NORDHAVN Rewrites Physics Textbooks
 

"Wilbur Hubbard" wrote in message
anews.com...

"toad" wrote in message
s.com...
On 14 Oct, 15:16, (Steve Firth) wrote:

Nor in the case of the motorsailer will the apparent wind be from dead
ahead.

Oh yes it will!


If only these ******s could learn to draw a simple vector diagram. They
would soon see there are no other vectors than one from the rear (motor
power) and one from the front (apparent wind drag). Duh!

The vector from the rear will be longer than the one from the front. But
the one from the front will effectively shorten the vector from the rear.
The result is a slower forward speed than if the boat was powering forward
in a vacuum where there would be no vector from the forward (from the
apparent wind, at least.)

Only when there is some wind other than apparent wind can you add any sort
of sideways vector to the diagram. The advert is WRONG! It demonstrates a
common ignorance that many sailor harbour.

Wilbur Hubbard

Best way to look at it!

NORDHAVN Rewrites Physics Textbooks
 

"Stephen Trapani" wrote in message
...
Ronald Raygun wrote:
Wilbur Hubbard wrote:

"Steve Firth" wrote in message
.. .
Wilbur Hubbard wrote:
Among other things, they claim to be able to create something from
nothing. The advert states, "Even in dead air the apparent wind when
motorsailing generates lift and reduces the amount of engine power
needed to maintain the same speed the engine would produce on its
own."
Huh? Tell me I ain't dreaming . . .
You're not dreaming, they're right and you don't understand physics.

Is there any more help that you need?
I had the utmost confidence that the post would usher forth the Looney
bin, perpetual motion crowd! Welcome, to you, sir. It's good to see a
Brit is the first to insert his foot into his mouth.

Well, perhaps the idea is that when sailing into a "dead" wind, the
sails be set horizontally, so that the lift generated by them is in
the direction which is traditionally associated with "lift", i.e. "up".
Like hydrofoils, these aerofoils would cause the hull to ride a fraction
of an inch higher in the water, reducing water resistance.

Alternatively, the idea might be to back the sails, which would generate
a sideways force on the boat, so that it actually travels with some
leeway. If the leeway angle is big enough, and the drag from all this
doesn't slow down the forwards speed much, the effective speed will be
enhanced by the Pythagoras effect. The helm must be instructed to steer
a few degrees off the intended destination, to compensate for this
beneficial leeway.

Ronald Raygun might be right, if the boat is designed in such a way to
take advantage of these effects. The actual effect proposed by NORDHAVN
will have to be known to know if Wilbur is entirely wrong, but we do know
that Wilbur is partly wrong because NORDHAVN doesn't claim any type of
perpetual motion, just that they can return *some* energy back to the
system to *lessen* the energy needed to propel the boat.

Stephen


There is perpertual motion. I will cite 3 examples, which are irrefutable.

1. Law of inertia. An object in motion tends to stay in motion
(perpertually) unless acted upon by an outside force. That's the law!

2. The electrons spinning around atoms. They have been doing it since the
beginning of time. The stout electron never tires, never wears out, never
slows down he just keeps going and going. What powers the little bugger? If
he required power the universe would have stopped a long time ago. He can
orbit under just about any condition, anytime and anyplace.

3. Electromagnetic waves and photons. Current theory has them going on and
on forever, never slowing down.

Our world is bathed in perpertual motion. One has only to look and think.

Bill

NORDHAVN Rewrites Physics Textbooks
 

On 15 Oct, 16:20, "Bill" wrote:
"toad" wrote in message

The guy who built the windmill boat could be a lying crackpot. I have not
seen one with my own eyes so your point is valid.

You wouldn't have to lie. Natural wind isn't all in one direction. You
could be steaming ahead in your windmill boat on the components of the
wind that are not directly on the nose and really believe yourself to
be sailing upwind. Pyro actually posted a picture of his cart working
- but in the photo he was blowing downwards on it. He wasn't lying, he
realy did think it was going upwind, he just didn't have a handy head
protractor!

It's also worth noting that some of the windmill craft identified in
the course of this 'debate' as craft that could sail directly into
wind turn out to be incapable of going direct into wind!

It's a futile to debate this in words. We need figures. It will be
resolved one day when somebody who genuinely knows (as opposed to
guessing based on gut feeling and justifying it with wordy posts using
analogies) simply posts the worked formula to prove it one way or the
other.

You only have to look at the Conundrum thread to realize just how much
of a pinch of salt you have to take with armchair physicists on usenet!

NORDHAVN Rewrites Physics Textbooks
 

Steve Firth wrote:

If one is motoring in a calm on a flat millpond then there is an
apparent wind equal to the speed of the boat from dead ahead. Hoist a
sail and you can make no use of that wind, agreed. However that only
applies if you maintain the same course. Now do what any sensible bloke
would do and adjust your course to make use of the wind as well as the
motor. You now have wind in your sails and you still have an apparent
wind. If you look at the force triangle there is still a component from
the apparent wind.


But since you are creating this apparent wind yourself from your own
forward motion, it will come from dead ahead wherever you go. Changing
course will not bring the apparent wind aft so that you can use it.

Jeannette

NORDHAVN Rewrites Physics Textbooks
 

"Jeannette" wrote in message
t...
Steve Firth wrote:

If one is motoring in a calm on a flat millpond then there is an
apparent wind equal to the speed of the boat from dead ahead. Hoist a
sail and you can make no use of that wind, agreed. However that only
applies if you maintain the same course. Now do what any sensible bloke
would do and adjust your course to make use of the wind as well as the
motor. You now have wind in your sails and you still have an apparent
wind. If you look at the force triangle there is still a component from
the apparent wind.


But since you are creating this apparent wind yourself from your own
forward motion, it will come from dead ahead wherever you go. Changing
course will not bring the apparent wind aft so that you can use it.

Jeannette

Suppose the boat could be trimmed under the waterline so it moved in the
water skewed. Then the apparent wind could come in several degrees off of
the bow. Then would it work?

Bill

NORDHAVN Rewrites Physics Textbooks
 

Stephen Trapani wrote:

Putting wings on a plane increases aerodynamic drag acting on the plane,
yet it increases the speed, right?

Stephen

I don't know that much but I think this statement is incorrect.

Putting the wings on a plane does not increase the speed. It creates
vertical lift which makes the plane go upward but it has to add to the
drag and in fact slow the plane down. The reduced speed is of no concern
to the plane as long as it doesn't slow it down enough to loose the
lift. It can compensate for the loss of speed by putting more power
anyway and getting more lift in the process which is what it is trying
to do in the first place. As it goes further up it reaches thinner air
which will cause less drag...

In other words, one doesn't put wings on a plane to make it go faster
but to make it go higher..

Jeannette

NORDHAVN Rewrites Physics Textbooks
 

"toad" wrote in message
ps.com...
On 15 Oct, 14:27, (Richard Casady) wrote:

Why wouldn't it accellerate indefinitely with no friction anywhere in
the system.

....because as it approaches the speed of light it will require
infinate energy.


My flashlight shoots out photons at the speed of light and it is powered by
a 1 1/2 volt battery. Even better, my flashlight moves away from the photons
at the speed of light with the same 1 1/2 volt battery. When do I need to
change the battery?

NORDHAVN Rewrites Physics Textbooks
 

"Ian" wrote in message
oups.com...
On 15 Oct, 14:27, (Richard Casady) wrote:


Kelvin-Froude actuator disk theory is your friend.


Isn't that valid only in the inertial range?

NORDHAVN Rewrites Physics Textbooks
 

"toad" wrote in message
ups.com...
On 15 Oct, 16:20, "Bill" wrote:
"toad" wrote in message

The guy who built the windmill boat could be a lying crackpot. I have not
seen one with my own eyes so your point is valid.

You wouldn't have to lie. Natural wind isn't all in one direction. You
could be steaming ahead in your windmill boat on the components of the
wind that are not directly on the nose and really believe yourself to
be sailing upwind. Pyro actually posted a picture of his cart working
- but in the photo he was blowing downwards on it. He wasn't lying, he
realy did think it was going upwind, he just didn't have a handy head
protractor!

It's also worth noting that some of the windmill craft identified in
the course of this 'debate' as craft that could sail directly into
wind turn out to be incapable of going direct into wind!

It's a futile to debate this in words. We need figures. It will be
resolved one day when somebody who genuinely knows (as opposed to
guessing based on gut feeling and justifying it with wordy posts using
analogies) simply posts the worked formula to prove it one way or the
other.

You only have to look at the Conundrum thread to realize just how much
of a pinch of salt you have to take with armchair physicists on usenet!


If the windmill did work we could put small wind turbines on bicycles and
reduce the pedaling load for cyclists and even increase their speeds into
strong headwinds. Or just cut the field current on their dc powered assist
motors and watch them cruise off into the sunset - perpertually!

NORDHAVN Rewrites Physics Textbooks
 

Steve Firth wrote:


If you're not moving how can the wind be on your nose?

You are MOTORING. That means MOVING. You can't motor / move on, say
course 180 degrees in a dead calm and then turn say 40 degrees to port
and expect the resultant relative wind to help your progress because the
relative wind is always directly on your nose.

Yes, the steam would make the water move in many directions but the
point is that it's not RUNNING uphill. It's being propelled uphill.