Warp Speed Will Kill You

Captain Kirk might want to avoid taking the starship Enterprise to warp speed, unless he's ready to shrug off interstellar hydrogen atoms that would deliver a lethal radiation blast to both ship and crew.

There are just two hydrogen atoms per cubic centimeter on average in space, which poses no threat to spaceships traveling at low speeds. But those same lone atoms would transform into deadly galactic space mines for a spaceship that runs into them at near-light speed, according to calculations based on Einstein's special theory of relativity.

The original crew of "Star Trek" featured as unfortunate examples at a presentation by William Edelstein, a physicist at Johns Hopkins University, at the American Physical Society conference in Washington, D.C. on Feb. 13. The physicist showed a video clip of Kirk telling engineer Scotty to go to warp speed.

"Well, they're all dead," Edelstein recalled saying. His words caused a stir among the audience.

Edelstein's personal interest in this thought experiment began 20 years ago, when his son Arthur asked him if there was friction in space. The father responded that yes, there would be hydrogen bumping off a spaceship. But he soon realized that the stray atoms of hydrogen gas would actually go right through the ship traveling close to light speed, and irradiate both crew and electronics in the process.

More recently, the physicist and his now-grown son calculated the scenario of a spaceship trying to travel halfway across our Milky Way galaxy in just 10 years. That's doable in theory, because special relativity states that time slows down and distances shrink for travelers approaching light speed.

Edelstein's work showed that a starship traveling at just 99 percent of the speed of light would get a radiation dose from hydrogen of 61 sieverts per second, when just one tenth of that number of sieverts would deliver a fatal dose for humans. And that's not even the 99.999998 percent of light-speed necessary to make the journey to the center of the Milky Way in 10 years

At the higher speed, the human crew of a starship would experience something like getting struck by the high-energy proton beam from the Large Hadron Collider particle accelerator at CERN in Geneva, Switzerland. On top of killing the crew, such powerful levels of energy would also likely destroy the starship electronics.

"I'm not claiming this is a brilliant new discovery or anything," Edelstein told SPACE.com. "I'm just saying that it's interesting."

Some audience members at the American Physical Society event protested that Kirk, Spock and the "Star Trek" crew would all still live because of the starship Enterprise having shields. But Edelstein noted some of the existing difficulties with creating an electromagnetic shield with any resemblance to "Star Trek" technology.

Solid shields seem even more hopeless. A starship might need anywhere from a 4.4 -meter to 4,400-meter thickness of lead shielding to deflect the hydrogen radiation ? added mass that would make travel at near-light speed even more impractical.

The physicist concluded by suggesting that extraterrestrials might not have visited Earth because of all the problems in traveling at near-light speeds, including how to deal with deadly hydrogen space mines. But for the record, he does believe that alien life exists.

"Getting between stars is a huge problem unless we think of something really, really different," Edelstein said. "I'm not saying that we know everything and that it's impossible. I'm saying it's kind of impossible based on what we know right now."

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