#relativity

#relativity

When you view anything at all in the Universe, you're not seeing it precisely as it is right now: at the moment you experience seeing it. The speed of light, even though it's the fastest speed that any signal can travel throughout the Universe, is still finite. No matter how close or distant an object is, you're only seeing it as it was a particular amount of time ago: at the moment the now-arriving light was emitted from the object you're observing.

Nothing can exceed the ultimate speed limit set by the laws of physics, known as the speed of light in a vacuum, or 299,792,458 m/s.

Black holes could be the key to a quantum theory of gravity, providing a deeper understanding of how reality, space, and time works. They are regions of space from which even light can't escape, and have fascinated physicists since their theoretical predictions, which date back to the early 20th century. The existence of black holes forces physicists to think about both quantum theory and general relativity together, highlighting the need for a unifying theory or quantum gravity.