What does syzygy mean in astronomy?
We can now observe the motions of millions of stars through the sky.
What astronomers observe, and what people think they observe are very different.
Lots of objects in the night sky are green, but they are green for a variety of different reasons.
The level of precision in astronomical data is amazing.
The laws of physics conspire to keep you trapped within a black hole. You could no more escape a black hole than you could walk backwards in time.
Cosmic rays are powerful. Too powerful, in fact.
Stars get warmer as they age, which means there was a time when our Sun was too cool to liquify water on Earth. But the evidence is clear water existed on Earth for much longer. What gives?
Nothing can be colder than absolute zero, or can it? Arthur Eddington wrestles with the paradox of stellar thermodynamics.