a fire-fighter uniform supplier.

In Mage: The Ascension, some characters can magic the laws of probability and win the lottery.  That may get a certain amount of unwanted attention, but you only need to do it once.  To deal with this sort of thing, all of these games have one basic rule: the moderator is always right.

Competitive Balance

Things get a bit more problematic in games without a moderator constantly adjusting the rules to avoid or limit game-breaking.  It doesn’t even have to require a large player base – AI programs can do the same thing.  In 1981 and 1982, a challenge using the rules from the sci-fi RPG Traveller was twice won by an early learning program.  It found that thousands of kamikaze ships would defeat any other solution.
A more recent example:  Starcraft is very close to competitive balance, but in scenarios with nearly-infinite resources and equally-skilled players, the Protoss game race has a slight advantage over the others.  They can assimilate enemy units and potentially have three times the army of anyone else (if the game lasts that long).

Game software can be updated.  This is easier for online games.  In World of Warcraft, there have been both positive and negative game-breaks.  On the positive side, there was a bug that could be exploited to allow a single paladin character to do death by a thousand cuts to the hardest-to-defeat enemies in the game in one move (as opposed to the usual method of two dozen characters taking several minutes to bring it down).  On the negative side, a programming bug caused the Corrupted Blood debuff to turn into a pandemic inside the game, killing off or wounding almost all characters.  Those were all fixed by obvious rule patches in short order.

The Limits of Rule Patching

But rule patching can only go so far.  The most complicated game breaks arise from interactions between many player characters, in effect a large synthetic economy.  The World Of Warcraft internal auction markets are nowhere close to equilibrium, and arbitrageurs can make lots of in-game money.  In some cases, trading bot programs have accumulated up to several times the total amount of money in circulation on any one game server.  Blizzard deals with that by shutting down bot accounts whenever they are detected.  But  Matt Fisher at Stanford tells me that bot programs can be programmed to appear almost identical to a human player who obsessively trades on the market, so there is no way to fix that.

Perhaps the limits of rule patching can be excused.  When game systems are so complicated that no-one can predict their outcomes, and when they involve the interactions of thousands of separate agents, fixing problems with them is as hard as fixing problems with the real-life economy.  Doing significantly better than random chance would be impressive.