Originally posted by twhitehead
Given that we know nothing about what some alien civilization might be doing with their Dyson sphere it seems rather premature to make any conclusions about it.
There is no reason to think it is a complete sphere. It could be something as simple as a very large solar sail type structure. And they could be moving it around or adjusting it over time depe ...[text shortened]... craft and then saying: it can't be a spacecraft, it doesn't have wings. I would have made wings.
Very VERY large structure for sure. I wonder what size telescope it will take to suss out just what is going on? 1200 light years is pretty close on a galactic scale, since the milky way is 200,000 light years across. Not going to be going there any time soon though🙂
Assuming the star is 1.6 million km diameter, at that distance it works out to an arc second size of 18.5 MICRO arc seconds. Taking Hubble to have a resolution of 50 milli-arc seconds at a mirror size of 2 meters, 1000 X bigger would still leave it at 50 micro arc seconds so it might take 10000X bigger or a mirror effective size of 20,000 meters or 20 km. It could be done but nobody is going to make a single mirror that large so it would have to be an array of smaller mirrors with separation of 20 km like a dozen Hubble's scattered across a 20 Km area. Or something similar. Won't be seeing THAT this century either.
One problem getting higher resolution that way is they are pushing the limits already as to how far the scopes can be separated. I think max right now is less than a km.
It might be able to be made on the ground but it sure would not be cheap. Billions I would expect even if they can extend the array size to 20 km like that. I think the furthest separation now is about 300 meters or so, which would max out at about 400 micro-arc seconds.