Thursday, October 31, 2013

E-bike Physics

Image of German-designed e-bike via Wikimedia

There’s a new class of electric bicycles prompting oodles of attention, collecting millions of dollars in funding and providing little more than dust-collecting, spider web-encrusted racks in bike shops.

Within the last five years, Panasonic and MIT unveiled e-bike prototypes, which boast batteries that can re-charge themselves through a process called regenerative braking. A regenerative brake reduces a vehicle’s speed, thus expending energy, but in the process it captures some of that lost energy and stores it in the battery for future use. Contrary to what they claimed in 2008 and 2011, neither Panasonic nor MIT has released their design to markets.

There are many possible explanations, but one that stands out above the rest is simply that the design does not work, or at least does not work well-enough to compete with e-bikes already available for purchase. This post explores some of the physics behind this design and whether it’s capable of acting as an efficient e-bike.

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Wednesday, October 30, 2013

Podcast: Thorium Nuclear Power

A schematic of the  Molten Salt Reactor Experiment
Image: Oak Ridge National Lab
On this week's podcast, we looked at the benefits of a particular kind of nuclear reactor, the thorium molten salt reactor. It's a kind of reactor that uses thorium and uranium suspended in liquified solution that generates heat to boil water and turn turbines. There's a debate in the United States as to whether to fund research into them. Proponents say that the technology could power the world with cheap clean energy, while critics say that it's untested and like all nuclear power has serious downsides. Here's a quick rundown of the main pros and cons:

PRO: Thorium reactors can produce plentiful, cheap power.

CON: Nuclear power industries have been promising that for decades, but the costs have yet to drop dramatically.

PRO: Thorium is plentiful. It's about as common as lead in the Earth's crust, making for cheaper fuel than traditional uranium reactors.

CON: The scarcity of uranium only makes up a tiny fraction, only about two percent, of the cost of electricity.

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Tuesday, October 29, 2013

Flying Machine Mimics Graceful Swimmers

When it comes to the skillful art of flight, insects must be doing something right.
About 350 million years ago, they were the first life on Earth to achieve lift off. Fast-forward to the 21st century and scientists and engineers realize that flying like an insect is harder than it looks.

In particular, the motion of insect wings lends little stability to the object itself. So, many prototype flying machines meant to mimic a flying insect often tumbled through the air like a somersaulting astronaut in zero-g. Attached technological sensory mechanisms can enable stability but also add weight, so the machine must expend more energy to boost itself off the ground.

A pair of mathematicians at New York University have overcome the obstacle of stability in a different way and built the first machine of its kind that is inherently stable. The bizarre part is that the machine moves unlike any insect in nature and instead resembles more of a jellyfish in air.

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Monday, October 28, 2013

Electrical Pulses Could Make Better Wine

Engineers test new technique to get more juice from grapes.

Originally published: Oct 17 2013 - 2:30pm, Inside Science TV
By: Marsha Lewis, ISTV Contributing Producer

The wine industry has come a long way, from exclusively small-scale operations to a multi-million dollar industry that’s booming. As the demand for quality wine grows, so does the thirst for a better way to make it.

To help satiate the palates of thirsty oenophiles, researchers at the University of Southern California in Los Angeles are developing a way to extract juice from grapes more efficiently and effectively.
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Friday, October 25, 2013

New Algorithm Helps Cochlear Implants Detect Music

Advancement allows patients to hear differences in pitch and timbre. 

Image by Phil Holmes via

People who have cochlear implants placed in their heads had often never heard a sound in their lives before their implant. Once the device is placed, they can experience hearing, and often can even understand human speech. Hearing music, however, has remained out of reach.

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Thursday, October 24, 2013

Dead Birds Adrift and the Killer Source

Two bird species common to parts of the northern U.S. have attracted the semi-morbid attention of scientists and engineers at Florida Atlantic University and the U.S. Geological Survey. Using carcasses of common loon and lesser scaup species, the team conducted experiments to determine how water current, wind velocity and the amount to which the carcass is submerged affect its drift.

USGS is using the results to develop computer simulations to potentially pin point the location of toxic sources in the Great Lakes region. One of the prime threats to birds frequenting the Great Lakes is type E botulism, a neurotoxin-producing bacterium that causes paralysis and death when ingested. USGS estimates that over 80,000 birds have died from botulism intoxication in the Great Lakes region since 1999. The sites of exposure remain unknown.

The team submitted an overview of their work in an abstract for the upcoming 66th Annual Meeting of the APS Division of Fluid Dynamics to be held in Pittsburgh, PA where they will present their results in detail.

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Wednesday, October 23, 2013

Podcast: RHIC

On this week's podcast, I visit Brookhaven National Lab's Relativistic Heavy Ion Collider, a machine that recreates the conditions of the universe a microsecond after the Big Bang. I got a chance to meet the scientists while they were taking data, and see what they see. However that also meat that I didn't get a chance to see any of the detectors in person because they were busy doing what they were designed to do, detecting particle collisions.

An ariel view of Brookhaven National Labs, with the two-mile-long RHIC accelerator tunnel highlighted and the STAR and PHENIX detectors marked. Inside, there are two beam tubes running parallel to each other but in opposite directions. Ions shoot around the beam tubes and collide with each other at the detectors where the tubes cross. 

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Tuesday, October 22, 2013

The Physics is Clear on Foamy Beer

A team of three international scientists has explained the physics behind why beer in a bottle transforms into an overflowing mass of foam when the bottle receives a vertical tap on the mouth, as shown in the video. They will present their work and its applications outside of the bottle at the 66th Annual Meeting of the APS Division of Fluid Dynamics.

The act is colloquially referred to as “beer tapping”: Someone hits a beer bottle on the head, often with the bottom of their own bottle, and within seconds the victim of the prank is left with a small amount of flat beer and a bottle dripping with foamy bubbles of carbon dioxide.

Javier Rodríguez-Rodríguez, assistant professor at the Fluid Mechanics Group of Carlos III University of Madrid and lead author of an abstract about the research, and his colleagues were at a bar discussing the process behind this phenomenon when they realized they did not fully understand it. And according to their unsuccessful search for a solution online and through scientific databases, neither did anyone else.

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Monday, October 21, 2013

Fluid Knots and Smoke Ring Physics

From mushroom clouds to smoke rings, "filamental vortex loops" abound in a number of fluid dynamics applications.

You can create your own smoke rings at home with this cool science experiment, but scientists waited over a century for experimental evidence of an elusive twist on this fluid flow: knotted vortex loops.

Earlier this year, scientists from the University of Chicago gathered that long-sought data with the help of a 3-D printer, lasers, and a high-speed camera. This month, those same scientists, headed by postdoctoral researcher Dustin Kleckner, released an updated video explaining the physics behind these beautiful, twisted fluid flows.

To observe the knotted loops, the research team first used a 3-D printer to create special hydrofoils tied in knots. Next, they accelerated the hydrofoils through a fluid to imprint the knotted structure onto the fluid, generating the vortex knots that they sought. Lasers and a high-speed camera tracked the knots as they twisted and morphed, giving the researchers a 3-D timelapse of the evolving fluid flow.

In the research team's video entry (embedded below) for the 2013 Gallery of Fluid Motion, you can see the beautiful images the team captured during their research.

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Friday, October 18, 2013

When You Gotta Go, You Gotta Go . . . for about 21 Seconds

People are mostly water. So are all mammals. Sometimes, we mammals are made of a little more water than we care for, which is when it becomes time to get rid of some - if you know what I mean.

Treadmill mouse has to go, for about 21 seconds, in this video by New Scientist magazine

I wouldn't have thought there was much a physicist would have to say about urinating, but that's where I would be wrong. At the upcoming APS Division of Fluid Dynamics meeting, a session on biofluids includes two papers dedicated to the physics of fluid elimination in mammals.

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D-Wave Computer's Solution Raises More Questions

Does D-Wave's computer owe its high performance to bizarre quantum effects?

Photo courtesy of D-Wave Systems, Inc.

An experimental computer made by a Canadian company has proved its ability to solve increasingly complex mathematical problems. But the question remains — just how much of this calculating power is actually due to the strange properties of quantum mechanics?

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Thursday, October 17, 2013

Explosive Energy of Dry Ice Bombs

Christopher from Salem, OR, USA via Wikimedia Commons
With Halloween around the corner haunted forests, hayrides, houses and more are setting up shop using new and old ways to frighten you. One ever-popular spooky effect is the foggy mist of dry ice – a solid form of carbon dioxide that has been making national news headlines for the last week, and not for the awesome way it looks when shooting out of a jack-o-lantern.

Last Tuesday, officials arrested the alleged dry-ice bomber of LAX airport. Dicarlo Bennett, a 28-year-old who handled baggage and ramp service at LAX, had created four dry ice bombs, two of which exploded within the airport facility. The other two were found and discarded before exploding.

Thankfully, no one was injured and in light of the coming holiday and LAX upset we’ve provided some calculations that indicate just how dangerous dry ice bombs can be and how to safely enjoy the misty aura of dry ice.

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Wednesday, October 16, 2013

Podcast: Weightlessness in Movies

This week's podcast is all about movie magic. How do filmmakers simulate weightlessness when they want to make movies that take place in space? Today I talk about three movies that each tried different approaches to this problem.

Popular Mechanics talks about how Gravity defied gravity. Here's the movie trailer:

Update: Listener Steve very politely pointed out an error I made in the podcast: in my description of a reduced gravity aircraft I stated that the period of "weightlessness" for the passengers ends as the plane turns back down toward the Earth. Actually, that period occurs during the entire peak of the parabola, including a few seconds as the aircraft starts to descend. Check out the graphic below to see exactly what I mean. 

Image: NASA

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Tuesday, October 15, 2013

Fluid Juggling

Fluid dynamics often produces some of the most beautiful, albeit under-appreciated, physics images and videos. To celebrate this field's striking images, the American Physical Society's Division of Fluid Dynamics holds a contest every year for related posters and videos that best display "artistic value, scientific content, and originality."

One promising entry this year features a high-speed capture of fluid jets juggling ping pong balls. It's a gorgeous video, and you can watch it below.

As researchers Roberto Zenit and Enrique Soto (National Autonomous University of Mexico) explain in the video, streams of water can suspend the balls due to a Bernoulli-like effect similar to the one responsible for lift in an aircraft. To levitate the ball for long periods of time, the researchers needed two things: a balance of vertical forces (we'll call this levitation) and horizontal forces (we'll call this stability).
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Monday, October 14, 2013


Hello, devoted readers. I am stoked to introduce myself as the new APS science writing intern and tell you a little bit about the journey that’s led me to this wonderful physics nook in College Park, Maryland. It starts in a place not too far from here at the Ohio State University where I studied astronomy and physics, dabbled in astronomy research and discovered my passion for science writing as an undergrad.

My path then veers south to the land of cowboy boots, BBQ and “Howdy!” greetings at Texas A&M University – the school from which I will earn a master’s in science and technology journalism this December. From there, I launched myself into a series of internships, each one with unforgettable people and invaluable experiences that I will forever carry with me.

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Friday, October 11, 2013

Physics Halloween Costumes

Caufield Novelty's take on an Einstein Costume
We've blogged about physics Halloween costumes in the past, but too late to help anyone come up with ideas in time to actually celebrate the greatest holiday of the year.

We're going to try to remedy that this year by suggesting a few themes for your nerdy trick-or-treating garb well ahead of the big day.

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Wednesday, October 09, 2013

Podcast: Life on Mars?

Is there life on Mars?

Even pop stars want to know. The Mars rover Curiosity (the fourth rover to explore Mars) touched down on the red planet just over a year ago, and scientists are now trying to make sense of the data it is sending back. In September, two groups of researchers published separate findings that may help scientists one day answer the question: are we alone in the solar system?
This week on the PhysicsCentral podcast I talk about those new results: Curiosity found Martian soil containing 2% water, but so far Curiosity can find no trace of methane in the Martian atmosphere.

Water in the soil means microbes that require water for life (like every singe living thing on Earth) could potentially live there. It also means astronauts could potentially harvest water from the soil. But the lack of methane (if it is confirmed) might mean there are no methane-producing microbes on Mars. Almost all the methane on Earth comes from biological entities, including microbes, livestock, and decaying plant matter. There are also microbes on Earth that do not produce methane, so it's absence doesn't mean there is or never was life on Mars. But the results pose a tricky question for scientists. Check out the podcast to hear more.
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Higgs Round-Up

The 2013 Nobel Prize in physics will go to Peter Higgs and Francois Englert, for their prediction of the existence of the Higgs boson. Experiments at the Large Hadron Collider at CERN announced the discovery of the Higgs in the summer of 2012.

The discovery of the Higgs boston was a big freakin' deal for physics (and in the long run, for all of humanity). We've talked about the Higgs and the LHC a lot around here, so if you need a refresher as to why these things are so important (and so cool), check out some of the links below.

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Tuesday, October 08, 2013

The Higgs Boson wins 2013 Nobel Prize in Physics

Englert and Higgs take it!

In other news, water still wet, sky still blue.

Just kidding, it could have gone to all sorts of other deserving people. Still, I don't think anyone was terribly surprised.

Peter Higgs doesn't know yet, though. The Nobel Prize Committee tried to call, but Higgs didn't pick up. If you see him, please let him know.

If you want a little more info, you can read the APS Announcement about the 2013 Nobel Prize for Physics.

Or you can check out APS Associate Executive Officer Alan Chodos' explanation of what the Higgs Mechanism is and why the Higgs Boson is important.

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Monday, October 07, 2013

Source Of 13th Century Volcanic Calamity Discovered

A tale of an Indonesian volcano, a monk, and the mass graves of London.

Originally published: Oct 1 2013 - 3:30pm, Inside Science News Service
By: Joel N. Shurkin, ISNS Contributor

(ISNS) -- The Benedictine monk Matthew Paris knew that 1258 was a really bad year. Winter seemed to last forever. The sky was always dark. There were no crops, he wrote, and hundreds of thousands of people were starving to death. It was the year summer never came.

Scientists, working from bores of glacial ice in Antarctic and Greenland, know that the cause of the atmospheric upset was a large volcanic eruption somewhere, something the good monk could not know.

The mystery was: what volcano, where?

Samalas caldera and Segara Anak lake
Image Credit: Céline M. Vidal, Institut de Physique du Globe de Paris (IPGP)

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Friday, October 04, 2013

And the 2013 Nobel Prize for Physics goes to . .

Simulated Higgs signature in the LHC's CMS detector. Rights
The Higgs Boson is the most talked about possibility for the 2013 Nobel Prize in Physics. We'll know for sure on Tuesday by about 5:45 AM EST. But the Nobel Committee has surprised us many time in the past so there's no guarantee they'll go with (or actually "have gone with," considering the choice was made some time ago) the popular expectation.

There are, in fact, a few problems with awarding the Nobel for the Higgs.

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Thursday, October 03, 2013

Big Stars Don't Need Siblings

There are some giant stars out there. Our sun is more than 300,000 times more massive than Earth. That's pretty big, but there are stars much larger. One particularly big one, imaginatively named WR 102ka, is located near the center of the galaxy is 100 times larger than our sun. Ever since scientists started noticing these behemoths near the galactic core, they've wondered where they came from. Now a team of scientists from the University Potsdam in Germany think they have an answer.

The Peony Nebula, which lies between us and WR 102ka. The nebula blocks out all but the giant star's
infrared light. The yellow circle indicates WR 102ka location behind the dust and gas. Image:NASA.

Stars form when vast clouds of gas and dust coalesce together, growing denser and denser, until its atoms start fusing together and set off a nuclear reaction. Sometimes they form by themselves with  no other stars nearby, and sometimes they're created within vast star cluster full of other newly formed stars and the ingredients for more.

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Wednesday, October 02, 2013

Podcast: Does Einstein Deserve More Credit?

Albert Einstein is hands-down the most famous scientist who ever lived, and one of the most famous people in history. His contributions to physics sparked one of history's greatest scientific revolutions, and fundamentally changed the way we look at the world. He has set the bar for what we consider a "genius."

That said, "under appreciated" seems like the last thing that would describe Einstein; and yet, it seems that most people, including most physics, aren't quite aware of just how great Einstein was. A new book by Douglas Stone, a professor of physics at Yale University, shows that Einstein made even more contributions to science than we give him credit for, particularly to the field of quantum mechanics. Stone, a quantum physicist himself, argues that many of those contributions are Nobel Prize worthy.

Perhaps the strangest part of this tale is that it was Einstein himself who wanted to downplay his work.

Listen to the podcast to hear my interview with Stone about his book Einstein and the Quantum: The Quest of the Valiant Swabian

Correction: The podcast states that Einstein's theory of relativity was tested during an eclipse. It is the Sun's gravity, not the Earth's, that is responsible for bending the light. In addition, the photoelectric effect involves an atom's absorption of light and emittance of an electron—not more light. 
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Tuesday, October 01, 2013

A 'Cyborg Astrobiologist' To Study Alien Planets

Originally published: Sep 30 2013 - 4:15pm, Inside Science News Service
By: Amanda Alvarez, ISNS Contributor

(ISNS) -- An international team of researchers has developed a simple way to make a future planetary rover behave more like a human geologist, using just a cell phone camera and laptop. Dubbed "the cyborg astrobiologist," the system is designed to pick out novel features in rocky landscapes to speed up exploration and identification of alien terrain.

The science missions of current rovers, like Curiosity on Mars, are slowed in part by their reliance on human operators, whose instructions take 14 minutes to reach the rover from Earth. Despite Curiosity's high-tech cameras, a human pair of eyes is still required to evaluate any images of Martian rocks, and even the rover's navigation is mostly under external control. The goal of the cyborg astrobiologist is to automate the geological analysis portion of the decision-making for future rovers, said the project's lead author, planetary scientist Patrick McGuire of Freie Universität in Berlin.

Image credit: P.C. McGuire, L. Wendt, B. Foing, C. Gross /Freie Universität Berlin, /CSIC-INTA/U. Malta/ESTEC/U. Chicago

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