Good afternoon,

On 6 Jul 2003, Henry Spencer wrote:

Christopher A. Bohn wrote:
Something I've been wondering about is the effect of the "heavier"
particles in the solar wind -- will the impacts of protons and alpha
particles have a significant effect, when compared to the acceleration
realized by the reflection of photons?

In principle, the solar wind -- which is just the charged particles, it
does *not* include the light --

Right -- minor parsing ambiguity -- I didn't mean to suggest the photons
were part of the solar wind, but rather I wanted to emphasize why I was
wondering about the solar wind's effects.

would have some small effect.

However, when looked at closely, the solar wind carries 100-1000 times
less momentum, per square kilometer, than the light does. The particles
are heavier, yes, but they are very widely spaced and their speed is
relatively modest. So they don't add noticeably to the thrust of a
solar sail.
[...]

Thank you very much.

Take care,
cb

--
Christopher A. Bohn ____________|____________
http://www.cis.ohio-state.edu/~bohn/ ' ** ** " (o) " ** ** '
"Si Vis Pacem, Para Bellum"
- Appius Claudius (the Blind), Roman Senate