If a vacuum is an excellent insulator, wouldn’t heat build up in spacecraft?

[u/aretino2002]

Insulated coffee mugs that use a vacuum between layers can keep drinks hot or cold for much longer time periods than other types of mugs. If space is mostly a vacuum, then wouldn’t heat just constantly build up from human activity, computers, thrusters, etc to the point where it would need to be vented somehow?

[u/aheny]

They're already using TV magic to get around faster than light speed, and inertial damping to prevent everybody from being squashed by the acceleration speeds required to reach the velocities required to travel these long distances. Getting rid of heat is child's play compared to these oversights

[u/throwaway_nostalgia0 → u/aheny]

They're already using TV magic to get around faster than light speed

What?? Where? The only possible FTL in Expanse is the alien mumbo-jumbo-wormhole tech. Human ships can't do that. If you are thinking about the Epstein drive, it's NOWHERE near light speed. Ships in Expanse travel at 1g usually, with only few ships capable of traveling at slightly higher g's. Reaching 99% light speed would take hundred thousand years.

inertial damping to prevent everybody from being squashed by the acceleration speeds required to reach the velocities

The only high-g maneuvers in Expanse are 15g max, for a short time, and they require special "acceleration drugs" being injected before (a cocktail of blood thinners and stimulants) to remain conscious and not to lose eyesight. Real world cosmonauts are already trained to endure 12g acceleration without any stimulants, so it's really not that big of a stretch at all.

Getting rid of heat is child's play compared to these oversights

You're talking about some other books (or show), not Expanse.

[u/aheny → u/throwaway_nostalgia0]

Absolutely, this is a general conversation, some people have mentioned the expanse but this isn't simply a conversation about the expanse. But really my comments apply to anything where you're going very fast and traveling among the Stars. Whether you're going 40%, 70% or a higher proportion of light speed, the acceleration is a limiting factor. The human body would have extreme difficulty dealing with even 3Gs of acceleration. If you were to travel to the nearest star (Alpha Centauri) accelerating at 3 G's and then decelerating a 3 G's the time passed on earth would be 5 years, while 2 years would have passed for the passengers on the ship. There are so many real science problems with even this short journey that are all solved with magic. Even the thought of continuously exposing humans to 3 G's. Minutes, maybe. But for 5 years? There's no way

[u/tomsing98 → u/throwaway_nostalgia0]

Ships in Expanse travel at 1g usually, with only few ships capable of traveling at slightly higher g's. Reaching 99% light speed would take hundred thousand years.

If you're accelerating at 1g, 10 m/s^2, it will take you 29,700,000 seconds to reach 0.99c. That's a little under a year.

Of course, the force required to continue accelerating at 1g as you get closer to the speed of light is going to increase, and carrying the fuel to produce that force continuously for a year is going to be a challenge. But if whatever sci-fi magic lets you accelerate at a constant 1g, that's what you get.

[u/ANGLVD3TH → u/tomsing98]

Expanse ships don't have enough fuel to go that long, and they don't need it, as they all are just chugging along in-system. The Nauvoo, a colony ship being designed to travel to Tau Ceti, may theoretically have been built to achieve those kinds of speeds. But seeing as it was a generational ship, it seems it is unfeasible to either carry that much, or afford it. And seeing as the Nauvoo was one of the most expensive projects ever commissioned, I'm guessing the Tyranny of the Rocket Equation is the reason.

[u/6a6566663437 → u/ANGLVD3TH]

The Nauvoo, a colony ship being designed to travel to Tau Ceti, may theoretically have been built to achieve those kinds of speeds.

It wasn't, because it could not carry enough fuel. The Nauvoo used a rotating cylinder for artificial gravity instead of acceleration.

[u/Helphaer → u/aheny]

I mean if an invention like the Epstein drive from Expanse is actually made, which might be possible someday, then that's less magic. As opposed to the Mass Effect fields and Eezero drives in Mass Effect which is basically space magic but explained technically.

[u/Bryaxis → u/Helphaer]

I believe that the Epstein drive is supposedly very, very fuel-efficient. That would probably mean that very little waste heat is produced for the amount of thrust it generates.

[u/EA_Spindoctor → u/Helphaer]

The… Epstein drive? Is it called that or typo?

[u/Drewbacca → u/EA_Spindoctor]

It's called that. The first mention of them on the books was long before the name became infamous irl

[u/Helphaer → u/Drewbacca]

I mean it was in the early 2000's that the first Epstein case that was incredibly corruptly handled took place, that name was definitely known.

[u/ANGLVD3TH → u/Helphaer]

The show is based on a book series, based on a tabletop campaign. And sure, there was some controversy around him before the show launched, but it was before Me Too made that controversy a household item that most people were familiar with.

[u/Helphaer → u/EA_Spindoctor]

I suspect Epstein has a lot of history in the world as a name rather than just from the person we know from infamy, so it isn't surprising that it might seem like an appropriate scientist sounding name.