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« September 2007 | Main | November 2007 »

The Breakdown: Indoor Tornado

Apparently classic cars aren't enough of a draw anymore. The Mercedes-Benz Museum in Stuttgart, Germany turned its smoke ventilation system into a spectacle, generating what the Guinness World Records organization is calling the world's largest artificial tornado. (See the November issue of Popular Science for an article about an engineer who thinks these man-made vortexes could be used to generate electricity.)

Though towering, the twister probably isn't dangerous. It's not going to suck up any bystanders, or cars. To create the effect, the museum's designers set up a disco smoke machine, then activated a set of 144 nozzles on the ceiling of the building's enormous atrium. The ventilation system, designed for emergencies, sucks the disco smoke up from below. To produce a spinning vortex, however, they blew air in from the sides, forcing the smoke to swirl.

The process took seven minutes, but the result, seen here, certainly looks capable of drawing crowds. Or making them run for their lives.—Gregory Mone

Giant Island of Trash

Trash A heap of trash that's twice the size of Texas is floating somewhere between San Francisco and Hawaii. The Great Pacific Garbage Patch, as it's called, is 80 percent plastic, and weighs in at 3.5 million tons. Trapped in a circular course by winds and currents, it's been around since the 1950s, and has been growing tenfold every decade. It's not a dumping ground in the sense that people are flying or boating by and throwing their refuse into the heap. Instead, it's picking up trash that originates onshore, and has since made its way out into the Pacific. Cleaning it up doesn't sound too likely, since the effort would cost billions, but it would be nice if we figured out a way to stop adding to it. Another possibility: turning it into a sort of anti-Disney World. Surely that would convert even the worst plastic-wasting offenders among us into ardent environmentalists.—Gregory Mone

Via SFGate

Pitching at Altitude

Pitch Prior to and during this past weekend's World Series games in Denver, there was a lot of sportscaster banter about how pitches fly differently at Denver's higher altitude. Breaking balls don't break quite the same way. Curveballs curve a little differently.

Normally, sportscasters are the last people in the world you'd want to listen to anytime a bit of science figures in, but in this case, according to physicist and baseball fan Alan Nathan, they were right.

Check out his detailed explanations of the physics of baseball here.—Gregory Mone

Lifejacket for Backcountry Skiiers

Lifebag It probably wouldn't seem so funny if a mountain's worth of snow were tumbling down the slope after you, but on its own, the Life Bag looks like a lock for ridiculous product of the year. In an avalanche situation, though, you pull a handle to inflate the bags, which keep you on your back, with your head up and out of the snow.

If you're buried, Snowpulse, the company that designed them, says the bags deflate and create a cavity around you, providing some breathing room. OK, so maybe they're not so funny after all.—Gregory Mone

Via Medgadget

Space Station Power Problems

Ripped_panels Astronauts working outside the International Space Station just noticed a tear in one of its solar panels. Two of these 110-foot-long panels were due to be unfurled, and the first unrolled without a hitch, but NASA halted the second one when its spacewalkers saw the damage.

This caps a tough few days for the station, as astronauts also confirmed a problem with one of the motorized joints that turns the panels to face the Sun. NASA had suspected there was a problem, and astronaut Dan Tani confirmed it up close, noticing shards of metal scrapings throughout the joint. Next up: figuring out where they came from.—Gregory Mone

(Image credit: NASA)

G-Phone Rumors Resurface

Gphone It's imminent! Implausible! And now imminent again! We're talking, of course, about the rumored G-Phone, which would mark the search giant's entry into the wireless market. It has been talked about for months, with leaks getting squashed as quickly as they pop up, but today the Wall Street Journal is reporting that Google will make an announcement on the subject within the next two weeks. The company is expected to announce a suite of new software and services for mobile phones—it doesn't sound like Google is actually going to start making hardware. While Google remains hush, Wall Street has been happy with the news: the company's stock has been edging close to $700 a share.—Gregory Mone

Mercury Rising... From Wildfires

Mercury_stats_fThe mercury is rising in more ways than one. As our planet warms, wildfires such as the recent blazes in California are expected to become more common. And, a recent study shows, such fires are a major source of mercury emissions.

The map at left shows the annual average (in metric tons) of mercury, a toxic metal, released into the atmosphere by fires. The estimates are based on fires from 2002 to 2006.

Scientists at the National Center for Atmospheric Research in Boulder, Colorado, calculate that fires in the continental U.S. and Alaska release about 44 tons of mercury every year. Industrial sources such as power plants and incinerators release about 108 tons.

Leaves and ground litter absorb mercury from the atmosphere. When a fire breaks out, the stored mercury is released back into the atmosphere. It is particularly dangerous if it ends up in rivers and lakes, where it can be taken up by fish. Pregnant women and children are discouraged from eating some types of fish because of high mercury levels, which can cause neurological and development problems such as attention and language deficits.—Dawn Stover

Image: National Center for Atmospheric Research

The Physics of Spiderman 3

Spidey Spiderman is arguably the most popular cinematic superhero since Superman, and with the imminent release of the DVD of Spiderman 3 on October 30th, what better moment to do a little Spiderman 3 physics? In most successful movie franchises it’s hard for the sequels to match the original, and in the case of superhero action movies the cohesiveness of plot and dialogue tend to diminish in favor of ever more spectacular (and improbable) action sequences and special effects. Spiderman 3 is no exception to this phenomenon, however, that said, it’s still really fun to watch and the CG sequences are truly amazing. (check out the “Birth of Sandman” scene).

Now when analyzing the physics in a superhero fantasy obviously you have to suspend disbelief and accept the basic (impossible) premise of the movie if you want to have any fun. No matter how cool it would be, being bitten by a “genetically enhanced super spider” cannot change your own genetic structure and give you amazing super powers as it does Peter Parker. But at least he’s still humanoid—unlike the Sandman who seems to offer proof that the human soul exists; not just because he’s actually a nice guy deep down, but because you can blast him into a million little pieces (of quartz) thus destroying his body altogether, and yet he can reconstitute himself at will.

Allowing for such fantastic elements, it may be instructive to apply some basic Newtonian mechanics to a few of the action sequences in order to analyze Spiderman’s astonishingly resilient physiology.

We see in the climactic battle scene (scene 43 on the DVD), that Spiderman can survive a fall of 80 stories without a single broken bone, concussion, or presumably any internal bleeding. Using Newton’s Second Law (Fnet = ma) let’s calculate how much force the ground exerts on Spiderman upon impact.

First of all, for an 80 story plummet, Spidey will be close to his terminal velocity before he crashes. In the case of a skydiver, or a falling Spiderman, 60 m/s (about 130 mi/hr) is a reasonable and conservative estimate.

What forces are acting on our superhero during contact with the ground? There are only two: his weight force acting in a downward direction, and the upward force of the ground. It is the value of the force that the ground exerts on Spidey that we are concerned about. Applying the second law we get:

Fnet = Fground – mg = ma

where mg is Spiderman’s weight (m is his mass which we estimate to be about 70 kg and g is the acceleration due to gravity), and a is the upward acceleration that Spiderman undergoes as the ground brings him to an abrupt halt. Since most collisions with hard objects (like concrete) occur on time scales of approximately one one-hundredth of a second we can calculate Fground as follows:

Fground = mg + ma = mg + mΔv/Δt

= (70 kg)(9.8 m/s2) + (70 kg)(60 m/s)/0.01 sec  ≈ 420,000 Newtons (that’s 47 tons!).

Spidey’s acceleration upon impact is 6000 m/s2 or 600 “g’s”. Since most bones will break if the body experiences forces exceeding 90,000 N, and concussions are pretty much inevitable for normal humans experiencing accelerations greater than 100 g’s we can already see that Spiderman has no ordinary skeletal system!

In particular consider Spiderman’s skull. It must be constructed of some truly phenomenal material. In Spiderman 3 our hero experiences at least a half dozen collisions of his head with various solid objects. In the most violent of these (scene 47), Spidey gets flung into a steel beam with a speed that we estimate to be at least 15 m/s. Since he is brought to a stop by the beam and almost all of the force is exerted directly on his head (in about 0.01 second), the force on his head will be about:

Fnet = ma = mΔv/Δt = (70 kg)(15m/s)/0.01 second = 105,000 N.

According to some experiments, a direct impact to the skull exceeding 873 N will always result in a fracture (in fact the skull may fracture when exposed to forces much less than that), but Spidey’s skull is capable of withstanding forces at least 120 times as big. I guess when M.J. says Peter is hard-headed she really means it!  —Adam Weiner


Another day, another failed attempt to forward space technology. Less than a week after the Space Elevator Games concluded without a winner, the X Prize Cup followed suit. The much favored Armadillo Aerospace—the only one of nine entrants ready by the start of the event—dashed hopes when their lander exploded while still on the launch pad. Accordingly, no one walked away with the $350,000 Level 1 purse, leaving our LANDR proposition (trading in the mid-60s at the start of the competition) to close out at $0. Sorry space fans, better luck next time.—Abby Seiff

New Emergency Plan: Take the Elevator

Elevator Forget the stairs. An engineer with the National Institute of Standards and Technology (NIST) says that it makes sense to rely more on elevators when evacuating high-rise buildings, since descending steps can be too slow, and overly taxing for those who aren't in good health. In an evacuation, elevators could be programmed to empty the upper floors first, and work down from the top, regardless of how often or firmly the people on the floors below are pressing their call buttons. Of course, people on the lower floors could still race down the stairs. But this new system would focus more on saving the occupants who have 50 stories to descend, and not a lot of time to do it.—Gregory Mone 

Via Newswise

The Health Effects of Climate Change

390pxjulie_gerberding Last week, Julie Gerberding, the head of the Centers for Disease Control and Prevention, addressed the Senate on the health impact of global warming. But the news emerged recently that her planned speech had been drastically cut down by White House editors.

The Senate did not, for example, hear her say that people in the Midwest and Northeast are expected to experience more heat-related illnesses as heat waves increase, or that the public health effects of climate change basically haven't been addressed. Presidential science adviser John Marburger responded to the resulting criticism, noting points on which he and his staff believed that Gerberding's conclusions drifted from the scientific consensus.

But another prominent scientist, University of Wisconsin Professor Jonathan Patz, insists that her original testimony was scientifically accurate, and, more importantly, that we need to start dealing with the fact that climate change poses serious health risks. Read his unsettling conclusions here.—Gregory Mone

One Laptop Per Cow

Cow_power The One Laptop Per Child initiative has had its share of development hiccups. The project hasn't gotten the notebooks down to goal of $100 per machine, and a few recent bugs have delayed the recently proposed Give One Get One plan, in which customers in developed countries buy one of the laptops for themselves, and another for someone in need.

But down at the grassroots level, the project seems to be taking hold. In India, for example, the group is developing a cow-powered system in an area short on sunlight, wind and other good renewable energy sources. Cattle would pull on a series of belts and pulleys, activating a dynamo that re-charges spent laptops. Which is exactly how I use my cows.—Gregory Mone

Via ArsTechnica

(Image credit: OLPC)

Peter Diamandis on the Future of the X Prize Cup

0510009_4 On day two of the 2007 X Prize Cup, between dealing with Armadillo Aerospace’s faltering attempts to win the Northrop Grumman Lunar Lander Challenge and serving as master of ceremonies for the day’s events, X Prize founder Peter Diamandis took a few minutes to talk to PopSci about the future of his organization’s marquee event. Read the interview after the jump.—Seth Fletcher

Image Courtesy Zero-Gravity Corp


Continue reading "Peter Diamandis on the Future of the X Prize Cup " »

No Winner This Year in Lunar Lander Challenge

Armadillo_1027 That tiny speck in the distance is Armadillo Aerospace's MOD 1 aircraft, right before not quite winning the Northrop Grumman Lunar Lander Challenge at the X Prize Cup in Alamogordo, New Mexico on Saturday. To win Level One, the lander has to rise up to 150 feet in the air, hover for 90 seconds and land on a pad 100 meters away. Then it has to do the same thing in reverse. MOD 1 nailed the first part, but failed in the final stretch of its reverse trip. A nozzle failure knocked the lander off balance with only seven seconds to go, causing it to miss the landing pad. As a result, the $350,000 prize is still unclaimed. —Seth Fletcher

Update: Sunday morning's attempt failed, too, again on the reverse trip. Sounds like the problem this time was a crack in the MOD 1's engine—MOD 1's new engine, which the Armadillo team installed after yesterday's failed try. Word is they'll try it Level One again this afternoon.

Another update: No dice for Armadillo this year. Their afternoon attempt failed; there was talk earlier today of a possible third attempt this evening, but according to an X Prize spokesperson, Armadillo founder John Carmack decided against it. That means it'll be this time next year, at the earliest, before anyone wins the prize.

Brilliant Ten Winner Gaspar Bakos

Look, I'll be honest. Sitting down with a hyper-intelligent scientist and discussing his or her work for a few hours isn't always the most socially comfortable situation. Fascinating? Absolutely. But there can be quite a few awkward silences as well.

Astrophysicist Gaspar Bakos, one of this year's Brilliant Ten, eased my pre-interview jitters right away when he suggested we leave his tiny office in Harvard's Center for Astrophysics and head up to the roof. Up there, standing around the corner from what was one of the world's great observatories a century ago, he proceeded to clearly and comfortably explain the intricacies of his technique for hunting down extrasolar planets. So I went back with a camcorder, to capture him using his water bottle as a stand-in for a planet, a star and even a telephoto lens. Enjoy. —Gregory Mone

Sleep Deprivation and Foul Moods

Sleeping The immune system. Metabolism. Learning and memory. Running short on sleep impairs each of these functions and processes, and now scientists say that it can affect our emotional balance, too.

A group led by Berkeley neuroscientist Matthew Walker used fMRI scans of subjects to show that a lack of sleep messes with the brain's ability to respond to negative stimuli. The researchers kept the volunteers awake for 35 hours, showed them images that would provoke positive or negative reactions, and recorded the response in brain activity. Regions of the brain associated with emotional reactions spiked in sleep-deprived subjects, relative to the well-rested. A word to fathers with newborns: Don't show this paper to your wife. She won't appreciate it.—Gregory Mone

Via MindHacks

Neanderthals May Have Been Redheads

Laluezafox1lr In Britain, redheads are known as “gingers” and are often treated as second-class citizens. The news that some Neanderthals may have been redheads probably won’t help.

When a team of European research scientists looked at DNA samples from two Neanderthal specimens, they found a gene that affects the body's production of melanin, resulting in red hair and pale skin. The finding is reported in the forthcoming issue of the journal Science. The scientists say that the Neanderthal gene sequence is different from the sequence in modern humans that produces red hair, so they probably arose separately.

Although some people have theorized that modern redheads are descended from Neanderthals, scientists disagree about whether there was any interbreeding between Neanderthals and the ancestors of modern man. They coexisted for many years, but Neanderthals disappeared from Europe more than 24,000 years ago.—Dawn Stover

Image: Michael Hofreiter and Kurt Fiusterweier/MPG EVA

In The Event of Moon Disaster...

Aldrin_near_module_leg_2 Hauntingly fascinating is this speech by William Safire (most famous these days for his "On Language" column in the New York Times), drafted for President Richard Nixon to read in the event of a mishap during the Apollo 11 mission that would have stranded Neil Armstrong and Buzz Aldrin on the moon:

Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace.

These brave men, Neil Armstrong and Edwin Aldrin, know that there is no hope for their recovery. But they also know that there is hope for mankind in their sacrifice.

These two men are laying down their lives in mankind's most noble goal: the search for truth and understanding.

They will be mourned by their families and friends; they will be mourned by the nation; they will be mourned by the people of the world; they will be mourned by a Mother Earth that dared send two of her sons into the unknown.

Read the full text here [via kottke.org]. —John Mahoney

PPX: A380 Does Indeed Fly

At long last, the long-delayed A380 has finally made its first commercial flight—over 18 months behind schedule but still early enough to meet the conditions of our PPX proposition. A380FLIES has been delisted and paid out at POP$100 per share.

Personally I was skeptical, but the market was leaning toward success all along, with the proposition trading above $80 for the last few months. It closed at POP$99.75—doesn't get much more certain than that!

Above is a video of the historic touchdown in Sydney, courtesy of the UK's Telegraph. —John Mahoney

Winds Begin to Calm in Southern California

Nasa_fires Nasa_fires_2

News reports last night reported that the Santa Ana winds pushing Southern California's wildfires had begun to slow down. These images, captured by NASA's Aqua satellite, offer some visual proof.

The image on the left was taken yesterday afternoon, and the one on the right was captured on October 22nd. Yes, there are still enormous clouds of smokes stretching west over the Pacific in yesterday's shot, but they're very different from the ones on the right, in which the winds create a narrow trail of smoke. You can really see how the strong winds are pushing on the fires.

On the other hand, in yesterday's image, on the left, the smoke sort of pools over the burns before flowing westward.—Gregory Mone

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