Neither wormholes or black holes have actually ever been seen directly, even with the sophisticated equipment in use today, but both follow inevitably from Albert Einstein’s General Theory of Relativity, and plenty of indirect evidence has been obtained (at least for black holes). The ideas have certainly been more than readily accepted by the science fiction community, for whom they suggest intriguing possibilities.
One of the most famous black hole theorists, the British physicist Stephen Hawking, proposed the four laws of black hole mechanics back in the 1960s, and calculated in 1974 that black holes should thermally create and emit sub-atomic particles, known today as Hawking radiation, until they eventually exhaust their energy and evaporate. Yet, as recently as 2004, he admitted to losing a bet he made with the Caltech physicists Kip Thorne and John Preskill, and overturned his long-held belief that any “information” crossing the event horizon of a black hole is lost to our universe, and is now convinced that black holes will eventually transmit, albeit in a garbled form as we perceive it in our observable universe, information about all matter they swallow (“information” in this sense may be loosely defined as “that which can distinguish one thing from another”, and essentially refers the identity of a thing and all of its properties).
This is a good indication that the theory is far from cut and dried, and research (both theory and observation) into this challenging area proceeds unabated. As an example of the complexity of the subject matter, a short quote from Professor Hawking’s 2004 presentation may suffice: “The Euclidean path integral over all topologically trivial metrics can be done by time slicing and so is unitary when analytically continued to the Lorentzian”. Wow!