A zombie apocalypse is virtually impossible. Here's why. Patient Zero gets medical help. Doctor sees new disease that could potentially turn people into zombies. Patient is incinerated, along with all bacteria being killed. Also, there are too many people with guns to even let the zombies live long enough to take out a large portion of Earth's people. You also have to take in the fact that zombies are rotting humans. They wont last long in the winter, and then on the first hot day, they'll decompose. Think of when you leave hamburger meat out for a long time. At room temp it will get infected with all kinds of bacteria that will kill a human. Also, frostbite will get a lot of zombies before they make it to summer.
