Friday, October 31, 2008

Happy Halloween!

Don't fret, it's not to late to find a geeky physics Halloween costume! GeekGirlGifts and Cocktail Party Physics suggest going as Maxwell's Demon or Schrodinger's cat.

If your want a easy costume that doesn't involve a whole lot of effort, throw on all things black and be a black hole.

Or how bout a neutrino? Act neutral and wear a sign that says "I barely have mass".

If you have the time and inventiveness, construct a Mars Phoenix Lander costume - be sure go around telling everyone you've discovered snow.

If you want to make a lasting impression, enter the party spinning rapidly (and stay that way). If anyone asks tell em' you're a pulsar.

For something more contemporary, be the main ring of Large Hadron Collider! Attach a giant hula loop with a bunch of magnets to yourself. You could even figure out a way to circulate "proton beams". If you've had enough partying, just tell your friends a magnetic quench shut you down for the night...
Read the rest of the post . . .

Thursday, October 30, 2008

Hubble Resurrected

Our dear old Hub's Wide Field Planetary camera snapped its first photo (on the left) on Oct 27-28 after nearly a month of dormancy.

The snapshot, taken just a few days after Hubble was resurrected from its offline slumber, shows a pair of gravitationally interacting galaxies called Arp 147. The galaxies lie more than 400 million light years away from Earth, in the constellation Cetus.

NASA and ESA scientists say the image indicates a full comeback, proof that the Hubble has recovered completely. The image is exciting for other reasons too, namely the chance alignment of the two galaxies. Take a closer look, and you'll see that the rose-colored galaxy on the left resembles a "1" and the shimmering periwinkle blue galaxy on the right forms an "0" shaped dense ring of star formation. A perfect 10!

The blue ring was formed after the left-most galaxy pushed through the galaxy on the right, causing a ripple of high density as the two galaxies collided. This excess density rammed into other material pulled inward by the gravitational pull of the two galaxies, producing shocks and dense gas.
Read the rest of the post . . .

Wednesday, October 29, 2008

Seeking Antimatter in a Former Salt Mine

In a former salt mine at the Department of Energy's Waste Isolation Pilot Plant near Carlsbad New Mexico, all that matters is antimatter. In this deep underground cavern (pictured on bottom right) physicists are putting the finishing touches on a new particle detector, the Enriched Xenon Observatory (EXO).

In the spirit of Halloween, think of antimatter as matter's ghostly counterpart, a doppelganger with an equal but opposite charge. Every particle has its own antiparticle ghost-twin, for example the antiparticle of the negatively charged electron is the positively charged positron, all other properties (mass, spin, etc.) remain deceptively the same.

But everyone learns at some point that the universe appears to be made entirely out of matter (lesson learned when I ran smack dab into a glass sliding door at the age of six). Which begs the question, if every bit of matter has an equal but opposite antimatter counterpart, why is there so more much matter around us? Where did the antimatter go? In true ghostly fashion, it seems to have vanished.

The EXO experiment is gearing up to find answers to those questions, the parts of physics that explain the puzzling imbalance of matter and antimatter in our universe. Frankly, imbalance is agood thing, no matter how ghostly. When particles and antiparticles draw close, they destroy or annihilate each other, leaving only the energy they were made of behind in the form of radiation. If during the evolution of our universe there were equal amounts of matter and antimatter, annihilation would have resulted in a desolate swamp of leftover radiation and not much else.

Of course, things get muddled when considering neutrinos, fundamental particles that have no charge. Scientists believe neutrinos are also antineutrinos. They act as their own antiparticles, little untraceable neutral ghosts. Experiments like EXO are hoping to discover what makes matter and antimatter behave differently, despite all their similarities. The answer may lie in neutrinos.

The ton-scale experiment is searching for a special type of nuclear decay called neutrinoless double beta decay in the 136 isotope of Xenon. Yet to be observed, neutrinoless double beta decay occurs when two neutrons in a nucleus are simultaneously converted to protons that emit two electrons without emitting any antineutrinos. In normal beta decay (first observed in 1986), two neutrons become protons that emit two electrons along with two antineutrinos.

Seeing neutrinoless double beta decay would prove that the neutrino really is its own antiparticle. Moreover, obtaining a measurement of the neutrinoless double beta decay half-life would allow scientists to determine the exact mass of the neutrino.

There are actually numerous experiments around the world focusing on differences in the decays of particles, like NEMO at the Frejus Underground Laboratory, the CUORE at the Cryogenic Underground Observatory for Rare Events, and COBRA at the Cadmium- Telluride O-neutrino double- Beta Research Apparatus, to name a few.

So this Halloween, while gorging on matter in the form of candy, think of a yet-to-be-discovered strange antiworld of antimatter. Scary!
Read the rest of the post . . .

Monday, October 27, 2008

Icarus at the Edge of Time

NPR's Robert Krulwich does an exemplary job of explaining the relationship between gravity and time in this article, while discussing theoretical physicist Brian Greene's new picture book Icarus at the Edge of Time. You can even hear Greene and Krulwich perform a shortened version of the book in the accompanying broadcast.

Laying the foundation of the book in concrete physics, Greene re-imagines the Greek myth Icarus, a boy whose wax and feather wings melt as he flies to close to the sun, ignoring the admonitions of is father. Consequently, he falls into the sea. The boy in Greene's story doesn't quite meet such a moribund demise, but he does return from exploring a black hole (against the warnings of his scientist father) to find that time had passed disproportionally while he was gone, everything he knew had changed.

Read the rest of the post . . .

Highlights from the Blogosphere

"Underground Rivers Frozen in Place"

A little-known fact about the construction of the Large Hadron Collider.

Cosmic Variance
Revisiting Einstein's challenge: is the moon still there when we're not looking at it?

A preview of Fermat's Room, a Spanish thriller screened at the recent Imagine Science Film Festival in New York City.

Shores of the Dirac Sea
It all comes down to deformation and air pressure.

The Loom
If you're in New Jersey on November 5th, check out the re-enactment of an experiment to prove an hypothesis conducted by Washington and Thomas Paine.

Built on Facts
The rotational motion of a flywheel.

Secret Technology
#2: Hazardous waste disposal... with catapults!

Scientific American
Four physicists qualify for this dubious honor.

Stephanie ponders the issue of gender bias in science.

Uncertain Principles
Some practical advice for job-seeking physicists.

Read the rest of the post . . .

Friday, October 24, 2008

Fermi Problem Friday

We are one week away from Halloween. Around the world, kids, parents and the undead (aka college students) are preparing their costumes for the big night of trick or treating. Tricks! Treats! That's the best of both worlds.

Now one has to be very careful when choosing a Halloween costume. Nothing would be more embarrassing than spending a week constructing a clever Hannah Montana costume only to find out that your best friend had the same idea! Who is going to dish out candy to two Hannah Montanas? You have to coordinate and play rock paper scissors to determine who has to be Lola.

However, there is one costume that breaks all of the rules. It's almost as if there is a law of physics that states: You can never have enough zombies on Halloween. Two Hannah Montana zombies could bring in up to 4 times as much candy. And this is the good kind of candy like Swedish Fish.

This brings us to the question that Fermi (might have) pondered every year: How many zombies will be roaming around on Halloween night?

Now, I know what you are thinking. A Hannah costume is too elaborate and expensive. Let me suggest some clever physics options:
Be a Physics Central Zombie. Print out the Physics Central homepage and duct tape it to an old shirt. Then squirt smear some ketchup on it.
Similarly, you could be a Fermi Problem or your favorite wave function.

Have Fun and be safe (don't be an LHC blackhole zombie -aaaahh!).

Photo credit: Mark Marek

Read the rest of the post . . .

Wednesday, October 22, 2008

Think Twice Before you Type

A team of researchers at the Security and Cryptography Laboratory at the Swiss Ecole Polytechnique Federale de Lausanne has figured out how to snatch information from your very fingertips, as long as those fingertips are pounding on a keyboard.

It's eavesdropping taken to a whole new level using electromagnetic signals produced by every pressed key. By analyzing these signals, the researchers managed to reproduce what a target typed.

Now I doubt any computer spy would be interested in Facebook posts- but computer login information and username/passwords for activities like online banking? Now that's much more interesting. The results of the study are troublesome to anyone concerned with protecting sensitive information.

Since wired keyboards contain electronic components, they emit electromagnetic waves. By measuring the electromagnetic radiation emitted by each key pressed, the researchers were able to identify individual keystrokes like code is used to decipher a message.

Using a radio antenna to pick up electromagnetic signals, they developed four ways to successfully attack 11 different keyboards, one of which works as far as 65 feet away. Although detailed results of the study haven't been published yet, they are sure to make some of us keyboard users queasy!

Read the rest of the post . . .

Tuesday, October 21, 2008

It's a Bird It's a Plane...It's a Sky Crane?

The Mars Science Laboratory's (MSL) aeroshell resembles (almost too ironically) a UFO straight out of Hollywood. At 15 feet wide, it's also huge. In fact, its the largest aeroshell in the history of space exploration.

Check out the intense virtual simulation above to view how the coolest part of the MSL, its novel "sky crane" works. Scientists designed the sky crane to control landing by slowing the spacecraft down to practically a halt right before it touches ground. Almost immediately afterward, the crane will detach itself and fly away.

Scheduled to launch in the fall of 2009, the Mars Science Laboratory will support the Mars Exploration Program in collecting as much data as it can to help determine whether the planet was ever habitable and to continue searching for clues to Mars' past climate and geology.

Read the rest of the post . . .

Friday, October 17, 2008

Fermi Problem Friday

How many times do your bicycle wheels spin around on your way to school?

Bonus question: Is this the same number of times your feet pedal around?

This might be difficult to answer if walk to school or take a train. In either case just cycle your feet around and pretend you are riding a bike. If people look at you funny, just tell them it's a physics project.

This excuse always works in any situation. For instance if you trip on the sidewalk and onlookers start laughing, just tell them you were testing Einstein's Theory of General Relativity. Suddenly they will be impressed.

Read the rest of the post . . .

A New kind of Pulsar

A new kind of pulsar has been discovered by NASA'S Fermi Gamma-Ray Space Telescope. The discovery adds to the growing pile ( nearly 1,800) of pulsars cataloged by astronomers.

But this pulsar is different-it beams only in Gamma rays, a property never before observed in pulsars.

Usually, pulsars are found through their radiowavelength beams. This marks the first time an all gamma ray energy pulsar has been spotted. The pulsar lies peripherally in the corpse of the CTA 1 supernova, located about 4,600 light-years away from Earth, in the constellation Cepheus.

Scientists believe CTA is only the first of a large population of similar objects. Based on the corpse's age and the pulsar's distance from its center, astronomers believe the neutron star is moving at about a million miles per hour, a typical speed.

A pulsar is a rapidly spinning neutron star, the crushed core left behind when a supernova explodes and its remnants collapse back together, welding into a messy conglomerate of of proton and electrons but mostly neutrons (hence the name neutron star).
Read the rest of the post . . .

Thursday, October 16, 2008

Sniff Sniff.

The smell of space is (according to NASA scientists) unusually redolent, somewhere between a steak joint and an auto body shop. Personally, I think smell is the strangest of the senses. While I enjoy inhaling the scent of a rose as much as the next person, my olfactory system is also fond of gasoline. Weird.

In an attempt to develop acutely realistic training environments for astronauts, NASA has embarked on a smelly mission, by hiring Steven Pearce, a "nose chemist" to recreate the smell of space in a laboratory. Pearce is also the managing director of Omega Ingredients, a fragrance manufacturing company.

Interviewed astronauts say the smell of space is similar to fried steak and hot metal, and the welding of a motorbike. Currently, Pearce has managed to recreate the smell of fried steak and is working on the more difficult hot metal.

If all goes well the final space smell should be complete by the end of the year.
Read the rest of the post . . .

Wednesday, October 15, 2008

Big Bang Wrap Up

Watch CBS Videos Online

In Monday's episode "The Griffin Equivalency", Raj is bestowed the honor of being included in People Magazine's "Top 30 Under 30 TO Watch" for the discovery of a new object (2008-NQ Sub 17) in the Kuiper Belt. Here's a little clip!
Read the rest of the post . . .

Tuesday, October 14, 2008

HiP European Fusion

Europe has been bitten by the fusion bug. With ITER currently under construction France, the EU is adding another mega-project to its fusion repertoire, HiPER ( HIgh Power laser Energy Research). Last week the current phase of HiPER was officiated as participating countries signed the necessary legal documents. Although there are just a few key players (The UK, France, and the Czech Republic) participation is global, involving 26 institutions from 10 countries, our own Lawrence Livermore National Laboratory in CA among them.

HiPER aims to demonstrate the feasibility of laser driven fusion. By now we've heard enough about the benefits of fusion energy that it has nearly become the poster child of clean, green power. And in many ways, it is. HiPER will use sea water as its main source of fuel while producing zero hazardous wastes (e.g. greenhouse gases and radioactive material).

Laser fusion works conceptually the same way any atom fusing technology would, by fusing two hydrogen nuclei forming helium and releasing a whole lot of energy in the process. In theory,
fusion creates more energy than it uses-but scientists haven't been able to achieve this outcome yet. All fusion attempts have put more energy into the system than received.

HiPER would use a high-power laser to compress a pellet of deuterium and tritium ( 'heavy' hydrogen isotopes) to a density 30 times that of lead. A second laser pulse would then shoot the pellet, raising its temperature to more than 100 million degrees Celsius.

Scientists already know laser driven fusion is possible, but the question remains as to whether this technique can be translated into viable commercial energy production. During the next few years, HiPER fusion scientists will be working on answering that question.

Read the rest of the post . . .

Monday, October 13, 2008

Expanison Not So Uniform

In 1929 Edwin Hubble showed (to an irritated Einstein) that distant galaxies were moving farther and farther away from the Earth, picking up speed the farther they traveled. It was the birth of Hubble's law, which says that the more distant the galaxy the greater its velocity or redshift.

Scientists concluded that for Hubble's observations to make sense, the universe must be expanding, swelling like a balloon or a loaf of bread in the oven. The beginnings of the Big Bang Theory began to emerge (hey all this expansion had to start from a single point, right?).

There are many hypotheses and much debate over how expansion occurs, but it is generally believed that expansion is the same everywhere, progressing uniformly. That may soon change. Recently, a team of American and Canadian researchers discovered that a certain region of our universe (400 million light years away to be exact, and thats considered 'close to home") is not expanding uniformly but rather unevenly; expansion is faster in one half of the region than the other.

What could be causing this boost of expansion? The researchers aren't sure yet, but if confirmed their results provide more evidence of obscure forces like dark energy and more recently, dark flow. Relatedly, scientists believe that dark energy is causing expansion as a whole to speed up.
Read the rest of the post . . .

Friday, October 10, 2008

Fermi Problem Friday

How many atoms thick is Niels Bohr's book: Atomic theory and the description of nature?
Read the rest of the post . . .

Sides of Mercury You've Never Seen

This is Mercury like you've never seen her: the image to the left was snapped by the Wide Angle Camera of MESSENGER'S Dual Imaging System (MDIS) Instrument, at a distance of about 17,000 miles away from the planet.

The particularly bright crater just south of the center of the image is the Kuiper crater (first viewed in the 1970s on the Mariner 10 mission, which imaged less than half of the planet).

The terrain east of Kuiper, toward the edge of the planet, has never until now been imaged by a spacecraft. This is the first the missing portions of Mercury's surface, the portions that Mariner could not capture, have been imaged. The large pattern of rays extending from the Northern parts of the planet all the way to the southern parts make Mercury almost resemble a giant basketball.

Adding to its accomplishments, MESSENGER recently set a record for accuracy on its recent flyby of Mercury's surface. The probe missed its intended distance by a mere 0.6 kilometers-the smallest miss distance during a flyby of a planet other than Earth ever. To perform such a feat, MESSENGER used a technique called solar sailing that manipulates weak pressure from sunlight to change the trajectory of the spacecraft.

Operated by Johns Hopkins University Applied Physics Laboratory, MESSENGER (MEcury Surface, Space ENvironment, GEochemistry, and Ranging) is NASA's first space mission designed to orbit Mercury. To achieve this goal, MESSENGER must travel through the inner solar system, completing one flybly of Earth, two flybys of Venus, and three flybys of Mecury.
Read the rest of the post . . .

Thursday, October 09, 2008

Star-Gazing with Liquid Mirrors

For years, scientists have wanted to put a telescope on the moon. Its lack of atmosphere makes for a clear, cloudless view of the universe.

However, the feasibility of lugging up tremendously heavy equipment into space and the economic cost of doing so are obstacles that have always accompanied the idea, until now.

An international team of researchers may have found a way to build a large lunar observatory on the Moon, using liquid mirror telescopes made of ionic liquids, a special class of organic compounds.

Traditionally, liquid mirror telescopes on Earth have used mercury for its ability to remain molten at room temperature and reflect a high percentage of light. Despite its good qualities, mercury is extremely dense or heavy, making it difficult to launch. Once on the moon, it would evaporate very quickly. Not to mention the price-mercury is very expensive.

Ionic liquids have properties that solve these issues. Scientists often describe ionic liquids as "molten salts". This catch-all phrase basically means a salt that has been heated to such extreme temperatures (thousands of degrees Fahrenheit) that it melts into a stable liquid, flowing much like water and only slightly denser. The team is currently trying to synthesize ionic liquids that will remain molten even at liquid-nitrogen temperatures, between -346 and -320 degrees Fahrenheit.

Ionic liquids aren't very reflective, but this can be remedied by coating a spinning mirror of the stuff with an ultrathin layer of silver-so thin that it solidifies on top of the liquid. This protects it from tarnishing or evaporating. Naturally, tilting a liquid mirror would ruin the telescope-the fluid would pour out of the container.

To get past this, optics experts are currently toying around with methods to "tilt" the view of a telescope, without actually doing any tilting. These include electromechanically warping secondary mirrors suspended above a liquid mirror, or even warping the liquid mirror itself.
Read the rest of the post . . .

Wednesday, October 08, 2008

Apollo Asteroid Explodes Over African Sky

Yesterday, the newly discovered Apollo Asteroid exploded over Sudan with the energy of about 1.1-2.1 kilotons of TNT. Earth bound space objects often explode, due to the pressure of slamming into the atmosphere.

Because the burst occurred over such a remote location no photographs were taken ( an obvious artist rendering can be seen to the left).

Apollo was about the size of a kitchen table, huge by asteroid standards. According to scientists at the Jet Propulsion Laboratory in Pasadena CA, similar sized asteroids hit the Earth every few months- but this is the first time a collision was predicted.

Any triumph here belongs to Spaceguard, a tracking system capable of identifying near-Earth objects.
Read the rest of the post . . .

Tuesday, October 07, 2008

Blaming 'Physicists' for the Crisis on Wall Street

Watch CBS Videos Online

Ah, a cop out if there ever was one, in my opinion. The clip above (thanks to Buzz Skyline for sending me the link) is from last Sunday's episode of 60 minutes, "A Look at Wall Street's Shadow Market". Steve Kroft makes the point that obscure and extremely complicated stuff (ya know, algorithms, models, the "fine print") may be to blame for this swamp of pecuniary mud we're currently wading in.

-60 Minutes requested interviews with top executives at Bear Stearns, Lehman Brothers, Merrill Lynch , Morgan Stanley, Goldman Sachs, and AIG. They all declined.

A snippet of transcript:

With its clients clamoring for safe investments with above average return, the big Wall Street investment houses bought up millions of the least dependable mortgages, chopped them up into tiny bits and pieces, and repackaged them as exotic investment securities that hardly anyone could understand.

These complex financial instruments were actually designed by mathematicians and physicists, who used algorithms and computer models to reconstitute the unreliable loans in a way that was supposed to eliminate most of the risk.

"Obviously they turned out to be wrong," Partnoy says.

Asked why, he says, "Because you can't model human behavior with math."

"How much of this catastrophe had to do with the instruments that Wall Street created and chose to buy...and sell?" Kroft asks Jim Grant.

"The instruments themselves are at the heart of this mess, Grant says. They are complex, in effect, mortgage science projects devised by these Nobel-tracked physicists who came to work on Wall Street for the very purpose of creating complex instruments with all manner of detailed protocols, and who gets paid when and how much. And the complexity of the structures is at the very center of the crisis of credit today."

"People don't know what they're made up of, how they're gonna behave, Kroft remarks.

(End of Transcript)

There are a combination of factors that contributed to the crisis, but it all comes down to your standard 'causation equals correlation' argument. The models and algorithms themselves did not cause this chaos nor did the physicists who created them- neither is "at the heart of this mess".

The fancy mathematical tools used to break up and restructure mortgage-backed securities were supposed to minimize risk. Executives and managers (whom employ fancy tool wielding physicists) made judgment calls based on information they did not understand. This is a problem when you are responsible for decision-making and oversight.

The rationale? "Hey! We messed up because we couldn't understand anything! If those physicists and mathematicians hadn't created those arcane instruments, we wouldn't have been able to screw everything up, so clearly, it's their fault!"

...not very convincing.

Here's an interesting Physicsworld article from January of 1999, "Mutual Attractions: Physics and Finance" that explains why physicists are drawn to Wall Street in the first place.
Read the rest of the post . . .

Nobel Prize for Broken Symmetries

Wow, was I ever wrong in my guess for this years Physics Nobel Prize.

Here's a press release I'm working on about the real winners.


2008 Physics Nobel for Broken Symmetries

College Park, MD - The 2008 Nobel Prize for Physics has been awarded to three physicists whose insights help to explain the existence of the universe and the properties of matter it contains. Half the prize goes to Yoichiro Nambu (University of Chicago) "for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics." Half will be shared by Makoto Kobayashi (High Energy Accelerator Research Organization Tsukuba, Japan) and Toshihide Maskawa (Yukawa Institute for Theoretical Physics, Kyoto University) "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."

The universe would be a bleak and boring place, and might not exist at all, if the laws of nature were perfectly symmetrical. The fact that most of the universe we see today is made of matter rather than a balance of mutually destructive matter and antimatter is the result of a broken symmetry that in turn makes stars, planets and life itself possible. Our understanding of the quarks and other particles that are the building blocks of matter relies on the broken symmetries uncovered by Nambu, Kobayashi and Maskawa.

"This year's prize recognizes two theoretical pillars of our modern understanding of the fundamental constituents of matter and the forces that act on them," explains APS Vice President Curtis Callan. “Nambu profoundly deepened our understanding of mass. His prescient work of the early 60s today allows us to explain how the proton and neutron (and, by extension, the atomic nucleus) can be made of nearly massless quark constituents and yet be very massive. Kobayashi and Maskawa developed a description of the intrinsic mass of the three generations of quarks which has been verified in spectacular experimental detail. It provides a framework for understanding why matter vastly dominates over anti-matter in our universe and also how neutrinos can change their character as they propagate to the Earth from the Sun."

All three of the 2008 Laureates have previously been recognized by the APS with the J. J. Sakurai Prize for Theoretical Particle Physics (Kobayashi and Maskawa in 1985, and Nambu in 1994). Nambu also won the 1970 APS Dannie Heineman Prize for Mathematical Physics. Nambu's initial papers leading to his portion of the prize in appeared in APS journals nearly fifty years ago.

"We are pleased that Nambu's work was published in Physical Review Letters in 1960," says APS Editor-in-Chief Gene Sprouse, "in the then nascent journal's second year of publication." The article is freely available online at

Relevant Links:

Axial Vector Current Conservation in Weak Interactions, Yoichiro Nambu, Phys. Rev. Lett. 4, 380 - 382 (1960)

1970 Dannie Heineman Prize for Mathematical Physics
Yoichiro Nambu
"For his diverse and profound contributions to theory, specifically for analysis of symmetry breaking into particle physics and of gauge invariance in the BCS theory of superconductivity, as examples of mathematical physics."

1985 J. J. Sakurai Prize for Theoretical Particle Physics
Toshihide Maskawa and Makoto Kobayashi
"For their contributions to the theory of electroweak interactions through their general formulation of fermion mass matrix and their prescient inference of the existence of more than four flavors of quarks."

1994 J. J. Sakurai Prize for Theoretical Particle Physics
Yoichiro Nambu
"For his many fundamental contributions to field theory and particle physics, including the understanding of the pion as the signaler of spontaneous breaking of chiral symmetry."


About APS

The American Physical Society is the leading professional organization of physicists, representing over 46,000 physicists in academia and industry in the United States and internationally. APS has offices in College Park, MD (Headquarters), Ridge, NY, and Washington, DC.


Read the rest of the post . . .

Monday, October 06, 2008

Physics Nobel Prize to be Announced Tomorrow

I make a prediction about who will win the Physics Nobel Prize every year. I've never been right in the past, so there's no harm to be done in sticking my neck out again this year.

My perennial favorite candidate is Vera Rubin who discovered that most of the material in the universe is mysterious and invisible dark matter.

Dr. Rubin made her discovery by measuring velocities of stars as they revolved around the outer edges of galaxies. Most physicists and astronomers expected that the stars far from the center of a galaxy should move slower in their orbits than the ones closer to the middle. Rubin found that isn't that case at all. The outer stars move much faster than they should.

There are all kinds of exotic ways to account for this, but the simplest is to accept that galaxies are a lot heavier than we'd assumed based on the stars and other matter we can see. There must be a halo of invisible matter entwined with the normal stuff - or we really have the whole theory of gravity thing messed up. Either way, Dr. Rubin's observations led to one of the most fascinating discoveries to come along in physics in a century.

Some of my friends here at the American Physical Society are betting on the people who discovered dark energy (Adam Riess and Saul Perlmutter). It's the mysterious energy that may be making the universe expand at an ever increasing rate, rather than slowing down as most people thought it should. Dark energy and dark matter aren't related (as far as we know) but it would be kind of cool if they both are the subject of this year's Physics Nobel.

So I'm gong to go with Rubin, Riess, and Perlmutter as my best guess for the 2008 prize.


Personally, I think it's cowardly to hedge your bets by making more than one prediction, but I've heard Dan Schectman and Roger Penrose mentioned by a few people for their work on quasicrystals. Penrose discovered them mathematically, and Shechtman discovered them in the lab.

Quasicrystals look a lot like regular crystals except they aren't perfectly identical from one point to the next. The pattern slowly changes, which makes them mathematically fascinating, and potentially very handy in commercial applications.

If Rubin weren't still in the running I would like to see Shechtman win in part because of the article I wrote about him a few years ago. I always have a soft spot for the folks I interview. Not to mention, it was an uphill battle for him to get people to believe his discovery was real. Here's an excerpt from the story I wrote back in 2003.

"For two years I did not have anybody who believed my results and was usually ridiculed," says Shechtman. "The scandal of polywater was still in the air, and I feared for my scientific and academic career."

He deserves the Noble Prize both for his scientific work and for sticking to his guns in the face of a lot of skepticism.
Read the rest of the post . . .

Friday, October 03, 2008

Fermi Problem Friday

How many miles of spaghetti have you eaten in your lifetime?
Read the rest of the post . . .

Physics is Phun, Especially on the Playground

"Phun" is a 2D physics playground, created by Swedish graduate student Emil Ernerfeldt. It lets you create things like cars and piston engines with easy, colorful shapes. Its also free and downloadable.
Read the rest of the post . . .

Thursday, October 02, 2008

400 Years Ago The Birth of the Telescope, Oct.2 1608

Its been 400 years since the birth of the telescope- at least according to some scientists and historians.

Nonetheless, the Netherlands is celebrating (aka conferencing) to mark 4 centuries of one of the most influential inventions ever.

Based on several sources, it is believed that on October 2 1608, eyeglass maker Hans Lippershey, originally born in Germany, filed a patent application in Netherlands (or in Belgium, no one is certain) for a device he called a "kijiker" or looker.

The story isn't without polemic. Some claim that Lipphershey's neighbor and fellow eyeglass maker Zacharias Janssen invented an instrument capable of viewing far-off objects up close. Despite the open questions, all of the potential inventors resided in the Netherlands so this year the Dutch are taking credit for the telescope.

In 1609, Galileo Galilei set about improving the telescope and was eventually able to gaze at the stars and moons. His observations offered proof that the Sun and planets do not revolve around the Earth, much to the chagrin of the Catholic Church.

In commemoration Italy, being home to the famous scientist, convinced the United Nations (U.N.) to hold the International Year of Astronomy in 2009, when the rest of the world will likely join in celebrating the birth of the telescope (the Netherlands will participate as well).
Read the rest of the post . . .

Wednesday, October 01, 2008

"I Guess I Prefer My Space Stringy, Not Loopy"

So I completely missed this season's start of the Big Bang Theory (how did this happen?!). Here's a clip from last week's episode "The Codpiece Topology". I'll be sure to cover next week's episode.
Read the rest of the post . . .