Experiment finds that gravity still works down to 50 micrometers

Previous discussion: https://news.ycombinator.com/item?id=22797729

Good, but on the atomic scale that's still a lot - as I understand it the key questions are how well it works on scales where the "strong" and "weak" forces also apply.

On very small scale the force would be very very high as the denominator, d^2, goes to zero. What limits the denominator going to zero? Could a close distance really be what leads to the strong or weak force?

Is the "Next: find old wardrobe." supposed to be a Narnia reference? If not I can't figure out what it is for.

If we find a small enough situation where gravity stops working I wonder if there will be an inverse square law observed as they approach that level of tiny. Like half way between the size where gravity works fullest and the tinier size where it doesn’t work anymore is 75% less gravity.

Was I foolish in thinking that gravity works at all scales?