Question: Well, excuse us, but when might stomach or intestinal gas have far more explosive consequences?

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.)

Flammable gases can also be produced in the stomach when it doesn't empty properly. In one case, a man lit a cigarette just as he belched uncontrollably: the cigarette shot from his mouth like a rocket, and his lips and fingers were burned. In another, when a guy lighting a cigarette belched, "the gas came up through his nostrils with a flare shooting out of each, making him look like a medieval, fire-breathing dragon."

Question: No point asking a scorpion about the math involved, but it sure knows how to apply some in hunting down a beetle. Explain.

Answer: The moving beetle inadvertently sends two sets of pulses along the sand's surface, one in the form of longitudinal waves that oscillate forward and backward at 150 meters per second (m/s), another in the form of transverse waves that go side to side at 50 m/s, say David Halliday et al. in "Fundamentals of Physics." That's a big difference, apparently detectable by the scorpion, which is nocturnal and can neither see nor hear the beetle. What the scorpion does is stand with its eight legs roughly in a circle so that the faster pulses are felt first, then the slower ones. The direction to the beetle is given by the first leg to feel a vibration; the distance is given by the time interval between the arrival of the two pulses. Having mastered the mental math (distance = 75 m/s x the time lapse), the predator scorpion turns toward the beetle and mad-dashes for dinner.

Question: Can anybody explain in solid numbers why marriages today so often degenerate into "The Ex-Files"?

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.

For round 3, you can see the faithful F's are scarcer still, the nasty N's are in abundance, and marriage licenses might as well be printed in disappearing ink.

Send STRANGE questions to brothers Bill and Rich at strangetrue@compuserve.com, coauthors of "Can a Guy Get Pregnant? Scientific Answers to Everyday (and Not-So- Everyday) Questions," from Pi Press.