Gravitational Lens

[Vikrant]

I have been fascinated by gravitational lens. They are one of the many wonders of the cosmos. Gravitational lens is a galaxy whose gravity is so strong that light passing through it gets bent just like light passing through an optical lens would creating a lens. Gravitational lens lies between an observer and the galaxy (object of observation) in a straight line alignment. When you observe an object (e.g. a galaxy) through a gravitation lens, the object appears brighter and bigger. Hubble telescope just discovered a gravitational lens about 9.6 billion light years away, which means we are looking at this gravitational lens as it was 9.6 billion years ago.

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Hubble Discovers Most Distant Gravitational Lens Yet | Astronomy | Sci-News.com

 

[Mr. H.]

Physics is phun.

 

[Delta4Embassy]

I have been fascinated by gravitational lens. They are one of the many wonders of the cosmos. Gravitational lens is a galaxy whose gravity is so strong that light passing through it gets bent just like light passing through an optical lens would creating a lens. Gravitational lens lies between an observer and the galaxy (object of observation) in a straight line alignment. When you observe an object (e.g. a galaxy) through a gravitation lens, the object appears brighter and bigger. Hubble telescope just discovered a gravitational lens about 9.6 billion light years away, which means we are looking at this gravitational lens as it was 9.6 billion years ago.

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Hubble Discovers Most Distant Gravitational Lens Yet | Astronomy | Sci-News.com

Isn't this how they confirmed parts of General Relativity which predicted stars behind our Sun would become visible?

 

[Vikrant]

Orest Chwolson was the first one to discuss Gravitational Lens in his paper. I think it was in 1924.

Theory of General Relativity, which primarily is a geometric model of gravity also talks about regions of space where matter is so dense that the gravity arrests light. This was confirmed by physicists later with discovery of existence of black-holes. Indian-American physicist Chandrasekhar was awarded Nobel prize for his work on black-holes. He is credited with calculating a limit (mass) which if surpassed will result in collapse of the star and formation of black-hole. It has been confirmed that light bends when it passes near a black-hole. Anyway, yes, Einstein's work predicted things like bending of light, black-holes, etc.

But, it was Chwolson who first specifically talked about Gravitational Lens.