4 ms·
You don't need to make a single sphere (swarm more likely). If you arrange the shells in layers the outer layers can efficiently capture the long wavelength rad
by danieltillett 9y ago
You don't need to make a single sphere (swarm more likely). If you arrange the shells in layers the outer layers can efficiently capture the long wavelength radiation using relatively little matter.
The question is if you could capture the energy and you had the material resources would you let it escape into the universe at 290K?
- _Codemonkeyism 9y agoOr do something else with the 625x more resources you need? I'd probably let the 4% escape and do something nice with the 625x more resources.
- danieltillett 9y agoYou don't need 625x the material resources to capture the last 4%. Think multiple shells with the outermost shell being 1 atom thick.
- falcolas 9y agoWhat atoms - when arranged in a single-atom-thickness structure - could collect, transform, and transfer radiant energy back towards the inner shells, while also remaining rigid enough to not deform under the pressure of that radiant energy (not to mention the energy emitted by other stellar phenomena)? For better or worse, we have to assume the alien civilizations have the same physics that we do, otherwise the civilization simply has to build their 1au sphere out of artificially created unobtainium to achieve 99% efficiency.
- hellcow 9y agoThe Three Body Problem (sci-fi book) had a similar puzzle in it--i.e. how can something as small as an atom have such a profound effect on our civilization? I won't spoil it, but it's well worth reading.
- danieltillett 9y agoCarbon. The outer shell does not need to be a single structure. A swam of micro satellites orbiting at 25 AU with 1 atom thick carbon antenna collectors (think black snowflake) would on average be not much more than 1 atom thick and would collect 99% of the energy emitted by the star or inner shell(s). This is all rather beyond what my post was about which is that only inefficient Dyson spheres can be detected in the infrared and that any civilisation capable of building a 95% efficient sphere is able to build one that is 99%.
- falcolas 9y ago> The question is if you could capture the energy and you had the material resources would you let it escape into the universe at 290K? If the cost of acquiring and constructing the material into a collector were greater than the benefits of collecting a mere 4% more energy, absolutely! Plus, for an advanced civilization, if given the choice between 99% efficiency around one star and 95% efficiency around a mere 100 stars - which is more likely to be done? To make the analogy more relevant to humans: Why - when we're technologically advanced enough and have sufficient materials - do we let so much energy escape Earth?
- tboughen 9y agoI think it depends entirely on the incentives of the civilization in question. If the primary goal was hiding your world from the Borg/Dalek/Alien bioweapon your species discovered was ravaging the galaxy, then a 99% Carnot efficient Dyson sphere seems like the ideal defensive structure.
- SomeStupidPoint 9y agoNo it doesn't. Anything with sufficiently advanced technology to threaten a dyson sphere wielding species would probably detect the gravitational anomaly of the missing star and go investigate there first. Taking a tiny portion of the energy from a bunch of stars seems wildly more efficient at surviving from a threat than putting all your resources into creating a system they're sure to investigate.
- sfifs 9y agoThat is similar to the plot point of one of those Star Wars prequels if I recall right