Today, we celebrate the award of Nobel Prize for the detection of Gravitational Waves (GW) to Rainer Weiss of MIT, Barry Barish and Kip Thorne of Caltech. Along with Ron Drever (1931 - March 2017), they were the founders of the Laser Interferometer Gravitational-Wave Observatory (LIGO) which detected GW for the first time in 2015.
Almost 100 years ago, Einstein's general theory of relativity had predicted that some of the energy of violent astrophysical phenomena would radiate out gravitational waves but the detection of GW has been difficult because the size of disturbance GW would produce at the Earth is very very small. Instruments in Washington State and in Louisiana simultaneously observed GW signals originating from two massive black holes spiraling to become one some 1.3 billion years ago! It is estimated that three solar masses were converted into GW in less than a second.
The VIDEO How to detect gravitational waves - LIGO Simply Explained is worth a look too. It does a great job of explaining the operation of the LIGO instrument in three minutes.
This week a third interferometer (called VIRGO) in Italy was involved with LIGO to observe another GW signal and it seems that GW detection is ready to take off as a completely new way of observing some unique features of the Universe.
Indirect evidence for gravitational waves has been accumulating since 1919 when Eddington observed bending of light from a distant star by the Sun in accordance with the predictions of the general theory. A landmark discovery by Taylor and Hulse of the binary pulsar PSR B1913+16 allowed observations leading to the most rigorous test of the general theory. Binary pulsars are two neutron stars rotating round each other - according to the theory of general relativity they will radiate energy in the form of GW and this can be estimated by the change in their rotational energy.
More on Gravitational Waves may be found here
In the following I provide links to my talks at the Life Long Learning Centre at the University of Strathclyde and also at East Kilbride James Watt Auditorium. The talks are suitable for most people with a school background in science and were prepared to celebrate Albert Einstein's life and work.
Please click on the lines below to see the slides of the talk