Reading this article I was puzzled by the Hubble Telescope footage be so neatly close to the animated illustration leaving no room for reality. Though the article title and content is focusing on the universe expansion rate faster than expected and also on techniques used to measure the expansion rate, this seemingly total match-up of animated illustration and footage looks so glaring or.... could be i'm missing something. I'd like to trust scientists and leave that trust intact, hence i'ill go with "i'm missing something"

Animated illustration of how gravity of a galaxy bends light to give the illusion of multiple images

Real Hubble Telescope footage

The animated diagram indicates there are four (conveniently like corners) rays coming from the distant quasar and bent by the gravity of the galaxy. While I completely see why the animation is like that (to be able to conceptually demonstrate how space warp works), in reality of space (a roughly symmetrically roundish spiral galaxy) there should be no left or right, no up or down, so in the real Hubble footage, there should be a continuous quasar light bending by the galaxy and thus instead of four corner light quasars, they should be continuously overlapping and hence the resultant would continuously overlap so much, it should appear as one - much bigger- roundish quasar.

Bearing in mind (though there are a couple of artist impressions in the article) this particular image is NOT an artist impression, it is said to be actual Hubble footage/imagery. So how come what emerges now looks similar to the animated illustration (created to make the concept understandable)?

I have, long ago, stopped saying scientists are wrong. These days I'd rather give them the benefit of doubt and rather say an explanatory gap is missing that needs to be plugged. Though... can't see how to plug the gap yet

Um, yup, based on Nypyren's comment, maybe it's some polarization effect of the lens. or.. something...

I mean the light from the object behind is polarized in a circular fashion by the object in front of it, and the lens has polarizing filter. so if you'd rotate the cam, the image of the four spots would rotate along. or.... something...

In some signals it shows up as moire patterns. In other signals it shows up as a beat or pulse. And in other patterns, it shows up as a series of neighboring items in a regular grid.

First time I heard of moire patterns, had to google it, Very interesting reads. Similar to, but a more complicated form of light wave interference's high and low trough

Even when it is circular objects creating the effects, it is perceived as an axis. In photography, circular polarizers always give a blue direction and a yellow direction even though the effect is circular. Using a variable filter, or mixing polarizers and diffusers, there will always be an X shape or + shape, no matter what orientation the filters, polarizers, or diffusers are placed.

Not being a physicist, going through some supporting articles online was burning my brain, but generally speaking I get the diffraction effect you described

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Finding a near complete ring like the one in the first post is actually pretty amazing. Though I'd wager with some better magnification, there would be some obvious imperfections (the lower left portion looks a lot fainter to me)

Speaking about perfect spherical gravitational lensing. This is a 'theoretical simulation', hence the absence of any diffraction. If lenses were near perfect, images could move close to this

[attachment=35363:grivational lensing.jpg]

Actually I found this. For extremely distant galaxies, as this real image shows ,it looks to me like the effect of polarisation is very minimal

Abell 2744 galaxy cluster - extremely distant galaxies revealed by gravitational lensing (16 October 2014).[26][27]

Light moves in perfectly straight lines. Always.

Gravitational lensing is no exception.

Gravity is a warping of spacetime itself. So, when light travels through this warped spacetime, it always goes straight but the warping of spacetime causes light to change direction.

Black holes are kind of interesting because they warp spacetime so drastically that it turns space in on itself. Light entering into this warped space will get trapped in an infinite loop. This part took me a while to understand: Black holes don't have a gravitational acceleration force which exceeds the speed of light. This can be observed by the X-Ray emissions which jet out from the poles of a black hole -- which also makes no sense because X-Rays are a form of light. I think our (or at least mine) understanding of the nature of spacetime is incomplete. I'm guessing that the rotational velocity of massive objects imparts some property to the warping of spacetime as well which allows XRay emissions to escape along the axis of rotation.