wired: By 2008, Hawking’s hand was too weak to use the clicker. His graduate assistant at the time then devised a switching device called the “cheek switch.” Attached to his glasses, it could detect, via a low infrared beam, when Hawking tensed

wired: By 2008, Hawking’s hand was too weak to use the clicker. His graduate assistant at the time then devised a switching device called the “cheek switch.” Attached to his glasses, it could detect, via a low infrared beam, when Hawking tensed

wired: By 2008, Hawking’s hand was too weak to use the clicker. His graduate