Friday, January 31, 2014

Understanding Our Universe at Levels Too Small to See

Among potential evidence that would further support the Big Bang theory is the cosmic gravitational wave background. Like ripples in a pond, gravitational waves distort the curvature of the spacetime continuum and were first predicted in 1916 by Albert Einstein.

Similar to the Cosmic Microwave Background, a ubiquitous backdrop of gravitational waves permeates space, cosmologists predict. This cosmic gravitational wave background (CGB) should have formed as a result of cosmic inflation, when the universe essentially exploded in size, expanding from smaller than the size of an atom to most of what we see today. All in the time it takes you to blink.

If observed, the cosmic gravitational wave background would be a smoking gun for cosmic inflation and is therefore a popular observing target in cosmology. But gravitational waves are tricky to detect because they do not emit electromagnetic radiation, and the only successful detection so far has been indirect. Most likely, observations of the CGB will also be indirect by observing how they affect light.

In the case of light from the CMB, the oldest and some of the only polarized light in the universe, an interaction with gravitational waves from the CGB will lead to what astrophysicists refer to as B-modes.

Temperature fluctuations in the CMB measured by the Wilkinson Microwave Anisotropy Probe. Credit: NASA.

An extensive team of scientists first presented observational evidence of B-modes last July. While the B-mode observations that the team reported proved that B-modes can be measured and detected, their observations were of B-modes created when the direction of a photon's travel is changed due to gravity from a massive object, like galaxy clusters, and not the CGB. Moreover, the July paper's B-modes were  about seven orders of magnitude more powerful, and therefore easier to detect, than the B-modes discussed here.

What's more is that recent results suggest B-modes from the CGB are even more difficult to detect than originally thought. The reason stems from a type of perturbation that past researchers have neglected in their calculations, some with the assumption that the effect was negligible. But one scientist shows through a series of complex calculations that the effect leads to CGB B-modes four times less powerful than the already small previously predicted values.

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Thursday, January 30, 2014

Correction: Does 1+2+3+4+ . . . =-1/12? Absolutely Not! (I think)

(If you'd rather just know what 1+2+3+4+ . . .actually is equal to, check out our next post in this series)

Brief Summary: 1+2+3+4+ . . . is not equal to -1/12, but both the infinite series and the negative number are associated with each other in a way that can be seen in this graph

The area of the little region below the horizontal axis equals -1/12, and the infinite area under the curve on the right gives you 1+2+3+4+. . . , which goes to infinity as you add terms, not to -1/12. 

(Update 2-6-14: of course, this graph shows what it looks like if you can only see a finite region of the graph. So 1+2+3+4+...+m is going to infinity, provided m is some finite number. This doesn't say anything about what happens if you could see all the way to infinity - I'd need a much bigger screen for that. For this reason, I am crossing out all the things that I am not so sure about in this post.)

That's a relief - the world makes sense again.

For a longer explanation, read on . . .

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Wednesday, January 29, 2014

Podcast: Astronaut Chris Hadfield

This week we have a very special guest on the podcast: astronaut Chris Hadfield. Hadfield is the first Canadian astronaut to space walk, and the first Canadian astronaut to command a spaceship (the ISS). He has flown on two US space shuttle missions and once on the Russian Soyez rocket. He's the author of An Astronaut's Guide to Life on Earth: What Going to Space Taught Me About Ingenuity, Determination, and Being Prepared for Anything, and last spring he sang and played guitar to the David Bowie song Space Oddity.

Listen to the podcast to hear how Hadfield approaches risky situations, what he misses most about space, and more. Plus, check out the bonus clips from the interview, posted below the fold.

You can see more videos at Hadfield's Youtube video and his Twitter account.

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Tuesday, January 28, 2014

Iconic Griffith Observatory Photo Tour

Earlier this week, several of your faithful bloggers attended a small meeting at perhaps our new favorite venue: the Griffith Observatory perched atop the hills overlooking Los Angeles.

Griffith Observatory takes its name from its founder, the wealthy 19th century mining expert Griffith J. Griffith (I'm not sure if it's named after his first or last name!). Despite generously donating the observatory and surrounding land to the City of Los Angeles in the early 1900's, Griffith was far from a perfect man.

In fact, he shot his own wife in the face during a drunken argument, permanently disfiguring her. After a surprisingly brief prison sentence of only two years, Griffith sought a new course for his life. During his search, he looked through a telescope at the Mount Wilson Observatory and was quoted as saying:

"Man's sense of values ought to be revised. If all mankind could look through that telescope, it would change the world!"

After this experience, Griffith set out to make an observatory widely available for public use and donated the land and money necessary to the city of Los Angeles. The observatory was finally built in 1935, 26 years after Griffith's death.

Today, the Griffith Observatory's exhibits, planetarium shows, and telescopes serve over a million visitors annually, and it houses the most widely (directly) used telescope in the world. Here's a few snapshots we took during our visit this weekend.

A view of the observatory shortly after sunrise.
Image Credit: Brian Jacobsmeyer

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Monday, January 27, 2014

How Radioactive (In Bananas) is the Room You're Sitting in Right Now?

According to recent research (and some of my own calculations) sitting in your living room for an hour yields roughly the same dose of radiation as eating half a banana. A team in China working on improving the way scientists measure a room's radioactivity calculated how much radiation an average room gives off.

Everything emits a trace amount of radiation. Bananas, dirt, seagulls, Abe Vigoda and coffee tables are all to some degree a very tiny bit radioactive. It's because radioactive elements like potassium-40, uranium-238 and thorium-232 are ubiquitous throughout the planet's surface, and get absorbed into different materials through various natural processes. They're part of what makes up the Earth's "background radiation."

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Friday, January 24, 2014

The Awesomest Physics Cake Ever

I defy anyone to come up with a better physics-themed cake than this.

PhysicsBuzz bloggers Quantum, Mathelete, and I (Buzz) came up with the idea as a way to commemorate the retirement of our boss, mentor, and friend Alan Chodos after 14 years at the American Physical Society.

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Thursday, January 23, 2014

From 14 to a Million: The Astronomical Growth of the Astronomy Picture of the Day

On June 16, 1995, Robert Nemiroff (MTU) and Jerry Bonnell (UMCP) posted the
first Astronomy Picture of the Day. The site received 14 page views that day.

The breathtaking beauty and didactic efforts of the APOD’s daily posts have earned it global renown, and the site now receives over one million page views each day.

From 14 to a million hits: Learn about the site first-hand from co-founder Robert Nemiroff in this telling Q&A, and don't forget to "Discover the cosmos!"

Q. How did you and Jerry first come up with the idea for APOD?

A. In 1995 Jerry and I shared an office at NASA's Goddard Space Flight Center and were watching the web develop. We would contemplate how we could contribute and brainstormed several ideas. The Astronomy Picture of the Day (APOD) was one of those ideas. This idea played off an underlying concern that astronomy images were sometimes being circulated as email attachments without people knowing what was being pictured. It looked like the web might become a place of little information, in particular about astronomy images. Or worse -- misinformation. APOD was supposed to counter that -- to create a slightly more informed web where astronomy images, at the least, would be coupled with explanations so that people would know at least a little bit about the images being circulated.

Immediately after formulating this idea we did what most scientists do after considering a new effort -- we just went back to our normal scientific routine. But a few lunches later APOD still seemed like a good idea so we started it up. That was over 18 years ago -- so it appears that we forgot to stop.

APOD's post for April 22, 2013. If you had infrared vision, like Predator's monster or in this case the Hubble Space Telescope, this is show the Horsehead Nebula would appear. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Q. Was the site an immediate hit or did it take some time to gain popular appeal?

A. APOD had 14 page views on the first day -- and I'm not sure how they knew about us. We got a bump when we appeared on the daily "NCSA What's New" list a few weeks later, which was a big thing back then. Since then, like most pages, APOD has experienced a slow but exponential growth. But since we started so early, we have had a long time to grow. Some people now consider APOD to be the first science blog.

Q. On average, how many web views does APOD receive in a day? How does this compare with how many daily hits the site had ten and almost twenty years ago?

A. Currently the main NASA APOD site typically receives over one million page views each day. That does not include now over 20 other-language mirror sites and "new technology" mirror sites such as Facebook, Twitter, and Google Plus.

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Wednesday, January 22, 2014

Women in Physics: STEMming the Leaky Pipeline

On this week's podcast, our contributor, Elizabeth Case, reports from a conference for undergraduate women in physics from this past week.

Elizabeth also participated in the conference herself as an undergraduate physics student, granting her an inside perspective on how such conferences can inform, inspire, and retain women in physics. Have a listen!

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Does 1+2+3+4+ . . . =-1/12?

(Spoiler alert: Yes it does . . . probably . . . um, maybe . . .I mean, it has to.)

An interwebs firestorm has been raging recently about a Numberphile video that makes the astounding claim that if you add up all the positive whole numbers from one to infinity, the result will be -1/12. To write it out more concisely

1+2+3+4+ . . . = -1/12 , (where the three dots indicate all the rest of the positive numbers up to infinity)

If you haven't seen the video, take a look - it's short.

Fascinating, isn't it?

Renowned science writer and astronomer Phil Plait (Bad Astronomy) blogged about the video recently, calling it "simply the most astonishing math you'll ever see." The post led to a Twitter and comment storm, fueled both by people bowled over by the calculation and a much larger number of people convinced it was nothing short of mathematical fraud.The passionate response he got to his post led Plait to write a follow up piece, partly in self defense, and partly as penance for his various mathematical sins as pointed out by his readers.

Clearly, only a fool would consider defending this absurd calculation after the reception Plait got.

So here I go . . .

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Friday, January 17, 2014

Olympic Snowboard Physics - the 1440 Triple Cork

Slopestyle snowboarding will make it's first appearance in winter Olympic competition this year. It'll be a thrill to see some of the world's top competitors going at it in one of the most entertaining forms of the sport.

Without a doubt, whoever takes home gold (and probably silver and bronze) will have to land a stunning and relatively new maneuver known as the 1440 Triple Cork.

Check out this video of Billy Morgan, one of the first people to master the confusing maneuver.

It can be tough to follow, but basically the move consists of four complete rotations (4 x 360 degrees = 1440 degrees) and three instances where Billy appears to be roughly upside down (i.e. inverted in snowboarding lingo).

The maneuver looks complicated, and is certainly one of the most difficult moves in the sport. You have to wonder how anyone could manage to put all the pieces together to land it consistently in competition. Fortunately, snowboarders have physics on their side, which makes this trick (a tiny bit) easier than it looks.

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Thursday, January 16, 2014

Part II: The Most Exciting Physics (and more!) to Happen at National Laboratories in 2014

During the mid-17th century, one of the hot spots for physics research was the house of Galileo Galilei. By timing objects that rolled down inclined planes, he was the first to prove that falling objects on Earth, regardless of their mass, should accelerate at the same rate in the absence of air resistance. His research laid the foundation for Newton’s law of gravity.

Today, if you are itching to know the next milestone in physics and its importance, look deep within the caverns of particle accelerators, neutrino detectors and supercomputers at U.S. national labs. Many questions remain unanswered, but perhaps 2014 will shed light on some of these perplexing mysteries.

This is a continuation from Tuesday’s post about what science you can expect to see this year from research laboratories across the country. Picking up where we left off is Ames National Laboratory.

In 1947, Ames National Laboratory was established for its success with the Ames Project, which started five years earlier. In 1942, Frank Spedding of Iowa State College applied his expertise in chemistry, specifically with rare earth elements, to sew the seeds for the Ames Project, which developed ways to reduce the production cost of high-purity uranium.

A sample of reduced uranium metal via the Ames Process. Credit: Ames Laboratory, U.S. Department of Energy.

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Wednesday, January 15, 2014

Podcast: The Mystery of Massive Star Formation

The most massive stars in our universe—those at least 10 times more massive than our sun—shape the environments of the galaxies they live in. They're also responsible for producing heavy elements, which are necessary to create complex life forms (like humans). But how these burning behemouths come into being is a scientific mystery. This week on The Physics Central Podcast I talk with physicist Paola Caselli, a professor of astronomy at the University of Leeds, about how she and her colleagues are trying to solve massive mystery.
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Tuesday, January 14, 2014

Part I: The Most Exciting Physics (and more!) to Happen at National Laboratories in 2014

Laboratories across the country stand at the forefront of scientific research in fields that include nuclear fusion, neutrino oscillation and the search for traces of dark energy as well as advances in biology, chemistry, medicine, geophysics, material science and more.

The year 2014 will bring some of these laboratories’ projects to a close, see the completion of other projects-in-progress and witness the first runs of long-awaited experiments like Fermi National Accelerator Laboratory’s NOvA experiment and Brookhaven National Laboratory’s National Synchrotron Light Source II.

In 1931, Earnest Orlando Lawrence founded Lawrence Berkeley National Lab. The lab initially served as a site for research using his new instrument, the cyclotron, which won him the 1939 Nobel Prize in Physics. Since then, the lab has led many scientific research experiments including the recent Baryon Oscillation Spectroscopic Survey (BOSS), which will conduct its last sweep of sky in June.

BOSS is an important tool for understanding the properties of dark energy by accurately measuring the expansion rate of the universe through determining galaxy distances to increasingly high precision. Just last week, the BOSS collaboration announced that they had determined the distances to galaxies more than 6 billion light-years away to within one-percent accuracy.

An artist’s concept of the latest results from BOSS on the accurate measurement of the universe. The circles, which outline the size of what scientists call baryon acoustic oscillations, are a kind of “standard ruler” for measuring accurate distances to galaxies both nearby and far away. Credit: Zosia Rostomian, Lawrence Berkeley National Laboratory.

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Monday, January 13, 2014

Theoretical Time Machine Could Also Clone Objects

Originally published: Jan 13 2014 - 2:45pm, Inside Science News Service
By: Charles Q. Choi, ISNS Contributor

(ISNS) -- Time travel is often a way to change history in science fiction such as "Back to the Future" and "Looper." Now researchers suggest a certain kind of time machine could also possess another powerful capability — cloning perfect copies of anything.

However, scientists noted the way these findings violate what is currently known about quantum physics might instead mean such time machines are not possible.

Image credit: RodgerCEvans via flickr |
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We are all time travelers in that we all move forward in time. However, scientists have suggested it might be possible to move back in time by manipulating the fabric of space and time in our cosmos. All mass distorts space-time, causing the experience of gravity, a bit like how a ball sitting on a rubber sheet would make nearby balls on the sheet roll toward it. Physicists have proposed time machines that could bend the fabric of space and time so much that timelines actually turn back on themselves, forming loops technically known as "closed timelike curves."

These space-time warps can develop because of wormholes — tunnels that can in theory allow travel anywhere in space and time, or even into another universe. Wormholes are allowed by Einstein's general theory of relativity, although whether they are practically possible is another matter.

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Friday, January 10, 2014

Anderson Cooper on Extremely Cold Bathroom Breaks and Quantum Physics

At the risk of typecasting ourselves at the Buzz, here's another post about the science of urinating, to follow up on this and this (and this and this).

The actual quantity of science in Anderson Cooper's Ridiculist story is relatively meager, but it includes two experiments, so that earns it some extra points. It also features Cooper's entertaining attempt at reciting some physics terms from the web page of physicist Brian Cole of Columbia University.

Although Cooper clearly has some fun with physics jargon, you ain't seen nuthin' until you watch Jim Carrey and Conan O'Brien discussing quantum physics. (Sorry, I can't find an embedable version of this. But click on it anyway - it's awesome.)

They were actually reading excerpts taken directly from a real Physical Review Letters paper.

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Thursday, January 09, 2014

Courageous Canine Seeks Space Station

In a heart-warming, ironic twist, a child’s book about a dog’s trip to the International Space Station is currently en route to that very place.

Today, at 1:10 p.m. EST time a rocket, the first of eight commercial logistics deliveries launched by Orbital Sciences Corp., fired up its rocket boosters and embarked on the roughly 260-mile trip to the ISS. Orb-1, as Orbital Sciences calls it, will resupply the ISS and its residents with experiments, spare parts, fresh fruit and more.

Perhaps the most exciting of Orb-1’s cargo is a dog, named Max. Max is a one-of-kind, wildly intrepid Rottweiler who has a knack for space travel. In the Max Science Adventure book series for children, author Jeffrey Bennett has sent Max to multiple destinations throughout our Solar System including the ISS, Mars and Jupiter. Bennett based Max on his own Rottweiler who has passed but who lives on in Bennett's endearing stories.

The International Space Station. Credit: NASA

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Wednesday, January 08, 2014

Podcast: Weather Physics 101

The recent cold snap that swooped in on the U.S. was a grim reminder of the power of nature. We're fortunate to live in an age when information about the weather is always at our fingertips, either via the internet, television or radio. Physics is the backbone of modern weather forecasting, but it also played a major role in the first technologies to bring weather forecasts to the masses. This week on the podcast, catch a bit of history about weather forecasting.

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Tuesday, January 07, 2014

Learn Physics Like the Professionals, by the Professionals

That furry feline friend of Schroedinger’s has become a staple for quantum physics fans everywhere. The cat’s ambiguous fate relates to scientists’ interpretation of quantum mechanics that deals only in probabilities.

In quantum mechanics, when physicists make an exact measurement, they find only one possible solution from many. Instead, most often they quantify the probability of an object’s position, momentum and other physical quantities falling within a certain range of possible values.

In the simple case of Schrodinger’s cat, when you observe the cat’s state, it will be either alive or dead. And that outcome will randomly change each time you run the experiment. Mathematically, how does Schroedinger’s cat fit into the equivocal universe of quantum mechanics?

James Binney, Quantum Mechanics Discussions at Oxford University. Credit: Oxford University

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Monday, January 06, 2014

Would Time Travel Leave Online Traces?

Originally Published: Jan 6 2014 - 5:00pm, Inside Science News Service
By: Jessica Orwig, ISNS Contributor

(ISNS) -- Scientists searched a corner of the Internet for evidence of time travel into the past. They found no evidence that this fantastical form of travel exists.

Time travel into the future is physically possible: Einstein's theory of special relativity predicts that the time between two events is slower for faster-moving objects. This has been experimentally proven by measuring clocks on commercial planes. But time travel into the past is trickier.

Although many scientists have proposed the possibility of time travel into the past using the equations and concepts of Einstein's subsequent theory of general relativity, few scientists have conducted experiments to test these theories.

Image: Digital art interpretation of traveling through a wormhole by Les Bossinas. Credit: Les Bossinas (Cortez III Service Corp.)

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Friday, January 03, 2014

Magnetically Aligned Dogs

Lots of organisms, from bacteria to deer,  can sense magnetic fields. It's an ability known as magnetoception. Birds and bats use the Earth's field to navigate, and naked mole rats may use it to orient their nests - although why a blind, naked animal that spends its whole life underground cares which way its nest is oriented is a mystery to me.

Which way should I go?

It's not particularly surprising that dogs can sense magnetic fields. It may even explain stories of their uncanny ability to find their way home from great distances. What is surprising, to me anyway, is how a group of Czech researchers discovered magnetoception in dogs. After 1,893 observations of dogs defecating, they found a significant preference for pooping along the magnetic field lines. That is, dogs prefer to face toward the magnetic north or south, rather than east or west, when relieving themselves. (Their preferences weren't so clear when it came to urinating, despite 5,582 observations of the dogs in action.)

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Thursday, January 02, 2014

Underwater Microphones Eavesdrop On Icebergs

Originally published: Dec 30 2013 - 2:00pm, Inside Science News Service
By: Jyoti Madhusoodanan, ISNS Contributor

(ISNS) – Icebergs are loud travelers, and underwater microphones listening in on nuclear tests can hear them. The acoustic arrays, designed to pick up minute sounds thousands of miles away, can overhear other ocean noise too: ships, marine life and icebergs.

In the process, two microphone arrays off the coast of Australia tracked the sounds of two icebergs as they cracked, collided and "screamed" their way along an Antarctic glacier.

Scientists know these icy behemoths well. Approximately 40-50 kilometers in diameter, they have been drifting for nearly ten years. Scientists usually track such icebergs with satellites, but new data published in the journal Geophysical Research Letters shows that hydroacoustic signals can also pinpoint their location. The acoustic signals could also identify icebergs when they grew too small for satellites to monitor.

Credit: NOAA
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