Hitting the Books: We'd likely have to liquidate Jupiter to build a Dyson Sphere around the Sun

The gargantuan artificial construct enveloping your local star is going to be rather difficult to miss, even from a few light years away. And given the literally astronomical costs of resources needed to construct such a device -- the still-theoretical-for-humans Dyson Sphere -- having one in your solar system will also serve as a stark warning of your technological capacity to ETs that comes sniffing around. Or at least that's how 20th century astronomers like Nikolai Kardashev and Carl Sagan e...