Reaction Shot

As Mark Twain apparently didn't say, a lie can travel half way around the world while the truth is still putting its boots on. And when that lie is powered by a breakthrough, NASA-approved space drive technology it can get to infinity and beyond, even if the truth is in hot pursuit.

In fairness, this is not a story about a lie, but a poorly-described experiment mixed with credulous journalism. Four days ago, a piece on described a breakthrough reactionless drive -- a closed box that could move entirely on its own without ejecting any "reaction mass" or otherwise interacting with its surroundings. These staples of science fiction are in the same category as perpetual motion machines -- but rather than breaking the laws of thermodynamics, reactionless drives violate Newton's Third Law, which says that every action much have an equal and opposite reaction.

Newton's Laws have survived all challenges (after a generalisation to accommodate relativity) for 350 years. Everything in science is one experiment away from being wrong. However, while thousands of scientists and backyard inventors have claimed to find loopholes in Newton but not one has stood up to scrutiny. Consequently anyone claiming to have built a reactionless drive should be treated with caution, unless they arrive at their press conference in a flying car.

Immediately after the Wired story, a posse of scientists pulled it apart. Sean Carroll called it "sub-Star-Trek-technobabble" and mathematical physicist John Baez gave it a thorough fisking. The whole kerfuffle was caused by a conference presentation from a group of NASA scientists and engineers of which which only the abstract is online. Amazingly, this abstract says they ran tests for both the "drive" and a "control" that was not supposed to work – and both of them "worked". But instead of worrying that this meant that the tiny effects they saw were due to some subtle experimental difficulty, they simply declared victory. Extraordinary claims require extraordinary evidence, but by any reasonable standard this experiment failed to demonstrate that the drive worked. Not even NASA can polish a turd, but it seems they know how to roll them in glitter. 



Many people are "wrong on the internet", but there is a bigger picture here. NASA has an astonishing grip on the public imagination. Long after the moon landings, I regularly meet kids who dream of "working for NASA" and its profile far exceeds that of other excellent Federal science organisations such as NIST or the CDC.  Consequently it is painful to see NASA's reputation being squandered, and the group behind this performance was also responsible for last year's warp drive fiasco (which I blogged about here and here).

This might seem like an academic debate, but NASA's apparent endorsement of fringe science can cause real harm. There is a veritable ecosystem of misguided enthusiasts and outright hucksters who peddle "breakthrough technologies" flying in the face of established physics, and NASA's imprimatur will help them soak the gullible and the optimistic.

Meanwhile the rest of us need a NASA that speaks with authority on climate and the environment, and can secure support for its otherwise excellent science programme – and this cannot help.