Volume II Issue 9
September 2006 |
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 Mercury
Atomic Clock Keeps Time with Record Accuracy
 An experimental atomic clock based on a single mercury atom is now at
least five times more precise than the national standard clock based on
a "fountain" of cesium atoms, according to physicists at the National
Institute of Standards and Technology (NIST).
The experimental clock,
which measures the oscillations of a mercury ion (an electrically
charged atom) held in an ultra-cold electromagnetic trap, produces
"ticks" at optical frequencies. Optical frequencies are much higher than
the microwave frequencies measured in cesium atoms in NIST-F1, the
national standard and one of the world's most accurate clocks. Higher
frequencies allow time to be divided into smaller units, which increases
precision.
 The
current version of NIST-F1 -- if it were operated continuously -- would
neither gain nor lose a second in about 70 million years. The latest
version of the mercury clock would neither gain nor lose a second in
about 400 million years.
Improved time and frequency
standards have many applications. For instance, ultra-precise clocks can
be used to improve synchronization in navigation and positioning
systems, telecommunications networks, and wireless and deep-space
communications. Better frequency standards can be used to improve probes
of magnetic and gravitational fields for security and medical
applications.
Find out more...
Freshmen
Intentions to Major in Science and Engineering
 Since
1972, an annual survey administered by the University of California at
Los Angeles, has asked freshmen at a large number of universities and
colleges about their intended majors. The data have provided a broadly
accurate picture of degree fields several years later.
For at least the past two
decades, about one-third of all freshmen planned to study a field within
science and engineering (S&E). The demographic composition of students
planning S&E majors has become more diverse over time. Women constituted
38% in 1983, rising to 45% in 2004. White students represent a smaller
percentage of the total, down from 85% in
1983 to 72% in 2004. On the other hand, Asian/Pacific Islander students
increased from 3% to 12%, Hispanic students increased from 1% to 8%, and
American Indian/Alaska Native students increased from 1% to 2%. Black
students made up 10% of freshmen intending to major in S&E both in 1983
and in 2004.
Find out more about degrees in science
and engineering...
The
Geometry of Musical Chords
 Composers
often speak of fitting chords and melodies together, as though sounds
were physical objects with geometric shape -- and now a Princeton
University musician has shown that advanced geometry actually does offer
a tool for understanding musical structure.
Dmitri Tymoczko has
journeyed far into the land of topology and non-Euclidean geometry, and
has returned with a new way of understanding how music is constructed.
His findings resulted in the first paper on music theory that the
journal Science has printed in its 127-year history, and may provide an
additional theoretical tool for composers searching for that elusive
next chord.
Making graphical
representations of musical ideas is not itself a new idea. Even most
nonmusicians are familiar with the five-line musical staff, on which the
notes that appear physically higher represent sounds that have higher
pitch.
One of Tymoczko's
musical spaces resembles a triangular prism, in which points
representing traditionally familiar harmonies such as major chords
gather near the center of the triangle, forming neat geometric shapes
with other common chords that relate to them closely. Dissonant,
cluster-type harmonies can be found out near the edges, close to their
own harmonic kin.
To bring these ideas
to life, Tymoczko has created a
short
movie that illustrates the chord movement in a piece of music by
19th-century composer Frederick Chopin. His E minor piano prelude (Opus
28, No. 4) has charmed listeners since the 1830s, but its harmonies have
not been well explained.
Find out more...
Degree
Profile: Chemistry
 Chemistry
helps explain the world and its workings, and plays an important role in
our lives. Chemists have contributed a great deal to technical advances
of society and have made many important contributions to modern life.
Everything is made from one or more chemical elements that occur in
nature. Chemists use different kinds of chemical processes to make the
elements more useful, and they create countless products that make our
lives healthier, easier, and more enjoyable.
 A
person with a bachelor's level education in chemistry is prepared to
assume a wide variety of positions in industry, government, and
academia. The more obvious positions for which a background in chemistry
is important are those in the chemical industry or in chemical
education. Chemists are also employed in a wide variety of related
professions such as molecular biology and biotechnology, material
science, forensic science, hazardous waste management, textile science,
and information management.
Chemists are challenged,
excited, and satisfied with their profession. Though chemists may change
employers several times during their careers, the majority in the field
stay in it their entire careers.
Find out more about careers in
chemistry.
Astronomers
Demote Pluto!
 The
world's astronomers, under the auspices of the
International Astronomical Union (IAU),
have concluded two years of work defining the difference between
"planets" and the smaller "solar system bodies" such as comets and
asteroids.
In late August, the group agreed that a "planet" is defined as a
celestial body that (a) is in orbit around the Sun, (b) has sufficient
mass for its self-gravity to overcome rigid body forces so that it
assumes a hydrostatic equilibrium (nearly round) shape, and (c) has
cleared the neighborhood around its orbit.
This means that our Solar System officially consists of eight planets:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A new
distinct class of objects called "dwarf planets" was also decided. It
was agreed that "planets" and "dwarf planets" are two distinct classes
of objects. The first members of the "dwarf planet" category are Ceres,
Pluto, and 2003 UB313 (temporary name). More "dwarf planets" are
expected to be announced by the IAU in the coming months and years. This
is the first change to the accepted configuration of our solar system
since Pluto was discovered in 1930.
With the advent of powerful new telescopes on the ground and in space,
planetary astronomy has gone though an exciting development over the
past decade. For thousands of years very little was known about the
planets other than they were objects that moved in the sky with respect
to the background of fixed stars. In fact the word "planet" comes from
the Greek word for "wanderer." Hosts of newly discovered large objects
in the outer regions of our Solar System presented a challenge to our
historically based definition of a "planet."
Find out more about career paths
leading from degrees in science...
Actuarial
Science and Statistics Added to Sloan Career Cornerstone Center
 Mathematics
career path resources on the Sloan Career Cornerstone Center have
tripled recently with the addition of two new fields:
statistics and
actuarial
science. The two fields complement the extensive careers in
mathematics resources already on the site.
Statistics is the
scientific application of mathematical principles to the collection,
analysis, and presentation of numerical data. Statisticians contribute
to scientific inquiry by applying their mathematical and statistical
knowledge to the design of surveys and experiments; the collection,
processing, and analysis of data; and the interpretation of the results.
Statisticians may apply their knowledge of statistical methods to a
variety of subject areas, such as biology, economics, engineering,
medicine, public health, psychology, marketing, education, and sports.
 One
of the main functions of actuaries is to help businesses assess the risk
of certain events occurring and to formulate policies that minimize the
cost of that risk. For this reason, those with degrees in
actuarial
science are essential to the insurance industry. Actuaries assemble
and analyze data to estimate the probability and likely cost of the
occurrence of an event such as death, sickness, injury, disability, or
loss of property. Actuaries also address financial questions, including
those involving the level of pension contributions required to produce a
certain retirement income and the way in which a company should invest
resources to maximize its return on investments in light of potential
risk.
Find out more...
Celebrating
Diversity in the Workplace
 The
job climate in the world is in a constant state of flux, creating more
opportunities for all, inclusive of differences in gender, ethnicity,
age, disability, marital status, religion, and sexual orientation. The
workforce of the future must be open-minded, cannot operate on
stereotypes, and must accommodate -- even celebrate -- these
differences, which are a reflection of our global workforce and
population.
The Sloan Career Cornerstone Center offers a variety of resources for
those interested in exploring diversity issues in the workplace
including links and information about organizations that focus on the
needs of specific segments of our diverse society. Many organizations
have student chapters on university campuses, which can help form
valuable networking opportunities for those working toward degrees in
science, technology, engineering, mathematics, computing, and healthcare.
Find out more...
Career Cornerstone News is a publication of the
Sloan Career Cornerstone Center. Click here
to subscribe.
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