Month: May 2018
https://phys.org/news/2018-05-instant-magnetization.html
Researchers achieve almost instant magnetization of matter by light
May 28, 2018 by José Tadeu Arantes, FAPESP
The production of devices to store or transmit information is one of the most frequent technological applications of magnetism. An experimental and theoretical study conducted at the University of São Paulo’s Physics Institute (IF-USP) in Brazil has discovered an ultrafast way of magnetizing matter with minimal energy consumption.
Using a technique called magnetization by light, the researchers magnetized a sample of europium selenide (EuSe) in 50 picoseconds with a 50-watt bulb located a few centimeters away. A picosecond is one trillionth of a second.
An article describing the experiment, titled “Ultrafast light switching of ferromagnetism in EuSe,” was recently published in Physical Review Letters.
The experiment was conducted by André Bohomoletz Henriques, a full professor at IF-USP, and collaborators with support from the São Paulo Research Foundation—FAPESP.
“Our aim was to find new mechanisms to change the magnetism of materials in an ultrashort time scale using only light. The novelty of our research is that it makes very strong magnetization possible with very small amounts of light,” Henriques said.
The process was experimentally derived at the University of São Paulo’s Magneto-Optics Laboratory, but interpreting the phenomenon required substantial theoretical work, involving procedures such as self-consistent quantum mechanical calculations and Monte Carlo simulations, on the part of the group led by Henriques.
The magnetization of a material is associated with the spatial ordering of the spins of its constituent particles. In an unmagnetized material, the spins of its atoms (resulting from the spins of its electrons) are disordered. Because vector magnitude is involved, the spin of each atom points in an arbitrary direction. In certain situations, these spins can be ordered by light, which, as a result, can completely magnetize an initially disordered material. The image above illustrates the process of magnetization by light.
The material chosen for the experiment was the semiconductor europium selenide (EuSe), in which each photon ordered the spins of 6,000 electrons.
“This happens because when a photon interacts with an electron, it changes a state that is strongly located in the atom to a state that extends to many atoms,” Henriques explained. “The result is that in an extraordinarily short time, about 50 picoseconds, all the atoms within reach of the electron’s wave function switch their spins to a common direction, creating a super-gigantic magnetic moment approaching 6,000 Bohr magnetons. That is equivalent to the magnetic moment of 6,000 electrons with spins all pointing in the same direction. The result, considered unexpected and spectacular by peer reviewers for Physical Review Letters, was that with a single photon, we were able to align the spins of 6,000 electrons.”
Spin is popularly understood as the rotation of a particle around an axis, but this conception does not correspond to reality and only serves as a representation of a particle associated with an electric current equivalent to a magnetic moment.
Particles not only have inertial mass and electric charge but also a third physical property called spin. This property, characterized as a vector (i.e. a physical quantity with magnitude and direction), describes the magnetic moment of the particle. Like a compass needle, which is oriented in a North-South direction by the pull of Earth’s magnetic field because it has a magnetic moment, a particle’s spin also tends to point in the direction of the magnetic field acting on it.
“To magnetize europium selenide, the photon must have enough energy to transfer an electron from an orbit very close to the atomic nucleus to a distant orbit in the conduction band. As a result of this transfer, the electron interacts magnetically with thousands of nearby atoms. The interaction between the electron’s magnetic momentand the magnetic moments of the nearby atoms aligns all their spins,” said the FAPESP-supported researcher.
Anti-ferromagnetic interaction
Europium selenide was chosen due to its high magnetic susceptibility, which results in the strong tendency of atom spins to align under the effect of a very small magnetic field.
“In addition to the magnetic interaction between the electron and the europium atoms, there is also magnetic interaction among the europium atoms themselves. Interaction between first neighbors is ferromagnetic; in other words, it favors alignment in the same direction. But interaction between second neighbors is anti-ferromagnetic and favors alignment in opposite directions,” Henriques said.
“These two interactions almost cancel each other out. Actually, the anti-ferromagnetic interaction just about prevails. For this reason, under usual conditions, the material is found in the anti-ferromagnetic state, without magnetism. However, any minor disturbance, such as the presence of an electron, can upset this delicate balance of interactions and favor the ferromagnetic state, i.e. the alignment of all spins in the crystal in the same direction, magnetizing the material almost instantly.”
There are different forms of magnetic interaction. The best-known form is dipolar interaction, which characterizes the attraction between two magnets, but there is also exchange interaction, which is far stronger and influences the magnetism of a compass needle or refrigerator magnet.
Exchange interaction is electrostatic in origin and constitutes a quantum phenomenon derived from the Pauli exclusion principle, which has no analogue in classical physics. This process makes ultrafast magnetization by light possible with minimal energy consumption.
Although they conducted this study strictly as basic research, Henriques and his team are aware of the potential technological applications in the context of the swiftly advancing electronics industry. According to an editorial published in March 2018 in the journal Nature Physics, the manipulation of magnetism in anti-ferromagnetic materials such as europium selenide is an emerging field of research with promising potential for application in electronic devices.
Explore further: Controlling spin for memory storage
More information: A. B. Henriques et al, Ultrafast Light Switching of Ferromagnetism in EuSe, Physical Review Letters (2018). DOI: 10.1103/PhysRevLett.120.217203
Read more at: https://phys.org/news/2018-05-instant-magnetization.html#jCp
https://electrek.co/2018/05/28/tesla-model-s-wagon-remetzcar
Another stunning Tesla Model S wagon unveiled
We already reported on a company building a Tesla Model S wagon, but now a second company is attempting to build an all-electric station wagon using the Model S. That company unveiled it today.
Station wagons, shooting brake, estate cars or whatever you want to call them, are quite popular in Europe and there are no all-electric options.It turns out that the Model S’ design actually translates fairly well into a wagon design.
Qwest’s Model S wagon showed that, but now RemetzCar, a Dutch conversion car company, is trying to take it to a new level.
RemetzCar is already known within the Tesla community for having turned a Model S into an all-electric hearse.
They were commissioned by Dutch collectioneur Floris de Raadt to transformed his Model S sedan into a shooting brake.
de Raadt explained the project:
“The idea was to translate my Tesla Model S into a dynamic and sporty yet elegant Shooting Brake, rather than creating a car with maximum luggage space. Niels van Roij Design developed several options for the conversion, focusing on premium design combined with limited conversion costs: thus making coach building available for a larger group of connoisseurs. Our favourite was the option called ‘Bold Chrome’, featuring remarkable high gloss chrome window trims emphasizing the bold dynamic lines of the car. The result is truly stunning!”
You can judge for yourself since RemetzCar released pictures and renderings today:
As you can see, they kept most of the design, but they also had to develop several new parts:
“RemetzCar’s craftsmen translated Van Roij’s design sketches into the actual car, leaving the full core structure of the car as well as the crumple zones intact. RemetzCar also a developed a completely new tailgate, featuring a rear spoiler with hidden rear window wiper and brake light. To give the car an even more bold stance also from a front view, Van Roij added a chrome trim that runs from the A-pillars all the way along the roofline and around the panoramic roof. Finally, the team developed a unique colour, based on De Raadt’s wishes. The green metallic with a twist of gold gives the Model SB an elegant yet striking appearance.”
The vehicle will have a public premiere at the International Concours d’Élégance Paleis Het Loo, held from 29 June to 1 July 2018 in Apeldoorn, The Netherlands, and the owner will tour Europe with the vehicle after that.
Electrek’s Take
Personally, I think I prefer this design over the one from Quest that came out of the UK. It looks more refined.
With this said, I know that they highlight it as a feature, but I am not a fan of the large chrome window trim in the back.
Also, I have never understood aftermarket modification companies removing the badging and replacing them with their own. I understand adding your own badging in a few places, but I have a problem with replacing existing badging.
The car is still mostly Tesla’s.
To be fair, RemetzCar is not the only one doing that. Saleen and others have been known to do that from time to time.
I know that they can be some issues with selling products with badging from another company, but in this case, we are talking about a private owner having his own vehicle modified and therefore, they can have anything they want on it, which is fair.
What about you? What do you think of this Model S wagon? Let us know in the comment section below.
https://www.bleepingcomputer.com/news/security/python-may-let-security-tools-see-what-operations-the-runtime-is-performing/
Python May Let Security Tools See What Operations the Runtime Is Performing
A new feature proposal for the Python programming language wants to add “transparency” to the runtime and let security and auditing tools view when Python may be running potentially dangerous operations.
In its current form, Python does not allow security tools to see what operations the runtime is performing. Unless one of those operations generates particular errors that may raise a sign of alarm, security and auditing tools are blind that an attacker may be using Python to carry out malicious operations on a system.
PEP-551 proposes two new APIs for Python
But in Python Enhancement Proposal 551 (PEP-551), Steve Dower, a core Python developer, has proposed the addition of two new APIs that will let security tools detect when Python is executing potentially dangerous operations.
“We propose two API changes to enable this: an Audit Hook and Verified Open Hook,” Dower says. “Both are not set by default, and both require modifications to the entry point binary to enable any functionality.”
The first of these, the Audit Hook API, will raise warning messages about certain type of Python operations.
“These operations are typically deep within the Python runtime or standard library, such as dynamic code compilation, module imports, DNS resolution, or use of certain modules such as ctypes,” Dower says.
Security or audit tools may use these messages as warning flags that something suspicious is going on, and flag or stop the Python process from continuing, before real harm is done.
The second, the Verified Open Hook API, is a mechanism to let the Python runtime know what files it is permitted to execute or tamper with. Dower explains:
Most operating systems have a mechanism to distinguish between files that can be executed and those that can not. For example, this may be an execute bit in the permissions field, or a verified hash of the file contents to detect potential code tampering. These are an important security mechanism for preventing execution of data or code that is not approved for a given environment. Currently, Python has no way to integrate with these when launching scripts or importing modules.
Python’s performance impact is negligible
Dower has proposed PEP-551, last year in August. Early tests suggest the performance impact of adding these two APIs is negligible, “with the vast majority of benchmarks showing between 1.05x faster to 1.05x slower” results.
Initial plans were to have PEP-551 ship with Python 3.7, scheduled for release in mid-June 2018, but the proposal did not make the final cut, according to a list of new features added for next month’s release. This doesn’t mean PEP-551 won’t ship with a future version of Python.
Python is the second major scripting engine that is addressing the issue of “security optics” —the concept that programming and scripting runtimes should provide minimum transparency to aid prevention of bad behavior. Similar actions are being taken by Microsoft to make PowerShell more transparent to security tools.
https://news.ubc.ca/2018/05/28/b-c-researchers-say-hearing-loss-contributes-to-seniors-isolation-loneliness/
B.C. researchers say hearing loss contributes to seniors’ isolation, loneliness
Hearing loss should be accounted for in community programs according to UBC researchers, CBC reported.
Charlotte Jones, a professor at UBC’s Okanagan campus, and her colleagues found many seniors weren’t getting the anticipated benefits from exercise groups due to hearing issues.
https://phys.org/news/2018-05-crystals-secret-coherence-quantum.html
Time crystals may hold secret to coherence in quantum computing
May 28, 2018, Aalto University
An Aalto University study has provided new evidence that time crystals can physically exist – a claim currently under hot debate.
A time crystal is a structure that does not repeat in space, like normal three-dimensional crystals such as snowflakes or diamonds, but in time. In practice this means that crystals constantly undergo spontaneous change, breaking the symmetry of time by achieving a self-sustaining oscillation.
The value is in the time crystal’s coherency, a property that allows temporal and spatial consistency, amounting to longevity otherwise not possible.
“Nature has given us a system that wants to be coherent over time,” says Senior Scientist Vladimir Eltsov, leader of the ROTA research group at Aalto University.
“The system spontaneously begins to evolve in time coherently, over long periods of time, even infinitely long,” he says.
With more understanding, the coherent nature of a time crystal may pave the way for eventual real-world applications. Researchers are hunting for systems that preserve coherence over the long term to make, for example, quantum information processing devices, but they struggle with sources resistant to decay.
Until recently, there has been little experimental evidence of the phenomenon. Physicists around the world have been racing to determine if – and how – these unique structures can be observed.
“There has been a lot of theoretical papers, but very few practical realizations. So ours is one of the few, and the first to demonstrate quasi-crystals,” says Eltsov explains.
By understanding the fundamentals of time crystals – as in, when and how they materialize – researchers may be one day able to harness these principles to develop coherency in other devices, regardless of environmental factors.
The finding, achieved by studying the Bose–Einstein condensation of magnons in superfluid Helium-3, also has implications for other branches of physics.
“Helium-3 is related to practically all branches of physics: gravity, topology, particle physics, cosmology,” says Professor Emeritus Grigori Volovik at Aalto University, a global pioneer in the study of connections between cosmology, high-energy physics and condensed matter.
In the future it may even be possible to look at time itself, including the possibility of constructing the boundary between time going forward and back, as theory suggests.
“It is an entire universe of study,” Volovik says.
The scientists observed the time quasicrystal and its transition to a superfluid time crystal at the Low Temperature Laboratory at Aalto University in Finland, which has a long-standing history of research on superfluidity.
The results of the study, funded by the European Research Council, were published in Physical Review Letters on May 25, 2018.
Explore further: Physicists find signs of a time crystal
More information: S. Autti et al. Observation of a Time Quasicrystal and Its Transition to a Superfluid Time Crystal, Physical Review Letters (2018). DOI: 10.1103/PhysRevLett.120.215301
https://gizmodo.com/this-ai-knows-who-you-are-by-the-way-you-walk-1826368997
This AI Knows Who You Are by the Way You Walk
Our individual walking styles, much like snowflakes, are unique. With this in mind, computer scientists have developed a powerful new footstep-recognition system using AI, and it could theoretically replace retinal scanners and fingerprinting at security checkpoints, including airports.
Neural networks can find telltale patterns in a person’s gait that can be used to recognize and identify them with almost perfect accuracy, according to new research published in IEEE Transactions on Pattern Analysis and Machine Intelligence. The new system, called SfootBD, is nearly 380 times more accurate than previous methods, and it doesn’t require a person to go barefoot in order to work. It’s less invasive than other behavioral biometric verification systems, such as retinal scanners or fingerprinting, but its passive nature could make it a bigger privacy concern, since it could be used covertly.
“Each human has approximately 24 different factors and movements when walking, resulting in every individual person having a unique, singular walking pattern,” Omar Costilla Reyes, the lead author of the new study and a computer scientist at the University of Manchester, said in a statement.
To create the system, Reyes compiled a database consisting of 20,000 footstep signals from more than 120 individuals. It’s now the largest footsteps database in existence. Each gait was measured using pressure pads on the floor and a high-resolution camera. An artificially intelligent system called a deep residual neural network scoured through the data, analyzing weight distribution, gait speed, and three-dimensional measures of each walking style. Importantly, the system considers aspects of the gait, rather than the shape of the footprint.
“Focusing on non-intrusive gait recognition by monitoring the force exerted on the floor during a footstep is very challenging,” said Reyes. “That’s because distinguishing between the subtle variations from person to person is extremely difficult to define manually, that is why we had to come up with a novel AI system to solve this challenge from a new perspective.”
Previous attempts at footstep recognition involved the scanning of individuals without their shoes on, and a 3D-imaging technique that compared a person’s walking style to CCTV footage. The new technique is more accurate than both, though it does require the use of special floor pads.
To test the SfootBD system, Reyes’ team monitored participants in three different scenarios: airport security checkpoints, workplaces, and homes. The researchers also tested a control group of imposters to see if the AI could tell when someone was trying to fake another person’s gait (which it could). Results showed that, on average, the system was 100 percent accurate in identifying individuals, with an error rate of just 0.7 percent. That’s obviously an impressive result, and a sign that the technology could be effective in real-world situations.
This new system does have some limitations. As noted, SfootBD requires the use of floor pads and a high-res camera, so this form of surveillance and identification can’t be used just anywhere. What’s more, the tool is only as powerful as its database; the only individuals who can be identified are those whose distinctive gaits have been previously recorded and cataloged in the system. This approach is probably not very scalable, since collecting everyone’s walking style is an order of magnitude more difficult than, say, collecting photos for facial recognition. Finally, there are also issues of privacy and consent to consider, as this technology could be used surreptitiously.
So it’s a neat advance, but only time will tell how practical this method is for the real world.
[IEEE Transactions on Pattern Analysis and Machine Intelligence]
Up next AUTOPLAY 54:01 Digital Audio: The Line Between Audiophiles and Audiofools Mark Furneaux 2 162K views 22:07 Low Divergence Laser Projector Tech Ingredients 73K views 25:19 Helium vs Noise Tech Ingredients 8.6K views 27:40 Hybrid Drone Generator Tech Ingredients 70K views The LED Traffic Light and the Danger of “But Sometimes!” Technology Connections 565K views How to Make High Performance Sound Absorption Panels for $5 DIY Perks 1.5M views The New UFO Documentary the Elite Hoped Would Never Be Aired in Public UAMN TV Recommended for you Hybrid Jet Engine Tech Ingredients 33K views Top 10 Smallest Cars and Best 2-seater Electric Vehicles for City Driving Automotive Territory: Trending News & Car Reviews Recommended for you OnePlus 6 Quality Control EXPOSED Linus Tech Tips 1.7M views After watching this, your brain will not be the same | Lara Boyd | TEDxVancouver TEDx Talks Recommended for you Why Hawaii’s volcano is so UNUSUAL Physics Girl Recommended for you Breakthrough in Nuclear Fusion? – Prof. Dennis Whyte MIT Club of Northern California Recommended for you Make your own stylish smartphone Faraday Box in 10 minutes ScottiesTech.Info Recommended for you Faster Internet for FREE in 30 seconds – No… Seriously Linus Tech Tips 3.2M views Heavy Lift Carbon Fiber Drone Tech Ingredients 27K views I built a PC out of rope and wood… DIY Perks 1.3M views Noise Cancellation As Fast As Possible Techquickie 209K views Monster of the Milky Way Armaita777 Recommended for you Soundproofing a Room Lando27Music 108K views Active Noise Cancellation
https://electrek.co/2018/05/27/tesla-model-3-update-reduce-braking-distance-elon-musk/
Tesla starts rolling out Model 3 update to reduce braking distance by up to ~20 ft, says Elon Musk
Following some inconsistencies in testing for the stopping distance of the Model 3 last week, Tesla CEO Elon Musk said that the company found an issue with the ‘ABS calibration algorithm’.
Now the automaker started rolling out a software update to fix the issue, according to Musk.
On Monday, we published an article about Consumer Reports getting inconsistent results in their Model 3 braking tests.
The magazine said that they were getting a 152-ft average stopping distance from 60 mph, while Tesla claimed an average of 133 feet in their own tests.
Musk responded to the article saying that it was surprising but they will investigate to see if something could cause the braking distance to be inconsistent.
He later said that they found an issue with the ‘ABS calibration algorithm’ that could result in some inconsistent results and that they were working on an update.
Last night, Musk confirmed that they started pushing the update Friday and that it “should improve braking distance by ~20 ft for repeated heavy braking events”:
Ryan McCaffrey✔@DMC_Ryan
Elon, might you be willing to answer 1 more thing about the brakes on Performance Model 3? I’m still hoping to get those red brake calipers you kindly said “maybe” to, but I’m also curious if the brakes are larger than on RWD. With all that power it’d seem like they need to be!
Elon Musk✔@elonmusk
Also, firmware fix for upgraded brake performance on standard Model 3 started rolling out yesterday. Should improve braking distance by ~20 ft for repeated heavy braking events. Thanks @ConsumerReports for excellent critical feedback!
He didn’t specify which software update includes this fix, but Model 3 owners are reporting receiving the update 2018.18.13 over the past few days.
Electrek’s Take
That was a very quick turnaround from finding the issue to pushing a fix and of course, that’s the big advantage of over-the-air updates.
But it’s not clear if the average stopping distance has been reduced with this update or if it’s really just for “repeated heavy braking events”, which correct me if I’m wrong, but it sounds like it would only affect the actual result of brake test or on a race track since no one really does “repeated heavy braking” in ordinary driving.
If you have to brake heavily in an emergency, you generally do it just once.
I’d be curious to see if owners can feel a difference without “repeated” events. Let us know in the comment section below.
https://electrek.co/2018/05/26/tesla-solar-roof-tiles-up-close-look/
First up-close look at Tesla solar roof tiles
Tesla is slowly ramping up installations of its solar roof tiles and we got to see a few final product from customer installations in the last few months, but never a close look at the actual tiles and their connection system – until now.
After unveiling the solar tiles, CEO Elon Musk said that making the connectors robust involved “a shocking amount of technology”:
“This is a connector that has to last for more than 30 years. It has to be weatherproof, heavy rain, snow, slush, salt, water leaking – it’s like connector hell.”
Tesla CTO JB Straubel then added that the automaker managed to leverage its experience manufacturing connectors for electric vehicles:
“A lot of the challenges here leveraged some great learning from the Tesla team on validating automotive connectors and volume production processes. Tesla is building all these tiles ourselves – we are not outsourcing it. We have been able to solve those more complexed design problems and hit those price points that you see.”
We never had a good look at those connectors or the back of the tiles in general, but a Tesla Energy installer shared a rare up-close look at the tiles on Instagram (hat tip to Broke3):
Electrek’s Take
It looks like Tesla’s ‘textured’ solar tiles and interestingly, we might be able to see the difference between Tesla’s solar and non-solar tiles.
The first one doesn’t appear to feature any solar cell or connector, which leads me to believe it’s one of Tesla’s non-solar tiles.
But we get to see the sort of mounting system to lock the tiles together:
As for the other tile underneath the first one, we get to see the connector, which appears to link the solar cells between the tiles:
As we previously reported, Tesla says that the “typical homeowner can expect to pay $21.85 per square foot for a Solar Roof” with a mix of regular tiles and solar tiles.
It’s a fairly expensive product, but it comes with a lifetime of the house warranty and 30-year power generation guaranteed. After the electricity production, Tesla estimates that its solar roof will be cheaper than a non-solar tile roof of similar style or virtually pay for itself through electricity savings.
Tesla claims that they can guarantee the product due to a new glass that they developed for the tiles and is reportedly much more durable than any roofing product to date.
From the little information and images that we have so far, it looks like a fairly well-built product, but I’m curious to see the reviews from owners in the next few years.
What do you think? Let us know in the comment section below.
Tesla solar roof products are interesting for homeowners who want solar and need a new roof relatively soon, but a regular solar panel installation is still a good solution for people who don’t need a new roof. Solar and energy storage prices are highly dependent on your market (electricity cost, gov incentives, etc.) and your property. We suggest getting quotes from more than one installer to make sure you get the best energy solution for your place. UnderstandSolar is a great free service to link you to top-rated solar installers in your region for personalized solar estimates for free.
Bruce's Blog 
Elgato is launching a new HomeKit accessory designed for the warmer weather: a small box that connects to an outdoor faucet to let you remotely control a hose. It’s called the Eve Aqua, and it’ll be available for $100 starting June 25th.
The Eve Aqua basically just turns a hose on and off. It’s pretty simple, and it seems like there’s no way to adjust the strength of the water flow. But using a connected app, you can remotely turn the hose on and off and, more usefully, set schedules for the hose.
So presumably, you hook the Aqua up to a sprinkler, then set the sprinkler on a schedule so you don’t have to deal with it yourself. While you might not want to leave a hose snaking around your house indefinitely, this could still be helpful if you just want to keep some plants watered while you’re away for a week.
Like all of Elgato’s Eve line, the Aqua connects to HomeKit, Apple’s smart home system. That means it can be controlled through Siri and Apple’s Home app; you’ll also be able to easily synchronize it with other HomeKit gadgets.
Elgato is one of the first with a HomeKit-enabled hose controller, but we’ve been starting to see more and more smart water control devices. Several companies have made house-wide water monitors, while Rachio makes a device that adds smart features to entire sprinkler systems.