Little experiment creating a bowl inspired by a damped sine wave – something like a ripple on the surface of water.
Carved in spalted beech (spalting is when a fungus has fed on the nutrients in tree and discoloured the wood), I think the black line gives it a really dramatic look.
I carved this with a 6mm ball nose bit on my CNC machine, with the finishing mostly done by hand sanding. It still needs final smoothing and then to decide what finish to go with – I’m thinking Danish oil, but perhaps a high-gloss varnish or oil might be better?
Designing the bowl involved created a 3D model first. I sketched a graph based on the formula below , and then tweaked the inputs to match the size of stock I had available.
Then it was pretty straightforward to take the SVG of the graph into Fusion 360 and create a revolved body from it. The centre of the ‘ripple’ is offset from the centre of the stock to allow for more of the ripples to cascade.
the formula engraved on the back 
roughing with a 6mm flat bit 
more roughing 
finishing pass with a 6mm ball nose 
after initial sanding 
cleaned up with white spirts to see how it’s progressing