The purpose of a Dyson sphere is not to collect solar power. They are intended to maximize livable space. Think of populations numbered in the thousands of trillions.
Actually, that’s exactly the purpose, in Dyson’s original concept. Since then, of course, science fiction writers have taken the concept and run with it, in many different directions.
And Wesley, while it’s true that battery tech would have to advance enormously to make that practical, there are so many other techs that would also have to advance enormously that it’s not inconceivable that by the time we have Dyson spheres, we just might do something like that. Ultracapacitors would be a lot more likely than chemical batteries, though, or possibly some sort of “nuclear battery”.
Not really. Solar isn’t a very dense energy source, and it’s unreliable. I doubt there’s enough desert on the planet.
And “as long as we can speculate we will be around” is more than long enough for us to expand into the solar system, which would make trying to support ourselves with a patch of land on Earth even more impractical.
By the time you get to the Dyson swarm stage, you have disassembled the earth for raw materials.
This is completely wrong. To power the entire United States, including the energy used by planes and cars, we would need about 100 x 100 miles of desert. Give or take a bit, it depends upon the efficiency of the panels and the efficiency of the other conversion steps. (for instance, to power airplanes with solar, you would have to convert that electricity to liquid hydrogen or some other appropriate fuel)
This doesn’t work, unfortunately. A spinning Dyson sphere would fall apart because of hoop stress. The largest hoop you could make which rotates to give one gravity of centrifugal force would be made from carbon nanotube, and have a radius of around one thousand kilometres.
You could make a swarm of smaller habitats in a range of different orbits that would, in total, have a fantastically vast surface area; but they would each have a maximum diameter of two thousand kilometres (smaller still if you allow for safety factors).
Oh nonsense. Scrith and gravity generators, exact design will be left as an exercise for the curious reader.
What are they teaching kids in school these days? Sheesh.
Until they used up Halley’s Comet. Because, according to Futurama, that’s the only source of ice in the solar system without giant bugs.
I’m glad you clarified what a “rectenna” is. I was really, really afraid it was going to be something very different.
The laws of thermodynamics are pretty clear on the issue of waste heat. No matter what useful energy you get out of a process, nothing is 100% efficient. Many processes have a calculated maximum efficiency and this can be pretty low. For example, metabolizing carbohydrates can’t be more than about 50% efficient, no matter how fine-tuned the system is.
If we had massive ships that were like barges, except they carried extremely low cost, high density batteries and they were somehow solar powered I could see it being feasible. The ships would have to carry thousands of tons of batteries I’m sure, if not more. But the cost of a ship going to/from the earth would have to carry a lot of electricity to be cost competitive with technologies on the earth which are also going down in price.
have the dyson sphere constantly reform (eg made up of loads of orbiting space stations or whatever which can rotate so the whole thing is roughly shaped like something) into a zone plate which focuses the suns rays onto the earth
That’s because the Dyson equipment produces smooth energy conversion, without the buffeting and choppiness of conventional blades.
The point of space-based energy collection is not to get energy to earth (beyond a certain point) - you cannot divert that much more energy on to the planet before heat buildup becomes a problem. The point of a Dyson sphere was to collect the entire output of the sun for space-based projects - planet disassembly to make the components of the sphere (assuming you have any planets left by this stage), manufacture of goods, living habitats, laser-powered interstellar craft, things like that. A chunk goes into maintaining the sphere itself - a rigid sphere is impossible (as noted above due to material strength limits), and a full cloud is not stable and requires energy to keep all the components in orbit. Most of that energy will eventually be re-radiated as IR radiation having done some work on the way through the sphere.
Ah yes - Dyson Engineering, you can be full of it and still suck 