Trivia: The show's two hour premier broke the SCI-FI's ratings record by attracting over 4.2 million viewers. It was also the most watched cable program that day.
Trivia: Rodney McKay's sister, Jeannie Miller is played by Kate Hewlett who is David Hewlett's sister in real life.
Trivia: In the final episode, 'Enemy at the gates' Sam Carter says that the new ship is to be named the General George Hammond in memory of the character Hammond who had died of a heart attack. This is a tribute to Don S. Davies, who played Hammond, who sadly died of a heart attack in June 2008, shortly after filming Stargate Continium.
Answer: Because even all 4 Naquadah generators (one was destroyed) together is only enough to dial Earth for approximately 1.2 seconds (As seen in the episode "Letter from Pegasus"). Further, if Earth had found a ZPM, they would dial Atlantis and let them know. After all, the SGC has no other use for a ZPM than to dial Atlantis.
Grumpy Scot