Capt. Neal® wrote:
That reminds me. Remember that idiot, over in England I think, who
claimed he could use a windmill contraption aboard his boat to power the
boat straight into the wind using only the power of the wind?

Which one was that, Neal?

Was it this one:
http://foxxaero.homestead.com/indrad_007.html

Or this one:
http://www.users.globalnet.co.uk/~fs...deos/page8.htm

Both of these boats will sail directly into the wind. They do not
"violate the laws of physics."


Bwaahahhahahahahahhahhahha. That solar sail will work but
only downwind or crosswind. It will never be able to go upwind.

Neither will a sailboat, unless it has the water to push against.

It is against the known laws of physics for a sailboat to sail
directly into the wind

A regular sailboat cannot convert the force of the wind into upwind
motion. A Wind Turbine Boat, with a propeller can. Not law is violated.

and it's the same for solar sails.

Without the force of the keel in the water, a normal sailboat can't tack
upwind either.