Interstellar space is an empty place. For every cubic centimetre, there are fewer than two hydrogen atoms, on average, compared with 30 billion billion atoms of air here on Earth.[...]
Special relativity describes how space and time are distorted for observers travelling at different speeds. For the crew of a spacecraft ramping up to light speed, interstellar space would appear highly compressed, thereby increasing the number of hydrogen atoms hitting the craft.[...]
The spacecraft's hull would provide little protection. Edelstein calculates that a 10-centimetre-thick layer of aluminium would absorb less than 1 per cent of the energy. Because hydrogen atoms have a proton for a nucleus, this leaves the crew exposed to dangerous ionising radiation that breaks chemical bonds and damages DNA. "Hydrogen atoms are unavoidable space mines," says Edelstein.
Well, duh, Edelstein. That's what the deflector dish is for.
Sheesh. When I read articles like this, I can only conclude that the peer-review system is completely broken.
via Popular Science