Ian Vega

A stick thrown into a pond sinks straight down. But if the pond's water is slowly rising, the stick will be delayed and sink somewhere unexpected. So it is with black holes: we usually assume they sit in a void, but the entire universe is gently stretching. This stretch, like the rising water, slightly alters the path of anything orbiting nearby.

From the center of a galaxy, where a black hole lurks, narrow jets of hot gas shoot out in opposite directions. They shine across vast distances, sometimes longer than the galaxy itself.

A wormhole is a tunnel connecting two distant regions of the universe. If such a wormhole existed and were traversable, a particle inside it would feel not only gravity but also a force from its own electric field. This force depends on how spacetime is curved around it.