Using the d3-inertia plugin.
Original research by Philippe Rivière for visionscarto.net.
Add inertia issue #27 to versor rotation of the globe.
Includes a modified versor.js, allowing the multiplication of the final rotation by a delta to the power alpha.
Moving average for velocity (exponential decay)
Trying to plug it in as cleanly as possible into d3.drag
Try it on mobile!