So here it is. These are the primes of ℤ[√-1], ℤ[√-2], ℤ[(1+√-3)/2], ℤ[√-5], ℤ[√-6], and ℤ[(1+√-7)/2], all in one picture (at the top) and individually (in that order, below.)

The reason these rings are interesting is that each of them consists of solutions to quadratic equations x²+bx+c=0 where b and c are integers and b²-4c is some square times -1, -2, -3, -5, -6, or -7, respectively.

(thx ebering for the idea)



Binhai Eco City aims to be a case study for green urban planning
The cities of the future are envisioned as green oases powered by clean, renewable energy. A joint Chinese-Singaporean project hopes to provide a case study for just such cities. Binhai Eco City is designed to be an example of how cities can be completely green developments. Binhai is located on the outskirts of Tianjin in north China and will be connected to another planned eco-friendly development in Beijing by a high-speed rail connection. Beijing Bohai Innovation City covers a planned 17.6 sq km (6.8 sq mi) and aims to set a new standard for environmentally-conscious urban planning. The Binhai Eco City Master Plan covers a much smaller 0.2 sq km (0.07 sq mi) but like the Beijing project has received international recognition, having been shortlisted for the World Architecture Festival 2014. The Eco City development has planned green belt land to the north of the site and aims to push the green land towards the center of the site. Founder of project architects Holm Architecture Office (HAO) Jens Holm explains that the plan mimics an outstretched hand, mixing green and functional areas. (via Binhai Eco City aims to be a case study for green urban planning)