https://www.sciencealert.com/einstein-s-cross-is-helping-measure-the-spin-of-distant-supermassive-black-holes
Einstein's Cross Is Helping Measure The Spin of Distant Supermassive Black Holes : ScienceAlert
Jul 4, 2019 - The rotation of giant discs of dust and gas swirling into supermassive black holes billions of light-years away may sound like a difficult thing to measure,...
einstein s cross
https://www.science20.com/news_articles/q22370305_einsteins_cross_under_the_gravitational_microlens-162463
Q2237-0305: Einstein's Cross Under The Gravitational Microlens | Science 2.0
Astrophysicists have obtained precise measurements for an object orbiting a black hole five billion light years away - and the innermost region of a disc of...
einstein s crossunder the