Copic Ciao Marker, Light Rouse R14, CM-R14
About this deal
A few months ago, a friend of mine sent me a photocopy of your article... Your figures 3 and 4, the 'continuous flight of steps', were entirely new to me, and I was so taken by the idea that they recently inspired me to produce a new picture, which I would like to send to you as a token of my esteem. Should you have published other articles on impossible objects or related topics, or should you know of any such articles, I would be most grateful if you could send me further details. 
Franklin-Christoph - So Many Models, So Little Time
In his final report - Power to the People - Mr Penrose recommends measures to reform the UK’s competition institutions for the digital age. working on the design of a new picture, which featured a flight of stairs which only ever ascended or descended, depending on how you saw it. [The stairs] form a closed, circular construction, rather like a snake biting its own tail. And yet they can be drawn in correct perspective: each step higher (or lower) than the previous one. [...] I discovered the principle in an article which was sent to me, and in which I myself was named as the maker of various 'impossible objects'. But I was not familiar with the continuous steps of which the author had included a clear, if perfunctory, sketch, although I was employing some of his other examples.  The Penrose stairs or Penrose steps, also dubbed the impossible staircase, is an impossible object created by Oscar Reutersvärd in 1937     and later independently discovered and made popular by Lionel Penrose and his son Roger Penrose.  A variation on the Penrose triangle, it is a two-dimensional depiction of a staircase in which the stairs make four 90-degree turns as they ascend or descend yet form a continuous loop, so that a person could climb them forever and never get any higher. This is clearly impossible in three-dimensional Euclidean geometry but possible in some non-Euclidean geometry like in nil geometry. The "continuous staircase" was first presented in an article that the Penroses wrote in 1959, based on the so-called "triangle of Penrose" published by Roger Penrose in the British Journal of Psychology in 1958.  M.C. Escher then discovered the Penrose stairs in the following year and made his now famous lithograph Klimmen en dalen ( Ascending and Descending) in March 1960. Penrose and Escher were informed of each other's work that same year.  Escher developed the theme further in his print Waterval ( Waterfall), which appeared in 1961.
Visiting Penrose | Cornwall | National Trust
John Penrose MP has today (16 February) published proposals to update the UK’s competition and consumer regime.There’s been a thread of beautiful mathematics over the last 60 years or so searching for ever smaller sets of shapes that do this,” Kaplan says. “The first example of an aperiodic set of shapes had over 20,000 shapes in it. And of course, mathematicians worked to get that number down over time. And the furthest we got was in the 1970s,” when the Nobel-prize winning physicist Roger Penrose found pairs of shapes that fit the bill. Harshbarger, Eric (2010-08-19). "The Never-Ending Stories: Inception's Penrose Staircase". Wired. ISSN 1059-1028 . Retrieved 2020-06-05.