This eight-minute Hubblecast video takes a look at gravitational lensing, explaining how it works and how it can help astronomers uncover the secrets of the Universe.
Hubblecast 70: Peering around cosmic corners
Last month saw the inauguration of a new Hubble observing program: Frontier Fields. This will use the powerful magnifying properties of massive galaxy clusters to peer even deeper into the space around us. Hubblecast 70 takes a look at this phenomenon — known as gravitational lensing — exploring how it works, and how it can help us to uncover the secrets of the very distant Universe.
Credit:
ESA/Hubble
Directed by: Nicola Guttridge
Visual design and editing: Martin Kornmesser
Written by: Nicola Guttridge & Georgia Bladon
Presented by: Joe Liske (Dr J)
Narration: Sara Mendes da Costa
Images and animations: ESA/Hubble, NASA, Martin Kornmesser
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2 Comments
The idea of gravity lensing is based on refraction of light due to gravity not deforming space. Einstein’s idea of deforming space is incorrect. The matter creates a velocity field v^2 = GM/r. The redshift is v/c= 1/n.
The universe is not expanding, it is in equilibrium when v/c=1 when v=c.
Hello! Wardell! You are making whole Physics topsy turvy by your ‘ingenious’ arguments. Well!Do you know that there is a basic difference between gravitational bending and refractive bending ? Gravitational bending is a collective bending of the whole spectrum of light by virtue of the lightest photon experiencing mass in extreme gravity of Dark Matter or any Black hole for that purpose. Whereas refractive bending is due to the different velocities of light wave for different wavelengths and dispersal is automatic thereby. Thus it is a case of bending without dispersal and bending with dispersal. Thus your case of refraction of galaxies will result in panaromic color of the same galaxy as against kaleidoscopic multiplicity of the same galaxy by its lensing effect. Moreover the speed of the light will retard down in any denser media other than vacuum,its velocity being greatest in vacuum “c”. Moreover the ray will bend outwards to produce the required lensing effect only when the light travels from a denser to rarer medium. Wardell’s case of refraction will leave the ray bending inwards the normal and thus there will be no lensing effect. Above all I have already written in one of my comments and analysis that a Uniform Universe will leave the galaxies uniformly spread out in a spherical volume. But actually the accelerating universe presents a paraboloid of cluster of galaxies. In the absence of the superpower it is not possible to explain that ordinary gravity alone has got the strength to drive apart all the galaxies with astounding velocity. Doppler attenuation and red shift clearly speaks of this and there is no doppler dispersion or refraction as argued. When you gainsay anything, it is well and good only if you prove within the physical nature of matter and energy. Thank You.