U.S. intelligence agencies and outside nuclear experts have cited the report, and its description of the size and scope of the centrifuges, to conclude they are so-called P-2 designs a generation beyond what Iran is using.

WSJ: North Korea Nuclear Find Raises Fears It Will Share With Iran

According to DARPA's research description, the robot should be about the size of a softball but capable of squeezing through a one centimeter hole and reconfiguring itself within 15 seconds.

CNN: Robotics discovers its soft side

The painting, also the same size, was previously identified as Constable's schoolmaster from Dedham, Dr Thomas Lechmere Grimwood, based on its description in a 1926 Sotheby's sale catalogue as a 'Portrait of the artist's schoolmaster'.

BBC: Artist captured parents on canvas