Einstein's general theory of relativity beautifully describes the nature of gravity and its effect on large objects in the universe. However, there are alternative explanations.
Astronauts on the International Space Station do not even have sinks because of the way water behaves in microgravity.
Stronger gravity requires stronger—and pricier—rockets to overcome.
Scientists hit the road with a high-precision clock hooked up to a trailer.
Weak nuclear force is stronger than gravity, but weaker than, you know, strong nuclear force.
The recently patented technology could one day save an astronaut from becoming lost in space.
The astrophysicist most recently chimed in about "Titanic." Is he veering away from his strictly science-based reviews?
The galaxy in question appears as it was 11 billion years ago, just 2.7 billion years after the Big Bang.
Einstein predicted that gravity and light could be used to calculate the mass of a star. But he never thought scientists could actually do it.
The theory breaks with the popular idea that expansion is caused by dark energy and suggests energy for expansion would never run out.
An American flight engineer who landed back on Earth in Kazakhstan Monday documented his months-long journey on social media.