arstechnica looks at Breakthrough Starshot, the goal to send a spaceship to the nearest star at 20% the speed of light. While this would mean visiting another solar system — we could visit Alpha Centauri in 20 years — travelling at those speeds means that impact with a stray atom or — worse — a dust particle, would have some catastrophic consequences.
Dust presents a somewhat different problem. Small dust particles will essentially act like a simultaneous bombardment by a lot of gas atoms. That's because the energy binding things together in a dust particle is tiny compared to the energy of the collision itself, and the dust is largely composed of heavier atoms. But a sufficiently large dust particle will create a collision energetic enough to destroy a craft. And "sufficiently large" isn't very big; the authors estimate that it only has to be 15 micrometers across to kill off the craft. Fortunately, dust particles this size are rare, and the authors calculate the odds of running into one at 1050 to one against.
Overall, the authors find the effect of gas to be minor and only likely to cause damage down to a depth of 0.1 millimeters. Dust, however, is a different story. It will evaporate about 1.5 millimeters off the surface of the spacecraft, and melting will happen at depths of up to 10 millimeters. When every gram counts, this could be significant.
|"Train on Earth for 10 years until they are ready to be shot into space strapped to a rocket, never to return."|
|A Dyson Sphere is Not Practical|
|Extinct Alien Civilisations|
|"The effects of an impact, even a comet or asteroid of a modest size, would be devastating."|
|Water Vapour Found in Atmosphere of Planet in Another Solar System|
|“Google and Facebook figured out how to commodify 'reality' itself by tracking what people do.”|
|“New York Central trains in the Hudson River valley in 1928 and 1929”|
|“The latest warning sign for cities who are considering signing over public spaces to major tech companies.”|
|“Scientific evidence that digital distraction is damaging our minds.”|
|“Buying a new smartphone every two years is taking a toll on the planet.”|
|The (Very Scary) People of Public Transit|
|CaptchaTweet: Write Tweets in Captcha Form|
|How to Avoid Jury Duty|
|"Waymo is reportedly planning to take the next step towards offering a commercial driverless car service in early December."|
|“Bias, error, and misuse of Artificial Intelligence technologies.”|
|“We need to make algorithms transparent, regulated, and forgiving of the flawed creatures that converse with them.”|
|“Forget reading the book of life—we’re now learning how to write it.”|