Gravitational Lensing

Because of Einstein's famous E=mc^2, energy and mass are the same thing. That means that light is bent by massive objects, just as the flight path of a baseball is bent by the Earth's gravity. Light doesn not bend sharply because it is moving so fast, but it can bend enough around a large cluster of galaxies so that you can see the same background object on both sides of the cluster.

This shows a Hubble image of CL0024 (a large galaxy cluster) where six images of the same blue background galaxy can be seen. The light from the background galaxy is bent by about 1 minute of arc (1/60 of a degree) as it passes the cluster.

Category:

Science & Technology

Tags:

• astronomy
• HST
• Hubble
• CL0024
• galaxy
• cluster
• quasar
• telescope
• lens