Tag Archives: Schrodinger’s cat

The physics of the multiverse of madness

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The Dr. Strange movie (Dr. Strange in the Multiverse of Madness released May 6, 2022) has inspired an essay on physics. From a May 9, 2022 news item on phys.org

If you’re a fan of science fiction films, you’ll likely be familiar with the idea of alternate universes—hypothetical planes of existence with different versions of ourselves. As far from reality as it sounds, it is a question that scientists have contemplated. So just how well does the fiction stack up with the science?

The many-worlds interpretation is one idea in physics that supports the concept of multiple universes existing. It stems from the way we comprehend quantum mechanics, which defy the rules of our regular world. While it’s impossible to test and is considered an interpretation rather than a scientific theory, many physicists think it could be possible.

“When you look at the regular world, things are measurable and predictable—if you drop a ball off a roof, it will fall to the ground. But when you look on a very small scale in quantum mechanics, the rules stop applying. Instead of being predictable, it becomes about probabilities,” says Sarah Martell, Associate Professor at the School of Physics, UNSW Science.

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A May 9, 2022 University of New South Wales (UNSW; Australia) press release originated the news item,

The fundamental quantum equation – called a wave function – shows a particle inhabiting many possible positions, with different probabilities assigned to each. If you were to attempt to observe the particle to determine its position – known in physics as ‘collapsing’ the wave function – you’ll find it in just one place. But the particle actually inhabits all the positions allowed by the wave function.

This interpretation of quantum mechanics is important, as it helps explain some of the quantum paradoxes that logic can’t answer, like why a particle can be in two places at once. While it might seem impossible to us, since we experience time and space as fixed, mathematically it adds up.

“When you make a measurement in quantum physics, you’re only measuring one of the possibilities. We can work with that mathematically, but it’s philosophically uncomfortable that the world stops being predictable,” A/Prof. Martell says.

“If you don’t get hung up on the philosophy, you simply move on with your physics. But what if the other possibility were true? That’s where this idea of the multiverse comes in.”

The quantum multiverse

Like it is depicted in many science fiction films, the many-worlds interpretation suggests our reality is just one of many. The universe supposedly splits or branches into other universes any time we take action – whether it’s a molecule moving, what you decide to eat or your choice of career. 

In physics, this is best explained through the thought experiment of Schrodinger’s cat. In the many-worlds interpretation, when the box is opened, the observer and the possibly alive cat split into an observer looking at a box with a deceased cat and one looking at a box with a live cat.

“A version of you measures one result, and a version of you measures the other result. That way, you don’t have to explain why a particular probability resulted. It’s just everything that could happen, does happen, somewhere,” A/Prof. Martell says.

“This is the logic often depicted in science fiction, like Spider-Man: Into the Spider-Verse, where five different Spider-Man exist in different universes based on the idea there was a different event that set up each one’s progress and timeline.”

This interpretation suggests that our decisions in this universe have implications for other versions of ourselves living in parallel worlds. But what about the possibility of interacting with these hypothetical alternate universes?

According to the many-worlds interpretation, humans wouldn’t be able to interact with parallel universes as they do in films – although science fiction has creative licence to do so.

“It’s a device used all the time in comic books, but it’s not something that physics would have anything to say about,” A/Prof. Martell says. “But I love science fiction for the creativity and the way that little science facts can become the motivation for a character or the essential crisis in a story with characters like Doctor Strange.”

“If for nothing else, science fiction can help make science more accessible, and the more we get people talking about science, the better,” A/Prof. Martell says.

“I think we do ourselves a lot of good by putting hooks out there that people can grab. So, if we can get people interested in science through popular culture, they’ll be more interested in the science we do.” 

The university also offers a course as this October 6, 2020 UNSW press release reveals,

From the morality plays in Star Trek, to the grim futures in Black Mirror, fiction can help explore our hopes – and fears – of the role science might play in our futures.

But sci-fi can be more than just a source of entertainment. When fiction gets the science right (or right enough), sci-fi can also be used to make science accessible to broader audiences. 

“Sci-fi can help relate science and technology to the lived human experience,” says Dr Maria Cunningham, a radio astronomer and senior lecturer in UNSW Science’s School of Physics. 

“Storytelling can make complex theories easier to visualise, understand and remember.”

Dr Cunningham – a sci-fi fan herself – convenes ‘Brave New World’: a course on science fact and fiction aimed at students from a non-scientific background. The course explores the relationship between literature, science, and society, using case studies like Futurama and MacGyver.

She says her own interest in sci-fi long predates her career in science.

“Fiction can help get people interested in science – sometimes without them even knowing it,” says Dr Cunningham.

“Sci-fi has the potential to increase the science literacy of the general population.”

Here, Dr Cunningham shares three tricky physics concepts best explained through science fiction (spoilers ahead).

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Cunningham goes on to discuss the Universal Speed Limit, Time Dilation, and, yes, the Many Worlds Interpretation.

The course, “Brave New World: Science Fiction, Science Fact and the Future – GENS4015” is still offered but do check the link to make sure it takes you to the latest version (I found 2023). One more thing, it is offered wholly on the internet.

A little more Christmas: “Kitty Q” award-winning game app explains quantum physics

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Caption: Kitty Q. Credit: Philipp Stollenmayer

It kind of reminds me of ‘Hello Kitty’. However, you can see in this larger version that 1/2 of this cat has a skeletal paw giving it kinship to Erwin Schrödinger’s cat.

The app was first announced in a September 28, 2021University of Würzburg press release on EurekAlert,

Cute but half-dead

Ding, dong. There is a box in front of the door. And inside there is … a cute but half-dead cat! The main character of the new game app “Kitty Q” of the Würzburg-Dresden Cluster of Excellence ct.qmat–Complexity and Topology in Quantum Matter of the Universities of Würzburg and Dresden accompanies children and teenagers aged 11 and older into the crazy quantum world. The adventure is intended to primarily get girls excited about the fascinating phenomena of quantum physics. The model for the lovingly designed “Kitty Q” is a popular thought experiment in quantum mechanics by Nobel Prize winner Erwin Schrödinger (1887 – 1961), known as Schrödinger’s cat–alive and dead at the same time.

But fun first

Those who embark on adventure with “Kitty Q” can tinker, try out, experiment on their smartphones and solve more than 20 attractive brainteasers along the way. Importantly, the kids don’t have to be math whizzes or physics geniuses. After all, “Kitty Q” is all about fun!

“The game is an Escape Game after all, even though it conveys quite serious scientific content. It is intended to awaken curiosity and encourage trying things out. Indeed, that’s what science is all about: discovering new things by thinking and experimenting,” says the app designer Philipp Stollenmayer, explaining the character of the game app he developed. “The gamers experience an exciting world, collect stickers and design their cat individually. Just like in real life, you need to work in the quantum world to acquire your knowledge. It was important to me to show how much fun this could be!” “Kitty Q” is the first commissioned project for Stollenmayer who otherwise works exclusively on his own and has won all the major prizes in game design since 2013–most recently the Apple Design Award 2020.

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Donuts, randomness, cold chips

The focus of the game app is on the more than 20 puzzles based on scientific facts from quantum physics–the concept of chance, donuts as “symbol” of topological quantum physics, cold chips for revolutionary high-tech and quantum computers, to name a few examples. Those who like can access background knowledge, edited in a popular way, as “Kittypedia articles” as soon as a puzzle has been solved.

“The research field of our Cluster of Excellence ct.qmat–topological quantum physics–promises revolutionary insights and groundbreaking developments. But the subject is still so young that it will take quite a few years before it arrives in classroom. We are trying to bridge this gap with the app,” explains Matthias Vojta, Professor of Theoretical Solid State Physics at Technische Universität (TU) Dresden and spokesperson of the Dresden branch of the ct.qmat research alliance. Topological quantum physics uses topology–a branch of mathematics–as a tool to theoretically describe the interior of novel quantum materials. This is a Nobel Prize-winning research approach that ct.qmat applies.

Attracting female physicists

The game takes unusual approaches to attract children and teens to mathematics, computer science, natural and technical sciences (STEM)–and especially to quantum physics–at an early age. The focus is particularly on girls, since young women are underrepresented in physics degree programs in particular. The game targets at an age group in which interest in physics and the natural sciences is shaped.

“At least since the German government passed the economic stimulus package last year and more than two billion euros flow into German quantum research, our field of science has arrived in society. Unfortunately, there is already a significant shortage of skilled personnel in physics. With our mobile game, we want to make physics an experience, appeal to tomorrow’s researchers and Nobel Prize winners, and thus keep Germany’s high tech economy running,” comments the spokesperson of the Würzburg branch Ralph Claessen, Professor of Experimental Physics at Julius Maximilian University (JMU) Würzburg.

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The latest about Kitty Q can be found in a December 21, 2021 Technische Universität Dresden press release on EurekAlert,

“We are thrilled that our app ‘Kitty Q’ was honored as a ‘Serious Game’ at the Games Innovation Award Saxony. The references to quantum physics are always there, but our game can also be played completely without math or physics know-how. Detailed background knowledge is optionally available in the ‘Kittypedia’. We invested a lot of work in compiling these generally understandable encyclopedia articles on quantum physics. We are immensely pleased that this award highlights the aspect of knowledge transfer in particular,” explains Prof. Matthias Vojta, Professor of Theoretical Solid State Physics at Technische Universität (TU) Dresden and spokesperson of the Dresden branch of ct.qmat.

The next round of ” Kitty Q” is now starting with the project “QUANTube–Science Break”: “From January 2022 on, our young researchers will be answering questions about quantum physics sent to us by players from all over the world in entertaining explanatory videos. We are challenging ourselves in terms of easy comprehensibility and language suitable for children and young people,” explains the spokesperson of the Würzburg branch of the Cluster Prof. Ralph Claessen, Professor of Experimental Physics at Julius Maximilian University (JMU) Würzburg. “The fact that the DFG has now awarded a Community Prize to ‘QUANTube’ is a special honor for us because it is awarded by marketing experts from the research community and not by a specialist jury. Perhaps there is even some curiosity about our implementation behind the vote.”

The game app “Kitty Q” has so far been downloaded 65,000 times worldwide. “It’s great to see how enthusiastically people are playing and how great the feedback and ratings are. That is anything but a matter of course for a game that imparts knowledge,” says app designer Philipp Stollenmayer, who developed the game for the Würzburg-Dresden Cluster of Excellence. So far, Stollenmayer has won all the major prizes in game design for the games he has developed on his own–most recently the Apple Design Award 2020.

Answering questions from the players using video

Whoever solves a certain puzzle in the mobile game “Kitty Q–a Quantum Adventure” earns a bonus app, which can be used to ask the researchers of the Cluster of Excellence ct.qmat a question. So far, more than 45 questions on physics and quantum physics have been sent via the in-game bonus app.

All questions will be answered by the doctoral and postdoctoral researchers of the Cluster of Excellence on a topic-related basis in YouTube explanatory videos starting as of January 2022–in school break length of about five minutes and in line with the Science Year 2022, which has the motto “Inquire into a matter”. For recruiting next generation of scientists, the cluster also relies on its strong network with five non-university partner institutes: Helmholtz-Zentrum Dresden Rossendorf, Leibniz Institute for Solid State and Materials Research Dresden, Max Planck Institute for Chemical Physics of Solids Dresden, Max Planck Institute for the Physics of Complex Systems Dresden and Bavarian Center for Applied Energy Research.

“QUANTube–Science Break” #1 Schrödinger’s Cat

The first QUANTube episode answers questions about “Schrödinger’s cat”. The video will be published on the YouTube channel of the Cluster of Excellence ct.qmat at the end of January: https://www.youtube.com/c/ClusterofExcellencectqmat

America, England, Vietnam, China, and Germany–questions about cats were sent in from all over the world: What does the Q in kitty Q stand for? Why is the cat half dead? How long do cats live when they are half dead? What do the cat’s atoms look like when it is dead and alive at the same time? Why did Schrödinger use a cat and not another animal in his thought experiment in the first place?

A little preview of the new QUANTube video series is provided by a teaser video that answers the question, “What do cats actually have to do with physics?”

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Here’s the QUANTube–Science Break video series teaser/preview,

You can find out more about Kitty Q (English language version) here or you can access the Katze Q (German language version) here.

Sunscreens: 2018 update

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I don’t usually concern myself with SPF numbers on sunscreens as my primary focus has been on the inclusion of nanoscale metal particles (these are still considered safe). However, a recent conversation with a dental hygienist and coincidentally tripping across a June 19, 2018 posting on the Schrodinger’s Cat blog shortly after the convo. has me reassessing my take on SPF numbers (Note: Links have been removed),

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So, what’s the deal with SPF? A recent interview of Dr Steven Q Wang, M.D., chair of The Skin Cancer Foundation Photobiology Committee, finally will give us some clarity. Apparently, the SPF number, be it 15, 30, or 50, refers to the amount of UVB protection that that sunscreen provides. Rather than comparing the SPFs to each other, like we all do at the store, SPF is a reflection of the length of time it would take for the Sun’s UVB radiation to redden your skin (used exactly as directed), versus if you didn’t apply any sunscreen at all. In ideal situations (in lab settings), if you wore SPF 30, it would take 30 times longer for you to get a sunburn than if you didn’t wear any sunscreen.

What’s more, SPF 30 is not nearly half the strength of SPF 50. Rather, SPF 30 allows 3% of UVB rays to hit your skin, and SPF 50 allows about 2% of UVB rays to hit your skin. Now before you say that that is just one measly percent, it actually is much more. According to Dr Steven Q. Wang, SPF 30 allows around 1.5 times more UV radiation onto your skin than SPF 50. That’s an actual 150% difference [according to Wang’s article “… SPF 30 is allowing 50 percent more UV radiation onto your skin.”] in protection.

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Schrodinger’s Cat (author of the ‘eponymous’ blog) offers a good overview of the topic in a friendly, informative fashion albeit I found the ‘percentage’ to be a bit confusing. (S)he also provides a link to a previous posting about the ingredients in sunscreens (I do have one point of disagreement with Schrodinger’s Cat regarding oxybenzone) as well as links to Dr. Steven Q. Wang’s May 24, 2018 Ask the Expert article about sunscreens and SPF numbers on skincancer.org. You can find the percentage under the ‘What Does the SPF Number Mean?’ subsection, in the second paragraph.

Ingredients: metallic nanoparticles and oxybenzone

The use of metallic nanoparticles  (usually zinc oxide and/or (titanium dioxide) in sunscreens was loathed by civil society groups, in particular Friends of the Earth (FOE) who campaigned relentlessly against their use in sunscreens. The nadir for FOE was in February 2012 when the Australian government published a survey showing that 13% of the respondents were not using any sunscreens due to their fear of nanoparticles. For those who don’t know, Australia has the highest rate of skin cancer in the world. (You can read about the debacle in my Feb. 9, 2012 posting.)

At the time, the only civil society group which supported the use of metallic nanoparticles in sunscreens was the Environmental Working Group (EWG).  After an examination of the research they, to their own surprise, came out in favour (grudgingly) of metallic nanoparticles. (The EWG were more concerned about the use of oxybenzone in sunscreens.)

Over time, the EWG’s perspective has been adopted by other groups to the point where sunscreens with metallic nanoparticles are commonplace in ‘natural’ or ‘organic’ sunscreens.

As for oxybenzones, Schrodinger’s Cat in a May 23, 2018 posting about sunscreen ingredients notes this (Note: Links have been removed),

Oxybenzone – Chemical sunscreen, protects from UV damage. Oxybenzone belongs to the chemical family Benzophenone, which are persistent (difficult to get rid of), bioaccumulative (builds up in your body over time), and toxic, or PBT [or: Persistent, bioaccumulative and toxic substances (PBTs)]. They are a possible carcinogen (cancer-causing agent), endocrine disrupter; however, this is debatable. Also could cause developmental and reproductive toxicity, could cause organ system toxicity, as well as could cause irritation and potentially toxic to the environment.

It seems that the tide is turning against the use of oxybenzones (from a July 3, 2018 article by Adam Bluestein for Fast Company; Note: Links have been removed),

On July 3 [2018], Hawaii’s Governor, David Ig, will sign into law the first statewide ban on the sale of sunscreens containing chemicals that scientists say are damaging the Earth’s coral reefs. Passed by state legislators on May 1 [2018], the bill targets two chemicals, oxybenzone and octinoxate, which are found in thousands of sunscreens and other skincare products. Studies published over the past 10 years have found that these UV-filtering chemicals–called benzophenones–are highly toxic to juvenile corals and other marine life and contribute to the fatal bleaching of coral reefs (along with global warming and runoff pollutants from land). (A 2008 study by European researchers estimated that 4,000 to 6,000 tons of sunblock accumulates in coral reefs every year.) Also, though both substances are FDA-approved for use in sunscreens, the nonprofit Environmental Working Group notes numerous studies linking oxybenzone to hormone disruption and cell damage that may lead to skin cancer. In its 2018 annual sunscreen guide, the EWG found oxybenzone in two-thirds of the 650 products it reviewed.

The Hawaii ban won’t take effect until January 2021, but it’s already causing a wave of disruption that’s affecting sunscreen manufacturers, retailers, and the medical community.

For starters, several other municipalities have already or could soon join Hawaii’s effort. In May [2018], the Caribbean island of Bonaire announced a ban on chemicals sunscreens, and nonprofits such as the Sierra Club and Surfrider Foundation, along with dive industry and certain resort groups, are urging legislation to stop sunscreen pollution in California, Colorado, Florida, and the U.S. Virgin Islands. Marine nature reserves in Mexico already prohibit oxybenzone-containing sunscreens, and the U.S. National Park Service website for South Florida, Hawaii, U.S. Virgin Islands, and American Samoa recommends the use of “reef safe” sunscreens, which use natural mineral ingredients–zinc oxide or titanium oxide–to protect skin.

Makers of “eco,” “organic,” and “natural” sunscreens that already meet the new standards are seizing on the news from Hawaii to boost their visibility among the islands’ tourists–and to expand their footprint on the shelves of mainland retailers. This past spring, for example, Miami-based Raw Elements partnered with Hawaiian Airlines, Honolulu’s Waikiki Aquarium, the Aqua-Aston hotel group (Hawaii’s largest), and the Sheraton Maui Resort & Spa to get samples of its reef-safe zinc-oxide-based sunscreens to their guests. “These partnerships have had a tremendous impact raising awareness about this issue,” says founder and CEO Brian Guadagno, who notes that inquiries and sales have increased this year.

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As Bluestein notes there are some concerns about this and other potential bans,

“Eliminating the use of sunscreen ingredients considered to be safe and effective by the FDA with a long history of use not only restricts consumer choice, but is also at odds with skin cancer prevention efforts […],” says Bayer, owner of the Coppertone brand, in a statement to Fast Company. Bayer disputes the validity of studies used to support the ban, which were published by scientists from U.S. National Oceanic & Atmospheric Administration, the nonprofit Haereticus Environmental Laboratory, Tel Aviv University, the University of Hawaii, and elsewhere. “Oxybenzone in sunscreen has not been scientifically proven to have an effect on the environment. We take this issue seriously and, along with the industry, have supported additional research to confirm that there is no effect.”

Johnson & Johnson, which markets Neutrogena sunscreens, is taking a similar stance, worrying that “the recent efforts in Hawaii to ban sunscreens that contain oxybenzone may actually adversely affect public health,” according to a company spokesperson. “Science shows that sunscreens are a key factor in preventing skin cancer, and our scientific assessment of the lab studies done to date in Hawaii show the methods were questionable and the data insufficient to draw factual conclusions about any impact on coral reefs.”

Terrified (and rightly so) about anything scaring people away from using sunblock, The American Academy of Dermatology, also opposes Hawaii’s ban. Suzanne M. Olbricht, president of the AADA, has issued a statement that the organization “is concerned that the public’s risk of developing skin cancer could increase due to potential new restrictions in Hawaii that impact access to sunscreens with ingredients necessary for broad-spectrum protection, as well as the potential stigma around sunscreen use that could develop as a result of these restrictions.”

The fact is that there are currently a large number of widely available reef-safe products on the market that provide “full spectrum” protection up to SPF50–meaning they protect against both UVB rays that cause sunburns as well as UVA radiation, which causes deeper skin damage. SPFs higher than 50 are largely a marketing gimmick, say advocates of chemical-free products: According to the Environmental Working Group, properly applied SPF 50 sunscreen blocks 98% of UVB rays; SPF 100 blocks 99%. And a sunscreen lotion’s SPF rating has little to do with its ability to shield skin from UVA rays.

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I notice neither Bayer nor Johnson & Johnson nor the American Academy of Dermatology make mention of oxybenzone’s possible role as a hormone disruptor.

Given the importance that coral reefs have to the environment we all share, I’m inclined to support the oxybenzone ban based on that alone. Of course, it’s conceivable that metallic nanoparticles may also have a deleterious effect on coral reefs as their use increases. It’s to be hoped that’s not the case but if it is, then I’ll make my decisions accordingly and hope we have a viable alternative.

As for your sunscreen questions and needs, the Environment Working Group (EWG) has extensive information including a product guide on this page (scroll down to EWG’s Sunscreen Guide) and a discussion of ‘high’ SPF numbers I found useful for my decision-making.

Congratulate China on the world’s first quantum communication network

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China has some exciting news about the world’s first quantum network; it’s due to open in late August 2017 so you may want to have your congratulations in order for later this month.

An Aug. 4, 2017 news item on phys.org makes the announcement,

As malicious hackers find ever more sophisticated ways to launch attacks, China is about to launch the Jinan Project, the world’s first unhackable computer network, and a major milestone in the development of quantum technology.

Named after the eastern Chinese city where the technology was developed, the network is planned to be fully operational by the end of August 2017. Jinan is the hub of the Beijing-Shanghai quantum network due to its strategic location between the two principal Chinese metropolises.

“We plan to use the network for national defence, finance and other fields, and hope to spread it out as a pilot that if successful can be used across China and the whole world,” commented Zhou Fei, assistant director of the Jinan Institute of Quantum Technology, who was speaking to Britain’s Financial Times.

An Aug. 3, 2017 CORDIS (Community Research and Development Research Information Service [for the European Commission]) press release, which originated the news item, provides more detail about the technology,

By launching the network, China will become the first country worldwide to implement quantum technology for a real life, commercial end. It also highlights that China is a key global player in the rush to develop technologies based on quantum principles, with the EU and the United States also vying for world leadership in the field.

The network, known as a Quantum Key Distribution (QKD) network, is more secure than widely used electronic communication equivalents. Unlike a conventional telephone or internet cable, which can be tapped without the sender or recipient being aware, a QKD network alerts both users to any tampering with the system as soon as it occurs. This is because tampering immediately alters the information being relayed, with the disturbance being instantly recognisable. Once fully implemented, it will make it almost impossible for other governments to listen in on Chinese communications.

In the Jinan network, some 200 users from China’s military, government, finance and electricity sectors will be able to send messages safe in the knowledge that only they are reading them. It will be the world’s longest land-based quantum communications network, stretching over 2 000 km.

Also speaking to the ‘Financial Times’, quantum physicist Tim Byrnes, based at New York University’s (NYU) Shanghai campus commented: ‘China has achieved staggering things with quantum research… It’s amazing how quickly China has gotten on with quantum research projects that would be too expensive to do elsewhere… quantum communication has been taken up by the commercial sector much more in China compared to other countries, which means it is likely to pull ahead of Europe and US in the field of quantum communication.’

However, Europe is also determined to also be at the forefront of the ‘quantum revolution’ which promises to be one of the major defining technological phenomena of the twenty-first century. The EU has invested EUR 550 million into quantum technologies and has provided policy support to researchers through the 2016 Quantum Manifesto.

Moreover, with China’s latest achievement (and a previous one already notched up from July 2017 when its quantum satellite – the world’s first – sent a message to Earth on a quantum communication channel), it looks like the race to be crowned the world’s foremost quantum power is well and truly underway…

Prior to this latest announcement, Chinese scientists had published work about quantum satellite communications, a development that makes their imminent terrestrial quantum network possible. Gabriel Popkin wrote about the quantum satellite in a June 15, 2017 article Science magazine,

Quantum entanglement—physics at its strangest—has moved out of this world and into space. In a study that shows China’s growing mastery of both the quantum world and space science, a team of physicists reports that it sent eerily intertwined quantum particles from a satellite to ground stations separated by 1200 kilometers, smashing the previous world record. The result is a stepping stone to ultrasecure communication networks and, eventually, a space-based quantum internet.

“It’s a huge, major achievement,” says Thomas Jennewein, a physicist at the University of Waterloo in Canada. “They started with this bold idea and managed to do it.”

Entanglement involves putting objects in the peculiar limbo of quantum superposition, in which an object’s quantum properties occupy multiple states at once: like Schrödinger’s cat, dead and alive at the same time. Then those quantum states are shared among multiple objects. Physicists have entangled particles such as electrons and photons, as well as larger objects such as superconducting electric circuits.

Theoretically, even if entangled objects are separated, their precarious quantum states should remain linked until one of them is measured or disturbed. That measurement instantly determines the state of the other object, no matter how far away. The idea is so counterintuitive that Albert Einstein mocked it as “spooky action at a distance.”

Starting in the 1970s, however, physicists began testing the effect over increasing distances. In 2015, the most sophisticated of these tests, which involved measuring entangled electrons 1.3 kilometers apart, showed once again that spooky action is real.

Beyond the fundamental result, such experiments also point to the possibility of hack-proof communications. Long strings of entangled photons, shared between distant locations, can be “quantum keys” that secure communications. Anyone trying to eavesdrop on a quantum-encrypted message would disrupt the shared key, alerting everyone to a compromised channel.

But entangled photons degrade rapidly as they pass through the air or optical fibers. So far, the farthest anyone has sent a quantum key is a few hundred kilometers. “Quantum repeaters” that rebroadcast quantum information could extend a network’s reach, but they aren’t yet mature. Many physicists have dreamed instead of using satellites to send quantum information through the near-vacuum of space. “Once you have satellites distributing your quantum signals throughout the globe, you’ve done it,” says Verónica Fernández Mármol, a physicist at the Spanish National Research Council in Madrid. …

Popkin goes on to detail the process for making the discovery in easily accessible (for the most part) writing and in a video and a graphic.

Russell Brandom writing for The Verge in a June 15, 2017 article about the Chinese quantum satellite adds detail about previous work and teams in other countries also working on the challenge (Note: Links have been removed),

Quantum networking has already shown promise in terrestrial fiber networks, where specialized routing equipment can perform the same trick over conventional fiber-optic cable. The first such network was a DARPA-funded connection established in 2003 between Harvard, Boston University, and a private lab. In the years since, a number of companies have tried to build more ambitious connections. The Swiss company ID Quantique has mapped out a quantum network that would connect many of North America’s largest data centers; in China, a separate team is working on a 2,000-kilometer quantum link between Beijing and Shanghai, which would rely on fiber to span an even greater distance than the satellite link. Still, the nature of fiber places strict limits on how far a single photon can travel.

According to ID Quantique, a reliable satellite link could connect the existing fiber networks into a single globe-spanning quantum network. “This proves the feasibility of quantum communications from space,” ID Quantique CEO Gregoire Ribordy tells The Verge. “The vision is that you have regional quantum key distribution networks over fiber, which can connect to each other through the satellite link.”

China isn’t the only country working on bringing quantum networks to space. A collaboration between the UK’s University of Strathclyde and the National University of Singapore is hoping to produce the same entanglement in cheap, readymade satellites called Cubesats. A Canadian team is also developing a method of producing entangled photons on the ground before sending them into space.

I wonder if there’s going to be an invitational event for scientists around the world to celebrate the launch.

Multimedia Nano

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Nano Today held an art competition for work to be featured on the six issues they’ll be publishing in 2009. Here’s one of the winners,

Pine tree-like nanowires

Spiraling pine tree-like PbS nanowires are evidence of nanowire growth driven by screw dislocations without the help of metal catalysts. Screw dislocation drives the rapid growth of the nanowire tree trunk and causes the lattice of the trunks to twist (called “Eshelby Twist”) and their epitaxial branches to spiral. See Science 2008, 320, 1060.
Matthew J. Bierman, University of Wisconsin-Madison, USA

And one of the runners up,

Nano Flower

The micrograph shows FeSEM image of ZnO nanoflower developed by ultrasonication method. The ZnO nanopetals have grown in all directions giving it an appearance of flower.
Prashant KR Singh and Ankit Mittal, Indian Institute of Technology Roorkee, India

They had over three hundred entries in the competition and you can see more winners and runners up here. Source for the images was Nano Today. You can also check out the Nano Werk article which alerted me to the art competition.

If your tastes run more to the audio side, Oxford University is producing podcasts on a variety topics. The series I’m excited about is called, “Caging Shrodinger’s Cat – Quantum Nanotechnology.” The series of three podcasts is here.