Gotcha! Photons Seen Without Being Destroyed in a First

By Jesse Emspak, LiveScience Contributor

Date: 22 November 2013 Time: 05:11 PM ET

 

     

 

Scientists have used a single atom trapped in an optical resonator to detect the presence of a reflected photon without destroying that packet of light.
CREDIT: MPQ, Quantum Dynamics Division.

If you want to see a packet of light called a photon, you have to destroy it. Any device that picks up on the presence of light has to absorb its energy, and with it, the photons. At least, that was what scientists thought until now.
At the Max Planck Institute of Quantum Optics in Germany, researchers found a way to detect single, visible-light photons without "touching" them and losing the photons themselves.
The work, detailed in the Nov. 14 issue of the journal Science Express, has important implications for quantum computing devices and communications. In an ordinary computer the presence of electrons — current — encodes the bits in logic circuits. Being able to keep photons around while still detecting them means photons could be used in a similar way. [Wacky Physics: The Coolest Little Particles in Nature]

 

"We could build gates between photons and atoms," Stephan Ritter, physicist and co-author of the study, told LiveScience. In any computer gates are the building blocks of logic circuits, which control functions such as AND, OR and NOT in a computer's brain.

Others have detected photons without destroying them, the most notable being Serge Haroche at the Collège de France in Paris, who won a Nobel Prize in 2012 for the achievement. However, he detected photons comprising microwave wavelengths of light. The Max Planck team detected visible-light photons, which are more useful for quantum communications.
Seeing photons
To see the photons, Ritter and his colleagues, Andreas Reiserer and Gerhard Rempe, trapped a single atom of rubidium in a cavity, just a half-millimeter across, with mirrors on the sides. The atom was in two states. In one, it is in resonance, or "coupled," with the cavity — one can think of them as vibrating in time with each other. In the other state it isn't — the atom is "out of tune" with both the cavity and the incoming photon. Atoms and subatomic particles are governed by the rules of quantum mechanics, which allowed the rubidium atom to be in both states at once.
They then fired laser pulses that, on average, had less than a single photon in them. When the photon reached the cavity, it would either continue inside and get reflected straight back or it would just bounce off the cavity, never entering — which happened if the atom was coupled to the cavity. The key is that there is a difference in the state of the atom after each outcome. They confirmed that the photon had reflected from the cavity a second time with an ordinary detector.
The photon didn't interact with the atom directly, but it did alter the atom's phase — the timing of its resonance with the cavity. The scientists could use the difference between the superposition state — when the atom is in two states at once — and the atom's measured phase to calculate whether or not the photon entered the cavity. In that way they "saw" the photon without destroying it, without touching it.
Photon qubits
Not "touching" the photon also means that certain quantum properties are never observed, preserving them. An unobserved photon can be in a "superposition" state — any one of its quantum properties, called degrees of freedom, can have more than one value simultaneously. Observing the photon forces it to be one or the other. For example, if a photon is polarized either horizontally or vertically, it's impossible to know which one until the photon is observed. In quantum mechanics that means the photon can be in both states, until it is measured and takes on a definite value. [How Quantum Entanglement Works (Infographic)]
This ability matters for quantum computing devices. Quantum computers are powerful because the bits in them, called qubits, can be both 1 and 0 at the same time, whereas an ordinary computer has to have its bits set at 1 or 0 sequentially. Essentially, a quantum computer can be in many states simultaneously, speeding up calculations such as factoring prime numbers.
If a photon is encoding the qubit, observing that photon directly would spoil its superposition state, and, thus, its ability to function as a qubit. But one might need to detect that the photon reached a certain place in the network. "Let's say you encode the qubit into the polarization," Ritter said. "The detection of the presence of a photon tells you nothing about its polarization."
By measuring the photon's state indirectly, however, it's possible to see the photon without destroying the quantum state (or the photon), and use different quantum states — such as polarization — to store qubits.
Going forward, Ritter says his group plans to work on boosting the efficiency of the detection – so far they can detect about 74 percent of the photons released. Stringing several detectors together would improve that — and one would end up with a detector that could pick up single photons better than those currently available.
Follow us @livescience, Facebook & Google+. Original article on LiveScience.

Noam Chomsky on the Freedom of Expression

by Big Think Editors      

December 7, 2013, 5:00 AM

"If we don't believe in freedom of expression for people we despise, we don't believe in it at all."
-Noam Chomsky (born on this date in 1928)

The EPA needs a Scientific Integrity Advocate?  Please, someone, tell me why?  Is this a backhanded way of labeling the agency lacking in scientific integrity.

 

Worse, if it does need one, why on Earth would it hire a long time employee of the so-called Union of "Concerned" "Scientists?"  This organization, like Greenpeace and "Friends of the Earth", has a multi-decade history of extremist environmental activism, particularly with regard to energy development in the US.  If you question my harsh judgment of the USC and similar organizations, for one, note the follow quote, taken from Kevin Mooney, of the Capital Research Center:

 

"Then there’s the so-called Union of Concerned Scientists (UCS), which is often quoted by the media as if it were a scientific, rather than political, organization. For one thing, UCS is in no sense an organization of scientists (unlike the EPA). Anyone willing to charge $35 on a credit card can join. One intrepid researcher even signed up his dog to drive the point home. The dog, Kenji, received a welcome kit and a signed letter from UCS President Kevin Knobloch."

 

The UCS's position on hydraulic fracking is clearly intended to fog over the mountainous scientific evidence of its safety and benefits by befuddling local residents and officials with open-ended questions that would make fracking appear unsafe whatever the evidence.  The quote below, taken from the UCS's web page:  Science, Democracy, and Fracking: A Guide for Community Residents and Policy Makers Facing Decisions over Hydraulic Fracturing (currently http://www.ucsusa.org/center-for-science-and-democracy/events/fracking-forum-toolkit.html) is a textbook example of this:

 

"Recent advances in hydraulic fracturing ( or “fracking”) technology leading to a rapid expansion in domestic oil and gas production.  The pace of growth is driving many communities to make decisions without access to comprehensive and reliable scientific information about the potential impacts of hydraulic fracturing on their local air and water quality, com­munity health, safety, economy, environment, and overall quality of life.

If you are an active citizen in a community facing decisions about fracking, this toolkit is for you. It provides practi­cal advice and resources to help you identify the critical questions to ask and get the scientific information you need when weighing the prospects and risks of shale oil or shale gas development in your region.

This toolkit can improve decision making on fracking by helping you to:

• Identify critical issues about the potential impacts of fracking in your area, and how to obtain answers to your questions
• Distinguish reliable information from misinformation or spin—and help your neighbors and local decision makers do the same
• Identify and communicate with scientists, journalists, policy makers, and community groups that should be part of the public discussion
• Identify and engage with the key actors in your community to influence oil and gas policy at the local and state level"

I suggest this passage, innocent on the surface, is about as deceitful a political tract as anyone could devise.  The fact is, anyone interested in the science supporting fracking -- and it is much more overwhelming than that supporting anthropocentric global warming -- can easily find it using a search engine or Wikipedia.  Talking with local people, even college scientists who will almost entirely have other specialties, is just going make a clear situation confused, leading to irrational opposition based on unfounded fears.  I suggest that an open-minded person can only come to one conclusion, that of Katie Brown's summary of situation (http://amedleyofpotpourri.blogspot.com/2013/12/report-environmentalists-opposing-shale.html):

"A report released today puts the folly of anti-fracking activism squarely in the spotlight. The report, authored primarily by University of California-Berkeley physics professor Richard Muller, comes to a sobering conclusion: “Environmentalists who oppose the development of shale gas and fracking are making a tragic mistake.”"

Nevertheless, here it is:

U.S. House of Representatives Committee on Science, Space and Technology/Democrats

Integral player. Francesca Grifo, here testifying before a congressional panel earlier this year, has been named to lead the U.S. Environmental Protection Agency’s efforts to implement policies designed to protect scientific integrity.

For more than a decade, Francesca Grifo of the Union of Concerned Scientists (UCS) advocated for improving scientific integrity policies at government agencies. When she commented on a draft of the policy at the U.S. Environmental Protection Agency (EPA) in 2011, she wrote: “These are great principles but how will this happen? Who will monitor? Who will detect problems and enforce these strong words?”
Well, it turns out, she will. EPA announced today that it has hired Grifo to oversee its new policy on scientific integrity. “It’s great news,” says Rena Steinzor of the University of Maryland School of Law in Baltimore, who studies environmental regulation and the misuse of science in environmental policy.
Grifo is charged with overseeing the four main areas of EPA’s policy: creating and maintaining a culture of scientific integrity within the agency; communicating openly to the public; ensuring rigorous peer review; and encouraging the professional development of agency scientists.
It sounds like a gargantuan task, but Grifo won’t actually be checking the integrity of every committee, scientific document, and peer review. Instead, she will be focusing on improving the process, says Michael Halpern, her former colleague at UCS. Part of the job will be educating staff members. Last week, EPA launched an online training guide for its staff members to make them aware of the policy and its protections. “It’s a cultural change so that [EPA] scientists feel they can participate in public life and the scientific community,” Halpern says, and better prepare them to deal with political pressure.

If problems come to light, Grifo will help investigate. She will work with an internal Scientific Integrity Committee, as well as the inspector general. Her job is not a political appointment, so it comes with civil service protections. She will report to Glenn Paulson, EPA’s science adviser. Grifo will also issue an annual report about any incidents with scientific integrity at the agency.
UCS has ranked EPA’s policy, which was finalized about a year and a half ago, as one of the stronger ones in the U.S. government. Unlike most other agencies, EPA’s plan called for a full-time position. “While strong improvements have been made on paper, we recognize that the agency is challenged in fully realizing those improvements” Halpern wrote in a blog post.
Jeff Ruch of Public Employees for Environmental Responsibility in Washington, D.C., says he is hopeful for progress. “She is coming from an organization that is probably responsible for the adoption of scientific integrity policies,” he says. “We think that these policies are potentially revolutionary. But progress has been slow and uneven.” It’s not clear, he says, what power she would have to bring relief in individual cases.

Hillary Clinton Touts Benefits of Oil, Natural Gas

5:05pm EST October 7, 2013    

by Nicole Jacobs
nicole@energyindepth.org , Hughesville, Pa.

 

Often times in media reports, the subject of natural gas development may come off as a bit of a partisan issue. Here in Pennsylvania, Democrats like State Senator Jim Ferlo have even pushed for a moratorium. Spanning out nationally, the topic is far from partisan, however – with Democratic Governors like Pat Quinn in Illinois, John Hickenlooper in Colorado, and even Jerry Brown in California rejecting the claims of anti-fracking activists and openly discussing the benefits of development.
Add to that list former Secretary of State Hillary Clinton, who showed during a speech at Hamilton College in New York on Friday that responsible development is something we can and indeed should embrace.
From the Democrat and Chronicle:

Late into the lecture portion of Clinton’s Oneida County appearance, she referenced a report that the U.S. in on track to surpass Russia in domestic oil-and-gas production.
That’s good news, Clinton said.
“What that means for viable manufacturing and industrialization in this country is enormous,” she said to the crowd of 5,800 in Hamilton’s athletic field house.

As IHS highlighted last month, shale is helping to transform the U.S. economy, and bringing manufacturing back to America after a decade of decline.
EID has also been following the U.S. and Russian oil and gas production race for the past year, and the United States has likely surpassed Russia to become the largest oil and gas producing country in the world – thanks in large part to shale development.
Needless to say, the former U.S. Senator from New York was spot on with her comments on the implications this can have for U.S. economic growth, as well as in other markets.
As many of you will remember, the State Department under Mrs. Clinton’s leadership actually promoted Gasland as part of its Annual Film Showcase. It’s good to see that she has evolved in her view of responsible oil and gas development.

Report: Environmentalists Opposing Shale Gas Are Making a ‘Tragic Mistake’

2:02pm EST December 6, 2013    

by Katie Brown
katie@energyindepth.org , Washington, D.C.

  

A report released today puts the folly of anti-fracking activism squarely in the spotlight. The report, authored primarily by University of California-Berkeley physics professor Richard Muller, comes to a sobering conclusion: “Environmentalists who oppose the development of shale gas and fracking are making a tragic mistake.”
The reason is because natural gas provides a solution for two major worldwide environmental concerns: air pollution and greenhouse gas emissions. For its ability to provide an affordable energy source that can also address these problems, the authors conclude that “shale gas is a wonderful gift that has arrived just in time.”
The report focuses heavily on the local air quality benefits of shale gas, which could be especially effective in places like China that have rapidly growing economies, and by extension a great need for affordable and abundant energy.  As the repot notes, shale gas “provides a solution to the pollution,” observing it’s “amazing” that local air quality benefits are “not more widely addressed by environmentalists.”
The report focuses mostly on shale gas and local air quality, but the reduction in greenhouse gas emissions made possible by shale gas is also addressed. The authors find that “both global warming and air pollution can be mitigated by the development and utilization of shale gas,” owing to the fuel’s ability to reduce carbon dioxide emissions, as well as low methane leakage rates (more on that later).
In addition to firmly establishing the environmental benefits of natural gas, the also report addresses a number of anti-fracking activists’ objections to responsible shale development, concluding that they are not credible: “These concerns are either largely false or can be addressed by appropriate regulation.”
While the authors express some concern about the volumes of water required for hydraulic fracturing, they explain that “viable alternatives exist,” including the fact that “most of the water that flows back from the well can be treated and reused.”  As an example, the report points to Apache, a company that has made news recently for its dramatic reduction in water use:

“[T]hey [Apache] eliminated fresh water use in fracking operations in Irion County, Texas; this year they have used only recycled produced water from fracking operations and oil fields together with brackish water obtained from the Santa Rosa formation at 800 to 900 feet depth [Reuters 2013]. In all of Apache’s hydraulic fracturing operations in the Permian Basin, more than half the water is sourced from non-fresh water sources, about 900 wells” (p. 6-7).

Of course, as we’ve pointed out many times, water recycling is quickly becoming standard operating procedure. In Pennsylvania alone, Marcellus producers are now recycling 90 percent of their flowback water, and that’s a trend we’re increasingly seeing elsewhere across the country.
Regarding anti-fracking activists’ claims on flaming faucets and the fraud of Gasland, the authors offer a scathing but entirely justified critique:

“The famous ‘flaming faucets’ shown in the movie Gasland (and on YouTube) were not due to fracking, despite what that movie suggests. The accounts were investigated by state environmental agencies, and in every case traced to methane-saturated ground water produced by shallow bacteria. Indeed, the movie FrackNation includes a clip in which the Gasland producer, writer, and star Josh Fox admits that flaming faucets were common long before fracking was ever tried” (p. 7).

The report states that any risk of leakage is “not particularly linked to shale gas wells.” It’s also clear that whatever risks there may be to drinking water supplies, they are manageable: “The solution lies in regulating shale at least as stringently as conventional oil and gas,” the report states.
As for activists’ claim that methane emissions during development cancel out the climate benefits of natural gas, the report says that’s simply wrong:

“The initial scare of the danger of ‘fugitive’ (leaked) methane came from mistaken use of the fact that its ‘greenhouse potential’ is 83 times that of CO2, kilogram per kilogram. That makes it seem that even 1% leakage would undo its advantage over coal. But if you take into account the fact that methane is rapidly destroyed in the atmosphere (with a much shorter lifetime than CO2), then the potency is reduced to about 34 times. And the fact that methane weighs less (molecule per molecule) than CO2 means that leaked methane is only 12 times more potent for the same energy produced.  Because natural gas power plants are more efficient than those of coal, even with leakage rate of up to 17% (far higher than even the most pessimistic estimates), natural gas still provides a greenhouse gas improvement over coal for the same electricity produced” (p. 8).

This is yet another rebuke of the research of Cornell anti-fracking activist Anthony Ingraffea, who has bizarrely claimed that natural gas is a “gangplank” to irreversible global warming.  Dr. Muller has offered harsh criticism for Ingraffea’s work before (in the New York Times, no less), so it’s unsurprising that he identifies a series of flaws in the infamous Howarth/Ingraffea methane paper:

“However, Howarth’s original work made assumptions for parameters that were not directly measured, and many of these were ‘conservative estimates’ – which means prejudicial against natural gas. It took two years, but finally a calibrated study of 190 wells showed that the leakage from shale gas production averaged about 0.4%. [Allen, 2013; Hausfather & Muller 2013]. If we add in leakage in pipelines and storage, the maximum is still only 1.4%, and the greenhouse advantage over coal is large. A recent report by Miller et al. [2013] suggests the rate could be twice that; but even if this new report is more accurate than the EPA value, fugitive methane is still a vast greenhouse gas improvement compared to coal” (p. 8).

On seismicity, the Muller report notes, ”No large earthquakes have been associated with fracking but rather with ‘disposal wells’.” Further, such seismic activity from wastewater disposal is already being mitigated by the surge in water recycling: “We can prevent disposal earthquakes by recycling water to minimize injection volumes and by taking care in the choice of disposal well locations.”
Finally, the report offers yet another blow to anti-fracking activists who contend that natural gas will somehow ‘crowd out’ renewables:

“Yet cheap natural gas can also make it easier for solar and wind energy to further penetrate electricity markets by providing the rapid back-up that those intermittent sources require. In addition, natural gas is the only base load fuel that can be downscaled into microgrids and distributed generation networks to provide that same flexibility and reliability for solar energy on rooftops and in buildings, expanding the market for urban solar systems. Particularly for areas focusing on distributed generation, natural gas can be an enabler of wind and solar” (p. 9-10).

To sum up: the report finds that shale gas “can be the solution” for addressing air pollution and reducing greenhouse gas emissions, and the numerous objections to fracking put forth by activists are simply not credible.  As the report puts it, environmental groups should “recognize the shale gas revolution as beneficial to society – and lend their full support to helping it advance.”

This technology could reduce the travel time to Mars to just 39 days

From: 

Science Recorder | Kramer Phillips | Saturday, December 07, 2013

Scientists now say it may be possible to travel to Mars in just over a month, reducing the one-way six-month journey to just under three months.  The advancement could have major implications for startups aiming to travel to Mars in the coming years, part of an increasingly competitive bid to put the first humans on Mars.

“VASIMR stands for Variable Specific Impulse Magnetoplasma Rocket, which makes use of argon gas (one of the most stable gasses known to man) and a renewable source of energy found in space, radio waves in the form of light.

The rocket will allow for a mission to Mars with a travel period of just 39 days, which is almost 6 times faster than current methods. With speeds estimated at 35 miles a second, the rocket system will make quick work of the distance between Earth and Mars. NASA rates a new system on a scale of one to ten based on its readiness to be deployed. The VASIMR system is at a six currently, which means that it is ready to be tested in space. It would seem that it won’t be much longer before the new rocket system is employed in all space missions.”

Read more: http://www.sciencerecorder.com/news/this-technology-could-reduce-the-travel-time-to-mars-to-just-39-days/#ixzz2moa6JM6S

Evolutionary biologist Alice Roberts was denounced by a very silly Christian as a "fanatical evolutionist" who peddles "vacuous subjective claims that our ape-like ancestors apparently miraculously (something in which perhaps only a minority at the BBC would believe) decided to walk upright in search of food".

This is from Atheism on Facebook, author currently unknown:

 

Evolutionary biologist Alice Roberts was denounced by a very silly Christian as a "fanatical evolutionist" who peddles "vacuous subjective claims that our ape-like ancestors apparently miraculously (something in which perhaps only a minority at the BBC would believe) decided to walk upright in search of food".

She has written an eloquent rebuttal, which to date (quelle surprise) has not met with a response:

//I wanted to register my disquiet at the paragraph in which I am d...escribed as a "fanatical evolutionist". Like most biologists, I think that evolution through natural selection best explains the diversity of life on this planet; this is not a minority view and not necessarily incompatible with religious belief: many Christians accept evolution.

However, I felt moved to respond to the criticisms of the series Origins of Us, and set the record straight. Firstly, the criticisms do BBC Science an injustice. Even if I wanted to present my own opinions and speculation (in any other way than clearly flagging them as such) the BBC would not allow me to do this in a science programme. Secondly, the criticism levelled at me brings my own academic integrity into question. Every hypothesis and fact discussed or presented in the programme is already "out there", in peer reviewed scientific publications. BBC Science (and I myself) are very careful about the factual basis of such programmes, and extremely careful to differentiate between fact and opinion.

The "vacuous subjective claims" to which Mr Stephen Green alludes are facts based on peer-reviewed scientific research. I am also surprised that Mr Green suggests I presented the extremely outdated "savannah hypothesis" as current science - this is something that was critically appraised and research suggesting, instead, an arboreal origin for bipedalism was put forward. The idea that tool-using and tool-making may have influenced the shape of our hands is, again, not idle speculation but based on published research. Any change in anatomy which leads to a survival advantage (whether that's an adaptation helping survival in a particular natural environment or an adaptation which makes you better at making technology which helps you to survive) is likely to be selected for.

I realise that few readers of this website will read my response objectively, but I object strongly to the criticism that my programmes with the BBC have lacked objectivity and include "idle speculation". That can only be true if you believe that the numerous academic papers which form the backbone of such a series are also "idle speculation".

Regards, Professor Alice Roberts