A novel proposal says that we should look for alien megastructures. But can we really expect an alien civilization to build them?

The massive structure designed to capture the energy of an entire star envisioned by Freeman Dyson is popular in science fiction. But can we build it? And have alien civilizations tried a similar idea?

No, a Dyson sphere around our sun isn't a plausible project for the next few thousand years. And maybe not even then.

Would aliens actually want to build a Dyson Sphere? It wouldn't be out of reach for them, but they might get a lot less power out of it, with a lot less utility than it seems at first glance...