The ultrafast switch is made out of an artificial material engineered to have properties that are not found in nature. In this case, the “metamaterial” consists of nanoscale particles of vanadium dioxide (VO2) – a crystalline solid that can rapidly switch back and forth between an opaque, metallic phase and a transparent, semiconducting phase – which are deposited on a glass substrate and coated with a “nanomesh” of tiny gold nanoparticles.
The scientists report that bathing these gilded nanoparticles with brief pulses from an ultrafast laser generates hot electrons in the gold nanomesh that jump into the vanadium dioxide and cause it to undergo its phase change in a few trillionths of a second.
Category Archives: STEM
Orbital computing: An amazing atomic-level tech for future computers
The new technology — or shall we say, science — is being developed by Joshua Turner at Stanford’s SLAC National Accelerator Laboratory. He calls the idea “orbital computing” since the bit that stores the it would be the orbits of electrons around the nucleus of an atom. The goal is to be able to probe the electron clouds of single atoms using terahertz waves of just the right size. The catch is that to generate a tight enough pulse of sufficient intensity to do this, you need an accelerator two miles long. But if you manage that, you can switch electron states 10,000 times faster than transistor states can be switched.
via Orbital computing: An amazing atomic-level tech for future computers | ExtremeTech.
Not even Joshua Turner is expecting orbital computing to be a workable technology any time soon. Most of his experiments are aimed at understanding what might be going on. He is merely looking into the crystal ball with a telescope and seeing what is even imaginable.
Battery-free technology brings gesture recognition to all devices
The researchers built a small sensor that can be placed on an electronic device such as a smartphone. The sensor uses an ultra-low-power receiver to extract and classify gesture information from wireless transmissions around us. When a person gestures with the hand, it changes the amplitude of the wireless signals in the air. The AllSee sensors then recognize unique amplitude changes created by specific gestures.
via Battery-free technology brings gesture recognition to all devices | UW Today.
Who needs sunlight? In Arizona, solar power never sleeps
In a parabolic trough plant like Solana, the mirrors are curved inward, with a glass tube running along the deepest point, or trough, of each mirror. The tube is full of synthetic oil (also known as heat transfer fluid, or HTF). The concave mirrors concentrate light onto this HTF, heating it to 740 degrees Fahrenheit. The system is extremely efficient in collecting heat and concentrating it to a blistering level; when I asked what would happen if I touched the tube, the reply was a curt “Trust me, you definitely don’t want to do that.”
Once the oil is up to temperature, about 270 miles of pipe transport it to the power block, where the HTF takes one of two pathways, depending on Solana’s current needs.
via Who needs sunlight? In Arizona, solar power never sleeps | Ars Technica.
Math Explains Likely Long Shots, Miracles and Winning the Lottery
So let’s look at the probability that none of the 23 people in the room share the same birthday. For two people, the probability that the second person doesn’t have the same birthday as the first is 364/365. Then the probability that those two are different and that a third doesn’t share the same birthday as either of them is 364/365 × 363/365. Likewise, the probability that those three have different birthdays and that the fourth does not share the same birthday as any of those first three is 364/365 × 363/365 × 362/365. Continuing like this, the probability that none of the 23 people share the same birthday is 364/365 × 363/365 × 362/365 × 361/365 … × 343/365.
This equals 0.49
via Math Explains Likely Long Shots, Miracles and Winning the Lottery – Scientific American.
Responding to Potential Asteroid Redirect Mission Targets
NASA is developing an Asteroid Redirect Mission (ARM) — a first-ever mission to identify, capture and redirect an asteroid to a safe orbit of Earth’s moon for future exploration by astronauts in the 2020s.
ARM will use capabilities in development, including the new Orion spacecraft and Space Launch System (SLS) rocket, and high-power Solar Electric Propulsion. All are critical components of deep-space exploration and essential to meet NASA’s goal of sending humans to Mars in the 2030s. The mission represents an unprecedented technological feat, raising the bar for human exploration and discovery, while helping protect our home planet and bringing us closer to a human mission to one of these intriguing objects.
via Responding to Potential Asteroid Redirect Mission Targets | NASA.
Here is an article from 12/24/2012 about this.
Open Bitcoin ATM
The world’s first completely open-source Bitcoin ATM for Education and Experimentation.
http://openbitcoinatm.org for more information.
via Open Bitcoin ATM.
Adjusting GPAs: A Statistician’s Effort to Tackle Grade Inflation
A recent analysis of 200 colleges and universities published in the Teachers College Record found that 43 percent of all letter grades awarded in 2008 were A’s, compared to 16 percent in 1960. And Harvard’s student paper recently reported that the median grade awarded to undergraduates at the elite school is now an A-.
Via Adjusting GPAs: A Statistician’s Effort to Tackle Grade Inflation
“That allowed me to look directly at the influence of course grades on student evaluations,” Johnson said. “As you might expect, the effect of either expected course grade or received course grade is very powerful in student evaluations of teaching. If a student was getting a C in a course, he or she was very unlikely to rate the instructor highly. If they were getting an A in the course, they’re more likely to rate the instructor highly. I think this provides quantitative evidence for something most instructors know: If they grade easier, they will tend to get better course evaluations.”
Wake up, Rosetta!
Rosetta was launched in 2004 and has since travelled around the Sun five times, picking up energy from Earth and Mars to line it up with its final destination: comet 67P/Churyumov–Gerasimenko. For the coldest, loneliest leg of the mission, as Rosetta travelled out towards the orbit of Jupiter, the spacecraft was put into deep-space hibernation.
In 2014, Rosetta will complete its cruise towards the comet, rendezvousing with it in August, before putting its Philae lander onto the comet’s surface in November, as it begins its journey closer to the Sun.
via Wake up, Rosetta! / Rosetta / Space Science / Our Activities / ESA.
Rosetta will arrive at 67P in August 2014, where it will become the first spacecraft to orbit the nucleus of a comet and, later in the year, the first to land a probe – Philae – on a comet’s surface. It will also be the first mission to escort a comet as it journeys around the Sun.
A list of four special Linux distributions for kids
Learning at an early age can be best enhanced in an environment that encourages exploration. There is no other operating system that offers such variety and autonomy to customize the system based on specific needs like Linux. Like toys and clothes for kids, the Linux community has developed specific operating systems that can offer them a fun learning environment. I believe that to boost curiosity in kids, it is important to create a set up that gives them a feeling of wonder.
via A list of four special Linux distributions for kids | opensource.com.
I haven’t installed any of these but found the concept interesting.