19
The megastructure first proposed by physicist Freeman Dyson may be possible, but with very specific limitations.
8
Analyzing astronomical data for evidence of alien technosignatures could point us to extraterrestrial civilizations.
4
The man who envisaged that an alien race could build a 'Dyson Sphere' around its star has died aged 96.
112
Could an alien civilization build a large spherical energy-harvesting structure around a distant star ?