Let's start our journey into the realm of pop culture with a franchise that has been attracting fans for the last 50 years. A generation of Star Trek enthusiasts grew up watching Star Trek: The Original Series which first aired in 1966. A lot has changed in the time since Captain Kirk fought a Gorn by hand in the original series. Star Trek isn't merely science fiction, but it's also known to challenge inequalities in society. But Star Trek is known for single-handedly inspiring a generation of scientists and engineers whose work saw human exploration of the moon and permanent laboratories in space. My favorite Star Trek movie rebooted the franchise in 2009 with an epic space adventure with a tagline, The Future Begins. The story begins following James Kirk's exploits as a cadet in Star Fleet academy, but an attack on the Vulcan home world forces the cadets to become crew of the newly commissioned USS Enterprise. Without spoiling too much of the movie, the writers of the film employed a strange form of fictional matter called red matter which appears to create black holes that can consume entire planets. In the movie, the Vulcan home world has been attacked and the planet's surface collapses inwards. Although visually impressive, Star Trek gets a lot of the black hole physics wrong. For one, the audience is meant to understand that red matter black holes are traversable. Unfortunately traversable wormholes are merely a theory and would require a super advanced civilization and a number of notable scientific discoveries to permit travel. In fact, travel through a wormhole if possible would likely expose travelers to a serious dose of radiation, making the journey fatal to a squishy humans like me. On the other hand, Star Trek explores some very interesting physics of black holes. Specifically how a spacecraft might escape if it becomes trapped within the gravitational pull of a black hole. In one scene, the Enterprise is at maximum thrust and is still being accelerated towards the black hole. In order to save the crew, the Chief Engineer Scotty suggests that the last option is to eject the warp core and ride the shock wave from the explosion to safety. At best, it explores interesting science fiction concepts. At its worst, it makes some small maybe forgivable errors in scientific judgment for the sake of entertainment. I enjoy watching Star Trek and Doctor Who, but often the treatment of science in these shows doesn't satisfy my sense of scientific consistency. One movie that did satisfy me was the 2014 movie Interstellar, which presents the science of black holes as accurately as possible. There's still black hole physics that is unknown; like what happens when you cross an event horizon? So the movie makers do engage in some speculation about what happens inside a black hole. The black hole in Interstellar is a supermassive black hole named Gargantua. Two planets are in orbit around the black hole at a safe distance which is a reasonable possibility, even though in the TV show Doctor Who they claim that planets orbiting black holes are impossible. It is important to the plot of Interstellar that gargantuan is a supermassive black hole since the strength of the tidal forces that could spaghettify an astronaut is weaker for more massive black holes. Although Gargantuan causes enormous tides on Miller's planet, the planet that orbits closest to Gargantua, the tidal forces aren't strong enough to destroy the planet or the characters on the surface. Another cool bit of science that Interstellar gets right are the extreme time differences between Miller's planet and the spaceship that orbits farther away from the black hole. When one hour passes on the planet, seven years pass for the astronauts far from the black hole. For me, the most exciting part of the movie is the view of the black hole and the disk of material flowing around it. This view of the black hole incorporates most of the science of how light travels on curved paths around regions with gargantuan gravity. The black hole gargantuan is extremely far away from us, but luckily the writers included a wormhole that allows a quick shortcut through space between Saturn and Gargantua. Black holes exist but wormholes probably don't, so this part is science fiction. In the movie, they speculate that the wormhole was constructed by aliens. I don't know how to construct a wormhole, but then I'm not an alien. I won't spoil the ending of the movie for you, however, I'll just let you know that there is a trip into the black hole. What happens when they enter the event horizon is pure speculation, but who knows? Maybe the screenwriters are correct. In 1977, George Lucas presented his creation, Star Wars: A New Hope to the world. It was packed with brand new special effects like fast-paced space battles and spectacular light saber duels. Sadly, Star Wars didn't include anything that we would really consider a black hole unless you include the insatiable hungry Sarlacc. We don't have much material from the Star Wars universe. Fortunately though, Disney was aware of the success of Star Wars, and in 1979 decided to fund their own space opera called The Black Hole. The film-makers relied on scientists of the day to tell them what it might look like. Have a look at this scene from the bridge of The Cygnus. A stark, starry background is punctuated with a tear in the fabric of spacetime. At the end of the 1970s, this was the picture of a black hole. In order to make such a convincing picture, the film-makers relied on 20 years of work from scientists like Roy Kerr, Roger Penrose, Werner Israel, and Stephen Hawking whose names come up a lot in this course. They had been working on models of how black holes behave and just what they might look like. In addition the nearby black hole; Cygnus X-1 which had then only been recently confirmed, became the namesake of the ship in the movie. The Black Hole did a lot of things correctly that other movies failed to do like an accurate representation of an accretion disk for the time and accounting for the time dilation effects around the black hole. However, in the film, the crew of the Palomino descend past the event horizon where their interpretation of the interior is almost certainly false. Instead of space bending physics, as the Cygnus descends into the black hole it becomes a fiery realm like a portrayal of Dante's Inferno. In reality, crossing the event horizon has dozens of dangers that would likely harm human explorers. A lot has changed in the 40 years since Disney released the black hole especially related to black hole physics. We now know the strength of gravitational waves produced by merging black holes and scientists are still developing theories to explain what the interiors of black holes might look like. This film introduces some of the interesting ideas about falling into a black hole, but there is one thing that I can tell you that none of these movies can. No one can tell you for certain what happens when you cross a black hole's event horizon.
