Comments on: AAS #12: Einstein’s Double Bulls-eye

By: Hubble spies eye in the sky | Bad Astronomy | Discover Magazine

Hubble spies eye in the sky | Bad Astronomy | Discover Magazine — Wed, 08 Oct 2008 17:00:09 +0000

[...] The "pupil" of the eye is actually a galaxy about 2.2 billion light years from Earth. That’s a fair bit! But it happens to sit almost directly between us and a much more more distant galaxy — one that is 11 billion light years away. As the light from the background galaxy passes by the nearer one, the gravity of the nearer one bends the path of that light, twisting it in what’s called a gravitational lens. [...]

By: Rob

Rob — Sat, 12 Jan 2008 16:39:28 +0000

Sort of an idle wonderment, but I wonder what astronomers would have made of such distorted images if GTR hadn’t been invented.

Maybe that they’d discovered the Ringworld.

By: Allen Thomson

Allen Thomson — Fri, 11 Jan 2008 16:08:42 +0000

Sort of an idle wonderment, but I wonder what astronomers would have made of such distorted images if GTR hadn’t been invented.

By: Conservation of Trolls

Conservation of Trolls — Fri, 11 Jan 2008 15:46:36 +0000

[...] I’m not even going to try to explain this, since Phil Plait explained the phenomenon perfectly here. [...]

By: YinYang0564

YinYang0564 — Fri, 11 Jan 2008 09:16:56 +0000

I think I have just read the best description of gravitational lensing I have seen. Thank you, Phil.

By: Kaptain K

Kaptain K — Fri, 11 Jan 2008 08:37:55 +0000

“…if we can find as few as 50 of these double rings…”

Now there’s an optimist for you! We finally find ONE and he says “if we can find as few as 50″! :0

By: Gary Ansorge

Gary Ansorge — Fri, 11 Jan 2008 02:30:12 +0000

ACK! The steam engine. It’ll put out everybody out of work,,,

,,,or not,,,

GAry 7

By: blizno

blizno — Fri, 11 Jan 2008 01:58:55 +0000

Gary Ansorgeon 10 Jan 2008 at 10:46 am

“I guess that would also mean, the galaxies beyond the nearer galaxy can see us too??

ACK! MAn all battle stations. The Aliens can see us!!!”

They are right now seeing us as we were 6+ billion years ago. I doubt that those distant aliens are alarmed enough to launch a faster-than-light attack against the dusty disk forming around proto-Sol.
It’s only the aliens a few hundred light years away from us who might be alarmed by our harnessing the horse and eventually…the steam engine.

By: Jeffersonian

Jeffersonian — Thu, 10 Jan 2008 23:17:52 +0000

[retrieves skullcap from across room]

By: Jack Hagerty

Jack Hagerty — Thu, 10 Jan 2008 20:35:31 +0000

tacitus: “given the amazing stuff we can do with warped images these days (i.e. Hubble’s mirror problem) I was just wondering if anything can be done at all.”

Just to be pedantic, Hubble’s mirror was not warped. It was ground to the wrong figure. It was actually very, very precisely ground wrong; it just focused at the wrong spot. That’s why they were able to fix it by placing a corrective mirror in the optical path, exactly the way human vision problems are corrected.

- Jack