Foundation and Collapse
Before every disaster comes a misguided sense of triumph
The first season of Apple TV’s series Foundation has now been released in its entirety. Parts of it are definitely worth watching, while other parts are not particularly good — it could have been edited down from ten episodes to eight without losing much.
What’s the Book? What’s the Show?
The Foundation series was published as a series of short stories in the 1940s, and compiled into 3 books. We only need discuss the first three short stories in the first book.
“The Psychohistorians” - Hari Seldon has a plan to prevent a thirty thousand year dark age: to start an encyclopedia. After Seldon explains his predictions to the royal court, the group is “exiled” to Terminus.
“The Encyclopedists” - Fifty years later, Anacreon tries to invade Terminus. The colonists are informed that the encyclopedia project was a fraud, and the plan is simply that they must survive. Salvor Hardin heroically leads a coup, and then solves a straightforward political crisis. There are no on-screen deaths.
“The Mayors” - Thirty years later, Terminus sells advanced technology (dressed up as religious magic) to Anacreon and other nearby planets. Anacreon tries to invade Terminus (again). Salvor Hardin solves two straightforward political crises.
However, most of the content of the TV series after the first episode is completely new. The Gaal Dornick storyline has elements inspired by later prequels, but basically every scene is original to the show. The Terminus/Anacreon storyline is inspired by The Encyclopedists, but the differences are so large as to make the characters and plot almost unrecognizable. Salvor Hardin, in particular, is best considered as a new character who happens to have the same name as a character from the books.
The storyline about the “genetic dynasty” of cloned emperors is much of the best material of the show, but again is largely original. Some elements of it are inspired by later prequels (in particular the character of Demerzel), and some themes are a re-mix of themes from The Mayors. In this case it is the Empire that harnesses the power of religion. Asimov’s storyline of technology as religion simply would not work on-screen today, so a new one must be written.
A Metaphor in High Resolution
The set piece in episode one is best described as “Space Elevator September 11”. Two terrorists1, possibly related to Anacreon, destroy a space elevator (called the Space Bridge). Between those on the structure and those on the ground, there are 150 million dead.
As a result, the Empire2 decides to massacre the home planet of Anacreon. Perhaps unsurprisingly, the survivors will (still) be out for revenge 35 years later.
The comparisons between this and the failed Afghanistan War are obvious. So obvious that I will leave them as an exercise to the reader.
Threat Models
When considering whether or not to build a space elevator, one of the concerns must be “what happens when it is destroyed”. Not if, but when; it is a certainty that it will happen eventually, and it is certainly a possibility it will happen far sooner than intended.
When considering a technology, one of the options must always be “this is too dangerous to build”. You see this frequently ignored in films: people build a Doomsday Device because they can, and are shocked when it causes utterly predictable doom.
Your scientists were so preoccupied with whether they could, they didn't stop to think if they should. - Jurassic Park
In practice, quite a lot of the space elevator would burn up in the atmosphere. My guess is there would be a lot fewer dead. However, the threats become more severe when we look at spaceships3.
The Foundation TV series somehow has “slow FTL ships”, a concept so far removed from modern physics4 I will consider it a deliberate plot tool and nothing more. It also has instantaneous “jump drive” ships, while obviously that technology does not exist it is more possible to imagine how it would fit within physics.
Yet sub-lightspeed ships are enough to cause disaster. We know how those work; the best way to move a spaceship is through the equivalent of shooting a gun backwards to propel a boat. You need energy, and you need mass (called propellant) to shoot the other way. Sometimes the energy comes from a chemical reaction, and the by-products are the propellant; other times the energy comes from some other source5, and the propellant is chemically inert.
How fast can you get? The spacecraft Dawn launched with a mass of around 1200kg. Around 1/3 of that mass was propellant6, and it gave a velocity change of 11 km/s (0.000037c) for the remaining 2/3 of the spacecraft. Clearly, our current technology cannot reach high speeds.
Chasing Chicxulub
But what happens if we can reach high speeds?
The Chicxulub impactor had an estimated diameter of 11–81 kilometers (6.8–50.3 mi), and delivered an estimated energy of 21–921 billion Hiroshima A-bombs (between 1.3×10^24 and 5.8×10^25 joules, or 1.3–58 yottajoules). For comparison, this is ~100 million times the energy released by the Tsar Bomba, a thermonuclear device ("H-bomb") that remains the most powerful human-made explosive ever detonated, which released 210 petajoules (2.1×10^17 joules, or 50 megatons TNT). Other estimates find the impact had an energy of 3×10^23 joules. (Wikipedia on [[Chicxulub crater]])
A spaceship is launched to Alpha Centauri. It contains 1000 people, and aims to make the 4 light-year trip in less than 20 years of experienced time on-ship. Four hundred years later, after a religious dispute, the colonists re-fuel the ship and aim to hit a city on Earth. Does the impact:
Kill everyone on Earth on impact? Probably not.
Kill everyone on Earth who doesn’t retreat to an “off-world shelter”? Maybe.
Kill everyone in the target city? Definitely yes.
What is the energy? 1e3 people, 1e3 kg/person, 0.4c ^ 2 = 1.4e16 m^2/s^2 gives 1.4 * 10^22 Joules (0.4c as we have double-speed for ramming). That is substantially below even the lowest estimates for Chicxulub, so probably not everyone on Earth dies. But maybe everyone dies if you build a ship for a million people.
The inevitable conclusion is “don’t build fast spaceships”. Maybe that’s the solution to the Drake equation …
What is a terrorist? My working definition is that a terrorist is a person who is engaged in asymmetric warfare outside of any declared state of war. That definition certainly applies here.
The title of the rulers of the empire is “Empire” rather than “Emperor”. This works well aesthetically but makes certain discussions more confusing.
The show hints at using a legendary ship known as Invictus to do this, but doesn’t actually follow through with even more on-screen deaths. The point is that it doesn’t take a legendary ship; any ship that can approach light-speed will do.
The show-writers must assume that the audience isn’t sufficiently aware of special relativity to object.
To get the math to work out to reach anything close to light-speed, we must presume the ship to run on unobtainium, or dilithium, or some other fictional substance that doesn’t have the logistical problems all known fuels would have. For low-speed propulsion within the solar system, we can just use solar panels.
The propellant used was xenon; I note a recent Hacker News discussion of a new engine using iodine.