Megastructures are big. Really big. You just won’t believe how vastly, hugely, mind-bogglingly big they are. I mean, you may think you live in a big city, but that’s just peanuts to even the smallest megastructure.
Three of the more famous megastructures:
- A Halo installation: 10,000 km by 318 km (¹)
- A Culture Orbital: 3,000,000 km by 12,000 km
- Larry Niven’s Ringworld: 299,200,000 km by 1,600,000 km (²)
Oh, and the Sun for scale. It’s at the end of the video, the small white dot in the middle of the Ringword’s… er… ring. Radius 695,700 km.
Rendered with https://threejs.org/editor/
¹ Do not put a big ring this close to the ground. If you do, the heavy stuff of the ring will pull on the big deep water between land, making the water go very high and over everything, and everyone will have a bad day and not go into space ever.
² A Dyson sphere is the same size, but fully encloses the star instead of just encircling it