Friday, September 30, 2011

The Physics of Beer

In honor of Oktoberfest and my last day as an APS intern, here's a post dedicated to one of the greatest inventions of all time: Beer.

[Wunderbar!]

The secret to a good beer? Pressure!

When it comes to beer, it's all about carbonation. Every vessel containing beer, from a glass to a keg, to cans and bottles, is created to keep beer fizzy and foamy down to the last drop.
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The Tevatron's Last Run

After 28 years of leading research in high energy particle physics, the Tevatron is shutting down today.

Farewell, Tevatron, you had a great run. Thanks to everyone who helped to build and operate this amazing machine.
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Thursday, September 29, 2011

Pixelated Art on the American Center for Physics

As her farewell to Physics Buzz and the American Physical Society, Echo Romeo left us some art crafted in Post It notes on the building windows. (I helped a bit.)



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Live Chat on Neutrinos today at 3PM EST

Today at 3:00PM eastern time, Science magazine will be hosting an hour-long discussion on the debate over the recent faster-than-light (supposedly) neutrinos announcement out of CERN.

Science's Dan Clery will be hosting this discussion, which will include guests Alan Kostelecky and Alfons Weber.

To participate, or just listen in, surf on over to the Science chat site.
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Wednesday, September 28, 2011

Shirt Happens: Pretty's Got Nothing To Do With It.



www.washingtonpost.com


Recently there was a lot of controversy surrounding a shirt sold by JC Penny's saying that "I'm too pretty to do homework so my brother has to do it for me." I, for one, am glad about the whole kerfuffle because it brought to the forefront something that is still an issue for most girls and women, that if you are pretty, you can't be smart and if you are smart you can't be pretty. Pretty girls are often judged to be "dumb blonds" and those getting straight A's aren't that attractive. "Boys don't make passes at girls that wear glasses" as the saying goes. This idea is out there and around us all the time but is rarely talked about openly until something like this shirt happens. It is this pervasive idea that led many, many people to think this shirt was a good idea in the first place. And that's just wrong. But some good things have come out of all of this.

There is one response to this issue that I liked the most. A blog called "Pigtail Pals" made a response t-shirt that says "pretty's got nothing to do with it." When most of the responses to the JC Penny's shirt were about how girls can be pretty and smart and don't need brothers to do well in school, pigtail pals had a slightly different take. There shirt says that yes, you can be pretty and smart, and yes you can be pretty and not academically gifted, and yes you can be plain and smart, and frankly you could be neither. All of those are ok and a girl's level of attractiveness has nothing at all to do with their brain power. Its a subtle difference in phrasing, but to me that makes all the difference.

The idea of correlating "pretty" and "smart" reminded me of this article, "Stop Global Warming, Become a Pirate!" Obviously the number of pirates will not affect earth's climate and the graph was made to point out the ridiculousness of assuming a causation just because of a correlation (see this comic for another laugh). Yet, people think it is acceptable to do this with women's looks and their brain power.

I like that this shirt opened the discussion about this topic. I really like the fact that so many people were outraged. Girls are surrounded by messages that tell them to be pretty and if they are pretty, smart doesn't matter. Its everywhere. But this shirt had people standing up and saying that that idea is simply not ok. And all those tween girls watched. They watched their moms, their teachers, their dads and their friends say that it was not ok for them to buy into that. Their roll models, the people they see everyday, stood up and took action and JC Penny's pulled the shirt and apologized. When those girls think that being pretty is what matters most I hope they remember the reaction to this shirt. And that reaction was awesome.

Everyone should check out two amazing girl power websites, Girl-Wonder and Pigtail Pals. There are others I am sure, so please post them in the comments so we can be fans of them too.

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Tuesday, September 27, 2011

Faster than Light Neutrinos sure ain't Cold Fusion

The recent detection of faster-than-light neutrinos may turn out to be an error, but this experiment was no cold fusion fiasco.

[The OPERA neutrino detector on the left is leagues above the cold fusion cell on the right.]

Lots of people in the news, in university hallways, and even in cartoon form are urging caution against putting too much confidence in the measurement of neutrinos that travel faster than light. Many of them have suggested that the whole thing looks a lot like the ill-fated cold fusion announcement of 1989.

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Monday, September 26, 2011

NASA's airborne telescope will always be state of the art

Imagine pointing a telescope out of your car window and scouring the heavens for new clues about the origins of the universe while cruising down the highway. That’s what SOFIA – NASA’s and the German Aerospace Center’s Stratospheric Observatory for Infrared Astronomy - does only it’s mounted in the back of a Boeing-747 flying at 500 miles per hour at 40,000 feet.

[SOFIA, the 'Stratospheric Observatory for Infrared Astronomy,' stopped at Joint Base Andrews near Camp Springs, Md., Sept. 22 on it's way back from Germany to its home at NASA's Dryden Aircraft Operations Facility in California. SOFIA is the world's largest airborne observatory.]


Link[The infrared telescope on board SOFIA is at the rear of the Boeing-747.The lens mirror itself is behind the white wall. The silver equipment at left is one of several interchangeable instruments that can be attached to the telescope.]

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Friday, September 23, 2011

Physicists Report Evidence of a Faster-Than-Light Particle

In what would represent the biggest physics discovery in the century thus far if confirmed, researchers announced that they have measured particles traveling faster than the speed of light, which -- at least up to now -- has been the speed limit of everything in the universe.


[Image courtesy of the OPERA Collaboration]

Researchers from the OPERA (Oscillation Project with Emulsion-tRacking Apparatus) experiment presented their results on Friday at a seminar at CERN, the European Organization for Nuclear Research, following a preprint post Thursday night on the science website arXiv.

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Live webcast from CERN

Physics enthusiasts at the American Center for Physics take a break mid-morning to watch the 10 a.m. EDT press conference about the CERN discovery that neutrinos may travel faster than the speed of light.

To watch the archived press conference, go here.
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Thursday, September 22, 2011

Newsflash: Tachyon Neutrinos Could be the Discovery of the Century

CERN's OPERA collaboration will announce tomorrow that they have found powerful evidence that some neutrinos travel faster than the speed of light. If true, this is the most important discovery since Einstein developed the Theory of Special Relativity in 1905.

For more information, see Geoff Brumfiel's story in Nature.
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Calculating the (Unlikely) Odds of NASA Satellite Casualties

How did NASA come up with the 1 in 3200 chance of anyone on Earth being hit by pieces of the Upper Atmosphere Research satellite (UARS) due to crash on Friday?



We contacted NASA yesterday to ask them what goes into their estimate of the risks that incoming satellites present. In short, the answer we received from NASA's Nick Johnson is "A complex computer program called ORSAT is used," to do the calculation. (The complete NASA reply is available at the end of this post.)

That's cool, but computer output is only as good as the input and programming. In my experience, it's always a good idea to get out a pencil and paper to make sure the computer's answer makes sense. So I thought I'd try to estimate the odds UARS hitting anyone all by myself. Here goes . . .

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Wednesday, September 21, 2011

Teaching With Portals: Videogames in the Classroom

To make a good video game, certain laws of physics can be ignored. For example, if I am floating through space killing ice aliens, I REALLY want to be able to use my flamethrower. (I’m not sure if that game exists yet, but if it doesn’t… free idea.) Unfortunately, boring old reality dictates that in order to burn, fire needs oxygen, of which outer space is lacking. Ignoring this truth leads to a much more enjoyable rampage, and in the meantime I could still accidentally learn a thing or two about the laws of universal gravitation.

One actual video game series that runs with this concept of adapting physics is Portal. In Portal, you control a human test subject that obeys all the conventional laws of physics. However, your character has a gun that can create a wormhole between any two surfaces you shoot. Jump in one portal and you emerge from the other. Put one on the floor and the other on the ceiling above, and you can fall through an infinite loop.


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Tuesday, September 20, 2011

Diamonds: Telling the Tale of an Epic Journey

Diamonds formed in the lower mantle carry the record of Earth's carbon cycle.


[Like an insect in amber, mineral inclusions trapped in diamonds can reveal much about the Earth’s deep interior. Image credit: Science/AAAS]

Hundreds of millions of years ago, six diamonds formed in our planet's lower mantle began a remarkable journey up to the surface of the world. They emerged in a diamond mine in Brazil, a travelogue of an epic voyage.

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Monday, September 19, 2011

New research may explain high runup from tsunami waves

Coastal residents need to know that when it comes to tsunamis, there may not be just one wave and the first wave isn’t always the biggest, three scientists are saying. Their new research shows that tsunami waves and coastline slopes might combine to create resonance that amplifies the water coming onshore.

Contrary to what many people might believe, a tsunami travels not as a single large wave but in a wave train of several large waves. The height a given wave reaches when it comes onshore is called runup. This is different from a wave’s inundation which is how far it travels horizontally – or inland – when coming onshore. Though scientists have known for a while that the first wave in a tsunami train doesn't always produce the highest runup, they have struggled to explain why.

New research published Friday in Physical Review Letters details how the three researchers used a computer model to show that a tsunami’s frequency – how closely in time one wave follows another – combined with a shoreline’s slope can result in a resonance that sends more water onshore.
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Friday, September 16, 2011

Why are there so many contrails today?

Driving in to work this morning, I noticed there were an awful lot of contrails in the sky. Why, I wondered, were there so many today?

[Holy contrails, Batman!]

Is it because it's a cold day today? Perhaps because we just had a front come through? To find out, I gave my old meteorology professor from Embry-Riddle Aeronautical University a call.

My guess is that you have a lot of moisture in the air there right now, Dr. Randell Barry said. Really? That's it? It's all because of water vapor? I'll explain it to you how he explained it to me. From the beginning...
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Thursday, September 15, 2011

Solar Bottle SuperHero



Solar Demi is a man who travels around installing solar bottles in order to bring light into homes in some of the poorest neighborhoods in the Philippines.



It's amazing to me that there are places where even minimal lighting is a luxury. I'm glad to see that basic physics principles are bringing a little sunlight into the dark days of some impoverished Filipinos. (Of course, if you feel like sending a donation to the cause, you can help spread the light and the love a little further.)

I've seen a lot of speculation about how, and even whether, solar bottles can light a room so well. The fact is, they do work, and they rely on some pretty nifty physics to do it.

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Wednesday, September 14, 2011

Mathlete Takes a Tumble, But How?




My blogger name is "Mathlete" because in my spare time I'm a triathlete. There is a whole lot of physics in swimming, biking and running. I learned this past weekend there is also a lot of physics in crashing. I was racing in the Mighty Hamptons Olympic Distance triathlon (1 mile swim, 24 mile bike, 6.2 mile run) on Sunday and about half way through the bike section, my back wheel stopped rotating and I ended up falling (for gross pictures, see below). After getting over the shock, I looked to see why my wheel had stopped. I have spent 3 days trying to use physics to explain what I saw and simply have not been able to. Can you guys help?


When I looked at my back wheel, I saw that a water bottle, 2/3 full of gatorade, had lodged itself half between my spokes. The bottle was about half way through, parallel to the axis of rotation of the wheel. I have a fancy dancy Cervelo P3 (affectionately named Firebolt) with an airplane wing frame so for aerodynamic reasons, I have the water bottle cages behind my saddle instead of on the frame. That is the problem set up, a water bottle launching and ending up in the spokes. So, hmm...



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Tuesday, September 13, 2011

Heat is the paintbrush in iron meteorite art

[What is this? Perhaps abstract expressionism or a new kind of carbon fiber, you might think. Would you believe me if I told you it's the inside of a meteorite? Photo by Kevin Walsh.]

Walking through the
geology hall in the National Museum of Natural History in Washington, D.C., a few weeks ago, I was struck by what looked like a Jackson Pollock painting on the face of a rock. In fact, it wasn't a rock at all but instead part of an iron meteorite and what had looked like artwork was actually its interior. Beautiful!

Some meteorites are stony but others, like the one that caught my eye, are made of iron and nickel alloys (mixtures of two or more elements). Not all iron meteorites look like abstract paintings on the inside, but most do.

[Two iron meteorites are on display at the National Museum of Natural History in Washington, D.C.]

Originally, these meteorites were made of only one very hot alloy, called taenite. As the taenite cooled very slowly over time - as little as 100 degrees Celsius per million years in some meteorites - another alloy called kamacite formed and grew alongside it. The two alloys formed bands next to one another, producing the beautiful pattern on display at the museum.
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Monday, September 12, 2011

(Possible) Solution to the Fermi Overpopulation Problem

The problem I posed last week was, "How much income you need before it makes sense to have fewer children rather than more?"


[A view of Dahka street crowds, Ahron de Leeuw]

The answer I've come up with, in case you can't stand the suspense, is this - Up to a point, the more money you have the fewer kids you need, but once people reach middle class, the more money they have the more kids they want.

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Friday, September 09, 2011

Fermi Problem Friday - Overpopulation Problem

By Halloween this year, the world population is expected to exceed 7 billion people. Are there sensible ways to slow down or reverse the trend?



Fertility rate by nation. The poorest countries tend to have the highest numbers of children per family.

Seven billion sounds like a lot of people, and I can understand why many folks feel like it's one of the most pressing issues facing the world today. Among the solutions I've seen promoted are education campaigns and birth control distribution. But there may be better ways to deal with the population explosion.

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Thursday, September 08, 2011

What Causes Traffic Gridlock?

New model suggests mass-vehicle slowdown, triggered by decelerating vehicle, spawns traffic impasse.


Gridlock resulting from vehicles and pedestrians "blocking the box" at the intersection of 1st Avenue and 57th Street in New York City. Credit: Rgoogin via Wikipedia


Everyday life enters a different phase on the Tuesday after Labor Day, the unofficial start of autumn in the United States. As students and employees return from vacation, and vehicles fully flood roadways once again, drivers face an increased risk of what may be the worst hassle a commuter can encounter: traffic gridlock.

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Wednesday, September 07, 2011

Physics, Anvils and Gunpowder

If you read the blog on Friday you will hopefully remember that I had my physics consultant debut. I got to be the physics consultant for the Science Channel's Flying Anvils special. No, I wasn't actually on TV, no I didn't get to shoot an anvil and no I did not meet Tory. But my name was in the credits and hey, that's a start. Ok, so it was very tiny in the credits but darn it, it was there. So hopefully you watched the show, but if you did not, I will sum up the physics and like any good physics student, show my work.




As we all learned during the show, anvil shooting has been a sport for roughly 200 years. Rowdy blacksmiths used to shoot anvils to amuse crowds and scare of invading armies. Much like the Scottish Caber Toss it developed from a fun and useful activity into a serious sport. Flying Anvils filmed the national championship of anvil shooting, following several teams including two teams from the same family of anvil shooting legends, the Bollingers (spoiler alert).

You first question is probably "how exactly does one shoot an anvil?" That was certainly my first question. You need three main components, a "base anvil" a pound of black powder and a 100lb shootin' anvil. The two anvils are placed base to base with black powder packed in between. A fuse is lit, the contestants walk away more slowly than I would, the powder explodes and the anvil shoots an average of 180 ft in the air. Teams receive points for the height of the anvil and ose points for every inch the flying anvil lands from the base anvil. So why did this show need a science advisor?


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Tuesday, September 06, 2011

Solution to Fermi Problem Friday - Car Week Edition

The question I posed last Friday was "what's the most horsepower a typical street car can use effectively?" (The answer, in case you don't feel like reading the whole post, is in the range 500-600 hp.)

As it turns out, the limiting factor when it comes to acceleration is usually grip. Cars with more power than their tires can handle are fun for making smoky burn-outs, but they don't tend to move very fast when they're doing it.



Street car tires are pushed to their limits during emergency stops. (The video here shows some people testing braking power on a car a lot like the one I drive to work every day.) So if you want to know the maximum amount of power a car can use, you just need to figure out the maximum power it can dissipate when coming to a stop, then imagine launching in the same amount of time and distance as you stopped, and you have a recipe for the quickest a car can possibly accelerate. Once you know that, you can calculate the work required, which in turn tells you how much horsepower you need to accelerate as fast as physically possible.

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Friday, September 02, 2011

Fermi Problem Friday - Car Week Edition

The Horsepower Wars are back on. No one knows how far it will go, but is there a limit to how much horsepower you can really use on the street?



Back in the muscle car days of the late 1960s and early 1970s, a battle erupted among the major US car makers. The ammunition they used was engine size and the prize was massive horsepower. Previously, few manufacturers saw any reason to build cars with more than 150 horsepower. But by 1969, you could pick up a stunning array of vehicles with optional engines putting out nearly 400 hp, and a few that went as high as 425 or more.

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Flying Anvils!



The Mathlete got her first science consulting gig. No, I am not actually on the show, but the physics was all mine. Hopefully I will be in the credits. Don't grade my homework too harshly, I'll post my work on Wednesday. Tune in to The Science Channel after all your Labor Day BBQs. Monday at 10pm, Science Channel.

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Thursday, September 01, 2011

Of G's and dBs (Lancer v. Jetta v. Element)

Ever since Jeremy Clarkson road-tested the Nissan GT-R in Season 11 of Top Gear*, I have wondered how many G's I might pull in my car on the average drive to and from work.

[How many G's do you feel when accelerating quickly?]

G-force is a measure of acceleration due to gravity. On Earth, an object accelerates down at 9.8 meters per second per second. Sitting at our desks, we experience this as 1G in the downward direction, but zero G's in the forward-backward and side-to-side directions.

Anyone who has accelerated quickly onto the highway knows, though, that feeling of being pushed back into your seat as the force of the car pushes against your back. It's the same thing you feel when accelerating quickly on a roller coaster ride. So how many G's do I pull doing that quick acceleration onto the highway?
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