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If "By far most of the solar system's mass is in the Sun itself: somewhere between 99.8 and 99.9 percent", then I can't help but wonder if there is enough matte
by _andromeda_ 10y ago
If "By far most of the solar system's mass is in the Sun itself: somewhere between 99.8 and 99.9 percent", then I can't help but wonder if there is enough matter to cover the sun's surface area to create a real Dyson sphere. Where would this matter come from? Is there enough matter in left in the 0.1% (shared by the rest of the solar system) to completely engulf the sun?
- piker 10y agoThe sun is quite dense. I have to think a Dyson sphere surrounding it could be as thin as, say, an onion's outer layer when compared to the onion itself. (Assuming enough distance from the sun to avoid burning up.)
- _andromeda_ 10y agoSomewhat true, but it still seems to me that the only way to build a proper Dyson sphere would be to not only achieve scientific breakthroughs that allow for interstellar travel, but to do so in a way that allows us to be able to ferry as much matter from other stellar systems as we need.
- venomsnake 10y agoor you can just harvest the heavy elements from the sun itself. Bonus - you prolong its life.
- _andromeda_ 10y agoPerfect! That would work.
- adrianN 10y agoThat depends on how thick you want your cover to be.
- api 10y agoDyson swarms are a far more practical idea than spheres and can be incrementally constructed. It's basically just a ton of satellites.
- Zardoz84 10y agoRing world
- api 10y agoNot orbitally stable, and shares many other issues with a Dyson sphere.
- mcv 10y agoA Dyson sphere _is_ a swarm. Though Jason Wright explains (in jasoncrawford's link) that a spherical swarm is very unlikely in this case. A ring swarm could work, though (he rates it as "unclear plausibility").
- fogleman 10y agoI was curious about your idea, so I whipped up some numbers in Python. A 1-meter thick spherical shell at 1 AU from our sun would be 0.02% of the volume of the Sun, or 260x the volume of the Earth. If you go down to 1-mm thick, you only need 0.26 Earths. :)
- mrfusion 10y agoYou could be a lot closer too. No reason to do one au.
- david-given 10y agoHeat, actually. All the energy the star produces has to escape into space somehow. The way it does this is by heating up the sphere until it radiates out into space at the same rate at which the star irradiates the sphere. The bigger the sphere, the cooler it is, because it has more surface area to radiate away heat. So if your sphere is too small, it may end up glowing at red heat, which might make it difficult to live on. Calculating the temperature is straightforward: http://www.aleph.se/Nada/dysonFAQ.html http://www.aleph.se/Nada/dysonFAQ.html
- mrfusion 10y agoI didn't know we were going to live on it. If so good point.
- jxy 10y agoYou can't assume that they can build a Dyson sphere while their technology is as limited as us earthlings. If you can imagine some alien species building a mega structure in such a short time, you should be able to imagine that they have a way to transfer and store that amount of energy. The laws of thermodynamics, as we know it, prevents 100% efficiency in doing that, but if they have a directional heat dissipation device, and their generator is highly efficient, we will hardly have any chance to detect that. I can imagine they could have some version of our power plant, only orders of magnitude more advanced. Instead of moving electrons, they could be generating and moving matter anti-matter stuffs.
- tynpeddler 10y agoI think the most practical approach would be to build something like a buuthandi from schlock mercenary. Of course, even that would contain a staggering amount of matter.