In case anyone was wondering, like me, what the MJy unit in the lower diagram is: It's Mega-Jansky. Just funny that it's then being rescaled by 10^-9. Why didn't they use Milli-Jansky in the first place?

https://en.wikipedia.org/wiki/Jansky

Fund the SGL Telescope!

https://www.universetoday.com/149214/if-we-used-the-sun-as-a...

Seriously, we could build that, it's at the limit of our tech but if it was either we walk on the moon again or build SGL, I'd pick SGL

If the lens curved light back toward us, could we see earth several million years ago?

This is seriously cool. One lens galaxy is amazing, but two! (Too bad that this is not steerable.)

Underlying paper: https://arxiv.org/abs/2411.04177

One fun thing think about is that these two galaxies are only aligned from our perspective in the universe. Viewed from a different location, and they're just two normal galaxies.

Also, imagine having the technology to send signals through the lens and get the attention of intelligent life on the other side.