There is a lot of curiosity about interstellar travel and planet colonization, but according to member of the Laser Interferometer Gravitational-Wave Observatory (LIGO) collaboration Teviet Creighton, humans are better off in large-scale space colonies.
Creighton, director of the facility Spacecraft Tracking and Astronomical Research into Gigahertz Astrophysical Transient Emission (STARGATE), is part of a team from the University of Texas Rio Grande Valley and is working on the Low Frequency All Sky Monitor radio telescope on the Hillsdale campus. On Oct. 22, he came to Hillsdale’s campus to discuss the plausibility of interstellar travel based on an article he published soon after the release of the movie “Interstellar.”
“With STARGATE, we were getting into the field of commercial space technology, and they were asking whether this was a plausible scenario,” Creighton said. “The premise of this is interstellar travel.”
Interstellar travel is glamorized in entertainment, said Creighton, and movies portray it with strange worlds, daring crews and spaceships, and surreal encounters with new civilizations. However, there is one simple question that stands in the way of its plausibility: how would we actually explore the universe?
“As they put it in the movie ‘Interstellar,’ to get somewhere, you have to leave something behind,” said Creighton. “How do you get a spaceship to move forward? You throw stuff out the back, and by throwing stuff out the back, you move the ship forward.”
The thing that Creighton said you must throw out is fuel to add impulse, but it becomes a diminishing return because you need to have fuel to take fuel. One idea is to use more efficient fuel, but even this is a remote possibility. For even an optimal thermonuclear rocket, one would need 9 x 10^3 kilograms of fuel per kilogram of payload to arrive to the nearest star outside of the solar system in a decade. One could expect to spend a lifetime on board.
There is also the idea of faster-than-light travel such as wormholes; however, though this is theoretically allowed, “theoretically and practically are very different things,” said Creighton. Any form of faster-than-light travel requires some sort of exotic matter like contramatter, which has negative energy density.
“Maybe it would require a ship that was the size of a solar system or a galaxy,” Creighton said. “And we don’t know because we don’t know what the properties of this contramatter actually are. It’s kind of making a narrative assumption for dramatic purposes to think that such a thing would happen to exist and happen to have the properties we need to fulfill our space exploration fantasies.”
One of the fascinations with interstellar travel lies in the possibility of colonizing new planets. According to Creighton, there are many different types of stars and “terrestrials” beyond our solar system, among them ice giants, sulfur terrestrials, and tholin terrestrials such as Saturn’s moon Titan. Water terrestrials are very sought after in interstellar travel.
“We are water chauvinists,” Creighton said. “We like water; it seems to be special to us.”
But even with the possibility of water terrestrials, there is a remote possibility that humans could inhabit any other planet because the chances of finding one with enough water and a breathable atmosphere are slim. Earth’s atmosphere is a product of its ecosystem, and to replicate that on any other planet, Creighton said there are two options: engineer the atmosphere and biosphere of a barren planet from scratch or already have life on the planet.
“If it happens to be an inhabited world with its own life forms and its own ecosystems, then you have Option B,” Creighton said. “You first eradicate what’s there because it’s not the atmosphere that you want, and then see A.”
If man does move off the earth, he said, it would be much more efficient to move to space habitats instead. We are more likely to utilize space for mercantilist purposes, to have another way to generate wealth. As for the earth’s environment, Creighton posits that any environmental problems can be addressed by exploiting resources in the solar system nearby; there is no need to go to distant stars to get it.
Students found Creighton’s points on interstellar space travel informative.
“I thought it was really satisfying to see someone actually do the math and present it intelligibly to non-scientists,” senior Tim Polelle said. “I thought his suggestion about the practicality of artificial space habitats was insightful.”
They also found his comments on the plausibility of space travel to be straightforward and honest.
“I appreciated the acknowledgment that fixing Earth is easier than moving the stars,” sophomore Sara Gasey said. “I feel that sometimes we view the potential of space as an excuse not to deal with the problems of Earth.”