The twenty-seventh book that I’ve finished reading this year is Stephen Hawking’s “A Brief History of Time: From the Big Bang to Black Holes”. This is the most difficult book I’ve read this year, and perhaps even over the last four years. Perhaps due to my rudimentary knowledge of physics, it was common for me to read over the same paragraph multiple times and yet fail to grasp the essence of its logic. Nonetheless, after some hard work in picking out the logic flow, I’ve finally come to some understanding about the properties of the universe and its origins. According to Hawking, the start of the universe was highly uniform and smooth, though as it progressed, disorder increased and this trend has continued (this is also known as entropy). It started to expand and is still in the process of expansion, though some areas with higher density (part of the minimum non-uniformity allowed, and possibly better explained by the no boundary theory than the singularity theory) collapsed due to gravitational energy to form galaxies, stars, and eventually ourselves. Not all parts of the universe can fulfil the conditions for intelligent beings like us to exist and survive, as the anthropic principle suggests; our existence may be the result of sheer probability, and we just happened to be lucky. Other space-time regions that are not so lucky may still be interesting to observe and study, ranging from multi-dimensional regions to black holes. In the event of black holes, it is only after reading this book that I came to a clearer picture that people who fall in black holes do not consciously experience eternity, as they are stretched out and torn like spaghetti (in Hawking’s words) due to the difference between the gravitational force acting on their feet and that acting on their heads (their heads are further away from the black hole than their feet, so the force on their heads is weaker compared to that on their feet). However, their information is preserved in particles, that are transmitted outside the black hole. This is sort of like a book that’s been put through a fire, leaving only its ashes (Hawking’s made a witty joke about this towards the end of the book). There is also growing evidence supporting the multiverse hypothesis, where our universe is governed by a set of laws that differ from the laws that govern other universes; not only are we not the centre of our solar system, we may well be at a far fetched corner of the multiverses!? Although Hawking has attempted to simplify academic terms and concepts using accessible analogies, it is still difficult for people with little or no physics foundation to digest them as the logical pace is definitely not slow. For instance, I still cannot confidently say that I understand the rotations of particles (the 0, 1 and 2 spins and the sort of energies they correspond to, e.g. photons with electromagnetic forces and gravitons with gravity), or define what an event horizon is (I’m guessing that it’s the boundary of the black hole, beyond which light cannot escape). Other concepts such as imaginary time and imaginary numbers are beyond my comprehension (to think that I’ve calculated equations with imaginary numbers back in Maths HL seems like remembering a distant dream); why is it possible to remember the future but not the past? The concept that time may be relative to everyone is already difficult to fathom, especially when the possibility of time travel is introduced in greater detail; perhaps nobody from the future has come to our era because we do not have the technology to bring them back safely, but time travel may happen in the future when technology is advanced enough (talk about wormholes and space-time warping). Towards the end of the book, Hawking raised the phenomenon that philosophy and science have taken separate paths (since the discovery of scientific theories that require deep understanding and application of technical and mathematical knowledge) despite their identical goal — to discover the origin of humankind and our universe. Since then, scientists have been specialising in small areas of knowledge that are difficult to access by others, unfortunately constructing barriers for mutually intelligible cross-discipline conversations. Hawking believes that if we find an ultimate theory of everything, we should be able to simplify it so that everyone can understand??and “take part in the discussion of the question of why it is that we and the universe exist”. I look forward to that day and hope that all areas of science may be made accessible one day, so that ordinary people like me get a chance to understand topics so fundamental as why we came into being and why we are where we are.