A T-shirt pinned to the wall of Arjun Dey's office capsulizes his
recent life: "I found the most distant galaxy in the universe,
and all I got for it was this lousy T-shirt."

To be truthful, that's not all Dey got for his accomplishment.
The Hopkins postdoctoral fellow and his colleagues also get to
report to the astronomical world (in Astrophysical Journal
Letters) that they had surpassed an astronomical milestone,
the 5.0 redshift mark. Redshift is an indication of an object's
distance from Earth. In astronomy,their accom-plishment is
comparable to breaking track's three-minute mile.

The galaxy they spotted has a red shift of 5.34. The next most
distant galaxy ever detected has a redshift of 4.92.

Since the most distant objects are also the oldest, the
researchers were, in effect, peering farther back in time than
astronomers have ever done before, to a time when the universe
was only about 800 million years old, or 6 percent of its current
age.

"The exciting thing is that nothing is known about this phase of
the universe," says Dey. "It's like saying, `If you see one
animal in the forest, what else might you see?'"

Dey and colleagues found the
universe's most distant galaxy entirely by
accident.Photo by Jay Van Rennselaer

The astronomers suspect that their object is a galaxy in its
earliest developmental stage. Embryonic galaxies such as these,
says Dey, "eventually turn into something like the one we live
in, and are undergoing their first episode of star formation.
They are essentially collapsing from a large gas cloud and
forming their first generation of stars." By studying this museum
of ancient cosmological history, astronomers will be able to
trace galaxy evolution.

The astronomers spotted and examined the galaxy using the world's
largest telescopes, Keck I and II, which sit atop a dormant
volcano in Mauna Kea, Hawaii. In September 1997, the team was
using one of the telescope's spectrographs to analyze the light
from galaxies that appeared to be candidates for having redshifts
greater than 4.0. Right next to one of their candidate galaxies,
they saw a spectral signature that looked like it came from
another high redshift object. In December, they went back for a
closer look.

"We found this galaxy entirely by accident," notes Dey. His
collaborators were Hyron Spinrad, Daniel Stern, and James Graham,
at the University of California at Berkeley; and Frederic
Chaffee, of the W.M. Keck Observatory, in Kamuela, Hawaii.

Light travels at a speed of approximately 186,000 miles per
second. That is a constant. But the universe is expanding, and
the farther away an object is from Earth, the faster the object
is receding. As a galaxy moves away, its light waves get
stretched out. The farther a galaxy is, the faster it is moving
away, and the more its light waves get stretched, or "shifted,"
toward the red end of the spectrum. Redshift, then, is
proportional to an object's distance from Earth.

The light reaching the Keck Telescope now was emitted by this
most distant galaxy 12 billion years ago.

The galaxy is in the constellation Triangulum, in the Northern
Hemisphere. It appears to be smaller than the Milky Way, says
Dey. The scientists plan to request time on the Hubble Space
Telescope for further observations.

Finding the highest redshift galaxy, "is pretty exciting, but I'm
sure the record will be broken in a matter of months, maybe
weeks," says Dey, who decided he wanted to become an astronomer
at age eight, when he joined an amateur astronomer's club in his
native Bangalore, India, and began grinding telescope lenses.

A new generation of powerful ground-based telescopes, including
the Keck, "have dramatically revolutionized our understanding of
high redshift objects," says Dey. A dozen similar strong
telescopes will be built in the next 10 years. --MH

Hopkins research professor Michael Karweit is giving freshmen a
way to get hands-on engineering experience. Well, sort of.

Karweit has developed a virtual laboratory that allows students
to tackle the type of engineering projects they would encounter
in the working world.

Take the spaghetti bridge. Through simulation in the
virtual lab, a student can design a
bridge and test its weight- bearing properties by clicking the
computer mouse on various bridge stress points. At the end, a
student builds a real model of the bridge out of uncooked
spaghetti. Karweit then tests it to see if it can hold weight.
Other projects are more high-tech, such as designing a robotic
arm--a costly project to conduct in a real world lab. Karweit's
students create and test a virtual two-segment arm, programming
its rotational movements.

"Students can do something and if it turns out wrong, they can
try this, or this, or this, just as they would in a laboratory,"
says Karweit, a research professor in the Department of Chemical
Engineering.

He's found that students who major in engineering often get
bogged down in physics and math courses before they get to the
engineering projects. They may bail out of the major early, or
find out too late that engineering doesn't interest them. The
introductory course, he hopes, will give freshmen a chance to
test their affinity for the field, quickly and easily.

Titled What Is Engineering? his course uses the new
computer programming language, Java. Anyone with a major Web
browser such as Netscape's Navigator, and a 32-bit operating
system such as Windows 95, can conduct experiments. The simulated
science lab is free and open to the public
(
www.jhu.edu/~virtlab).

Karweit recently received a $258,000 grant from General Electric
to expand his computer course offerings. His program could be
used by other colleges and advanced high school classes.
--JPC

What makes a woman's heart flutter when she's with a certain
special man? His physique? Yes. His sexy smile? Sure. But there
is also that inexplicable electric spark. Could this certain
je ne sais quoi be... his immune system?

If rodents are any indication, it could be, says Hopkins
psychology graduate student
Sabra Klein. In her studies with behavioral psychologist Randy
Nelson, Klein finds that females of certain rodent species sniff
out, literally, males with the most robust immune systems.

Klein began studying the interplay between immunity and mating
behavior after reading studies that show males generally have
lower immunity than females. The difference appears to hold
across species. Men are more susceptible to a variety of
infections, such as dysentery, gonorrhea, and malaria; and to
certain cancers, says Klein. (Conversely, females are at greater
risk of illnesses caused by an overactive immune system, such as
systemic lupus erythematosus.)

Studies also suggested that testosterone plays a role in reduced
immunity. Researchers found, for instance, that castrated
reindeer are less susceptible to infection with warble flies than
are uncastrated male reindeer.

Klein has continued in this line of research using meadow voles--
dark gray, hamster-size rodents.

Working with Nelson, Klein infected male voles with a
non-contagious parasite. She then allowed female voles to choose
between spending time in soiled bedding that had been used by an
infected male vole or an uninfected one. The female voles opted
for the bedding of the uninfected males.

"The results suggest that information about infection status is
carried in the urine," says Klein. The urine may contain
pheromones, volatile chemical cues that convey information from
one animal to the next. "In rodents, olfactory cues are very
important," she notes.

In an interesting twist to this experiment, the scientists
injected male meadow voles with an innocuous protein that causes
the vole's immune system to make antibodies but does not make the
animals ill. Again, they gave females a choice between bedding
previously used by either infected or uninfected males. The
female voles still opted for the bedding used by uninfected
males.

"A female wants a mate that is not prone to infection," Klein
hypothesizes. "By choosing an uninfected male, she may choose a
mate that has good genes for resistance. She will then pass on
those genes to her offspring. She herself is also less likely to
contract an illness. Also, by mating with an uninfected male, she
gains a mate who may provide more resources for her and her
offspring."

Initial research suggests that people, like voles, can also
detect "vibes" about a companion's immunity, say Nelson and
Klein. A recent Swiss study, for example, suggests that people
subconsciously perceive information about the genetics of a
person's immune system through that person's body odor. Here too,
says Klein, pheromones may be the silent, invisible communicator.
--MH

Hopkins senior Vivek Baluja thought that establishing a community
computer center would be a worthy cause. How to bring it about?
How else? Via a barrage of e-mail messages to the household of
Bill Gates, uber-rich founder of Microsoft.

"I didn't think there'd be any other way to reach Gates other
than e-mail," says Baluja. "I asked around and got his wife's
e-mail address and sent her e-mail for two to three months, about
40 or 50 times a week. Her reaction was: `I'm impressed by your
persistence, but you don't need to e-mail me this much,'" Baluja
recalls, "so she referred me to the Gates Foundation and said
she would talk to Mr. Gates."

Baluja, a computer science major, convinced Gates to donate
$40,000, plus $60,000 in Microsoft software, to the Greenmount
Recreation Center near Homewood. Area residents can now take
classes on 18 new computers. Additional contributions came from
the Abell Foundation and other community groups. Says Edward
Banks, the center's director, "We've got the best computer lab in
Baltimore City." --JPC