A distant supernova appeared to explode twice, baffling astronomers. This cosmic event was explained by Einstein's theory of general relativity. Gravity bends light, causing it to take different paths. This phenomenon, called gravitational lensing, allowed sc…
When a massive star reaches the end of its life, it dies in a blaze of glory. A supernova can briefly outshine billions of stars combined. Then it fades, never to return.So when astronomers saw a dis… [+4533 chars]
