“Oh, the places you’ll go when you can surf a supernova!”
While that sounds like a great title for a fictional children’s book on space travel by the late Dr. Seuss, it’s actually a real idea for near-speed-of-light space travel by a renowned theoretical physicist who has lately been thinking way outside the box. Will humans someday travel in spaceships propelled by the power of supernovas?
“In this paper, we explore the possibility of using natural astrophysical sources to accelerate
spacecrafts to relativistic speeds. We focus on light sails and electric sails, which are reliant on
momentum transfer from photons and protons, respectively, because these two classes of spacecrafts are not required to carry fuel on board.”
“By considering a number of astrophysical objects such as massive stars, microquasars, supernovae, pulsar wind nebulae, and active galactic nuclei, we show that speeds approaching the speed of light might be realizable under broad circumstances.”
Theoretical physicist Abraham “Avi” Loeb tore himself away from theorizing that interstellar comets might be alien spaceships to join brains with astrobiologist Manasvi Lingam to ponder ways humans might accomplish the same type of travel at much higher speeds. In a pre-published paper, “Propulsion of Spacecrafts to Relativistic Speeds Using Natural Astrophysical Sources” summarized in Scientific American, Loeb and Lingam propose using the already real technology of laser-pushed light sails with some massive propellants far more powerful than lasers. Loeb explains to Universe Today how he got the idea.
“Back in December 2019, my wife and two daughters were on travel and I had the luxury of staying at home alone for a week and thinking about science. While taking a shower, I thought on how the Sun is not effective at launching lightsails to high speed, but a brighter source of light might be. I followed this thought with detailed calculations on supernovae, which are billions of times brighter than the Sun for a week and realized that lightsails with existing parameters can reach the speed of light if they are strategically placed ahead of time around the massive star that is about the explode.”
How hot WAS that water? Loeb shared his idea with colleague Lingam, who helped determine (apparently without the benefit of a shower) that a supernova was the best source of speed-of-light, or even one-tenth speed of light, power. It doesn’t take a rocket scientist in a hot shower to see some big non-black holes in this idea – like finding supernovas when they’re just about to explode, positioning the sailing ship and insuring it and its crew survive the trip, regardless of how fast they arrive at their destination. Lingam says none of this is a problem.
“There are many challenges such as sail stabilization, maintaining high reflectance and preventing heating, and avoiding damage while traveling in the source environment as well as the interstellar medium. Most of these issues may be overcome, at least in principle, by utilizing electric sails instead of light sails. Alternatively, if one decides to stick with light sails, then one will have to fold the sail during some stages of the voyage, choose an unusual sail architecture, and rely upon nanophotonic structures to improve stability.”
Nuclear-powered cars once made sense too – have you seen any of those lately? That’s not a problem for deep, out-of-the-box thinkers like Loeb and Lingam. In fact, they invoke the name of the late Frederick Dyson in revealing the other, more attainable benefit of this kind of thinking – if our piddly human brains can come up with these ideas, advanced civilizations have probably implemented them already and are using them to get around the galaxy. If that’s the case, signs of them, like Dyson spheres, might point SETI researchers in the right direction for finding their location and putting a marker on the map for when we finally invent the ships ourselves. Better yet, we can aim our instruments at these spots to send messages to come and get us – kind of an interstellar Uber call. That assumes these aliens are benevolent. Otherwise, it could be more like a message telling extraterrestrials that their dinner is ready for pickup.
Food for deep thought.
Getting back to a human level of thinking, Supernova Surfers would be a great name for a band.