In director Christopher Nolan's new film "Interstellar," actor Matthew McConaughey's character Cooper leads a crew of astronauts into deep space on a mission to save humanity. They travel by way of wormhole, a technique that has become of trope of intergalactic science fiction. Now, the expert who oversaw the film's scientific bonafides suggests traversable wormholes are unlikely to ever be a reality.

"The jury is not in, so we just don't know," astrophysicist Kip Thorne, a researcher at the California Institute of Technology, told Space.com in a recent interview. "But there are very strong indications that wormholes that a human could travel through are forbidden by the laws of physics. That's sad, that's unfortunate, but that's the direction in which things are pointing."

Wormholes -- a component of Einstein's theory of relativity -- are interstellar tunnels that connect to disparate points on the space-time continuum. Traveling through one would be like taking a massive shortcut that bypasses vast cosmic distances.

Scientists don't have observational evidence of wormholes; they're purely theoretical. But even if they do exist, Thorne says traveling through one is probably impossible. The reason: There's no way to keep them stable and open.

"Wormholes -- if you don't have something threading through them to hold them open -- the walls will basically collapse so fast that nothing can go through them," Thorne explained.

Although previous quantum physics experiments show it's possible to generate the kind of negative energy that could theoretically open a wormhole, Thorne says: "We have very strong, but not firm, indications that you can never get enough negative energy that repels and keeps the wormhole's walls open; you can never get enough to do that."

Ironically, it was the 1997 film "Contact" that first introduced the concept of space travel by wormhole, and ultimately inspired scientists like Thorne and others to take a more serious look at the scientific hypotheticals. That movie, which was inspired by Carl Sagan's 1985 book by the same name, also starred McConaughey.

A few scientists have been critical of the film's foundation in quantum physics and America's most famous science communicator, Neil deGrasse Tyson, recently weighed in with his explanation of what the movie got right and wrong.

But Thorne told The Daily Beast the criticism doesn't bother him much. "I have thick skin -- I've been around the block a few times," he said.

Thick-skinned and honest -- he willingly admitted that "the science had to be compromised in order to make a great movie."