Light has yielded many insights into the universe over the years.

Arthur S. Eddington, world war one pacifist and one of the leaders of an expedition in 1919 to observe a solar eclipse in Principe. The deflection of light observed in the solar eclipse was predicted by Einstein's theory of general relativity.

Arthur S. Eddington, world war one pacifist and one of the leaders of an expedition in 1919 to observe a solar eclipse in Principe. The deflection of light observed in the solar eclipse was predicted by Einstein’s theory of general relativity.

The prediction and observation of stars in the sky might not sound like much, but together, they make for one of the most famous tales of physics. Ever since the early 19th century, astronomers hypothesized that some things were so massive that even light would be sucked in by their gravitational pull! It wasn’t until 1919, when the British Royal Society and Royal Astronomical Society decided to fund an expedition to Principe that this was demonstrated. The images of the stars around the sun showed positions consistent with Einstein’s theory of general relativity, and not Newtonian physics.

If you’re interested in astronomy, see what the people at the stardome are up to!

 

Bibliography

Tilman Sauer, “A brief history of gravitational lensing”, Einstein Online, http://www.einstein-online.info/spotlights/grav_lensing_history, accessed 15/09/2014

Steven S. Shapiro, Irwin I. Shapiro, “Gravitational Deflection of Light”, Einstein Online, http://www.einstein-online.info/spotlights/light_deflection, accessed 15/09/2014

Leonidas Moustakas, Adam Bolton, “Einstein Rings: Nature’s Gravitational Lenses”, Hubble 2006 Science Year in Review,  http://hubblesite.org/hubble_discoveries/science_year_in_review/pdf/2006/einstein_rings_natures_gravitational_lenses.pdf, accessed 15/09/2014

Image References

“Arthur Stanley Eddington” by George Grantham Bain Collection (Library of Congress) – Licensed under Public domain via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:Arthur_Stanley_Eddington.jpg#mediaviewer/File:Arthur_Stanley_Eddington.jpg

“A Horseshoe Einstein Ring from Hubble” by Lensshoe_hubble.jpg: ESA/Hubble & NASAderivative work: Bulwersator (talk) – Lensshoe_hubble.jpg. Licensed under Public domain via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:A_Horseshoe_Einstein_Ring_from_Hubble.JPG#mediaviewer/File:A_Horseshoe_Einstein_Ring_from_Hubble.JPG