Adding a new chapter to the research that cemented the phrase “six degrees of separation” into the language, scientists at Facebook and the University of Milan reported on Monday that the average number of acquaintances separating any two people in the world was not six but 4.74.
Category Archives: STEM
Planet Labs Unveils Plan To Launch 28 Nanosats on Antares’ 1st Cargo Run
SAN FRANCISCO — Planet Labs is seeking to revolutionize the Earth imaging industry with a constellation of 28 nanosatellites designed to offer frequent, low-cost images of any point on the globe. By providing high-resolution imagery quickly and inexpensively, the company’s founders hope to expand dramatically the customer base for Earth imagery and the use of that information to address humanitarian, environmental and business concerns
via Planet Labs Unveils Plan To Launch 28 Nanosats on Antares’ 1st Cargo Run | SpaceNews.com.
The Enron E-mails’ Immortal Life
This research has had widespread applications: computer scientists have used the corpus to train systems that automatically prioritize certain messages in an in-box and alert users that they may have forgotten about an important message. Other researchers use the Enron corpus to develop systems that automatically organize or summarize messages. Much of today’s software for fraud detection, counterterrorism operations, and mining workplace behavioral patterns over e-mail has been somehow touched by the data set.
via The Enron E-mails’ Immortal Life | MIT Technology Review.
MIT researchers can see through walls using ‘Wi-Vi’
Every time a Wi-Fi signal is reflected off an object, the shape and makeup of that object affects the signal that comes back. But when Wi-Fi hits a wall, most of the signal gets reflected off the wall and only a faint bit of it reflects off the people on the other side.
To get around this, Wi-Vi transmits two Wi-Fi signals, one of which is the inverse of the other. When one signal hits a stationary object, the other cancels it out. But because of the way the signals are encoded, they don’t cancel each other out for moving objects. That makes the reflections from a moving person visible despite the wall between that person and the Wi-Vi device. Wi-Vi can translate those faint reflections into a real-time display of the person’s movements.
via MIT researchers can see through walls using ‘Wi-Vi’ | ITworld.
NASA’s NEXT ion thruster runs five and a half years nonstop to set new record
NEXT is a solar electric propulsion system where electricity from the spacecraft’s solar panels is used to power a a 7-kW class ion thruster. In this, particles of xenon gas are electrically charged and then accelerated to speeds up to 90,000 mph (145,000 km/h). Such thrusters have already been used on spacecraft, such as NASA’s Dawn probe, and engineers are very interested in them because of their much higher performance compared to conventional chemical rocket engines.
via NASA’s NEXT ion thruster runs five and a half years nonstop to set new record.
Quantum-Tunneling Electrons Could Make Semiconductors Obsolete
In traditional circuits, transistors are laid down in a bed of silicon that acts as an insulator to prevent crosstalk between circuits. In circuits based on quantum tunneling, silicon is replaced by nanotubes made of boron nitride and electrical pathways consisting of quantum dots—carefully placed bits of gold as small as three nanometers across (PDF).
via Quantum-Tunneling Electrons Could Make Semiconductors Obsolete.
Statistics, Probability, and Survey Sampling
This web site provides training and tools to help you solve statistics problems quickly, easily, and accurately – without having to ask anyone for help.
Roman Seawater Concrete Holds the Secret to Cutting Carbon Emissions
The Romans made concrete by mixing lime and volcanic rock. For underwater structures, lime and volcanic ash were mixed to form mortar, and this mortar and volcanic tuff were packed into wooden forms. The seawater instantly triggered a hot chemical reaction. The lime was hydrated – incorporating water molecules into its structure – and reacted with the ash to cement the whole mixture together.
via Roman Seawater Concrete Holds the Secret to Cutting Carbon Emissions « Berkeley Lab News Center.
This seems like an amazing discovery.
Their analyses showed that the Roman recipe needed less than 10 percent lime by weight, made at two-thirds or less the temperature required by Portland cement. Lime reacting with aluminum-rich pozzolan ash and seawater formed highly stable C‑A-S-H and Al-tobermorite, insuring strength and longevity. Both the materials and the way the Romans used them hold lessons for the future.
Hacking into the Indian Education System
Technically put, I merely needed to write a script to iterate through the various school IDs, check the different servers, and start with a student ID of 1 yet have a way to detect when there were no more students for a given school. I had to retrieve the resultant html files and parse them to extract all the useful information – Name, Date of Birth, ID, School, Marks.
via Hacking into the Indian Education System – On the Stepping Stone – Quora.
Several hours later, I had all the ISC and ICSE results on my very own computer, in a bunch of comma-separated value files. It was truly incredible. 26 megabytes of pure, magnificent data. An Excel file I couldn’t scroll to the bottom of. Just for kicks, I Ctrl+F’d a few names I knew and what do you know? There they were. Line after line of names, subjects and numbers. It was truly mesmerizing.
Scientist Creates and Snaps Photographs of Microscopic Crystal Flowers
The process calls for dissolving barium chloride and sodium silicate in a container of water. A chemical reaction then forms barium carbonate crystals (thanks to carbon dioxide in the air). From there, the shape of these crystals can be manipulated with small pH changes to the solution.
via Scientist Creates and Snaps Photographs of Microscopic Crystal Flowers.