Okay. Just gives me the chance to say "Told ya' so!" 
The phrase "dead ringer" as in Tim is a dead ringer for his brother Bob (meaning he looks so much like him he could be mistaken for him). In Victorian times, it was not easy to determine whether a person was actually dead or in a deep coma. They attached a string to a finger or a toe. That string was attached to a bell above the gurney. They were left in the morgue for several days until decomposition set in. During that time, any movement would cause the bell to ring. In other words, they looked just like they were dead, but they weren't dead. Just like Tim looks just like Bob but isn't Bob. They were also known to attach a string to a corpse, run it through the lid of the coffin, and attach it to a bell there. The grave was not filled in for several days. Back then, the only way to determine death beyond a doubt was to see the body start to decompose.
Seriously...I can't make this stuff up! I've got another one that was done when science was pondering whether the brain retained consciousness after physical death, but it is really a bit gross so I won't go into it.
Actually, I got this stuff from neurobiological psychology texts. So...up to you. You can believe a website pulled from somewhere, or you can believe me.
