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The problem is that planetary civilization is inherantly fragile to those living up outside the gravity well. Every depressed belter asteroid-trucker with a bal

The problem is that planetary civilization is inherantly fragile to those living up outside the gravity well. Every depressed belter asteroid-trucker with a balistics computer, can throw a garbage can at earth or mars at speed and end planetary civilization.

CyberDildonics 3y ago
I think you're confusing reality with science fiction.
philwelch 3y ago
Rods from god are roughly as powerful as nukes, which is bad but a single nuke wouldn't end planetary civilization. If the belters were able to throw things at relativistic speeds you'd have a problem, but there's also no stealth in space so it's feasible to monitor space traffic around a large planet and deflect anything incoming, be it a projectile launched from longer range or an untrusted, uninspected, shady-looking belter ship.
- justinclift 3y ago
  The "rod from space" just need to deflect the orbit of an already existing large asteroid doesn't it? Which would hopefully be detected in time to "solve" the problem, but still... ;)
  - AlotOfReading 3y ago
    "just" is doing a lot of work there. It's a pretty serious engineering effort to move rocks around the solar system and unless you have unlimited-energy future tech, you're probably stuck with the current paradigm of nudging things slightly to take advantage of convoluted gravity assists and small time windows to move things about. It'd be a very slow and predictable weapon that we already watch for.
- m4rtink 3y ago
  Anything small enough will just burn up in the atmosphere and big stuff will be easy to detect, even at the boost stage as the initial orbit change might take weeks or months possibly. Orbitals at predictable orbits and surfaceinstallations on airless bodies might be more in danger though. There even a well targeted fast crowbar might do quite some damage.
- stametseater 3y ago
  I think rods from gods is oversold. The classic version of this is a "telephone pole of tungsten", or something along the lines of a 6 meter long cylinder, 0.3 meters across, which works out to 0.42 cubic meters of tungsten, which would be just over 8000 kilograms. If you do the math, rods coming in at orbit speeds are barely worth talking about; the actual rods from god USAF proposal had these tungsten telephone poles starting in orbit and impacting the ground at merely 3 km/s, equivalent to 11 tons of TNT. Faster then: the kinetic energy of such a mass moving at 12 km/s, faster than escape velocity, would be 'only' 137 tons of TNT, approximately 1/15th of the 2020 Beirut explosion. Even if you throw the rods into the ground at a blistering 50 km/s, that only gives you the equivalent kinetic energy of 2.4 kilotons of TNT, or 1/6th of the Little Boy nuclear bomb. Then there are the terminal effects; such a tungsten rod is basically an oversized armor piercing dart like tanks shoot at each other. It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose.
  - justinclift 3y ago
    > It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose. Wonder if it could be precision enough for non-military applications? eg possibly faster for deep geothermal drilling than using the existing surface based borehole drilling approach. For military applications though, it'd wonder if such a rod (or small sequence of them) could be effective when striking geological fault lines. eg the San Andreas Fault line Aka the old "use the terrain" approach.
myrmidon 3y ago
[flagged]
- wpasc 3y ago
  how dare you besmirch the Epstein drive
  - myrmidon 3y ago
    Don't get me wrong I obviously liked the books enough to read them, but I still firmly believe that it is vitally important for sci-fi authors to just shut up about scientific details that our current understanding is not equipped to provide. There are books that are WAYY farther from our current techlevel, like Murderbot Diaries or Ancillary Justice, which handle this much better. I just don't see how adding pseudoscience improves ANYTHING-- better to just gloss over it.
    - fennecfoxy 3y ago
      Ah, lovely to see Murderbot mentioned, I've just been re-reading it. I think it's fine to take scifi tech with a grain of salt; most authors skip the absolute technical details so we just have to assume that things work in some way we don't currently understand. Someone did the calculation for the Epstein and it doesn't look great: http://toughsf.blogspot.com/2019/10/the-expanses-epstein-drive.html http://toughsf.blogspot.com/2019/10/the-expanses-epstein-dri... but only based on the vague technical details provided in the books. The Jean Le Flambeur trilogy is one of my favourites, it does a LOT of quantum hand-waving but the price is worth it for all of the amazing things in that universe. "This sounds so fucking cool" > "That wouldn't work irl" for good sci-fi imo. As long as they don't mess with thoroughly understood concepts and rely on "things we don't know yet".
- stametseater 3y ago
  It's very far from practical technology, but in principle you can use pieces of the asteroid as reaction mass to 'cheat' the rocket equation. You could also modify the asteroid's albedo or use solar sails to modify the trajectory of the asteroid. Very far from practical. Such a plot would probably take centuries at least to carry out with reasonably conceived technology.

CyberDildonics 3y ago

I think you're confusing reality with science fiction.

philwelch 3y ago

Rods from god are roughly as powerful as nukes, which is bad but a single nuke wouldn't end planetary civilization. If the belters were able to throw things at relativistic speeds you'd have a problem, but there's also no stealth in space so it's feasible to monitor space traffic around a large planet and deflect anything incoming, be it a projectile launched from longer range or an untrusted, uninspected, shady-looking belter ship.

justinclift 3y ago
The "rod from space" just need to deflect the orbit of an already existing large asteroid doesn't it? Which would hopefully be detected in time to "solve" the problem, but still... ;)
- AlotOfReading 3y ago
  "just" is doing a lot of work there. It's a pretty serious engineering effort to move rocks around the solar system and unless you have unlimited-energy future tech, you're probably stuck with the current paradigm of nudging things slightly to take advantage of convoluted gravity assists and small time windows to move things about. It'd be a very slow and predictable weapon that we already watch for.
m4rtink 3y ago
Anything small enough will just burn up in the atmosphere and big stuff will be easy to detect, even at the boost stage as the initial orbit change might take weeks or months possibly. Orbitals at predictable orbits and surfaceinstallations on airless bodies might be more in danger though. There even a well targeted fast crowbar might do quite some damage.
stametseater 3y ago
I think rods from gods is oversold. The classic version of this is a "telephone pole of tungsten", or something along the lines of a 6 meter long cylinder, 0.3 meters across, which works out to 0.42 cubic meters of tungsten, which would be just over 8000 kilograms. If you do the math, rods coming in at orbit speeds are barely worth talking about; the actual rods from god USAF proposal had these tungsten telephone poles starting in orbit and impacting the ground at merely 3 km/s, equivalent to 11 tons of TNT. Faster then: the kinetic energy of such a mass moving at 12 km/s, faster than escape velocity, would be 'only' 137 tons of TNT, approximately 1/15th of the 2020 Beirut explosion. Even if you throw the rods into the ground at a blistering 50 km/s, that only gives you the equivalent kinetic energy of 2.4 kilotons of TNT, or 1/6th of the Little Boy nuclear bomb. Then there are the terminal effects; such a tungsten rod is basically an oversized armor piercing dart like tanks shoot at each other. It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose.
- justinclift 3y ago
  > It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose. Wonder if it could be precision enough for non-military applications? eg possibly faster for deep geothermal drilling than using the existing surface based borehole drilling approach. For military applications though, it'd wonder if such a rod (or small sequence of them) could be effective when striking geological fault lines. eg the San Andreas Fault line Aka the old "use the terrain" approach.

myrmidon 3y ago

[flagged]

wpasc 3y ago
how dare you besmirch the Epstein drive
- myrmidon 3y ago
  Don't get me wrong I obviously liked the books enough to read them, but I still firmly believe that it is vitally important for sci-fi authors to just shut up about scientific details that our current understanding is not equipped to provide. There are books that are WAYY farther from our current techlevel, like Murderbot Diaries or Ancillary Justice, which handle this much better. I just don't see how adding pseudoscience improves ANYTHING-- better to just gloss over it.
  - fennecfoxy 3y ago
    Ah, lovely to see Murderbot mentioned, I've just been re-reading it. I think it's fine to take scifi tech with a grain of salt; most authors skip the absolute technical details so we just have to assume that things work in some way we don't currently understand. Someone did the calculation for the Epstein and it doesn't look great: http://toughsf.blogspot.com/2019/10/the-expanses-epstein-drive.html http://toughsf.blogspot.com/2019/10/the-expanses-epstein-dri... but only based on the vague technical details provided in the books. The Jean Le Flambeur trilogy is one of my favourites, it does a LOT of quantum hand-waving but the price is worth it for all of the amazing things in that universe. "This sounds so fucking cool" > "That wouldn't work irl" for good sci-fi imo. As long as they don't mess with thoroughly understood concepts and rely on "things we don't know yet".
stametseater 3y ago
It's very far from practical technology, but in principle you can use pieces of the asteroid as reaction mass to 'cheat' the rocket equation. You could also modify the asteroid's albedo or use solar sails to modify the trajectory of the asteroid. Very far from practical. Such a plot would probably take centuries at least to carry out with reasonably conceived technology.