Question said:
I would believe gravity existed if
every object will start moving downward even though released moving in an upward direction and even though air currents where it was were moving upward there. Since I am reasonable, you need not demonstrate it for every object, but for three objects of my choice (not yours).
Excellent!
This is real scientific progress! This presenting of your own success criterion is a big, big step forward towards true understanding of the world around us. I am immensely proud of you.
Do you believe this would be reasonable for a preliminary test of gravity?
Well... even after congratulating you so loudly above, I have to answer this question with a "no". Not that it isn't commendable progress, because it is. Rather that it's not quite the end state of a rigorous success criterion.
Here are the gaps I see in it.
1) Not every object will start moving downward. Balloons filled with helium, for instance, will tend to move upward in an air-filled environment. This is not because there is no gravity; it is because gravity pulls the air around the balloon downward more than it pulls the balloon.
2) Since gravity is just a force, other forces acting on the object can counteract it. Sufficient upward air motion will impart a force on an object that could make it stay in place or even force it upward. A magnet could likewise force another magnet upward.
3) The three objects must be mutually agreed upon.
Here are my proposed solutions.
1) I propose the experiment be done in a vacuum, or as close to a vacuum as one can generate on the surface of the Earth. This would do away with the lighter-than-air problem.
2) In addition to the air-pressure issue solved by the vacuum, let's make sure that there are no other forces acting upon the objects. Having the objects be nonmagnetic would be a good start.
3) Considering that the vacuum chamber might be moderately small, I propose that the three objects be:
A) A feather;
B) A billiard ball;
C) A cubical 1 Kg weight.
I am sure that there is something in these statements that are unreasonable to you. Please specify what they are, and how you propose to solve them.
Divide by seven, reading numbers like a computer would.
Sorry, I have no idea what this means, nor do I have the time to decipher it. If you are trying to send me a message, please PM me in cleartext instead.