LIGHT SAILS:

The dark side gets hotter. The free particles are accelerated from that surface and it is pushed. If there was a fluid around the vanes, convection would turn them the other way ( Bernoulli etal). The radiation pressure, even from a reflective* surface is negligible. There is a US patent for a reverse turning radiometer; Cover the black surface with an insulating curved transparent foil, forcing all the heat to escape through the vanes from the shiny side, and for max efficiency make that side black too. Turn the vanes horizontal, and you have solar generated lift on an Airfoil with a transparent upper, black lower surface. Solar sail that can tack against the wind, if enough free particles are present.
It is fun to experiment with mouse milk.
* Radiation pressure in reflection is double than from absorption. (photons hitting, and then kicking, as they depart; not hitting only) think cat's, deer eyes.
Theorist:-- solar wind and solar radiation come at different angles at different altitudes (the different tails of a comet),so exciting prospects for those that have proposed Solar Sail regattas.

 

Log in or Sign up to hide all adverts.

Virtually all of that is wrong.

 

Log in or Sign up to hide all adverts.

The energy build up pushes back, Newtons third law I am thinking?

 

Log in or Sign up to hide all adverts.

Stop doing so much uninformed thinking and study the answers others have already worked out.

The following link will take you step by step through the arguments and to a description of the correct mechanism. Read all the way through, before you start thinking again.
http://math.ucr.edu/home/baez/physics/General/LightMill/light-mill.html

 

ok

 

Stopped here - the wrong way around assumption, Newtons third law states that the black side will oppose at a greater force, the black side is emitting a greater opposing force by heat build up.

'Light falling on the black side should be absorbed, while light falling on the silver side of the vanes should be reflected. The net result is that there is twice as much radiation pressure on the metal side as on the black. In that case the mill is turning the wrong way''

''Crookes at first believed this demonstrated that light radiation pressure on the black vanes was turning it around, just like water in a water mill. His paper reporting the device was refereed by James Clerk Maxwell, who accepted the explanation Crookes gave''

I am with Maxwell on this one. I will continue to read.

 

''But there is a problem with this explanation. Light falling on the black side should be absorbed, while light falling on the silver side of the vanes should be reflected.''

There is no problem with the explanation it is correct.

 

The light absorbed creates a greater heat , a greater energy level, an opposing force to the force of light causing an interference.

 

'' It was clear that the black side of each vane would absorb heat from infrared radiation more than the silver side.''

It will also emit more radiation than the silver side at a greater force.

 

No, bad. Read the whole article. It explains why it's incorrect.

 

What does ok, mean to you? You did exactly what you have been doing all along. You did not stop dreaming long enough to understand the whole of the reference.

And that leaves me not knowing anything about what you do or do not understand, about how and why

 

I read the article, I get it , you are saying it propels itself off the gases in the near vacuum by thermodynamic increase of the black side by the absorbing of the photons?, but I am saying the Photons build up an equal and opposing force that causes an interference that makes the motion and the gas is not a factor, although I can see gas working as well.

 

The gas in the vacuum finds an equilibrium of thermodynamic state and an equilibrium of pressure that is directed outwards, The black side of the paddles then creates heat that pushes itself around by means of the gas for propulsion swapping some of the energy to the gas.

Most of the energy rises across the paddles and the top of the paddles and top of the vacuum gains more heat compared to the lower layers.

 

Clearly you do not get it. The article explains why radiation pressure doesn't work as an explanation. You aren't understanding what is being said. You need to reread the part about the twice as much force on the silver side and think about it longer.

Perhaps consider a similar macroscopic example of a ball hitting and sticking to a wall vs bouncing off.

 

I already understand light I do not need time to think about, I understand what they are saying, but I also understand Newtons 3rd law, the ''black body'' will have a grater magnitude of force compared to the silver side, the silver side loses force by angular reflection deflecting the force, there is less heat build than black, the black sides have an equal and opposing force to the light.
The emitted radiation that builds up opposing an interference .

Black is literally a stop for light, you can see this in clouds by density.

 

Does this mean there's no way to stop this kite as it will just continue on with either side facing the sun?

 

That's all gibberish. Perhaps consider a similar macroscopic example of a ball hitting and sticking to a wall vs bouncing off.

 

Russ, the US patent examiners (many of them with PHD's in their field), do not grant patents on wrong premises, that can not be demonstrated to function as claimed. so:
"Virtually all of this wrong"-- Because?

 

Consider 2 macroscopic springs and one quickly bounces of a mirror loses little velocity impacts very little force by the quick change in velocity at impact point, then the second springs action is slower imposing more force.

 

That's patently untrue! You most certainly do not understand light, and this has been reflected in your many other erroneous interpretations that have been cesspooled, or totally discarded by yourself.

You are again using a science thread to push your light/dark/black theory that has previously been discarded and cesspooled.
You are fooling no one.