RESEARCH NOTEBOOK
CLOCKWISE FROM TOP: LINDA A. CICERO ( 2); COURTESY ETERNA
■ UNCODING COLOR The austere white
marble figures one normally sees in the classical wing of museums might not be what their
creators intended. At the Metropolitan Museum
of Art, for example, a Greek vase from the 4th
century B.C. shows an artist applying pigment
to a stone sculpture of Herakles. It’s long been
suspected that at least some ancient statues
were originally painted in vibrant colors.
Sophomore Ivy Nguyen wanted to test that
theory. A chemical engineering major, Nguyen
was inspired by a seminar entitled Art, Chemistry and Madness: The Science of Art Materials,
taught last spring by chemical engineering professor Curtis Frank and artist Sara Loesch Frank,
his wife. Nguyen entered a juried competition
sponsored by the Cantor Arts Center with a proposal to
use high-tech methods to look for paint traces on a marble statue, Maenad ( 4 B.C.-A. D. 25), discovered in a well
in what is now the West Bank. Her submission won, and
together with Susan Roberts-Manganelli, manager of
collections, exhibitions and conservation at Cantor,
Nguyen led a team that analyzed the statue and created an exhibition for the museum.
Nguyen used a black light, CSI style, to reveal
“ghost images” of pigments and pinpoint areas on the
sculpture to test further. Then she used X-ray
fluorescence imaging to determine the chemical
composition of the residues. From that, she was able to
deduce the colors of di;erent parts of the statue,
based on minerals known to have been used in paints
at that time: chalk to create white; goethite to create
yellow ochre; hematite to create red ochre; copper to
make “Egyptian” blue; and gold leaf for gilding.
The team made two foam replicas of the bacchanal
nymph using 3D rapid prototyping technology. One
was painted with the colors found during analysis; the
other provides an educated guess as to what the statue
originally looked like, with additional layers of paint
providing a more nuanced e;ect. Both painted ladies
will be on display through August 7 as part of the True
Colors: Rediscovering Pigments on Greco-Roman
Marble Sculpture exhibition
at the Cantor Arts Center.
SCIENCE IN ART:
Chemistry inspired
Nguyen’s investigation.
MAKING MOLECULES
Got 15 minutes to kill? You could
play another round of Angry
Birds. Or you could contribute
to biomedical research.
Working with colleagues
at Carnegie Mellon University,
Rhiju Das, PhD ’05, an
assistant professor in the
biochemistry depart-
ment, created an online
game called EteRNA
(
eterna.stanford.edu) that challenges players to design
RNA molecules. Das calls RNA, which tells cells how
much of which proteins to make and when, “the emerg-
ing superstar in the field of biochemistry.”
Like DNA, RNA strands are made up of chemical
units that partner in a specific way. But whereas in
DNA, bases form monogamous pairs (A-T, G-C), RNA
bases are swingers: In addition to their preferred mate,
they can form less stable bonds with other letters. This
property allows RNA to fold up into complex three-
dimensional shapes. It also means that changing a
single base can dramatically alter the molecule’s folded
form, which in turn a;ects its function.
GAME PLAN: Players score
with new RNA designs.
