A US boffin has effectively put the mockers on Star Trek-style warp speed travel to the stars by warning that interstellar hydrogen gas would become deadly to humans as they approached the speed of light.
Professor William Edelstein of the Johns Hopkins University School of Medicine explained to New Scientist that while interstellar space has just a couple of hydrogen atoms per cubic centimetre, as the crew of the Enterprise hit the gas pedal, a compression effect would greatly increase the number of atoms hitting the spacecraft.
As the spaceship reached 99.999998 per cent of the speed of light, "hydrogen atoms would seem to reach a staggering 7 teraelectron volts", which for the crew "would be like standing in front of the Large Hadron Collider beam".
This is a very bad thing, because humans in the path of this ray would receive a dose of ionising radiation of 10,000 sieverts, and as Bones McCoy would doubtless confirm, the lethal dose is 6 sieverts.
The result? Death in one second.
The spacecraft's structure would do little to mitigate the effects of the killer hydrogen. Edelstein "calculates that a 10-centimetre-thick layer of aluminium would absorb less than 1 per cent of the energy", and the intense doses of radiation would damage the ship's structure and fry its electronics.
Edelstein grimly concluded: "Hydrogen atoms are unavoidable space mines."
The professor presented his killer calculations to an American Physical Society meeting in Washington DC on Saturday.
Of course, Edelstein's conclusions are based on current scientific knowledge. No doubt future spacecraft designers will deploy advanced radiation-resistant alloys and magnetic shielding to protect Federation staff from instant death.