Pushing with great effort, you get the flywheel to inch forward. You keep pushing, and with persistent effort, you get the flywheel to complete one entire turn. You don’t stop. You keep pushing. The flywheel moves a bit faster. Two turns . . . then four . . . then eight . . . the flywheel builds momentum . . . sixteen . . . thirty-two . . . moving faster . . . a thousand . . . ten thousand . . . a hundred thousand. Then at some point—breakthrough! The flywheel flies forward with almost unstoppable momentum.