In 1971, this ferret played a key role in the construction of particle accelerators at Fermilab's Meson Laboratory. As sections of vacuum chamber were connected together, Felicia would run through them, dragging a string. After she had carried the string all the way through, researchers would use the line to run a rag doused in cleaning solution through the long, narrow tubes.

Particle physics is seldom this adorable, and Felicia became a media star — until her retirement in December of 1971 (scientists replaced her with a vacuum-chamber-cleaning robot). She died the next year of an intestinal abscess. But her memory lives on.

Read about Felicia in the Fermilab archives

Felicia's obituary

Thanks, Jennifer Ouellette!

If you've ever spent much time in American farm country, then you've probably noticed that there's a strong tradition there of coating barns and outbuildings with red paint. Why?

Because nuclear fusion.

Okay, the actual answer is simply because red paint has long been a cheap color to buy. But, explains Google engineer Yonatan Zunger, there is some really interesting physics lurking in the background of that price point.

What makes a cheap pigment? Obviously, that it’s plentiful. The red pigment that makes cheap paint is red ochre, which is just iron and oxygen. These are incredibly plentiful: the Earth’s crust is 6% iron and 30% oxygen. Oxygen is plentiful and affects the color of compounds it’s in by shaping them, but the real color is determined by the d-electrons of whatever attaches to it: red from iron, blues and greens from copper, a beautiful deep blue from cobalt, and so on. So if we know that good pigments will all come from elements in that big d-block in the middle, the real question is, why is one of these elements, iron, so much more common than all of the others? Why isn’t our world made mostly of, say, copper, or vanadium?

The answer, again, is nuclear fusion.

You can read the full story on Zunger's Google+ page. In my experience, white is another really common barn color, due to the fact that whitewash — a paint made from calcium hydroxide and chalk (which is also calcium) — is way cheap, as well. Calcium is also one of the most abundant elements in the Earth's crust ... clocking in at number 5, right under iron in the top 10. I'm sure there's some different science that accounts for the high concentrations of calcium on our planet, but the same principal applies. Cheap paint is paint made with abundant (and easily accessible) elements. And abundant elements happen because of physics.

Geoscientist Matt Kuchta explains why wet sand makes a better castle than dry sand — and what you can do to make your sand fortress even more impenetrable. Hint: The secret ingredient is window screens.

The other night, Joshua Foer posed this question was posed to a table full of science journalists. Most of us started talking about friction, and/or possibly something to do with the little flanges on either side of a train wheel.

We were all wrong.

This is a Richard Feynman video, yes, but it's more about mechanics than physics. Turns out, you can learn a lot about how trains stay on the track by looking under your own car.

Dry quicksand was a mythical substance — normal-looking sand that could swallow you in a flash. That is, until 2004, when scientists made the stuff in a lab. (Mark told you about that development.)

In this video, geologist Matt Kuchta explains how dry quicksand is different from both wet quicksand and stable sand. Hint: Think "Jenga".

There's a whole gallery of these eerie, psychedelic penguins at Wired, part of Nadia Drake's article about new research based on infrared thermal imaging. Strangely, researchers found that the exterior surface of the penguins was actually colder than the surrounding air. This, despite the fact that penguins maintain a fairly stable interior body temperature that's far warmer.

The researchers involved in the study think that discrepancy might be caused by an extreme form of radiative cooling. Basically, everything emits heat in the form of radiation. You, me, the Earth, penguins — we're all constantly losing heat as it radiates away from our surfaces. During the day, we get heat back from the Sun. At night, while there is some heat coming to us from space, it's much less. And on clear, windless nights — when there isn't a cloud clover to bounce our own heat back at us — we get even colder. As Drake points out, this theory doesn't totally work for the penguins. They were photographed on a pretty windy night. But it certainly produced some great images. Here's a link to the original paper, which you can read for free.

But now Davy and Millie have an adolescent daughter, Cent (short for Millicent), and she's not happy living in an isolated cabin in the Yukon with a pair of teleports who are her only means of getting to civilization. Though there are some perks: when Mom and Dad take her shopping, it's as apt to be in Tokyo or Sydney as at the local Sears.

Cent's parents are understandably (over)protective of her. They've been hunted like animals, tortured, gassed, shot, by the conspiracy of wealth and privilege that would turn them into property. The last thing they want is for their daughter to be hunted too -- especially since Cent can't teleport.

And then she does. Once Cent comes into the family gift, things change. Her demand to be put into a regular school, to have friends, and a semblance of a normal life, is finally taken seriously by her parents. After all, if Cent doesn't get what she wants, she might just jump away and take it.

What proceeds is a book with the twin geniuses of Steven C Gould novels: first, a plot that roars along at 150mph without a pause for breath (I read Impulse over the course of about three hours, without a break); second, a fantastic, fresh, thoroughgoing explanation of the untapped possibilities of a old science fictional idea made new by an imaginative approach. As with the other Jumper books, Gould plays out the possibilities of teleportation with a combination of physics tutorials and spycraft that is absolutely enthralling.

Watching Cent get into (and out of) trouble, fall in love, battle bullies, and even intervene in humanitarian disasters is a pure delight. Gould shows us that with the right mixture of creativity and rigor, any idea can be spun out in a thousand fascinating ways.

This is a marvellous, if long overdue, installment in a series that I love to pieces. Now, if only Gould would return to his (equally wonderful) Seventh Sigma world!

Impulse ]]> http://boingboing.net/2013/03/01/impulse-at-long-last-a-new.html/feed 13 http://boingboing.net/2013/02/24/marriage-proposal-in-the-form.html http://boingboing.net/2013/02/24/marriage-proposal-in-the-form.html#comments Sun, 24 Feb 2013 19:52:41 +0000 Cory Doctorow http://boingboing.net/?p=214930
Redditor bogus_wheel is a physicist in Sydney, Australia. Her boyfriend of seven years submitted a marriage proposal in the form of a physics paper that tracks their relationship (with a graph!). It is a beautiful piece of physics romance!

My boyfriend of 7 years and I are both physicists. Here's how he proposed to me. (imgur.com) (Thanks, Mark M!) ]]> http://boingboing.net/2013/02/24/marriage-proposal-in-the-form.html/feed 25 http://boingboing.net/2013/02/21/drones-toss-and-catch-inverted.html http://boingboing.net/2013/02/21/drones-toss-and-catch-inverted.html#comments Thu, 21 Feb 2013 23:36:18 +0000 Cory Doctorow http://boingboing.net/?p=214585

Ever see flying robots doing stuff that you never suspected flying robots could do? I have.

First, a state estimator was used to accurately predict the pendulum’s motion while in flight. Unlike the ball used in the group’s earlier demonstration of quadrocopter juggling, the pendulum’s drag properties depend on its orientation. This means, among other things, that a pendulum in free fall will move sideways if oriented at an angle. Since experiments showed that this effect was quite large for the pendulum used, an estimator including a drag model of the pendulum was developed. This was important to accurately estimate the pendulum’s catching position.

Another task of the estimator was to determine when the pendulum was in free flight and when it was in contact with a quadrocopter. This was important to switch the quadrocopter’s behavior from hovering to balancing the pendulum.

Second, a fast trajectory generator was needed to quickly move the catching quadrocopter to the estimated catching position.

Third, a learning algorithm was implemented to correct for deviations from the theoretical models for two key events: A first correction term was learnt for the desired catching point of the pendulum. This allowed to capture systematic model errors of the throwing quadrocopter’s trajectory and the pendulum’s flight. A second correction term was learnt for the catching quadrocopter’s position. This allowed to capture systematic model errors of the catching quadrocopter’s rapid movement to the catching position.

Video: Throwing and catching an inverted pendulum – with quadrocopters | Robohub (Thanks, Kate!) ]]> http://boingboing.net/2013/02/21/drones-toss-and-catch-inverted.html/feed 50 http://boingboing.net/2013/02/21/inside-a-nuclear-fusion-resear.html http://boingboing.net/2013/02/21/inside-a-nuclear-fusion-resear.html#comments Thu, 21 Feb 2013 19:37:07 +0000 Maggie Koerth-Baker http://boingboing.net/?p=214521 Follow along on their virtual tour of a plasma physics lab.]]> http://boingboing.net/2013/02/21/inside-a-nuclear-fusion-resear.html/feed 3 http://boingboing.net/2013/02/10/212100.html http://boingboing.net/2013/02/10/212100.html#comments Mon, 11 Feb 2013 02:27:24 +0000 Cory Doctorow http://boingboing.net/?p=212100

The finest moments in physics instruction always involves something going bang, blam, or boom, and this is no exception: Purdue's prof Mark French and grad students Craig Zehrung and Jim Stratton built a supersonic ping-pong-ball gun that attains supersonic muzzle velocity:

To demonstrate the conversion of subsonic to supersonic flow, Prof. French and his team designed the gun shown above. The end of the pressure vessel is sealed with laminating tape. Both the nozzle and the barrel are evacuated so the the gas flow is unobstructed. Overall, the gun is a bit less than 12 feet (3.65 m) in length.

To fire the gun, the pressure is increased in the pressure vessel until the tape breaks. French found that two layers of tape ruptured at about 60 psi (414 kPa), and three layers at about 90 psi (620 kPa). The speed of the ball was measured using a high-speed camera viewing the ball moving against a calibrated scale. A typical velocity was a bit over 1,448 km/h (900 mph) – nominally a velocity of Mach 1.23, which is about the top speed of the Soviet-era MIG-19 fighter.

The lead photo should convince the reader that this ping-pong gun is not a toy. The energy and momentum of the ping-pong ball is roughly the same as that of a .32 caliber ACP pistol – not the best choice for defense, to be sure, but quite lethal under the right circumstances.

Ping-pong gun fires balls at supersonic speeds [Gizmag/Brian Dodson]

(via DVICE) ]]> http://boingboing.net/2013/02/10/212100.html/feed 47 http://boingboing.net/2013/02/08/its-not-a-horror-movie-it.html http://boingboing.net/2013/02/08/its-not-a-horror-movie-it.html#comments Fri, 08 Feb 2013 15:05:18 +0000 Maggie Koerth-Baker http://boingboing.net/?p=211726 This creepy-looking image of U.S. swimmer Tyler Clary has its origin in the movement of water molecules. The Fuck Yeah Fluid Dynamics tumblr explains what's going on — and how physics can make a swimmer look like a shiny, face-melted ghoul.]]>

This creepy-looking image of U.S. swimmer Tyler Clary has its origin in the movement of water molecules. The Fuck Yeah Fluid Dynamics tumblr explains what's going on — and how physics can make a swimmer look like a shiny, face-melted ghoul.

Minute Physics tackles the greatest mystery in all the Internet and solves it with the power of science (and pedantry).

This happened in my friend's henhouse this morning.

My friend Kate Hastings, who took this photo, thinks this egg froze because the hen cracked it slightly. But it also looks like the kind of expansion cracking that you can get when eggs freeze and burst their own shells. When the water in the egg white and yolk freezes, it forms a crystalline structure — and that structure isn't very tightly packed. There's lots of space between the molecules, which means that solid ice takes up more space than the liquid it replaced. If the egg freezes solid enough, it's got nowhere left to expand except outside the shell.

Eggshells, as it turns out, are not a great insulator from the cold. Chicken butts are, but chickens also don't always sit on their eggs consistently enough to keep those eggs from freezing.

One side note: You can actually thaw and eat frozen eggs. But you shouldn't thaw and eat an egg like this. That's because the shell is actually a pretty good barrier against bacteria. If a fresh egg — the kind sitting under a hen — has cracked, there's a higher likelihood of bacterial infiltration.

They're the mullet of cold-protective clothing. Half glove, half mitten — really, fingerless gloves with a handy mitten flip-top.

They are also fantastic.

Now, partly, this is a matter of personal opinion. But partly, it's just good science.

Before you spend your weekend outdoors, or take your next chilly commute, let's talk briefly about glittens — and the science that makes them superior hand covering.

There's really two things going on here.

First: Mittens are warmer than gloves.

I spent years feeling like I failed at gloves. Even high-quality Isotoner-type things couldn't keep my fingers warm. At least, not for very long. After 10 or 15 minutes, my fingers would start to go numb and cold. The only way I could keep them comfortable was to slide my fingers out of the finger holes and ball up my hand inside the wide part of the glove. (At which point you become Edward FloppyFingers.)

And there's a very good reason for this. It has to do with the way we get cold.

Everything wants to be the same temperature. Hot things and cold things want to match, rather than be different. At the same time, it takes energetic work to make things hot — whether that's a furnace pumping in your basement, or the sun burning in outer space, or your body metabolizing food. Without those inputs, everything is cold. (Eventually, everything will be cold. Inevitable heat death of the Universe and all that.)

So hot things are special. And when they come into contact with cold things, heat moves from the hot thing to the cold thing, and the hot thing cools down. In fact, the bigger the difference in temperature between the hot thing and the cold thing, the faster the hot thing is going to become cold.

There are several ways that this heat transfer can happen, but when we're talking about your hands and the cold air, we're talking about convection — the transfer of heat between a solid object and a fluid. (My husband, an HVAC engineer, refers to this as, "One of my three favorite kinds of heat transfer.")

Cold air moves over your hands. Your hands and the air try to become the same temperature. Your hands get cold. You can't stop this process, but you can interfere with it, and that's what hand coverings are all about. Insulation — the cloth of the glove or mitten — creates a barrier between your warm hand and the cold air.

It's not a perfect barrier. But now the thing that is most in contact with your hand is closer to the temperature of your hand. With less of a temperature difference, heat transfer slows down.

But there's another factor that affects heat transfer — surface area. The more surface area on the hot thing, the more it comes into contact with the cold thing, the faster it loses heat. Gloves put more surface area in contact with cold air than mittens do. So they won't keep your hands as warm as the same amount of insulation in a mitten will. What's more, gloves force each finger to fend for itself. In a mitten, fingers are in direct contact with other fingers. They can share heat through the solid-object-to-solid-object process of conduction and help keep each other at a relatively stable temperature.

Downside to mittens: You can't use your cellphone, or your house keys, or really anything that requires you to be more dextrous than the average 18-month-old.

Second: Glittens offer more manual dexterity than mittens.

With the science firmly established, we now get into the personal preference portion of this review. From my experience, glittens offer all the warmth of mittens, plus the manual dexterity of gloves. In fact, with their help, I've stood outside in Minneapolis at a bus stop for 30 minutes while playing with my Android phone. I had to switch hands a few times. But, overall, my hands and fingers stayed warmer, longer — even with occasional fingertip exposure to the cold air — than they do when completely covered by gloves.

In mitten mode, my fingers are better protected and they can heat up each other. In glove mode, I can work my phone's screen. It's a win-win situation. And it's all thanks to thermodynamics.

READ MORE:
A Harvard animation by Dale Muzzey demonstrating the importance of surface area to heat transfer — and other things.

Image: IMG_6027crop, a Creative Commons Attribution (2.0) image from 97793800@N00's photostream

At supersonic and hypersonic speeds, a shockwave forms around the steak which helps protect it from the faster and faster winds. The exact characteristics of this shock front—and thus the mechanical stress on the steak—depend on how an uncooked 8 oz. filet tumbles at hypersonic speeds. I searched the literature, but was unable to find anything to help me estimate this.

For the sake of this simulation, I assume that at lower speeds some type of vortex shedding creates a flipping tumble, while at hypersonic speeds it’s squished into a semi-stable spheroid shape. However, this is little more than a wild guess. If anyone puts a steak in a hypersonic wind tunnel to get better data on this, please, send me the video.

If you drop the steak from 250 kilometers, things start to heat up. 250 kilometers puts us in the range of low earth orbit. However, the steak, since it’s dropped from a standstill, isn’t moving nearly as fast as an object re-entering from orbit.

Steak Drop ]]> http://boingboing.net/2013/01/15/cooking-steak-with-freefall.html/feed 40 http://boingboing.net/2013/01/11/space-shuttle-left-astronauts.html http://boingboing.net/2013/01/11/space-shuttle-left-astronauts.html#comments Fri, 11 Jan 2013 15:23:41 +0000 Maggie Koerth-Baker http://boingboing.net/?p=205190 a good week for pedantry. In a guest blog post at Scientific American, Kyle Hill discusses the durability of spaceship windows — both in the real world, and in Joss Whedon's movie Serenity.]]> a good week for pedantry. In a guest blog post at Scientific American, Kyle Hill discusses the durability of spaceship windows — both in the real world, and in Joss Whedon's movie Serenity. Spaceship windows have to be incredibly tough, because even tiny chips of paint become dangerous projectiles in space. But how would they stand up to frontal attack by a spear? Physics has the answers. ]]> http://boingboing.net/2013/01/11/space-shuttle-left-astronauts.html/feed 8 http://boingboing.net/2013/01/10/we-probably-found-the-higgs.html http://boingboing.net/2013/01/10/we-probably-found-the-higgs.html#comments Thu, 10 Jan 2013 19:39:36 +0000 Maggie Koerth-Baker http://boingboing.net/?p=205088 I got to join in on a great conversation this morning on Minnesota Public Radio's "The Daily Circuit", all about the Higgs Boson and what it means for the future of physics.]]>

I got to join in on a great conversation this morning on Minnesota Public Radio's "The Daily Circuit", all about the Higgs Boson and what it means for the future of physics.

This is a fascinating issue. Finding the Higgs Boson (if that is, indeed, what scientists have done) means that all the particles predicted by the Standard Model of physics have now been found. But that's not necessarily good news for physicists. For one thing, it would have been a lot more interesting to break the Standard Model than to uphold it. For another, we're now left with a model for the Universe that mostly works but still has some awkward holes — holes that it might be hard to get the funding to fill.

Daily Circuit host Kerry Miller, Harvard physics chair Melissa Franklin, and I spent 45 minutes talking about what is simultaneously a beautiful dream and a waking nightmare for the physics world. And I got to make a "Half Baked" reference in a conversation about particle physics, so you know it's a good time, too.

Listen to the whole conversation at Minnesota Public Radio's website.

Children's literature is about the wonder of discovering new worlds, the power of imagination, and the all the little triumphs and defeats that make up a life.

It's also an excellent place to find hypothetical questions that test the laws of physics.

For instance, presupposing that one could grow a peach to the size of a house, could one also really sail that peach across an ocean? And then, presupposing that one could harness the power of 501 seagulls, would that number of seagulls be sufficient to carry said peach through the air?

These are the questions posed in "James' Giant Peach Transport Across the Atlantic", a paper published last fall in the Journal of Physics Special Topics.

The paper was written and researched by four physics master's students from the University of Leicester in the UK — Emily Watkinson, Daniel Staab, Maria-Theresia Walach, and Zach Rogerson. Based on the events in Roald Dahl's James and the Giant Peach, the four set out to discover whether the book's fictional account of an adventure could stand up to serious scientific inquiry.

Turns out, it can. Mostly.

The team's analysis relied on two sets of equations — one to test the buoyancy of the peach and another to determine whether the 501 seagulls could produce enough lift force to overcome the weight of the peach and get it airborne.

In order for something to float, it needs to be less dense than the liquid it's meant to float on. Say you have the same amount — the same volume — of water and of rubber. That rubber will only float if it weighs less than the water, volume-to-volume. That's true whether you're talking about a rubber duckie or a giant peach. Or, for that matter, a boat. And this is where Roald Dahl made a very smart plot choice.

Turns out, the flesh of a peach is actually more dense than seawater. Technically, it should sink. But Dahl took advantage of the same trick that allows steel boats to float even though the metal they're made of is more dense than water — you just hollow out the inside. That's because air is less dense than water, and a boat is just a shell of steel surrounding a pocket of air. Taken together, air and steel are a lot less dense than just the steel by itself. So the boat floats. And, as the Leicester team found, so does the peach — provided that, for a peach with a radius of 6 meters, the flesh was no thicker than 1.24 meters.

Next, the team turned their attention to the skies. Could 501 seagulls really airlift a peach that large? The answer: No. To make it work, James would have needed approximately 2,425,907 seagulls. (Assuming we're talking about Common Gulls. Different birds, different numbers.)

That's because of lift force — a calculation that compares the pressure over and under each bird's wings with the area of those wings and the density of the air. (You might also know it as Bernoulli's Principle) To get off the ground, just by themselves, each seagull has to have a lift force greater than their own weight. Subtract the weight from the lift force and what you have left over is the amount of lift each bird can put towards carrying other things. The sad fact is, 501 Common Gulls don't have enough leftover lift force to get that peach to rise. Two and a half million gulls, though? That'll do just fine.

So why does science care?

What's the point of all this? That's the really interesting part.

You're right in thinking that the plausibility of fictional scenarios isn't exactly a great problem of our time. But nobody ever said it was. That wasn't the point of this paper, or any of the other eight papers Watkinson, Staab, Walach, and Rogerson published last year.

Instead, this was about teaching them how to be better scientists.

The Journal of Physics Special Topics is, itself, a pretty special journal. It's written, edited, peer reviewed, and published by students of physics professor Mervyn Roy. Throughout the course of a semester, teams of students come up with problems they can use physics to solve. They get a week to research and write each two-page paper. Then they hand those papers off to their peers, who put them through a rigorous peer review process — critiquing the physics, demanding edits in grammar and style, and sending the students back over and over until they've polished up something that is worthy of publication.

It's a microcosm of the way academic publishing is done in the real world and it gives the students a chance to learn through trial and error both how to write a paper AND how to peer review one. That's important. Remember the story I wrote here a couple years ago, explaining how the peer review process works? One of the big critiques that scientists have of that system is that nobody is really taught how to peer review. You're just kind of tossed into it. Some people figure out how to do it well. Others ... not so much. The Journal of Physics Special Topics is an attempt to solve that problem by having physicists learn peer review before they actually have to do it for real.

They also learn how to handle the social fallout of peer review. "There were some awkward moments. One of my housemates was in a different group and when I was writing reviews of what he'd written it was sometimes a bit difficult," Daniel Staab told me.

The research also forced the team to learn how to research subjects far outside their own specific field. For instance, the density of peach flesh. As you learned earlier in this article, knowing that number is a pretty important part of knowing whether a giant peach would float or sink. But it's also not a number that your average physics student in England has easy access to. At one point, Staab said, they thought they might actually have to do their own study, opening and analyzing a bunch of peaches. But in the end, they found a reference — a 1948 paper by researchers at the Georgia Institute of Technology.

So, in the end, we learn the physics of giant peaches, students learn how to be better scientists, and it's pretty much a happy ending for everybody. Except, you know, magic and wonder and suspended disbelief. But Emily Watkinson isn't too worried about that.

"When we were writing this paper, some people wondered whether it would take away from the magic of the story," she said. "But, for me, Roald Dahl keeps the magic. We just wanted to see whether you could actually implement his ideas, because if you could it would be even more fascinating."

Read the fully study on the physics of James and the Giant Peach

Read all the papers from the fall 2012 edition of the Journal of Physics Special Topics — including papers on the physics of "Breaking Bad", Spiderman, lightsabers, and Katrina and the Waves' 1983 song "Walking on Sunshine".