The "Terminator" movie franchise has built a cult following since it was first shown in theaters in 1984. Back then, the idea of learning and thinking machines was merely science fiction to most viewers — a very interesting and entertaining one at that — but the concept now after 30 years is no longer that far-fetched. Robotics engineering has come a long way.  The study is delving deeper into artificial intelligence, and developers are coming up with a variety of software and hardware that have some form of perception, reasoning, and learning abilities.

At present, prototype cars that can drive on their own have already made the headlines. Computer keyboard apps designed to predict what the user is going to type is no longer new. Digital assistants can take simple instructions. Robot guards make the rounds. But this set of examples is just the tip of the iceberg because researchers and developers are far from done trying to develop full thinking machines.

But while AI is both exciting and useful, it can also be perilous. Acclaimed theoretical physicist and cosmologist Stephen Hawking gave a warning that machines that can think for themselves pose a threat to the very existence of humans.

In a recent interview with BBC, the 72-year-old scientist said, "The development of full artificial intelligence could spell the end of the human race."

The current form of AI that humans are using is still rather primitive and, as Cleverbot creator Rollo Carpenter said, there is still a long way to go before full AI is actually achieved. The thing is, AI evolves at a faster speed than humans, thus its development would, at some point, overtake the thinking capacity of people.

"It would take off on its own, and re-design itself at an ever increasing rate," Hawking said. "Humans, who are limited by slow biological evolution, couldn't compete, and would be superseded."

Elon Musk, the man behind Tesla Motors, SpaceX and Solar City, is of the same opinion. While he is an investor in Vicarious, which is aiming to build a computer that can replicate some functions of the human brain, he also warns AI is like "summoning the demon" and that it is probably mankind's "biggest existential threat."

In an earlier interview, as reported by Vanity Fair, he said, "I don't think anyone realizes how quickly artificial intelligence is advancing. Particularly if [the machine is] involved in recursive self-improvement . . . and its utility function is something that's detrimental to humanity, then it will have a very bad effect."

The 43-year-old inventor explained, "If its [function] is just something like getting rid of e-mail spam and it determines the best way of getting rid of spam is getting rid of humans..."

So, perhaps the idea of Skynet is really not that far-fetched anymore.