Gravitational Lens (APOD 24May06)

[donax]

Dear List,

After trying to understand ap060524 I wrote this message
and hoped that it would reach Jerry Bonnell (maybe it did:-)

I have tried so much to get the text and picture of a
gravitational lens to fit together but I think there must be an
error, the picture may be turned and mirrored as far as I can guess.

As a non astronomer it is very hard to understand a picture,
and phenomena like this are especially hard.

Eran Ofek has a site with a similar picture on which he has
drawn some circles and has marked the quasars and galaxies.

His picture is turned some degrees and is mirrored in relation
to the APOD picture. Eran Ofek has marked only 4 quasars on his
picture. An insertion is marked Q5 but is probably a long distance
from 1 to 4. I "cc" his AstroClub on this.

The galaxies mentioned are even harder to find, and I fear
that some amateurs (like me) will feel left alone here.

Maybe some words of explanation on some soon-to-come APOD
would help amateurs a lot, and preferably with the circles from
Eran's picture which also shows "the lenses". In this way I think
that amateurs will become happy watchers with much curiosity and
no fear :-)


Regards/Donald Axel

[nicolecattaneo]

The main reason for your confusion is that gravitational lensing is THEORETICAL. I believe tt is one of Einstein's theories. I, along with you, have a very hard time seeing the supposed "mirror" images. I e-mailed Mr. Bonsall to ask him clarify when things on the APOD site are theoretical and not proven. He didn't really reply except to send me to some strange website. I think he understood what I was trying to say though. I am glad I finally signed up to this forum, it should be interesting

[harry]

Hello All

Graviational Lensing is not theoretical.
Its only theoretical to those who still think in theory.
See link with 32 items on lensing.

http://antwrp.gsfc.nasa.gov/cgi-bin/apo ... ch?Lensing