Frank Close tells us about the history of particle physics, and what it means that charge in our universe's matter is so closely balanced.
In his new book, Frank Close explores the mystery of why subatomic particles balance each others' charges. Since the discovery of the proton and the electron in the 20th century, a mystery persists at the core of the atom: Despite belonging to completely different particle families and being radically different in size, the charges of these two particles completely balance each other out — enabling a universe where gravity dominates. But why? To explore the clues, Live Science sat down with Frank Close , an author and emeritus professor of particle physics at Oxford University, to discuss his new book " Charge " (Oxford University Press, 2024). In it, Close traces out the conundrum through a concise history of particle physics, including the strong, weak and electromagnetic forces that operate over short distances, the discovery of the Higgs boson , and the hints of a yet-to-be-discovered grand unified theory. Ben Turner: Your book provides a fascinating summary of the current state of particle physics, and the remaining mysteries in it — most importantly the electrical neutrality of matter. What motivated you to write it? And why now? Frank Close: It's been a puzzle that's been with me for a long time. Why is it that, every breath you take, your hair doesn't stand on end, given that you're breathing in a billion billion billion atoms of oxygen and nitrogen in the air, each of which has got all this electricity in it? The negative charge on the electrons of all these atoms is triflingly small, but there are so many of them together that a single breath is like breathing in roughly 15,000 coulombs — that's enough to spark 1,000 bolts of lightning. The answer is that the atom is electrically neutral. The negative charge of the electron outside is precisely balanced by the positive charge of the nucleus in the middle. It's one of the unanswered questions in science, and it strikes me, perhaps, as the most immediate one. You don't have to have a huge…