Technically excellent study - like the background progression of light: really adds that little interest to the negative space, and pulls the eye to the subject. (I've used background light like this myself, and usually been knocked in comments for it - intrigued to know if you're getting something similar). Strong sense of texture on the wood. Just the slightest sense (and it's more significant in such a contrlled an simple image) of too much sharpening in some edges of the wood - top right especially.
not very fond of the position of the timeglass.... dunno what it is.... then it would be cooler if it wasnt the back of the timeglass that was lit up but the front.