The sustainable voyager’s guide to the galaxy
A sweet ride if you can get there. Advanced civilizations could sail away on black hole jets at the center of some galaxies. (Lynette Cook/)Greta Thunberg’s transatlantic voyage showed the world that inter-continental travel doesn’t have to rely on fossil fuels. By harnessing the freely available energy blowing in the wind, the 16-year-old Swede managed to sail around 3,500 miles from the UK to New York, all without burning an ounce of gasoline or diesel. But what she gained in energy, she paid for in time. A journey that most air passengers make in seven to eight hours took her and her crew two weeks. A desire to minimize carbon emissions motivated Thunberg’s unorthodox transportation choice, but economically-minded aliens wishing to conserve energy might make similar sacrifices, according to not-yet-peer reviewed research published on the website arxiv last week. Rather than attempting to cross the unimaginably vast gulfs between stars...