1782 - John Goodricke[?] notices that the brightness variations of Algol are periodic and proposes that it is partially eclipsed by a body moving around it
1964 - Subrahmanyan Chandrasekhar and Richard Feynman develop a general relativistic theory of stellar pulsations and show that supermassive stars are subject to a general relativistic instability
... \left( \frac{b}{a} \right) x + \frac{c}{a}=0
</math>
which is equivalent to
<math>x^2+\frac{b}{a}x=-\frac{c}{a}.</math>
The equation is now in a ...