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Tonight on NOVA: Ghosts of Machu Picchu

(Image of Machu Picchu courtesy of Martin St-Amant - Wikipedia.)

Airing tonight (February 2, 2010) at 8pm on PBS stations: NOVA's Ghosts of Machu Picchu. Set your DVRs now! If you miss the program, it will be streaming online starting February 3.

Machu Picchu is an Inca engineering marvel: located 8,000 feet above sea level, it contains 200 stone structures placed on a complex set of roughly 700 terraces. What's most surprising is not its buildings, though -- it's all about what was built underneath the structures. Underground, complex engineering has allowed the site to withstand 76 inches of rainfall per year (that's 2.5 times what Chicago gets) for over 500 years. Machu Picchu is all about water: it is constructed to last, using complex engineering to manage and divert water. Within the complex, more than 100 drains divert rainfall down the mountain; a system of 16 fountains (flowing at between 6-30 gallons per minute depending on the time of year) provided drinking water for a population of up to 1,000 people; and complex soil engineering allowed the terraces to withstand the pressures of rain and earthquakes. So how did the Inca -- lacking steel tools and the wheel -- make this place? How could people live in such a remote place, and how did they grow so much corn -- a "royal food" of the time? This week's NOVA explains.

Included after the video is an interview with Ken Wright, a hydrologist who appears in the documentary. Click on through to check it out!

Interview With Ken Wright, Hydrologist

Ghosts of Machu Picchu features the work of Ken Wright, a hydrologist who has worked on the site for 15 years, in cooperation with National Geographic. Wright and his wife Ruth wrote several books on Machu Picchu including, Machu Picchu: A Civil Engineering Marvel and The Machu Picchu Guidebook: A Self-Guided Tour. Together, the Wrights have garned incredible accolades for their work (check out this image showing their collection of awards, including honorary professorships). I was able to ask Mr. Wright a few questions after previewing tonight's NOVA episode -- read on for his answers!

mental_floss: As a modern hydrologist, were you surprised to discover the hydraulic engineering sophistication of the Inca?

Ken Wright: Both my field research colleagues and I were surprised to discover the level of hydraulic engineering performed by the Inca.  Field evidence leaves no doubt about what they knew and how they accomplished their engineering feats.

m_f: Do you have a sense of what tools were available to the Inca -- how might they have determined a level surface, or measured a precise grade over distance?

KW: Yes, we do know what tools they had.  The Inca had a variety of hammerstones, bronze levers, bronze knives, plumb bobs, rope and string.  They used clay models for conceptualization and for determining a precise grade, they had nice pottery and stone basins, about 18 inches in diameter, that they filled with water to use as levels.

m_f: What first drew you to study Machu Picchu?

KW: I was first drawn to Machu Picchu by the then-unanswered question: where did the Inca get their water for Machu Picchu?

m_f: This is a slightly silly question, but it nagged me a bit while watching the documentary.  The terraces appear to be covered by grass today (though perhaps in the past they were planted with corn).  The grass looked very tidy.  Do you know if someone mows the grass?

KW: The trimmed grasses on the terraces of Machu Picchu are maintained by free-range llamas and alpacas.  For the steep terraces like Huayna Picchu, where the animals can't get, the Peruvian government hires macheteros (laborers with machetes) to keep the grasses under control.

For more from Ken Wright check out this excellent interview on the NOVA website.

Images From The Documentary

Images courtesy of Ricardo Preve, showing some scenes from Ghosts of Machu Picchu.

Ghosts of Machu Picchu image 1

Ghosts of Machu Picchu image 2

Ghosts of Machu Picchu image 3

Blogger Disclosure

Thanks to WGBH for providing an advance copy of the episode, the images above, and access to Ken Wright. I was not paid or otherwise compensated to review this episode of NOVA -- I wrote about it because it's awesome, and you should watch it!

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Space
It's Official: Uranus Smells Like Farts
NASA, JPL-Caltech
NASA, JPL-Caltech

Poor Uranus: After years of being the butt of many schoolyard jokes, the planet's odor lives up to the unfortunate name. According to a new study by researchers at the University of Oxford and other institutions, published in the journal Nature Astronomy, the upper layer of Uranus's atmosphere consists largely of hydrogen sulfide—the same compound that gives farts their putrid stench.

Scientists have long suspected that the clouds floating over Uranus contained hydrogen sulfide, but the compound's presence wasn't confirmed until recently. Certain gases absorb infrared light from the Sun. By analyzing the infrared light patterns in the images they captured using the Gemini North telescope in Hawaii, astronomers were able to get a clearer picture of Uranus's atmospheric composition.

On top of making farts smelly, hydrogen sulfide is also responsible for giving sewers and rotten eggs their signature stink. But the gas's presence on Uranus has value beyond making scientists giggle: It could unlock secrets about the formation of the solar system. Unlike Uranus (and most likely its fellow ice giant Neptune), the gas giants Saturn and Jupiter show no evidence of hydrogen sulfide in their upper atmospheres. Instead they contain ammonia, the same toxic compound used in some heavy-duty cleaners.

"During our solar system's formation, the balance between nitrogen and sulfur (and hence ammonia and Uranus’s newly detected hydrogen sulfide) was determined by the temperature and location of planet’s formation," research team member Leigh Fletcher, of the University of Leicester, said in a press statement. In other words, the gases in Uranus's atmosphere may be able to tell us where in the solar system the planet formed before it migrated to its current spot.

From far away, Uranus's hydrogen sulfide content marks an exciting discovery, but up close it's a silent but deadly killer. In large enough concentrations, the compound is lethal to humans. But if someone were to walk on Uranus without a spacesuit, that would be the least of their problems: The -300°F temperatures and hydrogen, helium, and methane gases at ground level would be instantly fatal.

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Live Smarter
Feeling Anxious? Just a Few Minutes of Meditation Might Help
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iStock

Some say mindfulness meditation can cure anything. It might make you more compassionate. It can fix your procrastination habit. It could ward off germs and improve health. And it may boost your mental health and reduce stress, anxiety, depression, and pain.

New research suggests that for people with anxiety, mindfulness meditation programs could be beneficial after just one session. According to Michigan Technological University physiologist John Durocher, who presented his work during the annual Experimental Biology meeting in San Diego, California on April 23, meditation may be able to reduce the toll anxiety takes on the heart in just one session.

As part of the study, Durocher and his colleagues asked 14 adults with mild to moderate anxiety to participate in an hour-long guided meditation session that encouraged them to focus on their breathing and awareness of their thoughts.

The week before the meditation session, the researchers had measured the participants' cardiovascular health (through data like heart rate and the blood pressure in the aorta). They evaluated those same markers immediately after the session ended, and again an hour later. They also asked the participants how anxious they felt afterward.

Other studies have looked at the benefits of mindfulness after extended periods, but this one suggests that the effects are immediate. The participants showed significant reduction in anxiety after the single session, an effect that lasted up to a week afterward. The session also reduced stress on their arteries. Mindfulness meditation "could help to reduce stress on organs like the brain and kidneys and help prevent conditions such as high blood pressure," Durocher said in a press statement, helping protect the heart against the negative effects of chronic anxiety.

But other researchers have had a more cautious outlook on mindfulness research in general, and especially on studies as small as this one. In a 2017 article in the journal Perspectives on Psychological Science, a group of 15 different experts warned that mindfulness studies aren't always trustworthy. "Misinformation and poor methodology associated with past studies of mindfulness may lead public consumers to be harmed, misled, and disappointed," they wrote.

But one of the reasons that mindfulness can be so easy to hype is that it is such a low-investment, low-risk treatment. Much like dentists still recommend flossing even though there are few studies demonstrating its effectiveness against gum disease, it’s easy to tell people to meditate. It might work, but if it doesn't, it probably won't hurt you. (It should be said that in rare cases, some people do report having very negative experiences with meditation.) Even if studies have yet to show that it can definitively cure whatever ails you, sitting down and clearing your head for a few minutes probably won't hurt.

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