[Red Badger]

Hiding in plain sight Ping!..............

[Wuli]

“NGC 6505 is a well-known galaxy only around 590 million light-years from Earth”

“only” LOL

[Ken522]

So what galaxy is getting the “Einstein ring” treatment from a mere 500-odd million light years away?

[No name given]

Cool pictures.

[rktman]

I knew I set it down someplace.

[Magnum44]

[ProtectOurFreedom]

Thanks for posting, Red. This is really astonishing in so many ways.

The article says "...this perfectly formed Einstein ring stands as both a testament to Euclid’s capabilities and a preview of discoveries to come."

Yes, but it is more of a testament to the genius of Albert Einstein to predict these rings caused by gravitational lensing.

I was taught (generations ago) that photons were massless particles which begs the question as how they could be affected by gravitational fields. I asked Grok "Do photons have mass?" and it replied:

No, photons do not have mass in the traditional sense. According to the standard model of particle physics and established theories:

• Rest Mass: Photons are massless particles. They have zero rest mass (invariant mass), which means they do not have mass when they are at rest. However, photons are never at rest—they always travel at the speed of light (c) in a vacuum.
• Energy and Momentum: Even though photons have no rest mass, they do carry energy ((E)) and momentum ((p)).
• Implications of Masslessness:

  Photons always travel at the speed of light ((c)) in a vacuum, which is a fundamental consequence of having zero rest mass.

  They are affected by gravity not because they have mass, but because gravity warps spacetime itself (as described by General Relativity), and photons follow the curved paths of spacetime.

---

So there you have it. Photons are massless but gravity warps spacetime and photons follow those warped spacetime paths causing gravitational lensing.

Clear?

[alexander_busek]

I wonder if Euclid (or any other telescope) will ever discover Einstein rings displaying multiple images of the same galaxy at distinctly different periods of times, and with sufficient resolution to make it possible to make substantive statements about the distant galaxy's evolution over time.

In the case of a nearly "perfect" Einstein ring like the one discussed in this article, the different paths the light from the original galaxy takes are more or less equal in length, and thus show the galaxy at basically the same moment in time.

But imagine an Einstein ring with images of the same galaxy at different ages - separated by, say, 100 million years (because the paths were 100 million light-years shorter or longer)!

Regards,

[Nateman]

[SuperLuminal]

Outstanding work...