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I keep daydreaming about what a killer business might be. A few other ideas that probably won't pan out but are interesting to think about: - Since nuclear rea

I keep daydreaming about what a killer business might be. A few other ideas that probably won't pan out but are interesting to think about: - Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? - In The Moon is a Harsh Mistress the moon-dwellers fight earth by hurling rocks (maybe just threatening?), which strike with more force than nuclear weapons. What if you could use the gravity gradient to generate electricity instead? Instead of windmills we could drop rocks. :-) Of course if this actually worked we would solve global warming just in time to discover global massing. - Or if we had a way to transfer energy, we could just put big solar arrays up there. - I keep hoping that something will turn out to work much better in zero-gravity, like manufacturing or farming or energy production or some medical procedure. - Since superconductors require low temperature, what if we put them in space? What if our biggest supercomputers were in orbit? What else might superconductors be good for? What if quantum computers are easier to build in vacuum? As soon as something gets a toehold, then there will be economic incentive for mining, so that you don't have to launch all the stuff the other industries need.

nkrisc 10y ago
> Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? Yes, but it has its own drawbacks: https://en.wikipedia.org/wiki/Reason_(short_story) https://en.wikipedia.org/wiki/Reason_(short_story)
chris_va 10y ago
- Zero g manufacturing (good edit, has some potential) You have something with the spaced based solar (SBSP). The unsolved problem there is the microwave power beaming, which has some technical hurdles (synchronizing microwave frequencies across multiple dishes is apparently hard, but necessary for power beaming, and there is an ozone problem). Any other space based power system has this same transmission problem (people have proposed attaching conductive tethers to orbiting NEOs to drag through the magnetic field). The "nuclear reactors are dangerous" bit hasn't really been true in a long time (Chernobyl was the worst disaster, but killed a lot fewer people than hydro/coal/etc). Space is actually not great for computers. Dielectrics change in vacuum, and cooling is actually a big problem (turns out space isn't actually "cold" in the traditional sense, it is insulating, and heat tends to build up). Quantum computers are probably a red herring, there is vey little difference on an atomic scale in/outside of micro-gravity.
- pjungwir 10y ago
  Ha ha I knew someone would point out that vacuum isn't "cold", because lack of matter means heat can't transfer away from hot things. My comment about superconductors and computers tossed a bunch of stuff together I probably should have separated. I agree space wouldn't help for cooling conventional CPUs. Would it still help for superconductivity? (I have no idea.) Also for quantum computers I was wondering if vacuum would have any benefit for decoherence.
- extrapickles 10y ago
  Even if you solve the synchronization problem, you still have the main problem with power beaming of the massive sizes needed of the transmitter and receivers at space scale distances, thanks to diffraction. Microwaves need prohibitively large transmitter/receiver arrays if you go beyond LEO (drag is an issue in LEO). While putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized receiver for it on the ground is. At optical or smaller wavelengths, the arrays can be much smaller, but they will still be large structures. Disclaimer: I worked with a company that does terrestrial optical power beaming.
  - moreati 10y ago
    > putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized receiver for it on the ground is Wow, I would have guessed the exact opposite. What's the reason(s) for the higher difficulty on the ground? Planning permission? Cost of the land? Needing multiple sites in multiple countries for non-geosynchronous orbits? > Disclaimer: I worked with a company that does terrestrial optical power beaming. That sounds fascinating. Could you elaborate? What's the power level and the application?
    - extrapickles 10y ago
      Building the structure itself isn't too hard as it will be mostly empty space. For microwave it will be an area packed with odd looking antennas, optical is basically an off the shelf solar farm (though the cells should be tuned for the application rather than general sunlight). The hard bit getting all the regulatory ducks in a row, as you will need ground->space no fly zones, environmental approval, not be sited near anything else in case of alignment/focus/astigmatism (side lobes for rf) issues, etc. Generally out in the middle of nowhere there is some endangered animal (or its migration pattern) that will cause no end of issues regulatory wise for something this big/dangerous to wildlife unless you keep the energy density down below that of the sun (at that point you might as well use normal solar). You will also need controls to rapidly shutdown the system (or shunt to new location) in case an aircraft violates the no fly zone or another satellite is about to pass between the transmitter and receiver. > That sounds fascinating. Could you elaborate? What's the power level and the application? What they did when I was there was fairly diverse. The biggest was delivering 1kw at a distance of 1km with ~5-10% plug to plug efficiency. The primary application for that system was inflight refueling of electrically powered drones. They normally do much smaller/simpler (10w over dozens of meters) systems for oddball applications (eg: sensors that are sitting on something charged to 500+kv, etc) and power over fiber-optics.
TeMPOraL 10y ago
> Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? Any way of bringing down lots of beamed energy from the Moon could be also used as a weapon of mass destruction[0], so I imagine we first need to sort out terrestrial politics before this has a chance of catching on. [0] - possibly quite surgical, as WMDs go.
sixo 10y ago
I think it's housing, although there's a big hurdle to make it valuable since you need stuff for people to do first.
deleted 10y ago
[deleted]
senko 10y ago
> - Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? My pet scifi idea about it: turn Mercury (rim) into a giant powerplant, use it to create tons of antimatter, ship it to earth. Containment might be tricky tho :)
skykooler 10y ago
> Is there any way to generate energy there and get it back to earth? Not only nuclear, but space is a great place for solar as well - 24-hour sunlight, with no clouds or rain. That said, it's pretty prohibitively expensive unless we can build them out of silicon-based asteroids.

nkrisc 10y ago

> Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? Yes, but it has its own drawbacks: https://en.wikipedia.org/wiki/Reason_(short_story) https://en.wikipedia.org/wiki/Reason_(short_story)

chris_va 10y ago

- Zero g manufacturing (good edit, has some potential) You have something with the spaced based solar (SBSP). The unsolved problem there is the microwave power beaming, which has some technical hurdles (synchronizing microwave frequencies across multiple dishes is apparently hard, but necessary for power beaming, and there is an ozone problem). Any other space based power system has this same transmission problem (people have proposed attaching conductive tethers to orbiting NEOs to drag through the magnetic field). The "nuclear reactors are dangerous" bit hasn't really been true in a long time (Chernobyl was the worst disaster, but killed a lot fewer people than hydro/coal/etc). Space is actually not great for computers. Dielectrics change in vacuum, and cooling is actually a big problem (turns out space isn't actually "cold" in the traditional sense, it is insulating, and heat tends to build up). Quantum computers are probably a red herring, there is vey little difference on an atomic scale in/outside of micro-gravity.

pjungwir 10y ago
Ha ha I knew someone would point out that vacuum isn't "cold", because lack of matter means heat can't transfer away from hot things. My comment about superconductors and computers tossed a bunch of stuff together I probably should have separated. I agree space wouldn't help for cooling conventional CPUs. Would it still help for superconductivity? (I have no idea.) Also for quantum computers I was wondering if vacuum would have any benefit for decoherence.
extrapickles 10y ago
Even if you solve the synchronization problem, you still have the main problem with power beaming of the massive sizes needed of the transmitter and receivers at space scale distances, thanks to diffraction. Microwaves need prohibitively large transmitter/receiver arrays if you go beyond LEO (drag is an issue in LEO). While putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized receiver for it on the ground is. At optical or smaller wavelengths, the arrays can be much smaller, but they will still be large structures. Disclaimer: I worked with a company that does terrestrial optical power beaming.
- moreati 10y ago
  > putting a kilometer^2 scale transmitter in orbit isn't a problem, putting the similarly sized receiver for it on the ground is Wow, I would have guessed the exact opposite. What's the reason(s) for the higher difficulty on the ground? Planning permission? Cost of the land? Needing multiple sites in multiple countries for non-geosynchronous orbits? > Disclaimer: I worked with a company that does terrestrial optical power beaming. That sounds fascinating. Could you elaborate? What's the power level and the application?
  - extrapickles 10y ago
    Building the structure itself isn't too hard as it will be mostly empty space. For microwave it will be an area packed with odd looking antennas, optical is basically an off the shelf solar farm (though the cells should be tuned for the application rather than general sunlight). The hard bit getting all the regulatory ducks in a row, as you will need ground->space no fly zones, environmental approval, not be sited near anything else in case of alignment/focus/astigmatism (side lobes for rf) issues, etc. Generally out in the middle of nowhere there is some endangered animal (or its migration pattern) that will cause no end of issues regulatory wise for something this big/dangerous to wildlife unless you keep the energy density down below that of the sun (at that point you might as well use normal solar). You will also need controls to rapidly shutdown the system (or shunt to new location) in case an aircraft violates the no fly zone or another satellite is about to pass between the transmitter and receiver. > That sounds fascinating. Could you elaborate? What's the power level and the application? What they did when I was there was fairly diverse. The biggest was delivering 1kw at a distance of 1km with ~5-10% plug to plug efficiency. The primary application for that system was inflight refueling of electrically powered drones. They normally do much smaller/simpler (10w over dozens of meters) systems for oddball applications (eg: sensors that are sitting on something charged to 500+kv, etc) and power over fiber-optics.

TeMPOraL 10y ago

> Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? Any way of bringing down lots of beamed energy from the Moon could be also used as a weapon of mass destruction[0], so I imagine we first need to sort out terrestrial politics before this has a chance of catching on. [0] - possibly quite surgical, as WMDs go.

sixo 10y ago

I think it's housing, although there's a big hurdle to make it valuable since you need stuff for people to do first.

deleted 10y ago

[deleted]

senko 10y ago

> - Since nuclear reactors are dangerous, what if we build them on the moon instead? Is there any way to generate energy there and get it back to earth? My pet scifi idea about it: turn Mercury (rim) into a giant powerplant, use it to create tons of antimatter, ship it to earth. Containment might be tricky tho :)

skykooler 10y ago

> Is there any way to generate energy there and get it back to earth? Not only nuclear, but space is a great place for solar as well - 24-hour sunlight, with no clouds or rain. That said, it's pretty prohibitively expensive unless we can build them out of silicon-based asteroids.