[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Engine (EM radiation) problems

Timothy van der Linden writes:
 > Yes, I believe this pressure thing was something I imagined, and later it
 > seemed that the Bussard engine did not work that way.
 > The main reason for that pressure thing was to even out the velocities, this
 > way we would not get very fast and very slow particles all together.
 > Particles with high velocity have a worse momentum:energy ratio (a new
 > term?). This means that if you have some energy and want to make the most
 > velocity (momentum) from it, you get the most of it if you use low exhaust
 > velocities. Unfortunately this also means that more mass is needed, which is
 > not preferrable.

This statement bugs me because it is completely contradictory to
something I worked out a while ago and that you seemed to agree with,
which is that higher exhaust velocities are best, and the ideal case is
turning all your fuel into zero-mass photons moving at the speed of

You do want to get all your exhaust products moving backwards, which
implies confining the fuel reaction and reflecting any forward-moving
products backwards.  You're absolutely going to lose energy to heat if
you try to equalize the exhaust velocity.  In any case a gas at a
particular temperature doesn't have a uniform set of particle
velocities; it's still a statistical distribution about a mean that is
characteristic of the gas temperature.