LiveScience: Record-high heat has scorched Australia this week, with temperatures exceeding 104 degrees Fahrenheit (40 degrees Celsius) for several days in a row in some areas. Relief is expected for this weekend, however. Blazing temperatures have hit athletes and fans at the Australian Open in Melbourne, in what forecasters said could be the hottest stretch of weather in a century for the city. So what's causing the inferno? "Almost all heat waves form due to unusually strong areas of high pressure at high...