Sure about the 'possess' part? A model hasn't been required since the 1800's. The use of computers and video cameras in manufacturing was patented decades before it was practical.
I often see this on HN: ideas are nothing; execution is everything.
I don't think a model is necessary for a patent application, but some check on bullshit is necessary. If you are granted the patent, and following the instructions in it does not yield a working device--or if the instructions cannot be followed, because they require an impossibility or something that does not yet exist--that should be grounds for immediate disqualification.
There has to be some way to encourage "this is how you do it" over "so I have this really cool idea that I think is worth lots of money".
Possess the invention doesn't mean to actually use the invention. Just to fully understand the invention. As opposed to just envisioning an invention in broad strokes. The invention just has to be ready to be used, but that doesn't necessarily mean practically.
