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Past Shows
November 19, 2005
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Space Exploration: Humans or Robots
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Artist's impression of a Mars landing - Courtesy, ESA
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The development of new plans for human exploration of the Moon and Mars has raised an old argument again. Should we be sending humans into space? Many scientists have argued that robotic probes, rovers and satellites have produced far more science at a far lower cost than human astronauts. Will this still be the case as we look beyond Earth orbit?
Space pioneer Dr. James Van Allen, the Regent professor of physics at the University of Iowa, has worked with space probes like the Explorer, Pioneer and Mariner missions since the earliest days of the U.S. space program. In his view, human astronauts are obsolete.
Dr. Joel Primack, a professor of physics at the University of California at Santa Cruz, chaired a commission of the American Physical Society highly critical of a new human program to explore the Moon and Mars. He and his colleagues were concerned that scientific priorities were being ignored, and that space science would suffer as a result.
Dr. Lawrence Krauss, professor of physics at Case Western Reserve University, thinks we've done human astronauts a disservice by pretending they're flying to do science. He thinks we should face the truth: that human space flight is about adventure.
Dr. Roger Launius, the chair of the Division of Space Science at the Smithsonian Air and Space Museum, thinks human space flight should have an objective beyond science: establishing a human presence and perhaps human colonies beyond Earth.
Dr. Roberta Bondar, Canada's first female astronaut, and a research neurologist, points out that one of the most valuable things we've learned from human space travel is how the human body responds in zero gravity. This could provide insights into important issues in human physiology and disease.
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Web Extra
Listen to some of the full length interviews that went into our documentary about the debate about whether we should be exploring with humans or robots in space.
Dr. Lawrence Krauss discusses these issues at greater length, and the future of how we will explore the universe with advanced robots and we might consider colonizing beyond our solar system
Dr. James Van Allen discusses the problems of human space exploration and the great achievements of robotic explorers
Prof. Ken Pounds discusses the Royal Astronomical Society's report which came out in favour of human space exploration
Women Brewmasters
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Wari shawl pin found in ruins of brewery
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According to new research, women of the ancient Peruvian Wari society had a more powerful role than we knew in the pre-Incan world, and it all comes down to beer.
An archeological team, including anthropologist Dr. Susan deFrance of the University of Florida, has found shawl pins at the ruins of a large ancient brewery at Cerro Baul. The researchers suggest the artifacts are evidence that the elite women of that community were the ones making the chicha, or beer. The researchers conclude that if women were the brewmasters, then they had greater participation in important ceremonies of the Wari than previously thought.
But it’s when the Wari abandoned their mountaintop home in about 1000 A.D. that the story gets more interesting. The researchers have uncovered evidence of broken pottery, smashed brewing vats and burned down buildings that leads them to believe that the Wari ritualistically torched their industrial brewpub and trashed their beer “mugs” before they left.
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Snapping Spaghetti
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Breaking spaghetti - Courtesy, Dr. A. Belmonte
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If you've ever tried to break up dry spaghetti, you may have noticed that it doesn't snap into two even pieces. Usually it'll break into three, four or even more sections. It's a problem that's plagued engineers, that is, until recently. Dr. Andrew Belmonte is a mathematician at Pennsylvania State University. He's spent hours dropping weights on top of strands of spaghetti and taking high speed photographs. Thanks to his destruction of pasta, he's been able to work out the mathematics of breaking in thin rods. It turns out everything depends on how fast sound waves will travel through the object, and how large the rod's diameter is. All this is valuable if you're thinking of constructing new materials. For his next project, Dr. Belmonte plans to smash plates.
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Snails and their Slime
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Wolf snail in pursuit of prey- Courtesy, Dr. M. Harrington
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The rosy wolf snail is a predatory snail, with a taste for other gastropods. But when it's hunting for other snails it has a problem. When it comes up to a slime trail there are two questions. Was this left by a snail I'd like to eat? And which way was the snail travelling? Dr. Melissa Harrington at Delaware State University thinks she's found the answer to both these questions. She's discovered that wolf snails can identify what species left behind the slime. If it's from a prey snail, the wolf snail munches on the prey when the two meet. If it's slime from another wolf snail, then a meeting may result in a sexual tryst. And as far as heading the right way on a trail, wolf snails only succeed at this when chasing their own species. Dr. Harrington thinks there's something that distinguishes the left and right side of snail slime trails that allows one wolf snail to follow where another wolf snail has already gone.
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