Theory of General Relativity
NASA’s Roman Mission Might Tell Us if the Universe Will Tear Itself Apart in the Future
NASA's Nancy Gracy Roman Space Telescope won't launch until 2027, and it won't start operating until some time after that.…
Two Stars Do a Short-Orbit Tango Around the Milky Way’s Black Hole
Astronomers have known for some time there was one star orbiting fairly close to the black hole at the center…
Podcast: Einstein Was Right
At least once a week we get an email claiming that Einstein was wrong. Well you know what, Einstein was…
Gravity Probe B Confirms Two of Einstein’s Space-Time Theories
[/caption] Researchers have confirmed two predictions of Albert Einstein's general theory of relativity, concluding one of NASA’s longest-running projects. The…
Message in a Wobble: Black Holes Send Memos in Light
[/caption] Imagine a spinning black hole so colossal and so powerful that it kicks photons, the basic units of light,…
Einstein’s General Relativity Tested Again, Much More Stringently
[/caption] This time it was the gravitational redshift part of General Relativity; and the stringency? An astonishing better-than-one-part-in-100-million! How did…
What is an Event Horizon?
The event horizon of a black hole is the boundary ('horizon') between its 'outside' and its 'inside'; those outside cannot…