N
nimbus
Guest
From an off topic tangent in another thread:
http://nextbigfuture.com/2010/02/non-ma ... unter.html
robnissen":gd9a72iy said:Its kind of the worst of all worlds. The few atoms, molecules and dust in interstellar space are too few and far between to be useful for anything. While at the same time, those few atoms, molecules and dust would quickly destroy a space ship going at any significant % of c, like .1c because of the extreme energies they would have due to their high speed relative to the ship. So, not only can we not use them as resources for an interstellar journey, their very existence will make an interstellar journey in any reasonable time period virtually impossible.
http://www.newscientist.com/article/dn1 ... speed.htmlaremisasling":gd9a72iy said:robnissen,
I'll take issue with you on that one. I've never heard that raised as an issue by anyone from sci fi folks to engineers actually contemplating interstellar travel. Dust, maybe, but individual atoms are unlikely to be an issue. I've heard it suggested that we could travel fractions of the speed of light outside of the gravitational envelope of solar systems, accelerating once outside of our own and decelerating on approach to the destination. Sure there's dust out there, and frankly a whole lot of who-knows-what, but it appears to be few and far between.
And Brian Wang of NextBigFuture offers some suggestions:[...]
For a crew to make the 50,000-light-year journey to the centre of the Milky Way within 10 years, they would have to travel at 99.999998 per cent the speed of light. At these speeds, hydrogen atoms would seem to reach a staggering 7 teraelectron volts – the same energy that protons will eventually reach in the Large Hadron Collider when it runs at full throttle. "For the crew, it would be like standing in front of the LHC beam," says Edelstein.
[...]
The fatal dose of radiation for a human is 6 sieverts. Edelstein's calculations show that the crew would receive a radiation dose of more than 10,000 sieverts within a second. Intense radiation would also weaken the structure of the spacecraft and damage its electronic instruments.
http://nextbigfuture.com/2010/02/non-ma ... unter.html