Category Archives: Tech
The Groaning Grid
I remember when I was discussing a story about fast-charging batteries with someone that there was the conjecture that this was the hurdle to getting electric cars on the road. And I realized it wasn’t — heat dissipation issues aside (charging a cell-phone battery is one thing, but trying to scale that up is quite another) — the real issue is how much energy you need and how quickly you can deliver it. Grid capacity.
Electric cars will travel a few km per kWh of energy, so a 350 km range takes about 100 kWh, or 3.6 x 10^8 Joules. The good news is that this is more efficient than gasoline, which lets you go about 1 km per kWh. A gallon of gasoline has a little over 10^8 Joules stored in it, so 31 mpg is about 50 km/gal, and that makes an electric car with the above specs about twice as efficient. But if I can pump a gallon of gas in ten seconds, that means my energy transfer rate is 10 MW. That’s about 3 orders of magnitude higher than standard electricity delivery.
It’s pretty clear that any electric solution in the near future is going to involve shorter-range vehicles, be they pure electric or plug-in hybrid, which you could recharge overnight.
Challenges to grow with electric cars’ sales: Aging grid needs to handle more power
When a Chevrolet Volt is plugged into a 240-volt outlet, it will use about 3.3 kilowatts of power, or about the same amount of power as a dishwasher or air conditioner.
Most people are already familiar with what can happen when thousands of air conditioners are plugged in and running at the same time during the summer: brownouts.
“The last thing we would want is for everyone to come home … and plug them in at 5 or 6 o’clock on a hot, muggy summer afternoon … when we are at our peak,” DTE Energy Chairman Anthony Earley Jr. told the Free Press in an interview recently.
US residential consumption is about 30 kWh of electricity every day; houses probably more and apartments less. Regardless, 3.3 kW for 8 hours = 26.4 kWh, which is a significant bump.
You'll Shoot Your Eye Out
New laser pointer. 20 mW, $20. Elicited some “gotta get one” responses, as well as “That’s bright!” (It is, too)
It’s supposed to say “Laser” (3 second exposure on the camera)
Laser writing is hard. No mechanical feedback, no visual feedback.
R1D1
In New York, we are very occupied with getting from one place to another. I wondered: could a human-like object traverse sidewalks and streets along with us, and in so doing, create a narrative about our relationship to space and our willingness to interact with what we find in it? More importantly, how could our actions be seen within a larger context of human connection that emerges from the complexity of the city itself? To answer these questions, I built robots.
Tweenbots are human-dependent robots that navigate the city with the help of pedestrians they encounter. Rolling at a constant speed, in a straight line, Tweenbots have a destination displayed on a flag, and rely on people they meet to read this flag and to aim them in the right direction to reach their goal.
Schneier notes
It’s a measure of our restored sanity that no one called the TSA. Or maybe it’s just that no one has tried this in Boston yet.
Maybe We'll Do In a Squirrel or Two …
… hundred.
Spokane parks to detonate squirrels
The parks department says the Rodenator is a humane way to kill the squirrels. But it warns area residents that the explosions sound like gun shots, and to not to alarmed by them all week.
The Rodenator Pro pumps propane and oxygen into the tunnels of squirrels, then sends an electric spark that causes an explosion. The shock waves kill the squirrels and collapse their tunnels – but in a humane way, the agency said.
The agency spokesman sounds a lot like Carl Spangler.
Wet Shoe Problem — Check
The researchers calculated that shoes flick up about a pint of water after walking 20 kilometres on a damp day.
I wonder if the researchers really reported an imperial volume with a metric distance.
No Volcanoes Here
Angle of Incidence = Music
Turn your sound up. Draw lines on the black screen to bounce the balls. Enjoy the music.
Wonder Woman's Other Mode of Transportation
Spectacular and See-Through: Dude, Where’s My Canoe?
I have a sudden urge to take up scuba diving.
I Can No' Change the Laws of Physics, Cap'n!
Quantum setback for warp drives
Bad news I’m afraid — it looks as if faster-than-light travel isn’t possible after all. That’s the conclusion of a new study into how warp drives would behave when quantum mechanics is taken into account. “Warp drives would become rapidly unstable once superluminal speeds are reached,” say Stefano Finazzi at the International School for Advanced Studies in Trieste, Italy, and a couple of friends.