Answer: Forget those flame-throwing flatulators of college campuses of the 1960s. For this one, you can just ask your doctor: Surgical teams must take precautions to ensure that fires and explosions do not occur near or within a patient, since some 40 percent of the gas in the large intestine may be hydrogen and methane, says Jearl Walker in "The Flying Circus of Physics." Procedures such as removal of polyps require extreme care. Any heating or sparking during electrical cauterization can cause the gases to blow up, burning and rupturing the intestines. During one colonoscopy, there was a loud explosion and a blue flame shot out of the colonoscope for about a meter. Current protocol calls for the patient to fast for up to a day so that the intestines are empty. (Surgical fires today are rare, estimated at less than 1 in a million.)
Answer: Suppose 80 percent of spouses are F's "faithfuls" who try their best to keep a marriage going. The other 20 percent are N's "nasties," impossible to get along with over the long haul. You can estimate your own percentages, but everybody knows the types.
Now out of every 200 people marrying for the first time 100 couples 64 of the marriages, on average, will involve two F's (.8 times .8 equals .64) and will endure.
An average of 32 of the 100 marriages will involve an F and an N and eventually break up. Four of the 100 marriages will be between two N's ill-fated from the start.
It's apparent the overall divorce rate for this first round is 36 marriages out of the 100, or 36 percent.
OK, round 2: All of the F's who married F's are still together and not in the re-marriage pool. From the 32 divorced F-and-N couples, there will now be 32 F's and 32 N's making the dating rounds. From the 4 divorced N-and-N couples, there will be 8 N's. Total: 32 F's, 40 N's!
These 72 former spouses will form 36 new marriages. But only about seven of these, on average, will be F-and-F. The remaining 29 will be N-and-F, or N-and-N, and soon end. Divorce rate for round 2? A whopping 80 percent. Overall divorce rate for both rounds will be close to 50 percent.
Send STRANGE questions to brothers Bill and Rich at email@example.com, coauthors of "Can a Guy Get Pregnant? Scientific Answers to Everyday (and Not-So- Everyday) Questions," from Pi Press.