From New Scientist, a tour of our fundamental understanding of the world around us, starting with an attempt to define reality and ending with the idea that whatever reality is, it isn’t what it seems. David Berman on the ten dimensions of string theory (and part 2). The measurement that would reveal the universe as a computer simulation: If the cosmos is a numerical simulation, there ought to be clues in the spectrum of high energy cosmic rays, say theorists. Digging up the early universe: Cosmologists are uncovering relics from the dawn of time, letting them look back almost all the way to the Big Bang. The universe is almost done making stars: Star formation is now 30 times lower than at its peak 11 billion years ago. Constructor theory: David Deutsch on how many mathematicians to this day don't realize that information is physical and that there is no such thing as an abstract computer — only a physical object can compute things. Clay Dillow goes inside the largest simulation of the universe ever created: A giant supercomputer is making massively detailed models of the cosmos. Should 16–18 year olds be taught modern physics such as quantum mechanics?