Timothy Walters Kleinert
There are many people who, like myself, believe that "ki" is really just about certain bio-mechanical functions
To me, approaching Ki that way is like playing music. Someone learning to play the guitar can sit down and learn an incredible solo that, say, Jimi Hendrix played. They can learn it note for note, nuance for nuance, they can replicate the timing etc. But without the special something that Jimi had, it will never feel the same, it won't be experienced the same way. It may look and sound the same, but that's it.
Knowing what Ki is and using it in Aikido properly is similar to me. You can do something in a relaxed manner, moving your bdy properly etc.... but without Ki, the -experience- of it will never be the same. The feeling will ultimately be different. That's my experience anyway.