Nearly every second, a user on Twitter tweets about what time it is. It could be groaning about waking up, to telling a friend when to meet, to an automated train scheduler alerting when the next one is coming. By searching Twitter for the current time we get a tiny glimpse of how active and far reaching the social network is.
Category Archives: Tech
Me Tarzan
This cheetah
This video shows a demonstration of the “Cheetah” robot galloping at speeds of up to 18 miles per hour (mph), setting a new land speed record for legged robots. The previous record was 13.1 mph, set in 1989.
The robot’s movements are patterned after those of fast-running animals in nature. The robot increases its stride and running speed by flexing and un-flexing its back on each step, much as an actual cheetah does.
Soon to Replace The Javelin in Indoor Track Meets
Joe Ayoob throws a John Collins design, officially breaking the world record by 19 feet, 6 inches.
All Hail Our New Fish Robots Overlords
What Makes a Robot Fish Attractive? (Hint: It’s in the Moves)
The researchers designed their bio-inspired robotic fish to mimic the tail propulsion of a swimming fish, and conducted experiments at varying tail beat frequencies and flow speeds. In nature, fish positioned at the front of a school beat their tails with greater frequency, creating a wake in which their followers gather. The followers display a notably slower frequency of tail movement, leading researchers to believe that the followers are enjoying a hydrodynamic advantage from the leaders’ efforts.
Powered by Vodka Martinis, No Doubt
Flying robot quadrotors perform the James Bond Theme by playing various instruments including the keyboard, drums and maracas, a cymbal, and the debut of an adapted guitar built from a couch frame.
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These flying quadrotors are completely autonomous, meaning humans are not controlling them; rather they are controlled by a computer programed with instructions to play the instruments.
Velocitas Eradico
A test shot fires from the Office of Naval Research-funded Electromagnetic Railgun prototype launcher located at the Naval Surface Warfare Center Dahlgren Division.
A story from a little over a year ago reported a 33 MegaJoule test. A blog post at Scientific American puts the design range at 20-32 MJ, so it seems the refinements are now in areas other than the energy (e.g. better efficiency, moving from a research device to a better-engineered on that can be deployed). That article also refines the expected range of the gun.
The Navy says that the railgun project, initiated in 2005, will yield a 20- to 32-megajoule weapon that shoots a distance of 50 to 100 nautical miles (roughly 90 to 185 kilometers).
Death Star Economics Redux
The Death Star Is a Surprisingly Cost-Effective Weapons System
[H]ow big is the Republic/Empire? There’s probably a canonical figure somewhere, but I don’t know where. So I’ll just pull a number out of my ass based on the apparent size of the Old Senate, and figure a bare minimum of 10,000 planets. That means the Death Star requires .03 percent of the GDP of each planet in the Republic/Empire annually. By comparison, this is the equivalent of about $5 billion per year in the current-day United States.
Went there first, I did, but not in as much detail.
A Whole Lotta Shakin' Going On
The story where I saw this calls the phenomenon “ground resonance”. While it looks and acts a lot like an unbalanced washing machine in the spin cycle, which doesn’t seem like a resonance phenomenon, from what I understand this can be caused by a shock to the system from landing, and the helicopter is susceptible at certain rotor speeds. If the compensation is 180º out of phase with the wobble you get positive feedback, so it makes sense that this could happen; you’d either want to speed up or slow down the rotor, were it safe and easy to do so, to change the feedback. But this happened pretty quickly.
That's a Big Twinkie
How Big a Battery Would It Take to Power All of the U.S.?
Generating capacity is, however, only one side of the story. Storage systems are rated not only by their power, or how fast they can crank out energy (measured in gigawatts), but also by the total amount of energy they store (measured in gigawatt-hours). A facility with an energy capacity of one-gigawatt that can only supply electricity for 10 minutes would not be very helpful; in an ideal world it could do so for, say, 100 hours, thus storing 100 gigawatt-hours. Building up new pumped hydro-facilities similar to existing ones would probably help in all but the most disastrously long of wind lulls. For those worst-case scenarios, we might still have to brace for rolling blackouts.
Of course, this simple calculation also assumes current consumption levels. How would we power all those electric cars that we’re supposed to be driving in the future?