Tuesday, April 30, 2013

Roller Coaster G-Forces: We've Got Data

Last Friday, the Physics Central team met up at the local Six Flags theme park for a sunny day of thrills. We weren't just there for fun, however; a flood of high school students converged there as well for a day of roller coaster physics lessons.

We came armed with accelerometers to measure g-forces on four of the park's rides and coasters. Additionally, we sprinkled physics demos throughout much of the park such as a bucket of oobleck, an egg drop contest, and a bed of nails.

We have photos and acceleration data from our day at Six Flags America. Take a look below for our recap of Six Flags Physics Day 2013!

Superman Coaster


High schoolers ride the Superman roller coaster at Six Flags America on April 26, 2013.
Image Credit: Matt Payne/AAPT

The steel behemoth known as Superman: Ride of Steel launches riders to 75 MPH speeds and heights exceeding 20 stories. I rode it last year, and I can assure you it's definitely a rush.
Read the rest of the post . . .

Monday, April 29, 2013

Ants on Surfaces



For the past week my kitchen has had an ant problem.  Any normal person would get some ant traps and be done with the problem.  Not being a normal person I've spent the past week learning about ant behavior.  I learned that they only focus on one bowl of cat food, even though I have two in my kitchen.  They rarely form lines of ants unless there is something really good at the other end like a used lollypop stick.  If they can't find the cat food, they love the cat's water dish but I can't figure out why.  Leaving a path of ants killed by Windex doesn't stop them, just slows them down for a day.  Killing ant "scouts" is of no use.  My goal has been to deter the ants from coming in the house and I've had little luck.  After much office discussion and memories of my thesis, I've decided that if I can't beat them, I'll use them.  I will use them to learn about the topology of various surfaces.  When describing curvature of surfaces one often says "if I were an ant on a surface, it would look like this..."  Well, I have ants, and I can make surfaces!


Read the rest of the post . . .

Friday, April 26, 2013

Physicist Proposes New Way To Think About Intelligence

A single equation grounded in basic physics principles could describe intelligence and stimulate new insights in fields as diverse as finance and robotics, according to new research.

These diagrams show how software that harnesses "causal entropic forces" emulates the intelligent behavior required to walk upright or use tools. Courtesy of Alexander Wissner-Gross
Alexander Wissner-Gross, a physicist at Harvard University and the Massachusetts Institute of Technology, and Cameron Freer, a mathematician at the University of Hawaii at Manoa, developed an equation that they say describes many intelligent or cognitive behaviors, such as upright walking and tool use. 

Read the rest of the post . . .

Wednesday, April 24, 2013

PODCAST: Dating Ancient Water

Image: Böhringer Friedrich
Hey Folks! I'm back from the APS April Meeting that took place in Denver, Colorado this year. While I was there I heard a talk by Zheng-Tian Lu, who is a physicist at Argonne National Lab and a professor of physics at the University of Chicago. Lu is the kind of physicist who spends most of his time inside. In fact, because he often works with lasers, many of the windows in his laboratory are sealed off (for safety—can't have stray laser beams bouncing around). But in the past year Lu has been out in the field visiting with geologists; and those geologists are sending water and ice samples to Lu and his colleagues at Argonne. Why?

Lu and his group have developed a method for dating water samples. It's called the Atom Trap Trace Analysis, or ATTA. These samples come from underground wells, pockets of isolated ocean water, and glaciers, and the ATTA method can determine how long they have been sealed off from the atmosphere. Dating these samples could reveal when glaciers formed, show the path of ocean currents, and help hydrologists figure out which underground water sources will be the best suppliers for humans.

The ATTA method determines the age of water samples using something called radiometric dating. Radiometric dating (which includes radiocarbon dating) takes advantage of a cool physics concept: certain atoms break down over time, and effectively disappear (of course nothing just vanishes; they do leave behind traces of their presence). This is called radioactive decay, and the atoms that do this are called radioactive isotopes. What's great for scientists is that the isotopes do this on a very regular schedule. So if you have a sample and you know how much of a particular radioactive isotope was in the sample when it went into the ground, and you can measure how much is in it today, then you can figure out how old the sample is. Radiometric dating is what tells scientists the age of rocks and fossils and dead bodies and even the Earth itself.

There are a number of radio active isotopes in our atmosphere, and these get into both organic and inorganic material; when those materials become isolated from the atmosphere, they stop absorbing those isotopes, so they contain a (mostly) fixed amount. Carbon is the most commonly used radioactive isotope for radiometric dating, but it isn't the only radioactive isotope in our atmosphere. The ATTA method tests for Argone 39, Krypton 81 and Krypton 85.

You'll have to listen to the podcast to hear more. Find it here or subscribe via iTunes!
Read the rest of the post . . .

Tuesday, April 23, 2013

Rename the Higgs Boson?

One of the six scientists who helped divine the existence of the Higgs boson, Carl Hagen, is lobbying to rename the now world-famous subatomic particle. It's not just a case of sour grapes either, he has a pretty good point. All together six physicsts working together made roughly equal contributions to developing the theory in the 1960s.

Image: CERN
The "Higgs" boson was a group effort on the part of Robert Brout, Francois Englert, Gerald Guralnik, Carl Hagen, Peter Higgs and Tom Kibble.  The particle that gives all matter its mass got labeled the Higgs boson, because Peter Higgs was the first to present at a conference about it, and the name's stuck for nearly 50 years.

Read the rest of the post . . .

Monday, April 22, 2013

Study: 4 Percent of Power Disruptions Associated with Solar Flares

Although the sun provides the necessary energy for life on earth, its surface hosts one of the most hostile and violent environments in the galaxy. During the peak of the solar cycle, spots on the sun explode multiple times per day, burping out a plasma soup of electrons, protons, and light ions.

Usually, these coronal mass ejections (CMEs) cause little harm to the Earth and even cause the beautiful auroras seen near the Earth's poles. Some CMEs, however, have caused extensive damage in the past. In 1989, for instance, a huge CME damaged satellites, shutdown a Quebec, Canada power grid, and showered Texas with an extremely rare aurora.

A new study by researchers at Lockheed Martin has revealed that about 4 percent of power disruptions in the U.S. from 1992 to 2010 were associated with elevated solar activity — the kind of activity that releases CMEs. This finding clashes with government reports that blamed zero disruptions on solar activity during that same time period.

A long filament erupted from the sun on August 31, 2012, emitting a coronal mass ejection.
Image Credit: NASA/GSFC/SDO

Read the rest of the post . . .

Friday, April 19, 2013

NASA's Cold Fusion Folly

I am sad - horrified really - to learn that some NASA scientists have caught cold fusion madness. As is so often the case with companies and research groups that get involved in this fruitless enterprise, they tend to make their case by first pointing out how nice it would be to have a clean, cheap, safe, effectively limitless source of power. Who could say no to that?

NASA Langley scientists are hoping to build spacecraft powered with cold fusion. Image courtesy of NASA.
Here's a word of caution: anytime anyone, especially a scientist, starts by telling you about glorious, nigh-unbelievable futuristic applications of their idea, be very, very skeptical.


Read the rest of the post . . .

Life Elsewhere: NASA's Kepler Reveals Earth-Like Planets

Relative sizes of the known habitable zone planets identified to-date.
Image Credit: NASA Ames/JPL-Caltech
Today, we met the neighbors.

NASA astronomers announced that the Kepler mission has discovered three earth-like planets orbiting distant stars and which are within the 'habitable zone' -- where distances from the sun-like star maintain temperate surface temperatures that maintain liquid water.

Key to the planet-hunters' spotting is the Kepler spacecraft. NASA's Kepler space telescope has one primary sensor that detects the light of hundreds of thousands of stars all at once.

If a planet passes between our Solar System and a distant star, the sensor registers a tiny dip in the star's brightness. By studying the pattern of dips, researchers can determine how long it takes for the planet to orbit its sun.

Read the rest of the post . . .

Wednesday, April 17, 2013

PODCAST: Fusion Energy

On this week's podcast, we talked about two of the leading fusion energy experiments, the National Ignition Facility and ITER. It's hard to get a real idea of these facilities without seeing them.

Located at the Lawrence Livermore National Labs in California, the National Ignition Facility shoots powerful lasers at a tiny pellet of hydrogen in hopes of getting it to "ignite." This technique is called the Inertial Confinement, because the intense heat and pressure of the lasers to crush the hydrogen together from all angles. In a building the size of three football fields, workers prepare the 192 lasers aimed at the their targets. Each laser has to fire with better than millisecond precision so that each beam hits the fuel pellet at exactly the same time. (Image: DoE)


Read the rest of the post . . .

Tuesday, April 16, 2013

A Sign of Population Collapse

In January, researchers announced that decades of fishing has decimated the bluefin tuna population by over 90 percent. Just days earlier, one such Pacific bluefin tuna sold for $1.76 million at an auction in Tokyo.

The bluefin tuna can weigh over 1,000 lbs and swims at speeds over 50 mph. While most remain in the eastern Pacific waters off the coast of Japan, some bluefin species migrate across the Pacific to the coast of California. More than 90 percent of bluefin tuna are caught before they have reproduced, severely damaging the population.
 Image Credit: Aziz Saltik
Climate change, overfishing, and other ecological changes can push wild animal populations towards extinction. For years, scientists have observed changing wildlife populations and seek to measure the risk of population collapse in order to preemptively protect endangered species.

Now, a team of physicists at MIT have demonstrated that variations in population density may accurately reflect the population's risk of collapse. By studying spatial relationships of neighboring populations, the researchers hoped to catch early signs of population collapse. The research led by Jeff Gore, Lei Dai, and Kirill Korolev at MIT was published online in the journal Nature on April 10, 2013.

Read the rest of the post . . .

Monday, April 15, 2013

Game Theory Tackles Rising Health Care Costs

Operations research finds an increasingly important application in health care.


Image credit: U.S. Army Corps of Engineers Savannah District via flickr | http://bit.ly/Zm0xcG
Rights information: http://bit.ly/9h3qT6

By Joel Shurkin, ISNS Contributor

(ISNS) -- A new army is marching into the war against rising health care costs: engineer-mathematicians.

These individuals occupy a field called operations research, also known as advanced analytics. A subset is game theory, a way of modeling complex human behaviors and decision-making to produce the best outcomes. Applied to health care, the work includes scheduling operating rooms, setting fees, training technicians and deciding where to build hospitals.
Read the rest of the post . . .

Friday, April 12, 2013

Climate Change may have Doomed an Ancient American Society

Dramatic changes in the ocean's environment could be one of the reasons why the Moche, an early pre-Columbian civilization in Peru, fell apart over 1000 years ago.

Moche pottery. Link to original: http://bit.ly/13UWSKB
Image credit: Juan Carlos Martins, http://bit.ly/11sxp7s
Upwelling of cold, deep water diminished because of changes in El Niño in the Pacific, and interrelated climate changes upset the life of the Moche (pronounced Mo-CHAY) in ways that undermined their social structure and life so badly that within a few generations, their society collapsed. 

Read the rest of the post . . .

Thursday, April 11, 2013

POCAST: The Scientist Behind Breaking Bad

This week on the podcast I talk with Donna Nelson, a professor of chemistry at the University of Oklahoma and a science adviser on the AMC show Breaking Bad.

The show centers on high school chemistry teacher Walt White, who decides to start cooking methamphetamine to make money for his family. Science plays a major part in the show, so I was eager to hear Nelson explain exactly what she does as a science adviser. We also discussed why she thinks it's important to get the science right in TV shows and whether or not an organic chemist like herself could really figure out how to make methamphetamine. It's a great podcast whether you've seen the show or not, and there's no plot spoilers. So go listen to it!
Read the rest of the post . . .

Wednesday, April 10, 2013

DNA Sculpts Graphene Sheets

Scientists are using two nearly ubiquitous materials, carbon and DNA, to push cheap and scalable graphene electronics to the nanoscale.

At left, metallized DNA (red) forms letters on a graphene surface. Treatment with oxygen plasma etches the shape of the letters into the graphene, right. Image Credit: Zhong Jin / MIT News

DNA holds our genetic information in sequences of base pairs: guanine-cytosine and adenine-thymine. For a decade, scientists have been exploring DNA as a synthetic biological building block. By programming the sequences of base pairs on the computer, researchers are able to fold DNA into two- and three-dimensional shapes that some call DNA Origami.

Now, researchers at MIT and Harvard have used DNA origami to create tiny structures out of graphene. While current methods of patterning graphene rely on costly and time-consuming processes like electron-beam lithography to etch tiny shapes in the graphene, the new research, led by Peng Yin at Harvard and Michael Strano at MIT, proposed that using DNA to relay patterns and structural features may enable cheap and scalable production of graphene devices such as electronic chips. The study was published on April 9, 2013 in Nature Communications. 

Read the rest of the post . . .

Monday, April 08, 2013

A Scientific Analysis of Meme Success

When you have a joke, anecdote, or quip to share with the internet, attaching your message to a well-known meme — a cultural idea or style spread among people — will likely help it take off. Have a joke about an embarrassing social situation? Then use your joke as a caption for an image of "Socially Awkward Penguin," and there's a better chance thousands of redditors will appreciate your insight.

Ensuring your caption fits the general idea behind the meme will better your chances of upvotes, likes, or shares within an audience familiar with the meme. But what makes one meme more popular than another, and how might meme success depend on the popularity of other memes?

Does "Confession Bear's" latest secret impact the success of "Chemistry Cat's" latest nerdy joke? To investigate the relationships among Internet memes, postdoctoral computer scientist Michele Coscia from Harvard University has adapted ecology research methods and applied them to a popular website closely related to the social media website reddit: QuickMeme.com.

An implementation of "Chemistry Cat," one of many memes found on quickmeme.com

Read the rest of the post . . .

Friday, April 05, 2013

Coming Soon: the Fusion-Powered Mars Express

Some things are just better together: cream and coffee, peanut butter and jelly, cats and bread, fusion power and manned Mars missions . . .

Image Credit: University of Washington, MSNW
Feasible fusion power and Mars missions make such a wonderful pair because each one on its own is effectively impossible at the moment. So, what the heck? If you're going to do one impossible thing you might as well go ahead and do two. Thank goodness NASA is on the case.

Read the rest of the post . . .

Thursday, April 04, 2013

Laser Helps Measure Brain Activity

New tool may illuminate brain's inner workings.

Image credit: dmuth via flickr | http://bit.ly/YImhlM
Rights information: http://bit.ly/cfv4IF
European researchers have developed a new tool for studying nerve cells in the brain. The implanted tool can simultaneously inject fluid into individual cells, shine light on them, and record their electrical activity.

Read the rest of the post . . .

Wednesday, April 03, 2013

PODCAST: The Annual Physics Sing-Along

This week on the podcast we're talking about the annual Physics Sing-Along, which takes place every year at the APS March Meeting. Go listen to it!

Some of us are still recovering from the awesome intensity of the APS March Meeting, where we learned about such things as the physics of mosh pits; a new device to keep your moonshine safe; and a language map of New York City, constructed using data from Twitter.

Walter Smith and 95 Blues Berry Way at the 2013 Physics Sing-Along
L to R: Eugene Borovikov, Walter Smith, Victor Yakovenko and Sergey Yershov
If you've ever attended the meeting you know it's a whirlwind of amazing new physics, but it can also be mentally exhausting. Packing new information into your brain 8 hours a day for 5 straight days requires stamina, and it's important to take a break and unwind. And what better way to do that than by singing? And if you can sing about physics, well that's all the better!  

Which brings me to one of my favorite events at the March Meeting: the Physics Sing-Along. This is an event hosted by Walter Smith, who is a professor of physics at Haverford College. Smith and his wife, Marian McKenzie, started writing physics songs that Smith could use as a teaching tool in his undergraduate classes, but 8 years ago he decided to start the sing-along as a social activity at the meeting. The result is one of the most awesomely nerdy things I've ever seen.


Read the rest of the post . . .

Monday, April 01, 2013

Peer Reviewed Tweets: The Future of Open Access

By Flora S. Lipo

Earlier this year, the White House Office of Science and Technology Policy issued a memo requiring all papers stemming from federally-funded research to be accessible to the public within a year of publication. Publishers greeted the announcement with cautious approval, but industry experts are divided over how this will impact the publishing landscape.

As the push for open-access scientific research has strengthened recently, scientific publishers have tried to keep pace with new platforms and methods. Nonetheless, the entire process of peer-review remains hidden from public view, and most research papers still require specialized knowledge of the field and its jargon to comprehend.

Now a new publisher hopes to overcome these challenges with an innovative approach: publishing all of its research on Twitter. Peer Reviewed Tweets (PRT), a publication of PhysicsCentral Publishers, soft-launched last Friday. Its Editor-in-Chief, Dr. Rebecca Thompson, started the publication to bridge the gap between scientific research and the taxpayers who fund most of it.

"I believe Albert Einstein once said 'if you can't explain it simply, then you don't understand it well enough," said Dr. Thompson. "At PRT, We take that one step further: If you can't explain all of your research in 140 characters or less, you probably don't understand it at all."

All research papers published in Peer Reviewed Tweets will have to include a title, research summary, and author name in 140 characters or less. Currently, most journal papers range in length between five and twenty pages.



Read the rest of the post . . .