Scientists have long considered black holes to be dark vacuums in space that continually suck in material around them but, according to famed theoretical physicist Stephen Hawking, these holes are much more complicated and may not even be as black as initially thought.

At a speaking engagement at Harvard University on Monday, April 18, Hawking discussed his work on black holes as well as the information paradox, a theory that suggests the physical information of an object absorbed by a black hole becomes permanently lost.

This contradicts the long-held belief by scientists that information regarding a system at one point can still be used to find out its nature regardless if the system enters a different state later on.

"It is said that fact is sometimes stranger than fiction, and nowhere is that more true than in the case of black holes," the Cambridge theoretical physicist said.

"Black holes are stranger than anything dreamed up by science fiction writers, but they are clearly matters of science fact."

Hawking added that scientists have struggled to understand black holes, with many theories developed over the years only ending up contradicting one another and affecting people's understanding of what the universe is.

Some early theories suggested that black holes no longer have any information regarding the celestial body from which they were formed. The only information they are able to retain are about their angular momentum, their electrical charge and their mass.

Hawking said that the final state of a black hole does not have any clues about whether the celestial body that it was created from was made of matter or antimatter.

If this theory were to be upheld, then it would mean that identical black holes could be created using matter in an endless number of configurations. However, this was contradicted using quantum mechanics, which suggests that black holes could be formed only by amassing particles that have very specific wavelengths.

This conflict of ideas is what led to the information paradox regarding black holes, according to Hawking.

He said that if black holes are still able to retain information about the body that they originated from, it would mean that they contain a large amount of hidden information.

Hawking started to challenge the notion in 1974 that no material can escape a black hole's vacuum after he spotted particles coming from a hole in space at a consistent rate.

The discovery of this outflow of particles, which was later named Hawking radiation, helped advance scientists' understanding of black holes. It showed that some forms of energy could still escape these vacuums in space.