How can we see black holes? | ScienceBlogs
"According to the special theory of relativity nothing can travel faster than light, so that if light cannot escape, nothing else can either. The result would be a black hole: a region of space-time from which it is not possible to escape to infinity." -Stephen Hawking You may have encountered objects that are the same size as one another, but have very different masses.
Source: scienceblogs.com