“The brain sits snugly inside the skull, but it's not a completely flush fit - there is still a layer of fluid between bone and soft tissue that serves as a natural shock absorber. Some shocks, however, can't be absorbed, and when the head gets clobbered too hard, the brain can twist or torque or rattle around inside its skeletal casing.”

American magazine editor and author

Jeffrey Kluger is an American magazine editor and author. He is editor at large at Time magazine and has written thirteen books across a range of subjects. His books include works on psychology, medicine, family dynamics, and spaceflight, among them The Narcissist Next Door, Splendid Solution: Jonas Salk and the Conquest of Polio, The Sibling Effect, and Lost Moon: The Perilous Voyage of Apollo 13. Lost Moon later served as the basis for Ron Howard's film Apollo 13. He has also written two young adult novels and one novel for adults, Holdout.