I believe Roger Penrose draws all his own illustrations. For copius excellent examples, see his book Road to Reality. Here is one example: https://phys.org/new

I believe Roger Penrose draws all his own illustrations. For copius excellent examples, see his book Road to Reality. Here is one example: https://phys.org/news/2018-03-math-bridges-holography-twistor-theory.html https://phys.org/news/2018-03-math-bridges-holography-twisto... https://theportal.wiki/images/1/11/Penrose-Rindler-Clifford-parallels.jpg https://theportal.wiki/images/1/11/Penrose-Rindler-Clifford-... He also comes from the pre-ppt age of presenting with handwritten acetate transparencies - and still does afaik. Many of his slides have been captured for the infowebs. http://cgpg.gravity.psu.edu/online/Html/Seminars/Fall1998/Penrose/ http://cgpg.gravity.psu.edu/online/Html/Seminars/Fall1998/Pe... http://cgpg.gravity.psu.edu/online/Html/Seminars/Fall1998/Penrose/Slides/s19.html http://cgpg.gravity.psu.edu/online/Html/Seminars/Fall1998/Pe... Some of his original papers from the 1960s were not published at the time, but circulated as samizdat facsimiles of his handwritten notes, until later transcribed by professors or their students, then published in book collections: http://math.ucr.edu/home/baez/penrose/Penrose-TheoryOfQuantizedDirections.pdf http://math.ucr.edu/home/baez/penrose/Penrose-TheoryOfQuanti... Penrose is famous for his visual imagination, which seems to ground many of his insights. Here is a paper where he invents a visual notation for tensors and operators: https://en.wikipedia.org/wiki/Penrose_graphical_notation https://en.wikipedia.org/wiki/Penrose_graphical_notation http://homepages.math.uic.edu/~kauffman/Penrose.pdf http://homepages.math.uic.edu/~kauffman/Penrose.pdf This has inspired recent work by Bob Coecke, as captured in his beautiful book Picturing Quantum Processes. (arXiv example: https://arxiv.org/pdf/0908.1787.pdf https://arxiv.org/pdf/0908.1787.pdf)