Factoring out the geometric background part of the opener for this Bloomberg Businessweek story on ketamine. Move your mouse left and right to change the speed. Move your mouse up and down to change the amplitude.
Text can be overlaid with the query string variable text, e.g. http://bl.ocks.org/tophtucker/raw/500d2a010105cfcc87db/?text=KETAMINE.
It’s a bunch of concentric circles with exclusion compositing. The radius of the ith circle oscillates with amplitude * Math.sin(t/speed + (t/10000)*i), where t is the number of milliseconds since you loaded the page.
E.g., for amplitude = 5 and speed = 500 (which is the default if you position your mouse in the middle of the page), the radius of circle i at time t oscillates with period (20000π)/(20+i) in t (WolframAlpha).
Things sync up in cool ways when the derivative with respect to i (which comes out to (t cos(((i+20) t)/10000))/2000) is small (WolframAlpha):
Um because then the concentric circles oscillate in phase? Or close to it? Yeah… yeah that sounds right… right?
Obviously I just mashed periodic functions and variables and parameters together in various terms of various order until some li’l unexpected emergent thing happened.