Quote Originally Posted by mbeige View Post
Lastly, let's pretend you didn't say that I'm talking "rubbish" because if you ask me, yes that comes as offensive.
I'm sorry if you were offended when I referred to one of your comments as rubbish, but I'm not changing anything. Yes, let's just pretend it didn't happen, let's keep it from being personal.

Give me an airplane that doesn't go forward using engine thrust. It's obvious that engine thrust is needed to push the plane to get enough wind across its wings to generate lift.

Besides, even a car or a man, which uses the friction between the feet/tires to propel forward, CAN move forward on a platform that matches it's speed backwards. It's simple, get a friend, and a pair of moving platforms (or escalators, but that'll require extra athletic ability/balance). You and your friend stand on the platform at the exact same moment, he goes on the platform that goes forward, just standing (letting the platform move him forward). You go on the platform that goes BACKWARDS, and you try to keep up with him. With extra effort you can easily keep up with him and get to the other side at the same time or even FASTER than him. Gumalaw ka diba? At gumalaw ka ng halos parehong bilis nung platform na tinatayuan mo (your friend is standing on a similar platform, which should be moving at approximately the same speed).

Of course, you used extra effort. But that's because your feet is directly attached to your legs which is directly attached to your torso. To more accurately model the forces acting on the airplane, it would require that you'd be on rollerskates holding on to a piece of rope (syempre di pwede sa escalator) - if you pull on the rope, you move forward, regardless if the platform is going forwards, backwards, fast, slow, keeping up with your speed or not at all. All the platform does is spin the wheels, because the wheelbearings has effectively isolated your body from the moving platform.