Wondering about the Einstein Cross.

First, I need to explain gravitational lensing to you, unless you know all about it.  For those of you who aren't astronomers and don't know what it is, I will try to tell you.  A huge body has gravity and will attract other things.  It is something like magnetic forces but a lot weaker.  Oh, you thought gravity was stronger than a magnetic force.  Well, it could be if the thing we are talking about is very massive, but take a refrigerator magnet and I bet you can pick up a paperclip with it, right.  See, in this case the magnetic force on that paper clip was stronger than the earth's gravity.  Now, if we could stand on a planet the size of a massive star, that same magnet couldn't pick up that paperclip.

Now, there are things out in space that are so massive that their gravity can bend light.  This causes something that would normally be hidden behind it to be seen to the side of it or it will smear it around it like a halo.  How about an example.  This first picture shows the background galaxies smeared around a closer galaxy:

Now that is perfect example of gravitational lensing.

OK, now to get to the title, the Einstein Cross.  The center galaxy in the next picture (actually they are quasars, but I don't want to confuse you), has the other further away galaxy that is directly behind it projected as four galaxies around the center, closer one.  This picture is the Einstein Cross:

 

The reason it is named after Einstein is that it proves his theory that even light is affected by gravity.  Actually, the first picture shows the usual way this lensing would appear and the second picture is a rather rare type of lensing.

Now, an update for yesterday's blog.  We purchased a holder for the bird feeders that will get them away from the trees and, hopefully, the squirrels.  It can support two feeders from thin steel rods that will give the squirrels a real challenge when trying to raid the feeders.  Later, the smaller feeder will be replaced with a hummingbird feeder.  Here is a picture:

Now, I hope you all will be well fed, too, and I sure do want you to have a great day, you hear?