AValeriepieris circle[1][2][3] (/ˌvæləriːˈpaɪrəs/VAL-ə-ree-PY-rəs) is a figure drawn on the Earth's surface such that the majority of the human population lives within its interior. The concept was originally popularized by a map posted onReddit in 2013, made by an AmericanESL teacher named Ken Myers, whose username on the site gave the figure its name.[4] Myers's original circle covers only about 10% of the Earth's total surface area, with a radius of around 4,000 kilometers (2,500 miles), centered in theSouth China Sea and covers more than half ofAsia, including some of the world's most populous countries .[1] The map became a popularmeme, and was featured in numerous internet media outlets.[5][6][7]
Myers's original map uses theWinkel tripel projection, which means that his circle, not having been adjusted to the projection,does not correspond to a circle on the surface of a sphere.[8][9]
In 2015, Singaporean professorDanny Quah—with the aid of an intern named Ken Teoh—verified Myers's original claim, as well as presenting a new, considerably smaller circle centered on the township ofMong Khet inBurma, with a radius of 3,300 kilometers (2,050 mi).[1] In fact, Quah claimed this circle to be the smallest one possible, having been produced from more rigorous calculations and updated data, as well as being a proper circle on the Earth's surface.
In 2022, Myers's original circle was again tested by Riaz Shah, a professor atHult International Business School. Shah used recently published data from the United Nations' World Population Prospects to estimate that 4.2 billion people lived inside the circle as of 2022, out of a total human population of 8 billion.[10]
The smaller Valeriepieris circle is densely populated, containing almost all ofChina,India,Borneo and thePhilippines; large parts ofIndonesia,Pakistan andKorea; and the entirety ofTaiwan,Nepal,Bangladesh,Sri Lanka andMainland Southeast Asia.[2]
Myers's idea has been formalized[11] and a Valeriepieris circle can be defined for any spatial area, like a single country. These generalised Valeriepieris circles can be used for studying population changes over time, dimensional reduction and measuring population centralization.
Media related toValeriepieris circle at Wikimedia Commons