Donald L. Unger shows his hands Saturday at the Ig Informal lectures at the Massachusetts Institute of Technology. He cracked his knuckles on his left hand at least twice a day for 60 years but never developed arthritis (as his mom warned he would). (Photo: Marc Levy)

Of course the science behind the 2009 Ig Nobel Prizes can be funny — the idea is to “first make people laugh, and then make them think” — but winners explaining their work at the Ig Informal lectures revealed hard science and serious intent.

Of course there are important implications in the veterinary award that shows cows that have names give more milk than cows that are nameless. And there’s reason to understand the biology that makes pregnancy possible that emerged from the physics winner, an analytical determination of why pregnant women don’t tip over.

But the audience Saturday in a Massachusetts Institute of Technology lecture hall grew momentarily solemn as Elena N. Bodnar’s explained her invention of a brassiere with cups that can be made into gas masks.

“It’s more successful to prevent trauma than to treat the consequences, and much more can be done on personal readiness,” Bodnar told some 100 listeners, citing her bra as one way to filter out harmful airborne particles during crises such as last week’s Australian dust storms or — and this is when the audience stilled and grew silent — the terrorist attacks of Sept. 11, 2001.

Familiar images appeared on the screens raised on either side of Bodnar: dazed people finding their way through clouds of toxic dust raised by the collapse of  high-rise buildings, handkerchiefs, napkins or scarves held feebly to their faces. A readily available gas mask would allow people to make their way through dust and smoke and still have their hands free to carry things or for balance.

The inspiration for the bra gas mask, starting with Bodnar’s experiences as a young student in Ukraine, was just as serious: the Chernobyl nuclear reactor disaster of April 26, 1986, when a steam explosion and fire released some of the radioactive reactor core into the air. Bodnar saw the deadly effects firsthand.

Some things to consider when using the brassiere gas mask discussed at the 2009 Ig Nobel Awards. (Photo: Marc Levy)

Still, Bodnar said, the additional clasps built into the bra to allow it to be broken into two masks “does not interfere with its primary purpose, to support our breasts.” And she repeated from her Thursday award acceptance speech at Harvard’s Sanders Theatre that using a bra as a gas mask takes a woman about 25 seconds: five seconds to put on one cup and 20 seconds to select the man whose life you should save with the other.

Some other items from the Ig lectures, including serious intent and funny follow-up questions:

Fumiaki Taguchi, of Kitasato University Graduate School of Medical Sciences in Sagamihara, Japan, explained how he came to discover kitchen refuse can be reduced more than 90 percent in mass by using bacteria extracted from the feces of giant pandas, winning him an Ig Nobel in biology: He hypothesized the pandas’ stomachs must have powerful enzymes that allow them to break down the bamboo that is the main (nearly the sole) component of their diet.

Let bacteria extracted from panda feces do its work on more than 100 pounds of garbage, he said, and it will shrink to less than 10 within weeks. The byproduct is hydrogen that could power 1 million hydrogen fuel-cell vehicles driving dozens of miles for 137 days, adding to “conservation of the global environment  — this is a feces innovation.”

How many pandas would be needed? Each eats about 40 pounds of bamboo a day and excretes about 40 pounds, he told the audience. “You don’t need so many pandas.”

Javier Morales and Victor M. Castano traveled from Universidad Nacional Autonoma de Mexico to explain the hows and whys of creating diamonds from tequila. It was the most technical presentation of the day (“It all looked very complicated and sciency,” an audience member asked. “Could the process be simplified to include a funnel and surgical tubing, equipment available at certain social events?”) and made clear that the diamonds under discussion were for uses such as coating silicon wafers. It turns out diamond films are great semiconductors under extreme conditions such as high heat.

The elaborate formulas shown and equipment displayed, including devices containing vacuums, electric furnaces and substrate holders, didn’t dissuade questions such as “How much tequila do I have to give my boyfriend to receive a diamond?” and “Did the worm have any effect” on the results? (After some consultation, the scientists explained “No — this tequila is too cheap. Only expensive tequilas include that worm.”

Donald L. Unger, of Thousand Oaks, Calif., revealed why he’d cracked the knuckles of his left hand at least twice every day for more than 60 years, winning an Ig Nobel in medicine: a teenager’s need to determine a mother’s infallibility. “When I got to be a teen, I thought, ‘Maybe she wasn’t perfect,’” said Unger, a medical doctor. “But how could I check her out?”

He decided to test her warning that cracking his knuckles would give him arthritis. “Being a nasty teen, I decided to do the opposite,”  he said. But he never cracked the knuckles on the right hand, deciding to keep it as a control.

The results? “You were wrong, mom!” Unger yelled skyward during his lecture. She died never knowing the results of his experiment, and now, arthritis free, Unger is cheerfully facing his own mortality. He intends for his tombstone to say, “Here lies Donald Unger, who has finally stopped cracking his knuckles.”

Stephan Bolliger came from the University of Bern, Switzerland, to accept the Ig Nobel in peace, and explain whether it is better to be smashed over the head with a full or empty bottle of beer. (Empty bottles are better as weapons; they’re sturdier and can inflict more damage. “If you are fighting, I advise you to first drink,” said Bolliger to an appreciative audience. But full bottles will hurt the human skull too.) His slides showed the elaborate equipment used to explore the issue — including a CAT scan — but not why the tests were begun.

Simple: Bolliger is a forensic pathologist who testifies often in court cases. “It’s amazing the questions that get asked, and it’s not a good idea to start an answer with ‘I think so,’” he said after his lecture. “Bar brawls are not just John Wayne in Texas, they’re also Bern, Switzerland.”

The year’s Ig Nobel winner in veterinary medicine, Peter Rowlinson of Newcastle University, Newcastle-Upon-Tyne, U.K., ask Bolliger “if draft beer should be promoted on health and safety grounds?”