• "Penrose is truly one of the world's leading mathematical physicists"

    Scotland on Sunday
  • "Science needs more people like Penrose, willing and able to point out the flaws in fashionable models from a position of authority, and to signpost alternative roads to follow"

  • "A genuinely new idea about the origins of the universe that, although untested, seems to hold together theoretically and must be taken seriously given Penrose's status"

    Doug Johnstone, Scotsman
  • "Cycles of Time can be highly recommended as an example of how cosmologists are now thinking the unthinkable by trying to look back beyond the Big Bang and forward beyond the death of our universe"

    Literary Review
  • "Cycles of Time is as uncondescending in style and as impenetrable in content as his previous books. Which is not to say that there are not, as before, many pleasures to be had along the way"

    Sunday Times