Python -O won’t magically make every script faster, but in the right workloads it’s a free win—here’s how to test it safely.

Virgin Galactic has unveiled its Delta spaceship. It is designed to fly more frequently than its predecessor with more passengers. Credit: Virgin Galactic Satellite images of the secretive US military ...

Turn your phone into a portable planetarium, map the night sky and discover the best place and time to observe February's solar eclipse, with the best stargazing apps.