7 Billion: How Did We Get So Big So Fast?

"The U.N. estimates that the world's population will pass the 7 billion mark on Monday."

"Much of that growth has happened in Asia — in India and China. Those two countries have been among the world's most populous for centuries. But a demographic shift is taking place as the countries have modernized and lowered their fertility rates. Now, the biggest growth is taking place in sub-Saharan Africa."

"Due in part to that region's extreme poverty, infant mortality rates are high and access to family planning is low. The result is high birth rates and a booming population of 900 million — a number that could triple by the end of the century. Population expert Joel Cohen points out that, in 1950, there were nearly three times as many Europeans as sub-Saharan Africans. If U.N. estimates are correct, there will be nearly five sub-Saharan Africans for every European by 2100."

Eating Your Way To A Healthy Heart (If You're A Python)

"It's a huckster's dream: 'Try the new Burmese Python Diet. No calorie counting or special foods. Eat whatever comes along, up to a quarter of your body weight. Not only is it good for your waistline; it's good for your heart.'"

"Trouble is, what works in pythons probably won't work for humans."

"Pythons employ what scientists call a "sit and wait foraging tactic." In other words, they lie around in a Burmese jungle and wait for the food to come to them. And of course, this can mean months between meals."

Hormones and Metabolism Conspire Against Dieters

"There are some fresh insights from Australia that help explain why it's so difficult for dieters to keep off the weight they lose."

"Willpower will only take you so far, in case you haven't run that experiment yourself. Turns out our bodies have a fuel gauge, not entirely unlike the gas gauge on our cars, that tell us when it's time to tank up on food."

"The gauge relies on hormones that signal to the brain when and how much to eat. But as Dr. Louis Aronne, who directs the comprehensive weight control program at Weill Cornell Medical College in New York, explains, the human fuel gauge can sometimes be way off the mark — especially for dieters."

A DNA Check Reveals Widespread Fish Mislabeling In Massachusetts

"Beware, Massachusetts fish fans: If you're buying or ordering red snapper, white tuna, local cod or haddock, there's a pretty good chance that's not what you're going to get."

"Two intrepid reporters at the Boston Globe set out to figure out just how bad one form of fish fraud — mislabeling — is in restaurants, markets and grocery stores across the state. They collected 183 samples of fish from 134 sites and hired a laboratory in Canada to check the DNA. And they published their results in a two-part series this week: scientists found that 87 of 183 were sold with the wrong species name — some 48 percent."

Google To Deliver the Amazon Jungle in 3D

"Google has long offered anyone with an Internet connection a street-level view of cities and landmarks around the world, from the Golden Gate Bridge to the Roman Coliseum."

"Now, it's teaming up with a Brazilian environmental group to offer a 3-D, on-the-ground view of one of the planet's most remote areas: the hamlet of Tumbira in the center of the Brazilian Amazon. The goal is to show how people in the Amazon live — and educate the public about their effort to protect the forest."

"Once stitched together, the images will be posted on Google Earth Outreach, which offers panoramic, ground-to-sky photographs of isolated spots in places where people and the environment may be under duress."

Self-Starters Eat Up This Slow-Cooking Technique

"Sous vide cooking was once the province of chefs at fancy restaurants and home cooks willing to shell out close to $1,000 for a water oven. Now, do-it-yourselfers are making their own, inexpensive sous vide cooking rigs."

"With sous vide cooking, meat, fish or vegetables are placed in sealed plastic bags and cooked at relatively low temperatures for long periods of time — like 48 hours or so. The juices are saved, and foods don't get overcooked."

"People who cook at home with sous vide setups tend to rave about their steaks."

New Camera Focuses After It Is Shot

"Autofocus cameras hit the stores back in the 1970s, making it dramatically simpler for the average consumer to get a good shot. Later, the digital camera made it possible for just about anyone to process their own pictures at home on a computer. Now comes a camera that could represent another kind of photography revolution: the light field camera. Take the picture, but focus it afterward. Robert Siegel speaks with Lytro founder Ren Ng about the new light field camera that his company is producing."

What If We Paid Off the Debt? A Secret Government Report

"Planet Money has obtained a secret government report outlining what once looked like a potential crisis: The possibility that the U.S. government might pay off its entire debt."

"It sounds ridiculous today. But not so long ago, the prospect of a debt-free U.S. was seen as a real possibility with the potential to upset the global financial system."

"We recently obtained the report through a Freedom of Information Act Request. You can read the whole thing here. (It's a PDF.)"

"The report is called "Life After Debt". It was written in the year 2000, when the U.S. was running a budget surplus, taking in more than it was spending every year. Economists were projecting that the entire national debt could be paid off by 2012."

IQ Isn't Set In Stone, Suggests Study That Finds Big Jumps, Dips in Teens

"For as long as there's been an IQ test, there's been controversy over what it measures. Do IQ scores capture a person's intellectual capacity, which supposedly remains stable over time? Or is the Intelligent Quotient exam really an achievement test — similar to the S.A.T. — that's subject to fluctuations in scores?"

"The findings of a new study add evidence to the latter theory: IQ seems to be a gauge of acquired knowledge that progresses in fits and starts."

"In this week's journal Nature, researchers at University College London report documenting significant fluctuations in the IQs of a group of British teenagers. The researchers tested 33 healthy adolescents between the ages of 12 and 16 years. They repeated the tests four years later and found that some teens improved their scores by as much as 20 points on the standardized IQ scale."

100-Year Old Finishes the Toronto Marathon

Talk about a really amazing race:

"Fauja Singh, 100, finished Toronto's waterfront marathon Sunday evening, securing his place in Guinness World Records as the oldest person — and the first centenarian — to ever accomplish a run of that distance," CBC News reports."

"Singh, a British citizen born in India, crossed the line in just over 8 hours, 11 minutes — and, officially at least, wasn't the last finisher. Four people, who it appears were in a group accompanying Singh, were 1 to 10 seconds behind him according to the electronic chips they carried to record their times."

Chance to Spot Rare Supernova Fading Fast

"Supernova 2011fe is bringing out the stargazers. It's one of the brightest supernovas in the last century and it's now visible. It's the kind of event amateur astronomers dream of."

"The supernova will last for more than a decade, but it won't stay this bright. Within the next week, the light that took 21 million years to reach earth will fade out of view for amateur astronomers."

"On a Saturday night in the desert town of Yucca Valley, Calif., two hours east of Los Angeles and far away from the big city lights, the town's community center parking lot is buzzing. There's a group of excited backyard astronomers like Carolina Liechtenstein."

A Woman of Photos and Firsts: Ruth Gruber at 100

"At the age of 100, Ruth Gruber is responsible for a lot of firsts. When she was just 20, she became the youngest Ph.D. ever at the University of Cologne in Germany. She was the first photojournalist, much less female journalist, to travel to and cover both the Soviet Arctic and Siberian gulag. She documented Holocaust survivors and the plight of the ship, the Exodus 1947."

"Born in Brooklyn in 1911 to Jewish immigrants, Gruber has been the subject of a documentary film; of a made-for-TV movie; a musical; and, earlier this summer, she received a Cornell Capa Award and exhibition at the International Center of Photography (ICP) in Manhattan."

'Catch-22': A Paradox Turns 50 and Still Rings True

"Fifty years ago, a new phrase began to make its way into American conversations: "Catch-22." Joseph Heller's irreverent World War II novel — named for the now-famous paradox — was published on Oct. 11, 1961. His take on war meshed perfectly with the anti-authoritarian generation that came of age in the 1960s. And now, a half-century later, the predicament of a no-win trap still resonates with a new crop of young people distrustful of their elders."

"In August 1944, Heller flew on a mission over the French town of Avignon. Sitting in the plexiglass nose cone of a B-25 bomber, Heller faced the very real possibility of death for the first time. That mission, says Heller biographer Tracy Daugherty, shaped the way Heller thought about war, a sensibility that permeates his novel."

How Many Gills in a Cubic Decameter?

"It's National Metric Week – always celebrated in the week that contains Oct. 10, because that's the 10th day of the 10th month. Metric folks love the number 10."

"The International System of Units — that's the official name of the metric system — is a decimal system of weights and measures based on the meter and the kilogram. Abbreviated SI, for Système international d'unités, the metric system was first suggested as early as the 16th century."

"It's now used almost universally throughout the world, though a few places still use some non-metric measurements (known as English or Imperial standards). You can still order a pint in a British or Irish pub, for example."

"Although its use has been sanctioned in America since 1866, the U.S. has stuck to ye old English system of feet and ounces. Only three countries — Burma (also known as Myanmar), Liberia and the United States — have not adopted it."

The Economic Reality of Tough Immigration Laws

Gordon Hanson, an economist specializing in the impacts of immigration, studies the reality side of things at University of California-San Diego. He says that for decades there has been an unwritten social contract that says the U.S. isn't going to make it easy for immigrants to get in; there will be physical barriers and it will cost time, money and personal risk."

"What that did in effect was to select out people who weren't serious, to select out people for whom the opportunity of being in the United States didn't matter that much," Hanson tells weekends on All Things Considered guest host Robert Smith.

After Jobs, Who Will Be the Next American Visionary?Edison with his phonograph, 1877Edison With His Phonograph 1877

"Visionary. Uncompromising. Intuitive. Risk-taking. Steve Jobs — the man who helped build a company and used it to transform multiple industries and popular culture — could have been lifted from the pages of a college textbook on how to be a successful CEO."

"He was "the most incredible businessperson in the world," Apple co-founder Steve Wozniak told CBS News on Thursday, a day after Jobs' death."

Are You Among the "99 Percent?'

"As the Occupy Wall Street movement continues to spread, one of its rallying cries is generating a fair amount of debate."

"The protesters say they represent the "99 percent" — that is, everyone except the richest 1 percent of Americans or those who have been benefiting from the way things are going."

"Some conservative voices take issue with the 99 percent theme."

Steve Jobs: How Apple's CEO Help Transform Popular Culture

"When the death of Apple co-founder Steve Jobs was announced last night, if you were following Twitter, what you saw was a spasm of grief. Writers, actors, musicians, your friends, comedians ... the genuine sadness was palpable, not only because he was 56 years old, but because so many saw the news while holding one of his products in their hands. This is very much what popular culture is: this hive mind, this hum of collective response. And it makes all the sense in the world, because there's a good argument to be made that no one has affected popular culture more in the last — well, you can pick your number of decades — than Steve Jobs."

Israeli Chemist Wins Nobel Prize For Quasicrystals

"Israeli scientist Daniel Shechtman won the 2011 Nobel Prize in chemistry on Wednesday for his discovery of quasicrystals."

"The 1982 breakthrough fundamentally changed the way chemists look at solid matter, the Royal Swedish Academy of Sciences said."

"Scientists used to believe that atoms were arranged inside crystals only in ordered, repeating patterns, Shechtman's work showed that the atoms could be packed in a pattern that did not repeat – a new chemical structure known as a quasicrystal."

Dissolve My Nobel Prize! Fast! (A True Story)

"It's 1940. The Nazis have taken Copenhagen. They are literally marching through the streets, and physicist Niels Bohr has just hours, maybe minutes, to make two Nobel Prize medals disappear."

"These medals are made of 23-karat gold. They are heavy to handle, and being shiny and inscribed, they are noticeable. The Nazis have declared no gold shall leave Germany, but two Nobel laureates, one of Jewish descent, the other an opponent of the National Socialists, have quietly sent their medals to Bohr's Institute of Theoretical Physics, for protection. Their act is probably a capital offense — if the Gestapo can find the evidence."