Have gravitational waves been proven to exist 100%? Or are astrophysicists only about 99.9% sure that they are real? I read in a book by Timothy Ferris that some people from Princeton proved pretty much beyond a shadow of a doubt that they exist, but I wanted to make sure. Thank you for your time.
Gravitational waves are predicted by general relativity, which is one of the most well-supported theories in science. The first, indirect evidence for them has been from the decay of the orbits of close binary pulsars, which are predicted to emit gravitational waves. Astronomers find that the orbits decay at exactly the correct rate predicted by the theory of gravitational radiation and have no other explanation available.
On February 11, 2016, the LIGO collaboration announced the direct detection of gravitational waves from a double black hole system. Most recently, the first detection of gravitational waves from a neutron star binary was also confirmed in 2017 by LIGO.
I also want to point out that nothing in science is proven 100%, beyond any shadow of a doubt. The best you can do is to say that something is "so well supported that it would be perverse to deny it." Even such "facts," however, have been falsified from time to time. All scientific findings are tentative by their very nature.
Here are some pages with more information on binary pulsars:
- Nobel Prize in Physics 1993 - discovery of the binary pulsar: http://www.nobelprize.org/nobel_prizes/physics/laureates/1993/illpres/discovery.html
- The binary pulsar: http://www.astro.cornell.edu/academics/courses/astro201/psr1913.htm
- Binary pulsars and general relativity: http://hyperphysics.phy-astr.gsu.edu/hbase/astro/pulsrel.html
- Binary pulsars: https://astronomy.swin.edu.au/cosmos/B/Binary+Pulsars
This page was last updated on January 28, 2019.