Monday, September 29, 2008

tree power

Scientists have known that trees can produce extremely small amounts of electricity, but did not know how the energy was produced or how to take advantage of the power. In a recent issue of the Public Library of Science ONE, Zhang and MIT colleagues report the answer. "It's really a fairly simple phenomenon: An imbalance in pH between a tree and the soil it grows in."

The new sensor system taps into trees as a self-sustaining power supply. Each sensor is equipped with an off-the-shelf battery that can be slowly recharged using electricity generated by the tree.

A single tree doesn't generate a lot of power, but over time the “trickle charge” adds up, “just like a dripping faucet can fill a bucket over time,” said Shuguang Zhang, one of the researchers on the project. The system produces enough electricity to allow the temperature and humidity sensors to wirelessly transmit signals four times a day, or immediately if there's a fire. Each signal hops from one sensor to another, until it reaches an existing weather station that beams the data by satellite to a forestry command center in Boise, Idaho.

Thursday, September 25, 2008

my mean green machine


for your health

  • the average person loses 13 lbs their first year of commuting by bike
  • just three hours of biking per week can reduce your risk heart disease and stroke by 50%
  • a 140 pound cyclist burns 508 calories while pedaling 14 miles per hour

for the world

  • the US could save 462 millions gallons of gas a year by increasing cycling form 1% to 1.5%
  • each US rush hour auto commuter spends an average of 50 hours a year stuck in traffic
  • in 2003, cars stalled in traffic wasted 5 billion gallons of fuel

for our future

  • in 1964, 50% of kids rode to school and the obesity rate was 12% — in 2004, 3% rode to school and the obesity rate was 45%
  • between 1960 and today the average weight of a 6-11 year old has increased 11 pounds

for 5 miles or less

  • 60% of the pollution created by auto emissions happen in the first few minutes of operation, before the pollution control devices can work effectively
  • 25% of all trips are made within one mile of home
  • 40% of all trips are make within two miles of home
  • 50% of the working population commutes five miles or less to work

for fun

ride your bike to the park, around your neighborhood, to the corner store; ride with the wind...

Wednesday, September 24, 2008

finding time


long hikes
fertile earth
deep thoughts
simple pleasures
early morning
dark nights
blue skies
bare feet