"Dan Bloomquist" <public21@[EMAIL PROTECTED]
> wrote in message
news:N4oAj.5632$Sa1.5188@[EMAIL PROTECTED]
> daestrom wrote:
>>
>> "Dan Bloomquist" <public21@[EMAIL PROTECTED]
> wrote in message
>> news:7tdAj.5709$7d1.5641@[EMAIL PROTECTED]
>>> daestrom wrote:
>>>>
>>>> Whilst I don't agree with any of the OP's junk science, if you
arrange
>>>> the gyro's shaft so that it is perpendicular to the earth's axis, and
>>>> the shaft is limited to a track that is also perpencidular to the
>>>> earth's axis (on the equator it would be vertical, at other latitudes
>>>> it would be tilted away from the pole by the degree of latitude),
then
>>>> as the earth rotates each day, the gyro's shaft would make one
complete
>>>> revolution around the track. This revolution of the shaft around the
>>>> track could be harnessed to draw some power.
>>>
>>> Hi daestrom,
>>> This is about converting angular momentum to energy. But, angular
>>> momentum is conserved. i.e., you can't slow the rotation of the earth
>>> from a closed system.
>>>
>>> I'm sure the details would bare this out.
>>>
>>
>> On the 'big picture' I can see what you mean, but if we put the gyro on
>> the equator with the shaft pointing straight up at noon, six hours
later
>> the shaft is horizontal, six more hours and it points straight down,
>> etc...
>>
>> If we attach some mechanism to capture that 'revolution' of the shaft
>> around the track, we transfer some angular momentum (AM) from the earth
>> to the mechanism (albeit a tiny amount). Momentum is conserved but
>> kinetic energy is transferred from one rotating body (the earth) to
>> another (the mechanism).
>
> Hi daestrom,
> It has been a while and I never finished working through any math. But
> here is what I recall happens. As soon as you put some force on the axis
> of the gyro, (restrict precision), you the angular momentum of the
rotor.
> This change will exactly balance the change in the angular momentum of
the
> earth. And, of course, it will take a force to get energy, FxD. If there
> is any question that the rotor will change velocity with external force,
> see this toy:
>
> http://www.powerballs.com/
>
> I've been meaning to buy one of these for years. Question is, can I get
> one cheap enough on ebay to make the cost of fun balance. I'm thinking I
> can. :)
>
> So, the energy will come from what ever energy it took to accelerate the
> rotor.
So let me see, (using my earlier example of a gyro mounted with its shaft
vertical at the equator), as the earth rotates the shaft will turn from
up-down to east-west orientation if we don't restrict it at all. If we
*do*
attach some sort of mechanism that retards it in the east-west direction
(i.e. doesn't let the shaft top end tip to the west freely), then
precession
will try to tip the shaft towards the north-south direction. Okay, and I
postulated a 'track' that is oriented east-west' so any precession toward
north-south is restricted entirely.
A concrete example. Start with shaft vertical. Spin rotor such that the
'northern' side is moving towards the west, and the 'southern' side is
moving towards the east (i.e. CCW when viewed from 'above'). Since the
earth is moving towards the east, the top of the shaft tends to move
toward
the west. We retard this movement somewhat with our mechanism. Because
of
the particular spin and the force we are applying to the top of the shaft
to
try and get the top to move eastward with us and the planet, the gyro
precesses and a force is developed by the gyro to move the top of the
shaft
towards the north. If we let it move towards the north, things would
continue until it (the gyro shaft) is parallel with the earth's axis.
Then
all precession would stop. (Congratulations, we have a rudimentary
gyrocompass. I used to work on marine gyrocomp***** in the navy, they
take
a bit more than this, but we at least have a 'north-seeking' gyro)
But if we don't let it move north (constrained by the 'track'), then
whatever retarding force we are applying in the east-west direction is
translated to the north-south direction against the track. These forces
may
increase friction in 'real' bearings, but let's assume 'ideal' bearings so
this addtional force against the shaft doesn't slow the spin of the gyro.
The force against the track in the north-south direction moves through
zero
distance so no work there. But our retarding force in the east-west
direction is adjusted to allow the shaft to tilt west at something less
than
one revolution per day so we have a force working through an angular
displacement and have work.
As I said before, I believe this transfers some of the angular momentum
from
one part of the closed system to another (i.e. from the spinning planet to
the mechanism that is retarding the gyro shaft's east-west apparent
motion).
Momentum is conserved and energy is transferred.
But my earlier calcs show the amount of power involved is terribly small.
To measure it experimentally against all the frictions and other losses
would be pretty hopeless. Unless you find a planet with a much shorter
day
:-)
daestrom
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