Finally, if we limited ourselves to earth-based raw materials, we would eventually reach a point where the remaining mass of the earth would have less gravitational effect on the satellite fleet than the fleet itself, which would have deleterious effects on the satellite fleet.
Seven reasons are intuitive; I’m sure there are many others.
And the robot army being used to do the construction and resource extraction will likely have a much shorter lifespan. So needs to be self-replicating/repairing/recycling.
> What do you think the limiting factor is?
You need to be able to harness enough raw material and energy to build something that can surround the sun. That does not exist in the solar system and we do not yet have the means to travel further out to collect, move, and construct such an incredibly huge structure. It seems like a fantasy.
You don't build a rigid shell of course, you build a swarm of free-floating satellites in a range of orbits.
See https://www.aleph.se/Nada/dysonFAQ.html#ENOUGH for numbers.
There is plenty of material in the solar system (see my other response), and plenty of orbits, and launch capability can scale with energy harvested so the launch rate can grow exponentially.
Lots of people will probably decide they don't want any more satellites. But it only takes a few highly determined people to get it done anyway.
Also, he literally said it was a joke, and was miffed that he was best know for something he didn't take seriously.
The Earth's crust has an average thickness of about 15-20 km. Practically we can only get at maybe the top 1-2 km, as drill bits start to fail the deeper you go.
The Earth's radius is 6,371 km.
So even if we could somehow dug up entire crust we can get to and flung it into orbit, that would barely be noticeable to anything in orbit.
Do tell.
The manufacturing scale comes from designing factory factories. They aren't that far in the future. Most factory machinery is made in factories which could be entirely automated, so you just need some robots to install machines into factories.
That would suck to do to Earth, but we can launch all of Mars's mass into the swarm.
To be fair, he later added this:
>in a later interview with students from The University of Edinburgh in 2018, he referred to the premise of the Dyson sphere as being "correct and uncontroversial".[13] In other interviews, while lamenting the naming of the object, Dyson commented that "the idea was a good one", and referred to his contribution to a paper on disassembling planets as a means of constructing one.
Sources are in: https://en.wikipedia.org/wiki/Dyson_sphere
That's how that argument sounds like, particularly when you hear it from someone who is as broke as it can be.
It's easy to type those ideas in a comment, or a novel, or a scientific paper ... bring them to reality, oh surprise! that's the hard part.
1: The dumb version to invest
> correct and uncontraversial
From the original quote it is clear he was referring to the idea of aliens being detectable by infrared because they will absorb all of their sun's energy. Later in the same paragraph he says:
> Unfortunately I went on to speculate about possible ways of building a shell, for example by using the mass of Jupiter... > These remarks about building a shell were only order-of-magnitude estimates, but were misunderstood by journalists and science-fiction writers as describing real objects. The essential idea of an advanced civilization emitting infrared radiation was already published by Olaf Stapledon in his science fiction novel Star Maker in 1937.
So the Dyson Sphere is a rhetorical vehicle to make an order-of-magnitude estimate, not a description of a thing that he thought could physically exist.
Full quote from the video cited before "the idea was a good one":
> science fiction writers got hold of this phrase and imagined it then to be a spherical rigid object. And the aliens would be living on some kind of artificial shell. a rigid structure surrounding a star. which wasn't exactly what I had in mind, but then in any case, that's become then a favorite object of science fiction writers. They call it the Dyson sphere, which was a name I don't altogether approve of, but anyway, I mean that's I'm stuck with it. But the idea was a good one.
Again he explicitly says this "wasn't exactly what I had in mind." This one hedges a bit more and could be interpreted as his saying the idea of a Dyson Sphere is a good one. He may have meant that in the sense of it being a good science fiction idea though, and he subsequently goes on to talk about that.
The Dyson Sphere is good for order-of-magnitude calculations about hypothetical aliens, and also for selling vapourware to the types of people who uncritically think that vapourware is real.
A reason. I'm sure that theoretically it's possible, assuming infinite money and an interest to do so. But literally, why would we? There's no practical ways to get the power back on earth, it's cheaper to build a solar field, etc.
And I don't believe datacenters in space are viable, cost wise. Not until we can no longer fit them on earth, AND demand is still increasing.
He thought SETI listening to space radio waves was dumb, so made essentially a satirical paper saying we should look for heat instead, because "an advanced civilization would be using these Shells to capture all star energy, so we could only see the heat"
The "dyson sphere" was a made up and entirely unfounded claim, without justification.
He was throwing shade.