Getting out more than you put in: an overly efficient LED
Semiconductor
light emitting diodes (LEDs) have been around for decades and they're used in a wide variety of high-tech applications. When an
electrical potential is applied across an LED, work is done to...
Survival in academia, the tenure track not taken
Becoming a university professor requires a lot of work for very little financial reward, compared to most other professions. In STEM (science, technology, engineering, math) fields, the
minimum requirement is four
years of underg...
New membrane can block helium, yet allow water to flow freely
Membranes and barriers are
used all the time in industrial and lab settings, and you may even have a few of them around the home. They can help keep
materials apart that need to be
separated, or can...
Breaking up the indivisible to observe the implausible—particles with a fractional charge
It was 1909 when Robert
Millikan
and Harvey Fletcher carried out their famous oil drop experiment in
which they determined that
the smallest unit of charge possible was 1.592x10-19
Coulombs, a value
we now refer to as...
2011 Ig Nobels: beetle-on-beer-bottle sex and a wasabi-based fire alarm win big
Fall kicks off the scientific
awards season, which revved into high gear last night with the 21st
annual Ig Nobel awards. The ceremony, held once again at Harvard's
Sanders Theater, played host to scientists, interested aca...
Violating relativity by breaking equivalence
One of the tenets of
Einstein's theory of general relativity is that an observer, carrying
out local measurements, cannot determine if they are being accelerated in the absence of gravitational fields or
stationary but in t...
Astronomers find largest water reservoir ever, 12 billion years in the past
Using a pair of sub-millimeter
wavelength telescopes, two teams of astronomers have discovered the
largest reservoir of water
ever found in the Universe. The water-containing cloud was found near quasar APM 08279+5255, some 1...
Feature: Last flight of the Space Shuttle: a 30-year retrospective
The United States has been a
space-faring nation for just over 50 years, ever since Alan Shepard's
suborbital pop shot aboard Freedom 7 on May 5, 1961. In the following
eight years, the US, and mankind, went from being......
Biorefineries challenge petrochemicals with engineered yeast
The first session I attended as
part of this year's AAAS meeting
focused on the state of the art in, and technological hurdles that
limit, biorefineries. An analog to common petrochemical
refineries, biorefineries are facilities ...
The mathematics of fish schools and flocks of humans
What drives groups of
individual animals to act in a coherent
manner? Everyone has seen the oddly coordinated behavior exhibited by
flocks of birds or schools of fish as they turn, sweep, and rotate
seemingly as one. But how does...
Positrons at center of recent anti-progress in matter research
In a recent symposium on the
latest breakthroughs in antimatter research, two main questions were
prominent: how do we create new antimatter, and how can we store lots of
existing antimatter? The questions arise from an oddity in...
Measuring a kilogram by counting atoms
The kilogram, the actual
kilogram, sits in a vault in Sèvres,
France under numerous bell jars. It is the last SI unit to be defined
based on a physical quantity—in this case one kilogram of platinum
and iridium—as op...
