From what I understand:
Ki is actually "being aware in your mind" of the energy that's flowing through your body, the life-force.
When using that awareness, you can better control those physical movements in your body, or control the movements of your opponent caused by the energy flowing in his body.
To get slightly off-topic: here in Belgium they sell Aiki Noodles in our supermarkets. It's a brand of noodles containing the word aiki
. So those noodles also contain life-force. You eat, you burn calories, you get energy, you can control your movements better...
Thinking absurd enough, you can see ki in everything around you.
Now, coming back to this quote from my previous post:
For example, if your partner reaches for your wrist and you wait until he grabs you before you start to turn and throw, you will end up with someone's body hanging on to your arm as you try to throw. If, instead, you start the turn and throw before he actually grabs you, you will be able to lead his energy. In order to grab you, if you are already moving, your partner will have to track your movements and follow you. If he is intent on grabbing you, you will be able to lead his ki by just staying slightly ahead of his grab. Then you simply lead the movement into any convenient aikido form.
Is it as well possible to use Ki from starting in a static position. Most aikido techniques learned step by step, from the beginning in a static position while (for example) the uke holds your wrists, and then you have to start turning out of that 'lock' without trying to use your own strength. In this case, you can't start your technique using his movements or Ki.
Of course in a normal action, when already knowing the technique, you can do it more fluidly and quickly, already start turning before the uke had the chance to take your wrists and move the ki to the next direction,...
So actually, that Ki is no real "power" that is scientifically proven. Ki is in this case some movement or flow, coming from a physical movement, and not a physical movement coming from an inner power (Ki).
Can Ki be developped more by meditation? Or by breathing techniques (kokyu)?
BTW, a more courageous (hence provocative) way to phrase your question would have been: Does God exist?
We always could start a discussion around "creationism" versus "evolution".
And about science that proves Ki or can't prove Ki.
But maybe that's better to discuss in another thread, maybe in the "spirituality" forums?