I’ve been reading sci-fi for decades, and yet 10 minutes into an Isaac Arthur video I realise I’m still not thinking BIG enough! Can we hide from alien civilisations? It’s already too late. Forget TV and radio shows. As the great Isaac Arthur says: “We were betrayed by our own atmosphere a BILLION YEARS before life crawled onto land.”
Another comment ran along the lines of “A single Dyson Sphere* could point a telescope at every planet in the entire galaxy.”
* Note: Isaac Arthur has repeatedly stated that we cannot build actual Dyson Spheres with any known or hypothetical substance due to the centrifugal forces required to simulate one gravity, but has repeatedly stated that we can build Dyson Swarms with today’s technologies.