4 ms·

If you read the book (by Freeman Dyson's son) or even the wikipedia page, you'd know the bombs were quite specialized. And it would certainly be possible to al

by berntb 10y ago

If you read the book (by Freeman Dyson's son) or even the wikipedia page, you'd know the bombs were quite specialized. And it would certainly be possible to allow some verification (the trigger would not need inspection, that would probably be the really sensitive part, from a technology secrets point of view). [Edit: The bombs would be directed, throwing light weight molecules up against the pusher plate.] Also, there is no direct lack of ways to distribute nuclear devices to capitals today, for the countries able to build an Orion. Compare that with the possibility to launch enough material to e.g. start on getting an industrial infrastructure going outside the atmosphere.

arethuza 10y ago
The "directed" bomb designs used tungsten - in "The Curve of Binding Energy" I seem to remember there is a comment that they were spectacularly good at digging tunnels but I don't know if that was a theoretical prediction or an empirical result.
- berntb 10y ago
  I meant that the material thrown at the plate were planned to be plasma of more lightweight materials, iirc. (That is different than how to make an atomic bomb directed.) I haven't seen any real details of directed bomb design discussed. Thanks for the pointer to that book.
- madaxe_again 10y ago
  If you consider that it was contemporaneous with plowshare, that makes sense - likely a degree of shared research.
grkvlt 10y ago
Any mechanism that can propel a starship to 0.13c is going to make your day unpleasant if it is pointed at things you have a particular fondness for. Favourite pets, cities, aircraft carriers, that sort of thing.
- berntb 10y ago
  It is a theoretical "can". :-) It will be a long time before anyone use a fraction of C inside the solar system. Interstellar flight is a problem after we have gotten to a reasonable cost/kg for both launching from the Earth and for interplanetary travel. I doubt there will be a pressing need for getting close to even 100 km/s in the inner solar system for decades. (Yes yes, "640K is enough for anyone". :-) ) (Consider: An AU is 150 million km. 100 km/second means 8.64 million km a day; 2 AUs in 35 days! Then you have to lower the speed, even more energy.) Launching an Orion from the ground is probably not realistic after the 1960s either. It would have the problem with bombs and EMP killing satellites. I've seen suggestions to coast through the sensitive zone without using bombs, but haven't seen any discussion about how many Gs it would mean...
  - dalke 10y ago
    "I doubt there will be a pressing need for getting close to even 100 km/s in the inner solar system for decades" Quoting https://en.wikipedia.org/wiki/Solar_Probe_Plus https://en.wikipedia.org/wiki/Solar_Probe_Plus : > Solar Probe Plus or Solar Probe+, previously NASA Solar Probe, is a planned robotic spacecraft to probe the outer corona of the Sun. ... As the probe passes around the Sun, it will achieve a velocity of up to 200 km/s (120 mi/s) at that time making it the fastest manmade object ever, almost three times faster than the current record holder, Juno. ... Launch date: July 31, 2018 (planned).
    - berntb 10y ago
      He he, point. But a probe doing multiple gravity assists to get close to the sun is different from going from point A to point B -- and stopping at B. :-)
- SamUK96 10y ago
  Anything bigger than the size of a bag of sugar travelling at 0.13c actually poses a threat to the entire human species. If you have for example a standard 1kg bag of sugar travelling at 0.13c, that's carrying (2nd order estimate): 0.5 x 1kg x (0.13 x 3 x 10^8)^2 = 760 quadrillion joules = 0.1MT (small nuclear bomb's worth) Now this is linear, so a car (2000kg)? = 200MT (4 times Tsar Bomba, global disaster). A tiny spacecraft (5000kg maybe?)? = death of most of human race A large spacecraft? = death of everything.

by berntb 10y ago

arethuza 10y ago

The "directed" bomb designs used tungsten - in "The Curve of Binding Energy" I seem to remember there is a comment that they were spectacularly good at digging tunnels but I don't know if that was a theoretical prediction or an empirical result.

berntb 10y ago
I meant that the material thrown at the plate were planned to be plasma of more lightweight materials, iirc. (That is different than how to make an atomic bomb directed.) I haven't seen any real details of directed bomb design discussed. Thanks for the pointer to that book.
madaxe_again 10y ago
If you consider that it was contemporaneous with plowshare, that makes sense - likely a degree of shared research.

grkvlt 10y ago

Any mechanism that can propel a starship to 0.13c is going to make your day unpleasant if it is pointed at things you have a particular fondness for. Favourite pets, cities, aircraft carriers, that sort of thing.

berntb 10y ago
It is a theoretical "can". :-) It will be a long time before anyone use a fraction of C inside the solar system. Interstellar flight is a problem after we have gotten to a reasonable cost/kg for both launching from the Earth and for interplanetary travel. I doubt there will be a pressing need for getting close to even 100 km/s in the inner solar system for decades. (Yes yes, "640K is enough for anyone". :-) ) (Consider: An AU is 150 million km. 100 km/second means 8.64 million km a day; 2 AUs in 35 days! Then you have to lower the speed, even more energy.) Launching an Orion from the ground is probably not realistic after the 1960s either. It would have the problem with bombs and EMP killing satellites. I've seen suggestions to coast through the sensitive zone without using bombs, but haven't seen any discussion about how many Gs it would mean...
- dalke 10y ago
  "I doubt there will be a pressing need for getting close to even 100 km/s in the inner solar system for decades" Quoting https://en.wikipedia.org/wiki/Solar_Probe_Plus https://en.wikipedia.org/wiki/Solar_Probe_Plus : > Solar Probe Plus or Solar Probe+, previously NASA Solar Probe, is a planned robotic spacecraft to probe the outer corona of the Sun. ... As the probe passes around the Sun, it will achieve a velocity of up to 200 km/s (120 mi/s) at that time making it the fastest manmade object ever, almost three times faster than the current record holder, Juno. ... Launch date: July 31, 2018 (planned).
  - berntb 10y ago
    He he, point. But a probe doing multiple gravity assists to get close to the sun is different from going from point A to point B -- and stopping at B. :-)
SamUK96 10y ago
Anything bigger than the size of a bag of sugar travelling at 0.13c actually poses a threat to the entire human species. If you have for example a standard 1kg bag of sugar travelling at 0.13c, that's carrying (2nd order estimate): 0.5 x 1kg x (0.13 x 3 x 10^8)^2 = 760 quadrillion joules = 0.1MT (small nuclear bomb's worth) Now this is linear, so a car (2000kg)? = 200MT (4 times Tsar Bomba, global disaster). A tiny spacecraft (5000kg maybe?)? = death of most of human race A large spacecraft? = death of everything.