Expanse update #4: Physics Time (Patreon)
Content
In The Expanse, the colonisation of the solar system was made possible by the Epstein drive – an advanced rocket technology. The Epstein drive is fiction, but the physics around it are real. Like, in space, there’s no gravity, which sucks – because your muscles waste away, your drinks spill everywhere, and the VFX budget gets too big. A lot of sci fi shows get around this by inventing some magic ‘gravity plating’. But The Expanse is more realistic, because its spaceships make artificial gravity from acceleration. It’s like how accelerating a car pushes you back in your seat.
By accelerating constantly, a spaceship can use that pushback as gravity, pulling you down towards the thruster.
The faster you accelerate, the stronger the gravity – so flying at one g is Earth gravity, while two g is double Earth gravity, making you weigh twice as much. When you’re in a hurry, or in combat, ships might fly at five or six gs. The Expanse has a drug called the juice which helps people survive this – but too much g force will kill you. Usually an Epstein ship will accelerate at a comfortable half or third of g. They’ll constantly accelerate for the first half of the trip, then flip around and thrust in the other direction, to decelerate for the rest of the trip.
That way the ship slows to a stop at the destination, keeping thrust gravity the whole time. This is an actually plausible way to fly a spaceship – if only we had rockets as good as Epstein’s.
But sometimes you want gravity without having to constantly accelerate somewhere. So another method is to rotate an object so the centrifugal force pushes you outwards.
It’s like the Gravitron, that spinning carnival ride that pushes you outwards. Spin up a space station, and that force can be your gravity – like in 2001: A Space Odyssey. In The Expanse, they don’t just spin up ring stations. They take planetoids like Ceres that are too small to have their own gravity, and they artificially “spin up” the whole rock to give it centrifugal force. The spin gravity pushes outwards, so people walk around on the inside of Ceres, underground. This spin gravity in Ceres and Eros is a third as strong as Earth’s gravity – which what gives the Belters their tall, thin bodies. The people and cultures of The Expanse are shaped by real-world physics.
--- So does that make sense? The images are just placeholders - wanna get the wording right before we make proper animations.
In any case, this first Expanse video is looking sweet – should be out later this week. The second Expanse video about Book 1+Season 1 is also coming along. And just quietly, we might be getting to speak directly with Expanse authors Dan and Ty soon...
On the ASOIAF front, we're planning a much-requested video about the far east of the world of ice and fire – using artwork from the Unseen Westeros exhibition.
Have also made a final(?) version of the new ASX logo:
So good things are coming!
Cheers
ASX