difference between moving in the still wind vs being still in the moving wind

[raaaid]

for example ive done paraglide and use a strong wind to aquire height while still WITH respect to the ground while i cant do the opposite

also seagulls hardly move the wings while sparrows or pigeons move them a lot, the differnce is the wind in their habitats

also while classic physics say its the same take this proof

http://www.youtube.com/watch?v=4pgDs50A-Yw

the cart moves FASTER than the still wind while the ground moves

would it move by itself by in the inertial equivalent system of the cart moving faster than the wind when the wind is 0 in which case the road would move with respect to the cart as in the video

in fact the special profile of birds wings whic plane engineers copied save fuel, from where does come this FREE ENERGY?

[AndyJWest]

Yes, but the device is extracting energy from the wind to turn the wheels - it is no different than a boat tacking into the wind in this respect. There is no 'free energy' at all.

Seagulls can sometimes make use of local updrafts caused by the wind moving across the waves - again there is no 'free energy', instead they are extracting energy, and in the process will reduce the velocity of the wind.

[raaaid]

yes i guess is something like sailing crosswinds much faster than the wind

you know wheres the luxury of sailing?

that with the strongest wind you just have to let it blow behind the sails and youll feel zero wind while having a martini with a martini girl

something im pondering is learn german and french and work in turistic sailing

oh im brainwashed by child memories

http://www.youtube.com/watch?v=m_wFEB4Oxlo

[WTE_Galway]

Logically ...

If what you say is true an aircraft in a wind tunnel will behave totally different to one actually in flight.

Which would mean all those aircraft designers doing wind tunnel tests are really just wasting there time.

[raaaid]

well that they dont ignite the engines and let the thing fly in the tunnel shows is not the same

anayway i admit probably andy is right and the upwards effect i experimented paragliding was probably an up current not an horizontal so proably i was wrong and its the same