WHAT IS ELECTRIC CHARGE?

You have used electric charge every day of your life. It holds your body together, runs your phone, and occasionally bites your fingertips in January. Physicists know its value to a precision that would embarrass an accountant. And yet ask any of them what charge actually is, and you will hear what it does: it attracts, it repels, it is conserved, it comes in lumps. A description of behavior is not an answer.
Boris Kriger, a theoretical cosmologist, offers an answer, and he is frank that it comes from his own research programme and is contested. Charge, he argues, is not a substance a particle carries around like a coin in its pocket. It is something stranger and simpler, tied to the shape of the universe and to the direction in which time runs. That one idea explains why there are exactly two signs and never a third, why charge cannot be created or destroyed alone, and why a heavy proton and a featherweight electron carry precisely the same amount.
On the way, the book follows twenty-five centuries of people who were brilliant, reasonable and partly right; descends into a vacuum that is far from empty; looks inside the atomic nucleus; and then prints, openly, what the theory cannot do and exactly what discovery would destroy it.
Witty, warm and free of equations, this is a book for anyone who suspects that the most familiar things are the least understood.
Keywords: electric charge, physics, cosmology, history of science, vacuum, time, popular science