The following is an indirect result of being forced to take biology.

Ever wonder if the Stargate crew can run out of 'gate addresses?

There are thirty-nine symbols on the Stargate, and each 'gate address consists of seven symbols (locally). So...

For seven-symbol addresses (aka. local calling), there are 39 to the power of six times one, or 3,518,743,741 (3 billion), addresses.

Assuming that a hundred years later, Stargate is still running and they've somehow managed to use up 3.5 billion addresses, there's always the eight-symbol addresses (aka. long-distance calling) to consider. For that, there are 39 to the power of seven times one, or 137,231,006,700 (137 billion), addresses.

After that, when you want to throw fanfiction into the mix (as if one hundred-thirty-seven billion isn't enough), you can use the nine-symbol (because there are nine chevrons on the 'gate) addresses (aka. out-of-country calling). There are approximately (or exactly or no more than) 39 to the power of eight times one, or 5,352,009,261,300 (5 trillion), addresses.

Now, us faithful Stargate fans know that not every address connects, so, even if only fifty percent actually connect, there should be a total of... (lemme find my big calculator)... 2,746,379,505,880 (and a half) working 'gates.

The moral of this math-y stuff is: don't ever let anyone tell you that Stargate (or Stargate fanfics) should come to an end just 'cause there aren't enough 'gates!