Set in a sci-fi portrayal of the 22nd century, the game starts as seven contending philosophical groups land on the planet Chiron (“Planet”) in the Alpha Centauri star framework. Unless the people who took it to Proxima Centauri got really mad at the people back on Earth.Sid Meier’s Alpha Centauri is a 4X computer game, thought about an otherworldly spin-off of the Civilization arrangement. Of course, it would be an expensive ship and probably nobody would want to crash it. Flying 20 percent of light speed, a space shuttle would possess a kinetic energy roughly the equivalent of 1,000 hydrogen bombs (or millions of Hiroshima-sized bombs). Such a ship could, in the wrong hands, become the most devastating weapon ever imagined. But there’s no hope of hitching a ride on such a wafer, unless, perhaps, you’re a tardigrade.Įven if some futuristic technology permitted building a real ship, say the size of the space shuttle, that could fly 20 percent of the speed of light, it might not be a good idea. So there’s an outside chance of getting a message back from Proxima b before the Cubs win a World Series. Supposedly such nanocraft could reach 20 percent of the speed of light, allowing them to reach Proxima Centauri by maybe 20 years after launch. If current technological dreams come true, tiny cameras and lasers on the wafer could capture and transmit information about Proxima b back to Earth. (Proxima is the third star, presumably in orbit around Alpha Centauri A and B.) That plan envisions wafers weighing about a gram or so carried along by similar-mass light sails propelled by a powerful laser beam. Philanthropist Yuri Milner recently announced a research project to explore the prospects of sending numerous nanocraft to Proxima Centauri’s neighborhood - the Alpha Centauri triple star system. Other people already have ideas, as Science News astronomy writer Christopher Crockett noted in his story on the discovery of Proxima b. And surely within 4,000 years somebody will invent a faster technology that could pass the alpha-decay craft and get to Proxima b first.
![alpha centauri client alpha centauri client](https://i.redd.it/33gm8st4kb101.jpg)
“Interstellar travel definitely asks for even better propulsion technologies,” Zhang and colleagues understate. That would easily win the race against a solar sail, but would far exceed most people’s available vacation time. They calculate a travel time to Proxima Centauri between about 4,000 and 9,000 years (depending on the ratio of fuel mass to total spacecraft mass). (You won’t find any U-232 in uranium mines, though - it would need to be produced in nuclear transmutation factories.)Īssuming a suitably light and thin absorption material, Zhang and colleagues envision an alpha-powered interstellar sail about 24 meters across. It has a long enough half-life (almost 70 years) to last for an extended voyage, but it also decays into daughter nuclei that emit alpha particles more frequently, boosting the recoil effect. It helps to choose the right alpha-emitting material. Shot into space with standard technology (thereby achieving a 16 km/s start-up speed), an alpha recoil spacecraft could eventually reach a speed in the range of 200–300 km/s or so. True, alpha particles are tiny and the effect of their recoil would be small. The rest would stream away in the opposite direction, pushing the craft forward (by virtue of the law of conservation of momentum).
![alpha centauri client alpha centauri client](https://musicbuymail.com/cnt/shop/CD206/CD20662.jpg)
So your craft would need a shield on one side to absorb the particles before they got very far. Usually, of course, a chunk of radioactive matter would emit alpha particles in all directions. Therefore, Zhang and coauthors assert, “alpha decay particles … may be a potential solution for long-time acceleration in space.” Alpha particles emitted by radioactive substances, on the other hand, can speed away about 300 times faster. But that approach requires huge energy input and high voltage, Zhang and colleagues point out (and so would be prohibitively expensive). Ordinary rocket speed is limited by how fast the combusted fuel can eject exhaust NASA has investigated a plasma engine design that can attain exhaust speeds of 50 km/s. A sail driven by alpha particle recoil, for instance, provides some serious advantages over solar sails, as Wenwu Zhang and colleagues point out in the August issue of Applied Radiation and Isotopes. Novel propulsion schemes have been proposed that could reduce that time substantially. Solar sail propulsion - in which lightweight craft could be accelerated by pressure from sunlight - would be a little be faster, but not by much, taking (by one estimate) 66,000 years to make the Proxima Centauri run. At its top speed of 16 kilometers per second, New Horizons would need almost 80,000 years to get to Proxima Centauri. It took NASA’s New Horizons probe - the fastest spacecraft humans have ever launched - over nine years just to get to Pluto.