4 ms·

In the book series The Expanse, that was pretty much the only unrealistic technology that the humans had, which allowed them to colonize the solar system. Sure

In the book series The Expanse, that was pretty much the only unrealistic technology that the humans had, which allowed them to colonize the solar system. Sure, there was some might-as-well-be-magic alien stuff later in the book, but by page 1, humans have colonized the solar system, purely with a hand-wavy engine that can generate sustained thrust without needing tons of reaction mass and without turning your exhaust port into an unimaginable hell cannon.

neaden 3y ago
Eh, there is a ton of unrealistic technology in book 1, the stealth ship for instance is impossible. By the authors own words they don't think of the books as being Hard Sci-Fi, harder then Star Trek sure.
- mplewis9z 3y ago
  What makes you think the stealth ship is impossible? They explain the concept pretty well in the first book: extensive cooling systems to soak up waste heat, large liquid tanks to store that heat internally for a while, and radar-absorbing coatings. We literally have all of those pieces today, it’d just cost unfathomable amounts of money to build with our current technology. As a bonus, they even talk about the radar-absorbing coating not being perfect, and being able to detect the stealth ship as an object a few Kelvin above the background radiation when they pumped their radar into it.
  - fredthedeadhead 3y ago
    Project Rho gives several compelling reasons why there ain't no stealth in space https://www.projectrho.com/public_html/rocket/spacewardetect.php#nostealth https://www.projectrho.com/public_html/rocket/spacewardetect...
    - mplewis9z 3y ago
      I don't know when that was written, but it definitely feels like The Expanse authors read that exact page and built their stealth system to address those points - the stealth ships in the books aren't permanently stealthy (they have to radiate their heat from the internal heatsinks after some amount of time, seemingly on the order of months), and are immediately detected when they light up their engines (and hence coast until they reach their destination). The main characters also manage to find a stealth ship after coming across coordinates to it - it was parked and completely offline (and unmanned) in the orbit of a small asteroid, which would further obscure any signature it might give off.
      - neaden 3y ago
        Unfortunately for cool space battles, no this still doesn't work for the reasons outlined. First off you have to remember that when a ship turns it's engine on it's going to be visible effectively to the entire solar system unless there is a planet or something in the way. We already have the capability that we would notice a ship moving in the asteroid belt from Earth and in the Expanse it's going to be even higher. So everyone already will have known when you turned your engines on and can run the calculations to see where you are while you are coasting, so even within the confines of the fiction that shouldn't work. But let's ignore that and say that for some reason no one was looking when you turned your engines on. Assuming your ship is somehow running with all systems off it's going to be roughly 300 C hotter then the vacuum around it, even with a heatsink like you mention (and a heatsink that can store that heat for months is also unrealistic) you're going to be sticking out like a sore thumb to any infa-red. You're just too hot.
moron4hire 3y ago
No, the exhaust port definitely was an unimaginable hell cannon. The characters spoke several times about slagging a ship or a surface base in their drive plume.
- knodi123 3y ago
  Oh, I missed that! Seems like those drives ought to have been more carefully regulated then.
  - caust1c 3y ago
    Cool detail about that in the Nauvoo launch sequence, slagging the scaffolds / gantries / whatever the construction exoskeleton is. https://youtu.be/0KZRFIdbJzc?t=147 https://youtu.be/0KZRFIdbJzc?t=147
MilStdJunkie 3y ago
I'm going to embarrass myself horribly here, but I've only seen the series, so I'm not a hundred percent clear on how much acceleration they're pulling in cruise[1]. If it's something like .3 g then they're fairly close[2] to the limits of something like a fusion pulse drive (tiny nodules of deuterium or whatever, ejected out the back of the ship, then lasered into fusing, then the reaction pushes on the whatever - magnetic field, pusher planet, etc). That would make the solar system something more like what the Atlantic Ocean was in the days of sail. They'd need refuels every stop though. Like with early coal fired steamers back in the day. I got a funny feeling that without much better genetic muckety muck, the hard limit will be the human organism itself. Someone will get to the stars = if we don't screw everything up - but the someone won't be human, or maybe nothing like human. [1] I know in emergencies they pull mad g, but it doesn't seem like something they keep up for long. Would still burn through their deuterium in no time though. [2] Like, within an order of magnitude or two.
- Eddy_Viscosity2 3y ago
  The ships cruise anywhere from 0.3 to 1G, the lower end mainly for comfort of people who grew up in space. But, the fictional drive is so efficient it could sustain 10s of G for extended periods (weeks, months).
- taneq 3y ago
  Didn’t the guy who invented the drive essentially squish himself flat (too many G’s to lift his hand and reach the ‘off’ button, anyway) with his first prototype being efficient enough that it was still going during the story?
  - Chris2048 3y ago
    There's a scene about the discovery: He disables voice control (or switches it to Chinese) so at high-G he cannot hit the stop button, nor command it to stop.

neaden 3y ago

Eh, there is a ton of unrealistic technology in book 1, the stealth ship for instance is impossible. By the authors own words they don't think of the books as being Hard Sci-Fi, harder then Star Trek sure.

mplewis9z 3y ago
What makes you think the stealth ship is impossible? They explain the concept pretty well in the first book: extensive cooling systems to soak up waste heat, large liquid tanks to store that heat internally for a while, and radar-absorbing coatings. We literally have all of those pieces today, it’d just cost unfathomable amounts of money to build with our current technology. As a bonus, they even talk about the radar-absorbing coating not being perfect, and being able to detect the stealth ship as an object a few Kelvin above the background radiation when they pumped their radar into it.
- fredthedeadhead 3y ago
  Project Rho gives several compelling reasons why there ain't no stealth in space https://www.projectrho.com/public_html/rocket/spacewardetect.php#nostealth https://www.projectrho.com/public_html/rocket/spacewardetect...
  - mplewis9z 3y ago
    I don't know when that was written, but it definitely feels like The Expanse authors read that exact page and built their stealth system to address those points - the stealth ships in the books aren't permanently stealthy (they have to radiate their heat from the internal heatsinks after some amount of time, seemingly on the order of months), and are immediately detected when they light up their engines (and hence coast until they reach their destination). The main characters also manage to find a stealth ship after coming across coordinates to it - it was parked and completely offline (and unmanned) in the orbit of a small asteroid, which would further obscure any signature it might give off.
    - neaden 3y ago
      Unfortunately for cool space battles, no this still doesn't work for the reasons outlined. First off you have to remember that when a ship turns it's engine on it's going to be visible effectively to the entire solar system unless there is a planet or something in the way. We already have the capability that we would notice a ship moving in the asteroid belt from Earth and in the Expanse it's going to be even higher. So everyone already will have known when you turned your engines on and can run the calculations to see where you are while you are coasting, so even within the confines of the fiction that shouldn't work. But let's ignore that and say that for some reason no one was looking when you turned your engines on. Assuming your ship is somehow running with all systems off it's going to be roughly 300 C hotter then the vacuum around it, even with a heatsink like you mention (and a heatsink that can store that heat for months is also unrealistic) you're going to be sticking out like a sore thumb to any infa-red. You're just too hot.

moron4hire 3y ago

No, the exhaust port definitely was an unimaginable hell cannon. The characters spoke several times about slagging a ship or a surface base in their drive plume.

knodi123 3y ago
Oh, I missed that! Seems like those drives ought to have been more carefully regulated then.
- caust1c 3y ago
  Cool detail about that in the Nauvoo launch sequence, slagging the scaffolds / gantries / whatever the construction exoskeleton is. https://youtu.be/0KZRFIdbJzc?t=147 https://youtu.be/0KZRFIdbJzc?t=147

MilStdJunkie 3y ago

I'm going to embarrass myself horribly here, but I've only seen the series, so I'm not a hundred percent clear on how much acceleration they're pulling in cruise[1]. If it's something like .3 g then they're fairly close[2] to the limits of something like a fusion pulse drive (tiny nodules of deuterium or whatever, ejected out the back of the ship, then lasered into fusing, then the reaction pushes on the whatever - magnetic field, pusher planet, etc). That would make the solar system something more like what the Atlantic Ocean was in the days of sail. They'd need refuels every stop though. Like with early coal fired steamers back in the day. I got a funny feeling that without much better genetic muckety muck, the hard limit will be the human organism itself. Someone will get to the stars = if we don't screw everything up - but the someone won't be human, or maybe nothing like human. [1] I know in emergencies they pull mad g, but it doesn't seem like something they keep up for long. Would still burn through their deuterium in no time though. [2] Like, within an order of magnitude or two.

Eddy_Viscosity2 3y ago
The ships cruise anywhere from 0.3 to 1G, the lower end mainly for comfort of people who grew up in space. But, the fictional drive is so efficient it could sustain 10s of G for extended periods (weeks, months).
taneq 3y ago
Didn’t the guy who invented the drive essentially squish himself flat (too many G’s to lift his hand and reach the ‘off’ button, anyway) with his first prototype being efficient enough that it was still going during the story?
- Chris2048 3y ago
  There's a scene about the discovery: He disables voice control (or switches it to Chinese) so at high-G he cannot hit the stop button, nor command it to stop.