Friday, May 29, 2009

Eclipsing Newton

I can't believe I almost let it pass me by, but today is the 90th anniversary of the most ground breaking experiment of the 20th century. On this day in 1919 Arthur Eddington observed the solar eclipse that would ultimately revolutionize our understanding of the universe.

A huge part of Einstein's General Theory of Relativity is how gravity itself warps the fabric of space-time itself. According to his then brand new theory, a ray of light passing near a massive object will bend around the object. The classic illustration of this is a heavy bowling ball suspended on a flexible rubber sheet. All around the bowling ball, the sheet bends in because of its mass. Now picture a small marble rolling across the sheet, its path taking it near to the bowling ball. It will curve in where the sheet is bent, deflecting its otherwise straight course.

Eddington, with the backing of the Royal Astronomical Society, set out to test this theory and embarked on an expedition to the island of Príncipe off the coast of western Africa to observe a total eclipse of the sun. His goal was to see if the light from stars passing near to the sun were bent the way Einstein predicted, just like the marble passing by the bowling ball. He needed a total eclipse of the sun because that was the only way to observe starlight without it being diluted by the blue sky of day.

After a long and peril filled venture to the tiny West African nation (I won't recount the details here, for a better and more hilarious account of his adventure and others, I strongly recommend Bill Bryson's A Short History of Nearly Everything), Eddington arrived to find a thick bank of clouds, obscuring the sun.

Seemingly the voyage had been in vain, but miraculously the clouds parted just minutes before the eclipse was to occur. He snapped a series of photographs on glass plates of the eclipse and set about analyzing them in great detail. When he finished, he found that the amount that the starlight around the sun bent around the sun, exactly matched Einstein’s predictions. There in black and white was proof that the theory of relativity was correct.

This is the textbook example of the success of the scientific method. Einstein's postulates made clear predictions that could be scientifically tested and measured to either prove or disprove the theory. In this case, the proof completely revolutionized the field of physics. The traditional Newtonian view of the universe was uprooted and Relativity became the predominant framework for understanding the universe.


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Wednesday, May 20, 2009

Press Release About News Media Blindly Parroting Press Releases Blindly Parroted by News Media

Right now science journalism is facing many problems, mostly stemming from an industry being hit with a tough double whammy of approaching obsolescence and the acute market downturn. Across the country numerous science journalism staffs are being cut to save costs, leading to a decline in quality, leading to a decline in readership, leading to a decline in subscription and ad revenues, requiring more cost cutting…and so on. It's a vicious cycle.

The sure sign of this decline in quality of the mainstream press are journalists taking press releases about a new discovery and rewriting it, hyping it out of proportion. A recent study was conducted by the Annals of Internal Medicine took a look at this phenomenon in the medical world and found this to be a huge problem. Press releases put out by a university will hype a discovery, which will in turn be taken by journalists unfamiliar with covering science, and be hyped further.

It's not just in the medical sciences that are running these problems. Indeed, physics research is continually reported, hyped and distorted as well, especially in very popular and cutting edge fields. All the time, websites like EurekaAlert.org, PhysOrg.com or Science Daily will post press releases, hyping the latest graphene or quantum computing finding, and make it sound like Brookstone is about to carry a full line of graphene based quantum computers in every color. The releases, and articles based on them, usually couch their language saying things like "could lead to," but either intentionally or intentionally, the impression given is that any small advancement represents a groundbreaking revolution in the field. Realistically though, any applications from these advances are years away.

At the Columbia Journalism Review blog, Earle Holland writes about how journalists have used the Annals of Internal Medicine study to sort of pass the buck. Bloggers on USA Today and the Wall Street Journal have implied that the fault of this shoddy coverage is from these over-hyped press releases. Earle is correct criticizing these bloggers and not letting lazy journalists off the hook. It's as much their responsibility not to be taken in by these press releases.

This kind of weak journalism can get the world of science into trouble. This week, the British paper The Telegraph featured a fascinating piece about Jan Hendrik Schön, a scientist who falsified nearly all of his data, but was still widely published and featured before getting caught. He was able to exploit weaknesses in the system, both in the scientific community and the media for his own benefit.

What is needed is more scrutiny all around, both in the media and the scientific community. Mundane advances shouldn't be hyped in press releases, and those that are should be seen as such by responsible science journalists. Otherwise we get the warped science journalism cycle we see today.
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Tuesday, May 19, 2009

ATTACK OF THE ATOMIC STARFISH !!!

Experimentation is the essence of science. Checking fact against theory is truly what makes science great. Sometimes though either the theory hasn't evolved far enough to predict everything, or there's too many variables to accurately predict the result. But you really really want to see what happens, so you go and do it any way. I like to call this the "poke it with a stick and see what happens" scientific method. Such is the tale of the Starfish Prime nuclear test in 1962.

Back in the late 1950s and early 1960s, during the darkest days of the cold war, the military was testing nuclear weapons all the time. After leaving the old proofing grounds in Nevada, the military started testing them on small islands far out in the Pacific Ocean. After a while the military started itching to see what might happen if they detonated some of these nukes in space.
megaton nuclear bomb to a Thor rocket, blasted it into space and pressed "detonate" when it reached 250 miles above the surface. It exploded and though there was no fireball, all manner of lovely aurora formed above the Pacific Ocean.

However, 1400 miles away in Honolulu, things got pretty crazy because not only could they see the explosion but they could feel its effects. The nuclear blast released a large number of gamma rays which disrupted the local magnetic field causing an electromagnetic pulse to radiate outward. When this EMP wave hit Hawaii its energy caused huge disruptions in the electrical grid. Power lines fused, radio communication and TV signals went down and the phones went of the fritz. High up, above the atmosphere, the radiation from the explosion fried the sensitive circuits of a whole third of the low flying satellites at the time. Whoops!

That in a nutshell is exactly what I mean by the "poke it with a stick and see what happens" scientific method; detonating a large nuclear weapon miles above Earth and discovering one of its side effects was chaos across much of the Pacific's communication grid!

Sounds like a great idea for a movie!

Oh wait, they already made it. Bonus: It's narrated by William Shatner!



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Friday, May 15, 2009

Easy as α β γ ?

Sometimes there are two sides to a story. For a long time one of my favorite fun physics stories is about the famous "Alphabetical Paper" of 1948. The brilliant young PhD student Ralph Alpher working with his advisor George Gamow were about to publish a major work about the origins of the elements after the Big Bang. In a burst of inspiration, Gamow invited the physicist Hans Bethe to include his name on the paper, even though he had not contributed to it at all. That way the paper would have been authored by Alpher, Bethe, Gamow, a play on the first three letters of the Greek alphabet alpha, beta, and gamma. It was a delightful pun, and their one page paper serendipitously ran in the April 1st issue of Physical Review Letters.

The theory itself was groundbreaking, and helped establish the groundwork for proving the universe began in a proverbial "Big Bang." The paper argued that if the universe began as a thick soup composed of hydrogen atoms, they would start bonding with each other forming heavier and heavier elements (Helium, Lithium Beryllium etc.) at predicable rates. Most importantly it predicted that by this nucleosynthesis method, there should 10 times more hydrogen in the universe than helium. AND THEY WERE RIGHT! Mostly, but more on that later. Actual observations of the ratio of H to He agreed with the 10:1 prediction and the paper would later serve as an important piece of evidence to prove the Big Bang.


However there is, like many things in life, much more to the story. It turns out that Ralph was never completely comfortable with the impromptu inclusion of the famous physicist on the author list. Hans Bethe was already an established and well known physicist, known for his work on nuclear reactions. During World War II he worked on the Manhattan Project helping to solve major theoretical issues with the bomb, among which were calculating the critical mass of uranium-235 and determining the explosive yield of the bombs.
Likewise George Gamow was also a giant in the field. He was able to first explain the radiation of alpha particles from radioactive sources, a particularly thorny problem that had plagued physicists for years.

Alpher however was still only a doctoral student at the time and was never happy about Bethe's inclusion on the list. Though Alpher had done the majority of the calculations and work in the paper, it often seemed that the two physics leviathans listed as authors received the lion's share of the attention. This was compounded later when Hans Bethe continued to develop the theory. He found later that while the paper's major finding about hydrogen fusing into helium was correct, helium fusing into other heavier elements could only happen in the intense pressures at the cores of stars and supernovas. That meant that these elements couldn't have formed on their own in the dense soup after the Big Bang, and Alpher's predictions for the heavier elements were incorrect.

Unfortunately for Alpher this wasn't the only time credit for one of his major discoveries went to someone else. After writing the "Alphabetical Paper" Alpher and Gamow partnered with Robert Herman and calculated that the Big Bang should have left an echo in all directions of the sky detectable as a very slight amount of heat. Unfortunately they predicted this at a time before the Big Bang was generally accepted, and his calculations were mostly forgotten.

Years later in 1964 Arno Penzias and Robert Wilson accidentally discovered the very cosmic microwave background radiation that Alpher predicted. Ironically they weren't even looking for it, they thought at first the echo of the beginning of the universe was from bird droppings! During their acceptance of the 1978 Nobel Prize, Wilson and Penzias made a special effort to thank Alpher for his contribution, but sadly today the memory of his importance to modern cosmology has largely fallen by the wayside.


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Thursday, May 14, 2009

Hubble's fix'n for an upgrade.

NASA Shuttle Mission STS-125 is currently performing spacewalks to repair and replace cameras on the Hubble Space Telescope. You can watch it live on NASA TV. Thanks to the internets you don't need one of those old school humongous satellite dishes to watch NASA TV (like when I was a kid).

On the average day, highlights from NASA TV will include watching people milling around mission control and drinking their coffee. However, the current repair mission includes 5 spacewalks. The crew concluded the first walk today and plans to conduct one a day for the next four days. Watching some of today's spacewalk really gave me a sense of how life in space is much different from the movies. The first thing I noticed is that astronauts don't actually move in slow motion. This sounds strange and obvious but just watch and see how your astronaut intuition is skewed. Secondly, astronauts are people too. Even though the space walk missions are thoroughly planned, there are always difficulties and problems that come up. Let's just say its like bit like the Mythbusters meets Cspan.

The NY Times has an impressive interactive animation that illustrate the repairs planned for the Hubble telescope.

The amazing photo blog, The Big Picture from the Boston Globe, documented the preparation for the current STS-125 repair mission. Did we already mention that these photos are spectacular? You really get a feeling for the size of the rocket boosters and the giant orange monster fuel tank. Speaking of orange, be sure to wave and say hello to Megan as you scroll through the pictures.
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Friday, May 08, 2009

Highlights from the Mile High City


Last weekend over 1250.0 physicists from around the world converged onto the mile high city of Denver Colorado. Some of the greatest minds in the field converged not for the city's legendary buffalo burgers, but the annual April Meeting of the American Physical Society. Ironically it was held this year in May. Maybe some physicists are just more concerned with answering the big questions about black holes and the universe than the difference between months of the year.
Anywho, this year's meeting featured many talks on topics ranging from quantum gravity to arms control to philosophy. Here's just the first part of some of the highlights from the Mile High City.



The physicists were easy to spot roaming around Denver because of their name tags.



Many students presented their work at the meeting during the poster sessions. Here we see a physicist asking a student why there is not a yellow box around a particular equation.



While many physicists at the meeting were presenting their theories on the expanding universe, this young physicist amazed everyone with her demonstration of the expanding marshmallow!



One physicist is explaining to another why it is not the fizzy bubbles that keep this center of mass demonstration from toppling over.

In this photo we see a physicist asking another for her autograph.

One of the leading science journalists at the meeting was doing her part to promote Phil Plait's public lecture about killer meteors and bad astronomy.


Phil Plait tortured the audience with the some short clips from Hollywood's exploits on meteors and science. Then he wowed everyone with the actual science of asteroids and comets!

Photo Credit: Brian Mosley, American Physical Society
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