Wednesday, May 25, 2011
Tuesday, May 24, 2011
Multiverse = Many Worlds, Say Physicists - Technology Review
05/23/2011
Multiverse = Many Worlds, Say Physicists
Two of the most bizarre ideas in modern physics are different sides of the same coin, say string theorists
The many worlds interpretation of quantum mechanics is the idea that all possible alternate histories of the universe actually exist. At every point in time, the universe splits into a multitude of existences in which every possible outcome of each quantum process actually happens.
So in this universe you are sitting in front of your computer reading this story, in another you are reading a different story, in yet another you are about to be run over by a truck. In many, you don't exist at all.
This implies that there are an infinite number of universes, or at least a very large number of them.
That's weird but it is a small price to pay, say quantum physicists, for the sanity the many worlds interpretation brings to the otherwise crazy notion of quantum mechanics. The reason many physicists love the many worlds idea is that it explains away all the strange paradoxes of quantum mechanics.
For example, the paradox of Schrodinger's cat--trapped in a box in which a quantum process may or may not have killed it-- is that an observer can only tell whether the cat is alive or dead by opening the box.
But before this, the quantum process that may or may not kill it is in a superposition of states, so the cat must be in a superposition too: both alive and dead at the same time.
That's clearly bizarre but in the many worlds interpretation, the paradox disappears: the cat dies in one universe and lives in another.
Let's put the many world interpretation aside for a moment and look at another strange idea in modern physics. This is the idea that our universe was born along with a large, possibly infinite, number of other universes. So our cosmos is just one tiny corner of a much larger multiverse.
Today, Leonard Susskind at Stanford University in Palo Alto and Raphael Bousso at the University of California, Berkeley, put forward the idea that the multiverse and the many worlds interpretation of quantum mechanics are formally equivalent.
But there is a caveat. The equivalence only holds if both quantum mechanics and the multiverse take special forms.
Let's take quantum mechanics first. Susskind and Bousso propose that it is possible to verify the predictions of quantum mechanics exactly.
At one time, such an idea would have been heresy. But in theory, it could be done if an observer could perform an infinite number of experiments and observe the outcome of them all.
But that's impossible, right? Nobody can do an infinite number of experiments. Relativity places an important practical limit on this because some experiments would fall outside the causal horizon of others. And that would mean that they couldn't all be observed.
But Susskind and Bousso say there is a special formulation of the universe in which this is possible. This is known as the supersymmetric multiverse with vanishing cosmological constant.
If the universe takes this form, then it is possible to carry out an infinite number of experiments within the causal horizon of each other.
Now here's the key point: this is exactly what happens in the many worlds interpretation. At each instant in time, an infinite (or very large) number of experiments take place within the causal horizon of each other. As observers, we are capable of seeing the outcome of any of these experiments but we actually follow only one.
Bousso and Susskind argue that since the many worlds interpretation is possible only in their supersymmetric multiverse, they must be equivalent. "We argue that the global multiverse is a representation of the many-worlds in a single geometry," they say.
They call this new idea the multiverse interpretation of quantum mechanics.
That's something worth pondering for a moment. Bousso and Susskind are two of the world's leading string theorists (Susskind is credited as the father of the field), so their ideas have an impeccable pedigree.
But what this idea lacks is a testable prediction that would help physicists distinguish it experimentally from other theories of the universe. And without this crucial element, the multiverse interpretation of quantum mechanics is little more than philosophy.
That may not worry too many physicists, since few of the other interpretations of quantum mechanics have testable predictions either (that's why they're called interpretations).
Still, what this new approach does have is a satisfying simplicity-- it's neat and elegant that the many worlds and the multiverse are equivalent. William of Ockham would certainly be pleased and no doubt, many modern physicists will be too.
Ref: arxiv.org/abs/1105.3796: The Multiverse Interpretation of Quantum Mechanics
Copyright Technology Review 2011.
Monday, May 23, 2011
Inland Storms, Growing in Violence, Drive Insurers to Accept Riskier Reality - NYTimes.com
Inland Storms, Growing in Violence, Drive Insurers to Accept Riskier Reality
By EVAN LEHMANN of ClimateWire
First, the focus was on hurricanes. Now, their sneakier cousins are lashing the nation with rain, hail and tornadoes at a record-breaking pace that's convincing some insurers the rising risk is permanent.
Thunderstorms caused record losses in the past three years by punishing Americans with $13 billion in damage annually, almost $10 billion of which was insured each year. That's higher than the cost of many hurricanes and approaches the damage inflicted on 9/11, priced at $18 billion to insurance companies.
Now, 2011 storms are threatening to extend that streak. Tornadoes killed more than 300 people in four days last month, spawning between $3.5 billion and $6 billion in insured losses in Alabama and other Southern states, estimates Risk Management Solutions.
"So you have seen a dramatic increase in the amount of hailstorms, golf balls, football-sized hail, straight-line winds at 80 miles an hour, 120 tornadoes. It's just you see a lot more severe weather," Thomas Wilson, chairman and CEO of Allstate Insurance Co., told Wall Street analysts in a conference call last month.
The heightening ferocity of thunderstorms parallels a 15-year stretch of more intense and frequent hurricanes, prompting financial risk to skyrocket in Florida and other coastal states with public insurance programs.
But landfall hurricanes have hibernated for the past two years. That absence has helped focus a clearer, if grim, light on thunderstorms: U.S. damage in each of those years is the highest ever without a hurricane. The number of all natural disasters in 2010 also set a new record, at 247 events, according to the Insurance Information Institute.
That broke a record set the year before when, in 2009, there were just over 200 natural disasters. Most of the disasters in both years were thunderstorms. For comparison, the number of natural catastrophes in 1980 was about 60. Thunderstorms accounted for almost all of them.
While the financial impacts of the numbers are clear, what's causing them is not. Scientists agree that climate change will increase the number of downpours, while reducing light rainstorms. That can mean more floods and drier conditions between rainfalls. Many also believe that the number of intense hurricanes could increase.
'Rapid' move to clean energy sought
But the insurance industry is divided about the impacts of climate change on financial losses. European reinsurers openly warn their customers about the effects of man-made emissions, while some American companies tend to be more cautious about identifying causality.
The chairman of Munich Re, Nikolaus von Bomhard, told shareholders in a letter last month that the company is pressing for "a more rapid transition" to renewable energy around the world by underwriting those projects.
"We are thus also contributing significantly in our core business to curbing climate change and at the same time creating value for the Company and for you as shareholders," he wrote.
Swiss Re is another climate leader. But opinions are often different in the United States, where some industry trade groups and state regulators last year argued successfully against requiring companies to disclose the efforts they're taking against financial risks from climate change.
Climate scientists, also, are careful about assigning blame to climate change for specific floods, wildfires and storms. The climate, after all, contains the average statistics of weather over a period of decades, says Katharine Hayhoe, a climate scientist at Texas Tech University.
"And over the past 10, 20 and 30 years -- 50 and even 100 years -- we have seen those average statistics of weather changing," she told reporters on a conference call this week. "It's not just getting warmer. It's also affecting the frequency and intensity of our precipitation, both snow and rain around the country."
Insurers bid adieu to the 'good old days'
Insurers also see it. But they are looking through a different lens. They focus on the destruction caused by weather events in specific ZIP codes. Some of that might be climatic, but it can also be influenced by increased development, shifting populations and the strength of buildings.
"We don't totally understand the way things happen like they do," said Robert Hartwig, president of the Insurance Information Institute. "We don't have perfect information about the vagaries and volatilities of weather, or why there have so many earthquakes in other parts of the world recently. But we do have to reflect that in the rate. So we do."
He expects homeowners insurance premiums to rise next year because of a 25-year rise in violent thunderstorms. And while hurricanes remain one of the biggest challenges to insurers, convective storms on the Midwestern plains, and everywhere else, are gaining attention, Hartwig says.
"There will be no loss of focus on the hurricanes," he said. "I think what there is, is an increase of focus on [thunderstorms]."
Allstate, the largest publicly traded insurer in the United States, has reduced its exposure in hurricane-prone areas and stopped writing new homeowners policies in California altogether, because of earthquake risk. It has also trimmed back its risk from inland storms.
Those efforts indicate that Allstate is saying goodbye to the "good old days," as its chief put it, when thunderstorms -- called "non-model catastrophes" in industry jargon -- were less violent.
"The assumption underlying some people's view is that this is an anomaly in severe weather, and that we'll go back to the good old days when non-model cats [catastrophes] were in the $500 million range, not the $2 billion range," Wilson said last month.
"We're not running our business that way. We're running our business as if this change ... is permanent," he said. "We don't know whether the genesis of that increase over the last three years is just a cyclical movement in weather, whether we're to 'normal' or we were at 'normal' before, or it's global warming or anything else, but we're acting as if this will be permanent and we need to recover those costs."
Copyright 2011 E&E Publishing. All Rights Reserved.
via nytimes.com
Sunday, May 22, 2011
Religion and Sex Quiz - NYTimes.com
Religion and Sex Quiz
By NICHOLAS D. KRISTOF
Faith is a huge force in American life, and it’s common to hear the Bible cited to bolster political and moral positions, especially against same-sex marriage and abortion. So here’s my 2011 religion quiz. Choose the best responses (some questions may have more than one correct answer):
1. The Bible’s position on abortion is:
a. Never mentioned.
b. To forbid it along with all forms of artificial birth control.
c. Condemnatory, except to save the life of the mother.
2. The Bible suggests “marriage” is:
a. The lifelong union of one man and one woman.
b. The union of one man and up to 700 wives.
c. Often undesirable, because it distracts from service to the Lord.
3. The Bible says of homosexuality:
a. Leviticus describes male sexual pairing as an abomination.
b. A lesbian should be stoned at her father’s doorstep.
c. There’s plenty of ambiguity and no indication of physical intimacy, but some readers point to Ruth and Naomi’s love as suspiciously close, or to King David declaring to Jonathan: “Your love to me was wonderful, passing the love of women.” (II Samuel 1:23-26)
4. In the Bible, erotic writing is:
a. Forbidden by Deuteronomy as “adultery of the heart.”
b. Exemplified by “Song of Songs,” which celebrates sex for its own sake.
c. Unmentioned.
5. Jesus says that divorce is permitted:
a. Only after counseling and trial separation.
b. Never.
c. Only to men whose wives have been unfaithful.
6. Among sexual behavior that is forbidden is:
a. Adultery.
b. Incest.
c. Sex with angels.
7. The people of Sodom were condemned principally for:
a. Homosexuality.
b. Blasphemy.
c. Lack of compassion for the poor and needy.
This quiz, and the answers below, draw from a new book, “Unprotected Texts: The Bible’s Surprising Contradictions about Sex and Desire.” It’s by Jennifer Wright Knust, a Bible scholar at Boston University who is also an ordained American Baptist pastor.
Professor Knust’s point is that the Bible’s teachings about sexuality are murky and inconsistent and prone to being hijacked by ideologues (this quiz involves some cherry-picking of my own). There’s also lots we just don’t understand: What exactly is the offense of “arsenokoitai” or “man beds” that St. Paul proscribes? It is often translated as a reference to homosexuality, but it more plausibly relates to male prostitution or pimping. Ambiguity is everywhere, which is why some of you will surely harrumph at my quiz answers:
1. A. Abortion is never mentioned as such.
2. A, B and C. The Bible limits women to one husband, but other than that is all over the map. Mark 10 envisions a lifelong marriage of one man and one woman. But King Solomon had 700 wives and 300 concubines (I Kings 11:3). And Matthew (Matthew 19:10-12) and St. Paul (I Corinthians 7) both seem to suggest that the ideal approach is to remain celibate and avoid marriage if possible, while focusing on serving God. Jesus (Matthew 19:12) even seems to suggest that men make themselves eunuchs, leading the early church to ban enthusiasts from self-castration.
3. A and C. As for stoning on a father’s doorstep, that is the fate not of lesbians but of non-virgin brides (Deuteronomy 22:13).
4. B. Read the “Song of Songs” and blush. It also serves as a metaphor for divine relations with Israel or with humans.
5. B and C. Jesus in Mark 10:11-12 condemns divorce generally, but in Matthew 5:32 and 19:9 suggests that a man can divorce his wife if she is guilty of sexual immorality.
6. A, B and C. We forget that early commentators were very concerned about sex with angels (Genesis 6, interpreted in the Letter of Jude and other places) as an incorrect mixing of two kinds.
7. C. “Sodomy” as a term for gay male sex began to be commonly used only in the 11th century and would have surprised early religious commentators. They attributed Sodom’s problems with God to many different causes, including idolatry, threats toward strangers and general lack of compassion for the downtrodden. Ezekiel 16:49 suggests that Sodomites “had pride, excess of food, and prosperous ease, but did not aid the poor and needy.”
Hmm. “Did not aid the poor and needy.” Who knew that that’s what the Bible condemns as sodomy? At a time of budget cuts that devastate the poor, isn’t that precisely the kind of disgusting immorality that we should all join together in the spirit of the Bible to repudiate?
via nytimes.com
Saturday, May 21, 2011
ThinkProgress » REPORT: Meet The Billionaires Who Are Trying To Privatize Our Schools And Kill Public Education
Meet The Billionaires Who Are Trying To Privatize Our Schools And Kill Public Education
Voucher advocate Betsy DeVos
This rapid expansion of voucher programs — which undermine and undercut public education by funnelling taxpayer money to private schools — is remarkable. After all, vouchers have been unpopular with the American public. Between 1966 and 2000, vouchers were put up for a vote in states 25 times, and voters rejected the program 24 of those times.
Yet if one looks behind the curtain — at the foundations, non-profits, Political Action Committees (PAC) — into the workings of the voucher movement, it’s apparent why it has gained strength in recent years. A tight-knit group of right-wing millionaires and billionaires, bankers, industrialists, lobby shops, and hardcore ideologues has been plotting this war on public education, quietly setting up front group after front group to promote the idea that the only way to save public education is to destroy it — disguising their movement with the innocent-sounding moniker of “school choice.”
ThinkProgress has prepared this report to expose this network and give Americans the knowledge they need to fight back against this assault on the nation’s public schools. Here are some of the top millionaires and their organizations waging war on our education system:
– Dick DeVos: The DeVos family has been active on education issues since the 1990′s. The son of billionaire Amway co-founder Richard DeVos, Sr., DeVos unsuccessfully ran for governor of the state of Michigan, spending $40 million, the most ever spent in a gubernatorial race in the state. In 2002, Dick DeVos sketched out a plan to undermine public education before the Heritage Foundation, explaining that education advocates should stop using the term “public schools” and instead call them “government schools.” He has poured millions of dollars into right-wing causes, including providing hundreds of thousands of dollars into seed money for numerous “school choice” groups, including Utah’s Parents for Choice in Education, which used its PAC money to elect pro-voucher politicians.
– Betsy DeVos: The wife of Dick DeVos, she also coincidentally happens to be the sister of Erik Prince, the leader of Xe, the mercenary outfit formerly known as Blackwater and is a former chair of the Republican Party of Michigan. Mrs. DeVos has been much more aggressive than her husband, pouring her millions into numerous voucher front groups across the country. She launched the pro-voucher group All Children Matter in 2003, which spent $7.6 million in its first year alone to impact state races related vouchers, winning 121 out of 181 races in which it intervened. All Children Matter was found breaking campaign finance laws in 2008, yet has still not paid its $5.2 million fine. She has founded and/or funded a vast network of voucher front groups, including Children First America, the Alliance for School Choice, Kids Hope USA, and the American Federation for Children.
- American Federation for Children (AFC): AFC made headlines recently when it brought together Govs. Scott Walker (R-WI) and Tom Corbett (R-PA) and former D.C. Schools Chancellor Michelle Rhee at a major school choice event in Washington, D.C. AFC is perhaps the most prominent of all the current voucher groups, having been founded in January 2010 by Betsy DeVos. Working together with its PAC of the same name and the 501c(3) organization also lead by DeVos, the Alliance for School Choice, it has served as a launching pad for school choice legislation across the country. AFC made its mark in Wisconsin by pouring thousands of dollars into the state legislative races, donating $40,000 in the service of successfully electing voucher advocate Rep. Kathy Bernier (R) and donating similar amounts to elect Reps. Andre Jacque (R), John Klenke (R), Tom Larson (R), Howard Marklein (R), Erik Severson (R), and Travis Tranel (R). DeVos front group All Children Matter also donated thousands to many of these same voucher advocates. Altogether, AFC spent $820,000 in Wisconsin during the last election, making it the 7th-largest single PAC spender during the election (behind several other mostly right-wing groups with similar agendas).
- Alliance for School Choice (ASC): The Alliance for School Choice is another DeVos front group founded to promote vouchers and serves as the education arm of AFC. In 2008, the last date available for its financial disclosures, its total assets amounted to $5,467,064. DeVos used the organization not only for direct spending into propaganda campaigns, but to give grants to organizations with benign-sounding names so that they could push the radical school choice agenda. For example, in 2008 the organization gave $530,000 grant to the “Black Alliance for Educational Options” in Washington, D.C. and a $433,736 grant to the “Florida School Choice Fund.” This allowed DeVos to promote her causes without necessarily revealing her role. But it isn’t just the DeVos family that’s siphoning money into the Alliance for School Choice and its many front group patrons. Among its other wealthy funders include the Jaquelin Hume Foundation (which gave $75,000 in 2008 and $100,000 in 2006), the brainchild of one of an ultra-wealthy California businessman who brought Ronald Reagan to power, the powerful Wal Mart Foundation (which gave $100,000 in 2005, the Chase Foundation of Virginia (which gave $9,000 in 2007, 2008, and the same amount in 2009), which funds over “supports fifty nonprofit libertarian/conservative public policy research organizations,” and hosts investment banker Derwood Chase, Jr. as a trustee, the infamous oil billionaire-driven Charles Koch Foundation ($10,000 in 2005), and the powerful Wal Mart family’s Walton Family Foundation (more than $3 million over 2004-2005).
- Bill and Susan Oberndorf: This Oberndorfs use their fortune, gained from Bill’s position as the managing director of the investment firm SPO Partners, to funnel money to a wide variety of school choice and corporate education reform groups. In 2009, their Bill and Susan Oberndorf Foundation gave $376,793 to AFC, $5,000 to the Center for Education Reform, and $50,000 to the Brighter Choice Foundation. Additionally, Bill Oberndorf gave half a million dollars to the school choice front group All Children Matter between 2005 and 2007. At a recent education panel, Bill Oberndorf was credited with giving “tens of millions” of dollars of his personal wealth to the school choice movement, and said that the passage of the Indiana voucher law was the “gold standard” for what should be done across America.
- The Walton Family Foundation (WFF):The Wal Mart-backed WFF is one of the most powerful foundations in the country, having made investments in 2009 totaling over $378 million. In addition to financing a number of privately-managed charter schools itself, the foundation showered ASC with millions of dollars in 2009. It also gave over a million dollars to the New York-based Brighter Choice Foundation, half a million dollars to the Florida School Choice Fund, $105,000 to the Foundation for Educational Choice, $774,512 to the Friends of Educational Choice, $400,000 to School Choice Ohio, and gave $50,000 to the Piton Foundation to promote a media campaign around the Colorado School Choice website — all in 2009 alone. WFF’s push for expanding private school education and undermining traditional public schools was best summed up by John Walton’s words in an interview in 2000. An interviewer asked him, “Do you think there’s money to be made in education?” Walton replied, “Absolutely. I think it will offer a reasonable return for investors.” (He also did vigorously argue in the same interview that he does not want to abolish public education).
The wealthy families and powerful corporate-backed foundations presented here are just a sampling of some of the forces currently taking aim at public education. By demonizing traditional public schools and the teachers that staff them, this corporate education movement is undermining a very basic aspect of our democracy: a public commons that provides true opportunity for all, no matter what their background or socioeconomic status.
While the goals of the figures in this movement are varied, their assault on our public education system is one and the same. Joseph Bast, the president and CEO of the Heartland Institute, explained his own thinking about vouchers once, saying, “The complete privatization of schooling might be desirable, but this objective is politically impossible for the time being. Vouchers are a type of reform that is possible now, and would put us on the path to further privatization.” It’s up to Americans to protect their schools, teachers, kids, and communities from that fate.
NASA - Galaxy Evolution Explorer Helps Confirm Nature of Dark Energy
NASA's Galaxy Evolution Explorer Helps Confirm Nature of Dark Energy05.19.11
In this artist's conception, dark energy is represented by the purple grid above, and gravity by the green grid below. Gravity emanates from all matter in the universe, but its effects are localized and drop off quickly over large distances. Image credit: NASA/JPL-Caltech
› Full image and caption
This diagram illustrates two ways to measure how fast the universe is expanding -- the "standard candle" method, which involves exploded stars in galaxies, and the "standard ruler" method, which involves pairs of galaxies. Image credit: NASA/JPL-Caltech
› Full image and captionPASADENA, Calif. -- A five-year survey of 200,000 galaxies, stretching back seven billion years in cosmic time, has led to one of the best independent confirmations that dark energy is driving our universe apart at accelerating speeds. The survey used data from NASA's space-based Galaxy Evolution Explorer and the Anglo-Australian Telescope on Siding Spring Mountain in Australia.
The findings offer new support for the favored theory of how dark energy works -- as a constant force, uniformly affecting the universe and propelling its runaway expansion. They contradict an alternate theory, where gravity, not dark energy, is the force pushing space apart. According to this alternate theory, with which the new survey results are not consistent, Albert Einstein's concept of gravity is wrong, and gravity becomes repulsive instead of attractive when acting at great distances.
"The action of dark energy is as if you threw a ball up in the air, and it kept speeding upward into the sky faster and faster," said Chris Blake of the Swinburne University of Technology in Melbourne, Australia. Blake is lead author of two papers describing the results that appeared in recent issues of the Monthly Notices of the Royal Astronomical Society. "The results tell us that dark energy is a cosmological constant, as Einstein proposed. If gravity were the culprit, then we wouldn't be seeing these constant effects of dark energy throughout time."
Dark energy is thought to dominate our universe, making up about 74 percent of it. Dark matter, a slightly less mysterious substance, accounts for 22 percent. So-called normal matter, anything with atoms, or the stuff that makes up living creatures, planets and stars, is only approximately four percent of the cosmos.
The idea of dark energy was proposed during the previous decade, based on studies of distant exploding stars called supernovae. Supernovae emit constant, measurable light, making them so-called "standard candles," which allows calculation of their distance from Earth. Observations revealed dark energy was flinging the objects out at accelerating speeds.
Dark energy is in a tug-of-war contest with gravity. In the early universe, gravity took the lead, dominating dark energy. At about 8 billion years after the Big Bang, as space expanded and matter became diluted, gravitational attractions weakened and dark energy gained the upper hand. Billions of years from now, dark energy will be even more dominant. Astronomers predict our universe will be a cosmic wasteland, with galaxies spread apart so far that any intelligent beings living inside them wouldn't be able to see other galaxies.
The new survey provides two separate methods for independently checking the supernovae results. This is the first time astronomers performed these checks across the whole cosmic timespan dominated by dark energy. The team began by assembling the largest three-dimensional map of galaxies in the distant universe, spotted by the Galaxy Evolution Explorer. The ultraviolet-sensing telescope has scanned about three-quarters of the sky, observing hundreds of millions of galaxies.
"The Galaxy Evolution Explorer helped identify bright, young galaxies, which are ideal for this type of study," said Christopher Martin, principal investigator for the mission at the California Institute of Technology in Pasadena. "It provided the scaffolding for this enormous 3-D map."
The astronomers acquired detailed information about the light for each galaxy using the Anglo-Australian Telescope and studied the pattern of distance between them. Sound waves from the very early universe left imprints in the patterns of galaxies, causing pairs of galaxies to be separated by approximately 500 million light-years.
This "standard ruler" was used to determine the distance from the galaxy pairs to Earth -- the closer a galaxy pair is to us, the farther apart the galaxies will appear from each other on the sky. As with the supernovae studies, this distance data were combined with information about the speeds at which the pairs are moving away from us, revealing, yet again, the fabric of space is stretching apart faster and faster.
The team also used the galaxy map to study how clusters of galaxies grow over time like cities, eventually containing many thousands of galaxies. The clusters attract new galaxies through gravity, but dark energy tugs the clusters apart. It slows down the process, allowing scientists to measure dark energy's repulsive force.
"Observations by astronomers over the last 15 years have produced one of the most startling discoveries in physical science; the expansion of the universe, triggered by the Big Bang, is speeding up," said Jon Morse, astrophysics division director at NASA Headquarters in Washington. "Using entirely independent methods, data from the Galaxy Evolution Explorer have helped increase our confidence in the existence of dark energy."
Caltech leads the Galaxy Evolution Explorer mission and is responsible for science operations and data analysis. NASA's Jet Propulsion Laboratory in Pasadena, manages the mission and built the science instrument. The mission was developed under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. Researchers sponsored by Yonsei University in South Korea and the Centre National d'Etudes Spatiales (CNES) in France collaborated on this mission. Caltech manages JPL for NASA.
Graphics and additional information about the Galaxy Evolution Explorer are online at http://www.nasa.gov/galex and http://www.galex.caltech.edu .
Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
Whitney.clavin@jpl.nasa.gov
via nasa.gov
Friday, May 20, 2011
As Big Hurricane Season Looms, NOAA Chief Calls Satellite Cuts a "Disaster": Scientific American
As Big Hurricane Season Looms, NOAA Chief Calls Satellite Cuts a "Disaster"
The loss of Earth-monitoring satellites impairs scientists' ability to track hurricanes--and they are predicting a lot of them this year
| May 20, 2011 | 
This year's Atlantic hurricane season will be "above normal," with 12 to 18 storms, thanks in part to unusually warm ocean temperatures, the National Oceanic and Atmospheric Administration said yesterday.
Six to 10 of those storms are likely to reach hurricane strength, the agency said in its initial forecast for the 2011 storm season, which begins June 1 and ends Nov. 1. NOAA forecasters expect three to six of those storms to become major hurricanes with winds reaching 111 miles per hour or greater.
"The active Atlantic hurricane era that we entered back in 1995 continues," NOAA Administrator Jane Lubchenco said. "During this period, the conditions in the oceans and the atmosphere have produced a larger number of storms and more powerful hurricanes."
This year, NOAA forecasters expect above-average warmth in the tropical Atlantic Ocean and the continuing influence of La Niña to drive a high level of storm activity.
The region's surface waters are 2 degrees Fahrenheit warmer than the average of this time of year, providing an extra burst of fuel to developing storms. Meanwhile, the current La Niña weather pattern -- expected to remain in place through early summer -- reduces the wind shear that can hinder hurricane development.
Speaking with reporters yesterday, Lubchenco touted her agency's forecasting ability, calling NOAA's forecast for last year's hurricane season "spot on." But she also warned that spending cuts enacted by Congress threaten NOAA's ability to produce detailed hurricane forecasts and track storms in the future.
"Because we have insufficient funds in the [fiscal] '11 budget, we are likely looking at a period of time a few years down the road where we will not be able to do the severe storm warnings and long-term weather forecasts that people have come to expect today," Lubchenco said in remarks at NOAA's Satellite Operations Center in Suitland, Md.
A 'coverage gap' in future years
The agency had sought $910 million this year for its Joint Polar Satellite System (JPSS), which will provide data for weather forecasts, search-and-rescue operations and climate change research. But Congress approved just $382 million for the program.
NOAA says it has enough money to launch the first JPSS satellite in October. But the agency says this year's budget shortfall will force it to delay the launch of the program's second orbiter by 14 to 18 months, beyond the expected lifetime of the first satellite. The likely result is a gap in crucial weather and climate data (ClimateWire, May 4).
"Satellites are a must-have when it comes to detecting and tracking dangerous tropical weather. Not having satellites and their capabilities could spell disaster," Lubchenco said yesterday. "NOAA's satellites underpin hurricane forecasts by providing meteorological data over vast areas where we don't have other means of information."
The information those satellites collect is also key to understanding climate change -- an unpopular topic on Capitol Hill -- but the agency has downplayed that aspect as it presses lawmakers for more cash.
"We are working very closely with Congress for this satellite program," Lubchenco said. "We continue to emphasize how much, how important this program is as a matter of public safety. This is of national significance, and we are hopeful we will be able to get the funding to get this program back on track."
A major scientific group echoed those concerns yesterday.
"Funding JPSS is a national preparedness issue," Christine McEntee, executive director of the American Geophysical Union, said in a statement yesterday. "A gap in satellite coverage could jeopardize everything from agriculture and aviation safety, to the oil and gas industry, to wildfire response and other search and rescue operations."
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
Thursday, May 19, 2011
Print Story: U.S. weather extremes show "new normal" climate - Yahoo! News
U.S. weather extremes show "new normal" climate
WASHINGTON (Reuters) – Heavy rains, deep snowfalls, monster floods and killing droughts are signs of a "new normal" of extreme U.S. weather events fueled by climate change, scientists and government planners said on Wednesday.
"It's a new normal and I really do think that global weirding is the best way to describe what we're seeing," climate scientist Katharine Hayhoe of Texas Tech University told reporters.
"We are used to certain conditions and there's a lot going on these days that is not what we're used to, that is outside our current frame of reference," Hayhoe said on a conference call with other experts, organized by the non-profit Union of Concerned Scientists.
An upsurge in heavy rainstorms in the United States has coincided with prolonged drought, sometimes in the same location, she said, noting that west Texas has seen a record-length dry period over the last five years, even as there have been two 100-year rain events.
Hayhoe, other scientists, civic planners and a manager at the giant Swiss Re reinsurance firm all cited human-caused climate change as an factor pushing this shift toward more extreme weather.
While none would blame climate change for any specific weather event, Hayhoe said a background of climate change had an impact on every rainstorm, heat wave or cold snap.
"What we're seeing is the new normal is constantly evolving," said Nikhil da Victoria Lobo of Swiss Re's Global Partnerships team. "Globally what we're seeing is more volatility ... there's certainly a lot more integrated risk exposure."
CHICAGO'S SEWERS
In addition to more extreme local weather events, he said, changes in demographics and how materials are supplied make them more vulnerable.
"In a more integrated economic system, a single shock to an isolated area can actually end up having broad-based and material implications," da Victoria Lobo said. For example, if a local storm knocks out transport and communications systems, "someone 1,000 miles away is not receiving their iPad or their car."
Aaron Durnbaugh, deputy commissioner for natural resources and water quality for Chicago, said adapting to climate change is a daunting task.
Citing the down-to-earth example of Chicago's 4,400 miles of sewer mains, which were installed over the last 150 years and will take decades to replace, Durnbaugh said accurate forecasting of future storms and floods is essential.
The city of Chicago's cost of dealing with extreme weather events through the end of this century has been conservatively estimated in a range from $690 million to $2.5 billion, Durnbaugh said, with the cost to homeowners and local businesses expected to be far higher.
Globally, da Victoria Lobo said the annual average economic losses from natural disasters have escalated from $25 billion in the 1980s to $130 billion in the first decade of the 21st century.
via news.yahoo.com
Study: How a ‘Fat Gene’ Affects Cholesterol and Diabetes – TIME Healthland
How a 'Fat Gene' Affects Cholesterol and diabetes
Seth Joel / Photographer's Choice via Getty Images
Scientists have long known that obesity is associated with a host of other health conditions, including Type 2 diabetes and heart disease. Now a team of researchers at King's College London and the University of Oxford have shed light on why: a gene found in fat tissue acts as a "master regulator," controlling the effect of a bunch of other genes that are linked to obesity, cholesterol and diabetes.
The master gene in question is called KLF14, and while it has previously been linked to Type 2 diabetes and cholesterol, the new research clarifies how — and offers a new target for treatment of obesity-related diseases.
"This is the first major study that shows how small changes in one master regulator gene can cause a cascade of other metabolic effects in other genes," said lead author Tim Spector in a statement.
The research was part of a large-scale multinational study called the MuTHER study (for Multiple Tissue Human Expression Resource). Scientists analyzed more than 20,000 genes found in fat samples taken from just under the skin of 400 pairs of female twins in the U.K. They found an association between KLF14 and the expression of other genes, also found in fat, that affect a range of metabolic traits including body-mass index, cholesterol and insulin and glucose levels.
To confirm the findings, the researchers further tested 600 fat samples from a separate group of Icelandic women.
Interestingly, the researchers say, the activity of the KLF14 gene is inherited from the mother; the copy of the gene inherited from the father is switched off. So how a person's KLF14 gene may affect expression of other metabolism-related genes is dependent on the copy received from the mother.
The findings further corroborate existing evidence that metabolic traits — everything from weight to insulin levels are interrelated — and that those relationships have a genetic component.
The researchers hope their discovery will spur further research and someday help improve medical treatments for obesity and its associated metabolic diseases. "This has great therapeutic potential," said Spector. "By studying large detailed populations such as the twins we hope to find more of these regulators."
The study was published in Nature Genetics on May 15.
'Like' Button Follows Web Users - WSJ.com
'Like' Button Follows Web Users
These so-called social widgets, which appear atop stories on news sites or alongside products on retail sites, notify Facebook and Twitter that a person visited those sites even when users don't click on the buttons, according to a study done for The Wall Street Journal.
These widgets are prolific. They have been added to millions of web pages in the past year. Facebook's buttons appear on a third of the world's 1,000 most-visited websites, according to the study. Buttons from Twitter and Google Inc. appear on 20% and 25% of those sites, respectively.
The widgets, which were created to make it easy to share content with friends and to help websites attract visitors, are a potentially powerful way to track Internet users. They could link users' browsing habits to their social-networking profile, which often contains their name.
For example, Facebook or Twitter know when one of their members reads an article about filing for bankruptcy on MSNBC.com or goes to a blog about depression called Fighting the Darkness, even if the user doesn't click the "Like" or "Tweet" buttons on those sites.
For this to work, a person only needs to have logged into Facebook or Twitter once in the past month. The sites will continue to collect browsing data, even if the person closes their browser or turns off their computers, until that person explicitly logs out of their Facebook or Twitter accounts, the study found.
Facebook, Twitter, Google and other widget-makers say they don't use browsing data generated by the widgets to track users; Facebook says it only uses the data for advertising purposes when a user clicks on a widget to share content with friends.
Facebook and Google, which has a widget for its "Buzz" social-networking service, say they "anonymize" browsing data so the information is not traced to a particular user. Facebook says the data are deleted within 90 days, while Google says data are deleted within two weeks. Facebook and Google say they use the information to measure the widgets' effectiveness and help other websites attract visitors.
Twitter says it doesn't use such browsing data and deletes it "quickly." A spokesman says the company could in theory use the data to "surface better content" for users in the future.
Revelations about the social widgets come amid growing concern about the privacy of Internet and smartphone users. Members of Congress have introduced at least five privacy-related bills this year, including three that aim to create a mechanism that would let users disable tracking.
Some privacy advocates express concerns, citing prior Facebook and Google stumbles over privacy issues.
"Our reading habits online encompass everything we're thinking about, political and religious views, health and relationship problems," said Peter Eckersley, a senior technologist at the Electronic Frontier Foundation, a privacy-advocacy group. "Do you want to have an invisible person peering over your shoulder as you walk through the library?"
Widget makers say the collection of users' Web-browsing activity is an unintended side effect of how the tools work. In order to show a user which of their online friends "liked" a particular article, for example, the widget must know who the user is.
To determine the prevalence of widgets and how they collect information, the Journal asked Brian Kennish, a former Google engineer, to examine the 1,000 most-popular websites, as ranked by Google's advertising network. Mr. Kennish last year launched Disconnect Inc., which offers software to block data collection by widgets.
Mr. Kennish's study examined more than 200,000 Web pages on the top 1,000 sites. He found Facebook obtained browsing data from 331 sites, and Google obtained data from 250 sites, some of it from its Buzz widget. Twitter got browsing information from about 200 sites.
Social-sharing widgets first appeared about five years ago, when online services such as Digg Inc. allowed users to share news articles. At the time, widgets did not cause browsing data to be collected by social sites. Widgets are installed by website owners, who like them because they can help generate more Web traffic.
Last year, Facebook introduced the "Like" button and other "smart" widgets. The widgets work with cookies that Facebook places in a Web browser when a user creates an account or logs in to its site. Together, they allow Facebook to recognize its users on any site with Facebook widgets.
Bret Taylor, Facebook's chief technology officer, says the technology lets websites show visitors what articles their friends liked, for example. "We don't use them for tracking and they're not intended for tracking," he says.
But Facebook says it still places a cookie on the computer of anyone who visits the Facebook.com home page, even if the user isn't a member. Mr. Taylor says Facebook uses such cookies to protect the site from cyberattacks by people who try to break in to users' accounts, among other things.
Until recently, some Facebook widgets also obtained browsing data about Internet users who had never visited Facebook.com, though Facebook wouldn't know their identity. The company says it discontinued that practice, which it described as a "bug," earlier this year after it was disclosed by a researcher in the Netherlands.
—Geoffrey A. Fowler contributed to this article.Write to Amir Efrati at amir.efrati@wsj.com
via online.wsj.com
Wednesday, May 18, 2011
Atmosphere Above Japan Heated Rapidly Before M9 Earthquake - Technology Review
Atmosphere Above Japan Heated Rapidly Before M9 Earthquake
Infrared emissions above the epicenter increased dramatically in the days before the devastating earthquake in Japan, say scientists.
Geologists have long puzzled over anecdotal reports of strange atmospheric phenomena in the days before big earthquakes. But good data to back up these stories has been hard to come by.
In recent years, however, various teams have set up atmospheric monitoring stations in earthquake zones and a number of satellites are capable of sending back data about the state of the upper atmosphere and the ionosphere during an earthquake.
Last year, we looked at some fascinating data from the DEMETER spacecraft showing a significant increase in ultra-low frequency radio signals before the magnitude 7 Haiti earthquake in January 2010
Today, Dimitar Ouzounov at the NASA Goddard Space Flight Centre in Maryland and a few buddies present the data from the Great Tohoku earthquake which devastated Japan on 11 March. Their results, although preliminary, are eye-opening.
They say that before the M9 earthquake, the total electron content of the ionosphere increased dramatically over the epicentre, reaching a maximum three days before the quake struck.
At the same time, satellite observations showed a big increase in infrared emissions from above the epicentre, which peaked in the hours before the quake. In other words, the atmosphere was heating up.
These kinds of observations are consistent with an idea called the Lithosphere-Atmosphere-Ionosphere Coupling mechanism. The thinking is that in the days before an earthquake, the great stresses in a fault as it is about to give cause the releases large amounts of radon.
The radioactivity from this gas ionises the air on a large scale and this has a number of knock on effects. Since water molecules are attracted to ions in the air, ionisation triggers the large scale condensation of water.
But the process of condensation also releases heat and it is this that causes infrared emissions. "Our first results show that on March 8th a rapid increase of emitted infrared radiation was observed from the satellite data," say Ouzounov and co.
These emissions go on to effect the ionosphere and its total electron content.
It certainly makes sense that the lithosphere, atmosphere and ionosphere are coupled in a way that can be measured when one of them is perturbed. The question is to what extent the new evidence backs up this idea.
The Japan earthquake is the largest to have struck the island in modern times and will certainly turn out to be among the best studied. If good evidence of this relationship doesn't emerge from this data, other opportunities will be few and far between.
Ref: arxiv.org/abs/1105.2841: Atmosphere-Ionosphere Response to the M9 Tohoku Earthquake Revealed by Joined Satellite and Ground Observations. Preliminary Results.
Rogue planets! Scientists detect Jupiter-sized roamers inside the Milky Way -- Printout -- TIME
Wednesday, May. 18, 2011
Rogue Planets: Billions of Jupiters on the Loose in the Milky Way
The bitterly fought Pluto wars of a few years back showed that even the experts disagree on what is and what isn't a planet. One thing there's no quarrel about, of course: a planet is, by definition, something that orbits a star.
Except, it turns out, when it isn't. Writing in the latest issue of Nature, a team of astronomers is reporting the discovery of ten objects roughly the size of Jupiter that seem to be on the loose, roaming the galaxy untethered to any star. And while ten seems like an insignificant number in a galaxy packed with 200 billion or more stars, the search was an extremely limited one. Unless the observers happened to be absurdly lucky, there could actually be a lot more of these rogue Jupiters — perhaps twice as many stars as there are in the Milky Way. See the top 50 space moments since Sputnik.
"The implications of this discovery," writes Joachim Wambsganss, of the Center for Astronomy at the University of Heidelberg in an accompanying Nature commentary, "are profound."
They aren't, however, completely unexpected. As the known number of more conventional exoplanets — that is, those that actually do orbit stars — has grown to more than 500 in recent years, astronomers have begun to realize that our own well-behaved Solar System isn't necessarily typical. The eight planets orbit the Sun in nearly circular orbits, all moving in the same direction as the Sun rotates. But plenty of alien worlds orbit their stars in eccentric, somewhat egg-shaped orbits and surprising numbers move around their stars in highly tilted orbits as well. (Non-planet Pluto inscribes just such an inclined and elliptical path.) Some planets even orbit backwards. See pictures of Saturn.
That suggests that sometime in the past, close gravitational encounters with other planets flung them out of their previously conventional orbits. Theorists have predicted for years that such close encounters might also fling planets out into interstellar space.
"There's nothing physically mysterious about this," says David Stevenson, a Caltech astronomer who has been working on rogue-planet scenarios for more than a decade. "It's a perfectly natural outcome." See pictures of five nations' space programs.
Still, he says, it's exciting to see something that had been purely theoretical backed up by hard evidence. It's also notable that these planets were discovered with a technique that sounds like something out of Star Trek. As Einstein explained nearly a century ago, the gravity of a massive object such as a star or a planet warps the spacetime that surrounds it. If a ray of light passes close by, the light will be diverted, just as though it were passing through a giant lens. In the 1930's, Einstein realized that if one star passed in front of another, the closer star could act as a "gravitational lens," focusing the light of the more distant star and making it look brighter. We'd never actually see such an effect, conceded Einstein. All stars orbit the center of the galaxy at slightly different speeds, meaning that they are in constant motion relative to one another; still, the exact lineup needed to make true lensing occur would happen only very rarely, Einstein believed.
For once, though, the great man was wrong. The first gravitational lens was spotted in 1979 and they've become a mainstay of astronomical research ever since. This has aided in the search for exoplanets, as astronomers scan the skies for double flashes — one caused by a foreground star moving in front of a background star, and one following soon after, caused by the orbiting planet.
(See TIME's space shuttle covers.)
It's not the most efficient way to discover planets, since you never know when just the right line-up will occur, but about dozen star-planet pairs have been found with this technique. The ten free-floating planets revealed themselves the same way, but what distinguished them, says Takahiro Sumi, of Osaka University, the study's lead author, is that when they pass in front of a background star, "we don't see any evidence of the host star." Not, at least, within a billion miles or so of the planets, and based on more conventional studies of exoplanets, that suggests that many if not all of the planets indeed have no host stars at all.
The one caveat offered by both Stevenson and Wambsganss is that while these objects are certainly similar in mass to Jupiter, they could, in fact, be more like small stars, having condensed as the central object out of a swirl of cosmic dust and gas, albeit without sufficient mass to light their nuclear fires. Conventional planets condense out of similar clouds, but they are made up of the leftover dust a parent star didn't use. Some planetary theorists argued that the term "planet" should only apply to the latter, even if two objects have exactly the same mass. See pictures of Earth from space.
But offsetting that caveat is an even more exciting possibility. If close encounters can throw Jupiter-sized planets out of a solar system, they can throw smaller, Earth-sized worlds out even more easily — meaning they may outnumber even the hundreds of billions of drifting Jupiters. The brief magnifying flashes they produce would be very hard to detect from the ground, but a proposed space telescope known as the Microlensing Planet Finder could do it, and even find planets as small as Mars.
In theory, the mission could fly by 2020. In these days of reduced budgets, however, there's no guarantee that will actually happen. But if it does, we may soon know what the theorists already suspect: that the Milky Way is teeming with free-range planets of all sizes, floating silently and forlornly in the spaces between the stars.
via time.com
Tuesday, May 17, 2011
Augmented Reality in a Contact Lens - IEEE Spectrum
Image: Raygun Studio
The human eye is a perceptual powerhouse. It can see millions of colors, adjust easily to shifting light conditions, and transmit information to the brain at a rate exceeding that of a high-speed Internet connection.
But why stop there?
In the Terminator movies, Arnold Schwarzenegger’s character sees the world with data superimposed on his visual field—virtual captions that enhance the cyborg’s scan of a scene. In stories by the science fiction author Vernor Vinge, characters rely on electronic contact lenses, rather than smartphones or brain implants, for seamless access to information that appears right before their eyes.
These visions (if I may) might seem far-fetched, but a contact lens with simple built-in electronics is already within reach; in fact, my students and I are already producing such devices in small numbers in my laboratory at the University of Washington, in Seattle [see sidebar, "A Twinkle in the Eye"]. These lenses don’t give us the vision of an eagle or the benefit of running subtitles on our surroundings yet. But we have built a lens with one LED, which we’ve powered wirelessly with RF. What we’ve done so far barely hints at what will soon be possible with this technology.
Conventional contact lenses are polymers formed in specific shapes to correct faulty vision. To turn such a lens into a functional system, we integrate control circuits, communication circuits, and miniature antennas into the lens using custom-built optoelectronic components. Those components will eventually include hundreds of LEDs, which will form images in front of the eye, such as words, charts, and photographs. Much of the hardware is semitransparent so that wearers can navigate their surroundings without crashing into them or becoming disoriented. In all likelihood, a separate, portable device will relay displayable information to the lens’s control circuit, which will operate the optoelectronics in the lens.
These lenses don’t need to be very complex to be useful. Even a lens with a single pixel could aid people with impaired hearing or be incorporated as an indicator into computer games. With more colors and resolution, the repertoire could be expanded to include displaying text, translating speech into captions in real time, or offering visual cues from a navigation system. With basic image processing and Internet access, a contact-lens display could unlock whole new worlds of visual information, unfettered by the constraints of a physical display.
Besides visual enhancement, noninvasive monitoring of the wearer’s biomarkers and health indicators could be a huge future market. We’ve built several simple sensors that can detect the concentration of a molecule, such as glucose. Sensors built onto lenses would let diabetic wearers keep tabs on blood-sugar levels without needing to prick a finger. The glucose detectors we’re evaluating now are a mere glimmer of what will be possible in the next 5 to 10 years. Contact lenses are worn daily by more than a hundred million people, and they are one of the only disposable, mass-market products that remain in contact, through fluids, with the interior of the body for an extended period of time. When you get a blood test, your doctor is probably measuring many of the same biomarkers that are found in the live cells on the surface of your eye—and in concentrations that correlate closely with the levels in your bloodstream. An appropriately configured contact lens could monitor cholesterol, sodium, and potassium levels, to name a few potential targets. Coupled with a wireless data transmitter, the lens could relay information to medics or nurses instantly, without needles or laboratory chemistry, and with a much lower chance of mix-ups.
Three fundamental challenges stand in the way of building a multipurpose contact lens. First, the processes for making many of the lens’s parts and subsystems are incompatible with one another and with the fragile polymer of the lens. To get around this problem, my colleagues and I make all our devices from scratch. To fabricate the components for silicon circuits and LEDs, we use high temperatures and corrosive chemicals, which means we can’t manufacture them directly onto a lens. That leads to the second challenge, which is that all the key components of the lens need to be miniaturized and integrated onto about 1.5 square centimeters of a flexible, transparent polymer. We haven’t fully solved that problem yet, but we have so far developed our own specialized assembly process, which enables us to integrate several different kinds of components onto a lens. Last but not least, the whole contraption needs to be completely safe for the eye. Take an LED, for example. Most red LEDs are made of aluminum gallium arsenide, which is toxic. So before an LED can go into the eye, it must be enveloped in a biocompatible substance.
So far, besides our glucose monitor, we’ve been able to batch-fabricate a few other nanoscale biosensors that respond to a target molecule with an electrical signal; we’ve also made several microscale components, including single-crystal silicon transistors, radio chips, antennas, diffusion resistors, LEDs, and silicon photodetectors. We’ve constructed all the micrometer-scale metal interconnects necessary to form a circuit on a contact lens. We’ve also shown that these microcomponents can be integrated through a self-assembly process onto other unconventional substrates, such as thin, flexible transparent plastics or glass. We’ve fabricated prototype lenses with an LED, a small radio chip, and an antenna, and we’ve transmitted energy to the lens wirelessly, lighting the LED. To demonstrate that the lenses can be safe, we encapsulated them in a biocompatible polymer and successfully tested them in trials with live rabbits.
Photos: University of Washington
Second Sight:
In recent trials, rabbits wore lenses containing metal circuit structures for 20 minutes at a time with no adverse effects.
Seeing the light—LED light—is a reasonable accomplishment. But seeing something useful through the lens is clearly the ultimate goal. Fortunately, the human eye is an extremely sensitive photodetector. At high noon on a cloudless day, lots of light streams through your pupil, and the world appears bright indeed. But the eye doesn’t need all that optical power—it can perceive images with only a few microwatts of optical power passing through its lens. An LCD computer screen is similarly wasteful. It sends out a lot of photons, but only a small fraction of them enter your eye and hit the retina to form an image. But when the display is directly over your cornea, every photon generated by the display helps form the image.
The beauty of this approach is obvious: With the light coming from a lens on your pupil rather than from an external source, you need much less power to form an image. But how to get light from a lens? We’ve considered two basic approaches. One option is to build into the lens a display based on an array of LED pixels; we call this an active display. An alternative is to use passive pixels that merely modulate incoming light rather than producing their own. Basically, they construct an image by changing their color and transparency in reaction to a light source. (They’re similar to LCDs, in which tiny liquid-crystal ”shutters” block or transmit white light through a red, green, or blue filter.) For passive pixels on a functional contact lens, the light source would be the environment. The colors wouldn’t be as precise as with a white-backlit LCD, but the images could be quite sharp and finely resolved.
We’ve mainly pursued the active approach and have produced lenses that can accommodate an 8-by-8 array of LEDs. For now, active pixels are easier to attach to lenses. But using passive pixels would significantly reduce the contact’s overall power needs—if we can figure out how to make the pixels smaller, higher in contrast, and capable of reacting quickly to external signals.
By now you’re probably wondering how a person wearing one of our contact lenses would be able to focus on an image generated on the surface of the eye. After all, a normal and healthy eye cannot focus on objects that are fewer than 10 centimeters from the corneal surface. The LEDs by themselves merely produce a fuzzy splotch of color in the wearer’s field of vision. Somehow the image must be pushed away from the cornea. One way to do that is to employ an array of even smaller lenses placed on the surface of the contact lens. Arrays of such microlenses have been used in the past to focus lasers and, in photolithography, to draw patterns of light on a photoresist. On a contact lens, each pixel or small group of pixels would be assigned to a microlens placed between the eye and the pixels. Spacing a pixel and a microlens 360 micrometers apart would be enough to push back the virtual image and let the eye focus on it easily. To the wearer, the image would seem to hang in space about half a meter away, depending on the microlens.
Another way to make sharp images is to use a scanning microlaser or an array of microlasers. Laser beams diverge much less than LED light does, so they would produce a sharper image. A kind of actuated mirror would scan the beams from a red, a green, and a blue laser to generate an image. The resolution of the image would be limited primarily by the narrowness of the beams, and the lasers would obviously have to be extremely small, which would be a substantial challenge. However, using lasers would ensure that the image is in focus at all times and eliminate the need for microlenses.
Whether we use LEDs or lasers for our display, the area available for optoelectronics on the surface of the contact is really small: roughly 1.2 millimeters in diameter. The display must also be semitransparent, so that wearers can still see their surroundings. Those are tough but not impossible requirements. The LED chips we’ve built so far are 300 µm in diameter, and the light-emitting zone on each chip is a 60-µm-wide ring with a radius of 112 µm. We’re trying to reduce that by an order of magnitude. Our goal is an array of 3600 10-µm-wide pixels spaced 10 µm apart.
One other difficulty in putting a display on the eye is keeping it from moving around relative to the pupil. Normal contact lenses that correct for astigmatism are weighted on the bottom to maintain a specific orientation, give or take a few degrees. I figure the same technique could keep a display from tilting (unless the wearer blinked too often!).
Like all mobile electronics, these lenses must be powered by suitable sources, but among the options, none are particularly attractive. The space constraints are acute. For example, batteries are hard to miniaturize to this extent, require recharging, and raise the specter of, say, lithium ions floating around in the eye after an accident. A better strategy is gathering inertial power from the environment, by converting ambient vibrations into energy or by receiving solar or RF power. Most inertial power scavenging designs have unacceptably low power output, so we have focused on powering our lenses with solar or RF energy.
Let’s assume that 1 square centimeter of lens area is dedicated to power generation, and let’s say we devote the space to solar cells. Almost 300 microwatts of incoming power would be available indoors, with potentially much more available outdoors. At a conversion efficiency of 10 percent, these figures would translate to 30 µW of available electrical power, if all the subsystems of the contact lens were run indoors.
Collecting RF energy from a source in the user’s pocket would improve the numbers slightly. In this setup, the lens area would hold antennas rather than photovoltaic cells. The antennas’ output would be limited by the field strengths permitted at various frequencies. In the microwave bands between 1.5 gigahertz and 100 GHz, the exposure level considered safe for humans is 1 milliwatt per square centimeter. For our prototypes, we have fabricated the first generation of antennas that can transmit in the 900-megahertz to 6-GHz range, and we’re working on higher-efficiency versions. So from that one square centimeter of lens real estate, we should be able to extract at least 100 µW, depending on the efficiency of the antenna and the conversion circuit.
Having made all these subsystems work, the final challenge is making them all fit on the same tiny polymer disc. Recall the pieces that we need to cram onto a lens: metal microstructures to form antennas; compound semiconductors to make optoelectronic devices; advanced complementary metal-oxide-semiconductor silicon circuits for low-power control and RF telecommunication; microelectromechanical system (MEMS) transducers and resonators to tune the frequencies of the RF communication; and surface sensors that are reactive with the biochemical environment.
The semiconductor fabrication processes we’d typically use to make most of these components won’t work because they are both thermally and chemically incompatible with the flexible polymer substrate of the contact lens. To get around this problem, we independently fabricate most of the microcomponents on silicon-on-insulator wafers, and we fabricate the LEDs and some of the biosensors on other substrates. Each part has metal interconnects and is etched into a unique shape. The end yield is a collection of powder-fine parts that we then embed in the lens.
We start by preparing the substrate that will hold the microcomponents, a 100-µm-thick slice of polyethylene terephthalate. The substrate has photolithographically defined metal interconnect lines and binding sites. These binding sites are tiny wells, about 10 µm deep, where electrical connections will be made between components and the template. At the bottom of each well is a minuscule pool of a low-melting-point alloy that will later join together two interconnects in what amounts to micrometer-scale soldering.
We then submerge the plastic lens substrate in a liquid medium and flow the collection of microcomponents over it. The binding sites are cut to match the geometries of the individual parts so that a triangular component finds a triangular well, a circular part falls into a circular well, and so on. When a piece falls into its complementary well, a small metal pad on the surface of the component comes in contact with the alloy at the bottom of the well, causing a capillary force that lodges the component in place. After all the parts have found their slots, we drop the temperature to solidify the alloy. This step locks in the mechanical and electrical contact between the components, the interconnects, and the substrate.
The next step is to ensure that all the potentially harmful components that we’ve just assembled are completely safe and comfortable to wear. The lenses we’ve been developing resemble existing gas-permeable contacts with small patches of a slightly less breathable material that wraps around the electronic components. We’ve been encapsulating the functional parts with poly(methyl methacrylate), the polymer used to make earlier generations of contact lenses. Then there’s the question of the interaction of heat and light with the eye. Not only must the system’s power consumption be very low for the sake of the energy budget, it must also avoid generating enough heat to damage the eye, so the temperature must remain below 45 °C. We have yet to investigate this concern fully, but our preliminary analyses suggest that heat shouldn’t be a big problem.
Photos: University of Washington
In Focus:
One lens prototype [left] has several interconnects, single-crystal silicon components, and compound-semiconductor components embedded within. Another sample lens [right] contains a radio chip, an antenna, and a red LED.
All the basic technologies needed to build functional contact lenses are in place. We’ve tested our first few prototypes on animals, proving that the platform can be safe. What we need to do now is show all the subsystems working together, shrink some of the components even more, and extend the RF power harvesting to higher efficiencies and to distances greater than the few centimeters we have now. We also need to build a companion device that would do all the necessary computing or image processing to truly prove that the system can form images on demand. We’re starting with a simple product, a contact lens with a single light source, and we aim to work up to more sophisticated lenses that can superimpose computer-generated high-resolution color graphics on a user’s real field of vision.
The true promise of this research is not just the actual system we end up making, whether it’s a display, a biosensor, or both. We already see a future in which the humble contact lens becomes a real platform, like the iPhone is today, with lots of developers contributing their ideas and inventions. As far as we’re concerned, the possibilities extend as far as the eye can see, and beyond.
The author would like to thank his past and present students and collaborators, especially Brian Otis, Desney Tan, and Tueng Shen, for their contributions to this research.
About the Author
Babak A. Parviz wakes up every morning and sticks a small piece of polymer in each eye. So it was only a matter of time before this bionanotechnology expert at the University of Washington, in Seattle, imagined contact lenses with built-in circuits and LEDs. “It’s really fun to hook things up and see how they might work,” he says. In “For Your Eye Only”, Parviz previews a contact lens for the 21st century.
To Probe Further
You can find details about the fabrication process using self-assembly in “Self-Assembled Single-Crystal Silicon Circuits on Plastic,” by Sean A. Stauth and Babak A. Parviz, in Proceedings of the National Academy of Sciences, 19 September 2006.
Slingbox Founder Makes Homes Smarter with Android: Mobile Technology News «
Crestron has already had a similar application for iOS devices since September of last year, so Kirkorian turned to Android for his hobby. But he didn’t just develop an Android application. In this video from last fall, Kirkorian explains that R2 can run Crestron projects developed for iOS tablets and phones without the need to recompile. R2 is both an application and a platform in that sense.
I have my own home automation system that I control with a much cheaper Android application, but there’s a huge difference in my solution. I’m building my system piecemeal as a do-it-yourself project. Crestron is, in Kirkorian’s words, “the 800-lb gorilla in the home/building control space,” with more than 2,000 products that interface with different products and systems. These various home automation products are sold through Crestron dealers which offer professional installation of the entire system. The private firm was founded in 1969 and currently employs more than 2,500 people to help develop, sell and install its high-end home automation systems.
The price and scope of smart sensors available for smartphones (think cameras, gyroscopes and more) are finding their way into various new products that can help our homes become more intelligent. My outdoor lights turn on 15 minutes prior to sundown daily, for example, thanks to a small computer and a connected switch that can receive wireless commands. The system parts are there; connectivity is available; and software is the last part needed to make such systems work together.
Much like the final mile of broadband, Kirkorian again shows he has a knack for understanding for that last little bit needed to make a home solution go from concept to reality.
via gigaom.com
First habitable exoplanet? | ScienceDaily.com
First Habitable Exoplanet? Climate Simulation Reveals New Candidate That Could Support Earth-Like Life
ScienceDaily (May 16, 2011) — The planetary system around the red dwarf Gliese 581, one of the closest stars to the Sun in the galaxy, has been the subject of several studies aiming to detect the first potentially habitable exoplanet. Two candidates have already been discarded, but a third planet, Gliese 581d, can be considered the first confirmed exoplanet that could support Earth-like life. This is the conclusion of a team of scientists from the Institut Pierre Simon Laplace (CNRS, UPMC, ENS Paris, Ecole Polytechnique) in Paris, France, whose study is published in The Astrophysical Journal Letters.
Are there other planets inhabited like Earth, or at least habitable? The discovery of the first habitable planet has become a quest for many astrophysicists who look for rocky planets in the "habitable zone" around stars, the range of distances in which planets are neither too cold nor too hot for life to flourish.
In this quest, the red dwarf star Gliese 581 has already received a huge amount of attention. In 2007, scientists reported the detection of two planets orbiting not far from the inner and outer edge of its habitable zone. While the more distant planet, Gliese 581d, was initially judged to be too cold for life, the closer-in planet was thought to be potentially habitable by its discoverers. However, later analysis by atmospheric experts showed that if it had liquid oceans like Earth, they would rapidly evaporate in a 'runaway greenhouse' effect similar to that which gave Venus the hot, inhospitable climate it has today. A new possibility emerged late in 2010, when a team of observers led by Steven Vogt at the University of California, Santa Cruz, announced that they had discovered a new planet, which they dubbed Gliese 581g, or 'Zarmina's World'. This planet, they claimed, had a mass similar to that of Earth and was close to the centre of the habitable zone. For several months, the discovery of the first potential Earth twin outside the Solar System seemed to have been achieved. Unfortunately, later analysis by independent teams has raised serious doubts on this extremely difficult detection. Many now believe that Gliese 581g may not exist at all. Instead, it may simply be a result of noise in the ultra-fine measurements of stellar 'wobble' needed to detect exoplanets in this system.
Today, it is finally Gliese 581g's big brother -- the larger and more distant Gliese 581d -- which has been shown to be the confirmed potentially habitable exoplanet by Robin Wordsworth, François Forget and co-workers from Laboratoire de Météorologie Dynamique (CNRS, UPMC, ENS Paris, Ecole Polytechnique) at the Institute Pierre Simon Laplace in Paris. Although it is likely to be a rocky planet, it has a mass at least seven times that of Earth, and is estimated to be about twice its size. At first glance, Gliese 581d is a pretty poor candidate in the hunt for life: it receives less than a third of the stellar energy Earth does and may be tidally locked, with a permanent day and night side. After its discovery, it was generally believed that any atmosphere thick enough to keep the planet warm would become cold enough on the night side to freeze out entirely, ruining any prospects for a habitable climate.
To test whether this intuition was correct, Wordsworth and colleagues developed a new kind of computer model capable of accurately simulating possible exoplanet climates. The model simulates a planet's atmosphere and surface in three dimensions, rather like those used to study climate change on Earth. However, it is based on more fundamental physical principles, allowing the simulation of a much wider range of conditions than would otherwise be possible, including any atmospheric cocktail of gases, clouds and aerosols.
To their surprise, they found that with a dense carbon dioxide atmosphere -- a likely scenario on such a large planet -- the climate of Gliese 581d is not only stable against collapse, but warm enough to have oceans, clouds and rainfall. One of the key factors in their results was Rayleigh scattering, the phenomenon that makes the sky blue on Earth. In the Solar System, Rayleigh scattering limits the amount of sunlight a thick atmosphere can absorb, because a large portion of the scattered blue light is immediately reflected back to space. However, as the starlight from Gliese 581 is red, it is almost unaffected. This means that it can penetrate much deeper into the atmosphere, where it heats the planet effectively due to the greenhouse effect of the CO2 atmosphere, combined with that of the carbon dioxide ice clouds predicted to form at high altitudes. Furthermore, the 3D circulation simulations showed that the daylight heating was efficiently redistributed across the planet by the atmosphere, preventing atmospheric collapse on the night side or at the poles.
Scientists are particularly excited by the fact that at 20 light years from Earth, Gliese 581d is one of our closest galactic neighbours. For now, this is of limited use for budding interstellar colonists -- the furthest-travelled human-made spacecraft, Voyager 1, would still take over 300,000 years to arrive there. However, it does mean that in the future telescopes will be able to detect the planet's atmosphere directly. While Gliese 581d may be habitable there are other possibilities; it could have kept some atmospheric hydrogen, like Uranus and Neptune, or the fierce wind from its star during its infancy could even have torn its atmosphere away entirely. To distinguish between these different scenarios, Wordsworth and co-workers came up with several simple tests that observers will be able to perform in future with a sufficiently powerful telescope.
If Gliese 581d does turn out to be habitable, it would still be a pretty strange place to visit -- the denser air and thick clouds would keep the surface in a perpetual murky red twilight, and its large mass means that surface gravity would be around double that on Earth. But the diversity of planetary climates in the galaxy is likely to be far wider than the few examples we are used to from the Solar System. In the long run, the most important implication of these results may be the idea that life-supporting planets do not in fact need to be particularly like Earth at all.
via sciencedaily.com
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