John Reppy
Encyclopedia
John D. Reppy is a physicist who studies the quantum properties of superfluids at Cornell University
as well as a notable rock climber of long standing, who established a number of widely known climbing routes particularly in the Northeastern United States.
in New Hampshire, as well as a number of routes in the Shawangunks and elsewhere. He made early attempts on Armadillo, a long alpine rock climb on Mount Katahdin
, Maine. In addition, he has climbed extensively in England
, the Alps
and western America where one of his most notable first ascents includes a long and difficult north face route in the Tetons during the formative years of climbing there.
Reppy has said his earliest interest in rock climbing as a very young teenager was related to the re-opening of small open-pit mica mines in eastern Connecticut during World War II in response to increased war-time demand for electronics materials.
Reppy was among the first climbers in the United States to practice so-called "clean climbing
" techniques, which he learned in England. While most climbers of the day were hammering their way up the cliffs with pitons, Reppy helped introduce the use of nuts, which at the time consisted of hex nuts from truck wheels, strung with nylon webbing. Unlike pitons, nuts are placed and removed without the use of hammers and save the rock from permanent damage. The technique often makes placements easier and faster to achieve, and thus may make difficult climbs easier to complete. Many advances in rock climbing were made possible by this method. Among a substantial number of others deserving credit for this trend in the U.S. are Yvon Chouinard
and John Stannard.
Memorial Prize in 1981 and the NASA Distinguished Public Service Medal for leadership and support to the NASA
microgravity fundamental physics program in 2000. Reppy is also a member of the National Academy of Sciences
.
As physics professor at Cornell University
, he studies quantum properties of superfluids with an emphasis on boundary conditions and phase transitions in systems of reduced dimensionality. His research group has a close association with those of David M. Lee and Robert C. Richardson
also of Cornell, who shared the 1996 Nobel Prize in Physics with Douglas D. Osheroff
for discoveries related to super fluidity in helium-3 ice. Lee, in his Nobel Prize speech, credited Reppy's "extraordinary technical ingenuity" in experiments leading to the discovery. In the speech, Lee made other references to Reppy, noting that his work helped confirm related insights.
Reppy also figured at least on the fringes of the 2001 Nobel Prize for Physics which was awarded to Eric Cornell and Carl Wieman
of the Joint Institute for Laboratory Astrophysics, or JILA, in Boulder, Colo., and Wolfgang Ketterle
of the Massachusetts Institute of Technology. Bose-Einstein condensation was predicted in 1924, and was seen decades ago in liquid helium, according to Ketterle, who acknowledged a controversial earlier claim by Reppy. Ketterle says that Reppy brought this finding to his attention, and that the priority claim was fair. "I think the results appeared conclusive," Ketterle reportedly said. But co-laureate Wieman said that Reppy's claim is "really a stretch" and that Ketterle may have acknowledged the helium experiments merely to appease Reppy. "Ketterle is being gracious," Wieman reportedly said, "and Reppy makes a lot of noise."
Physicists generally agree that the atoms in superfluid
helium-4
is not a Bose-Einstein condensate in the original sense of the term because its atoms interact too strongly. Reppy studied an exception: tiny amounts of helium trapped in nanometer-sized pores of a spongelike glass called Vycor
. Even though the pores keep its atoms too far apart to jostle one another much, the helium still behaves like a three-dimensional fluid. In 1983 Reppy and colleagues reported results that suggested the helium was sloshing through the glass as a true Bose-Einstein condensate.
Separately, work from Cornell physics laboratories has been used to test a theory of cosmic strings, hypothetical objects, which may have been important in the formation of galaxies, and may have arisen through "phase transitions" in a fraction of a second after the Big Bang
.
Cornell University
Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
as well as a notable rock climber of long standing, who established a number of widely known climbing routes particularly in the Northeastern United States.
Rock climbing
In the 1950s and 60s, Reppy was active on Ragged Mountain in Connecticut where he collaborated on many first ascents and on publishing an area guidebook with Sam Streibert. He is also credited with the first ascent of Reppy's Crack on Cannon MountainCannon Mountain (New Hampshire)
Cannon Mountain is a peak in the White Mountains of New Hampshire. Known for both its technical rock and ice climbing and its skiing , the mountain was home to the Old Man of the Mountain until the formation collapsed on May 3, 2003...
in New Hampshire, as well as a number of routes in the Shawangunks and elsewhere. He made early attempts on Armadillo, a long alpine rock climb on Mount Katahdin
Mount Katahdin
Mount Katahdin is the highest mountain in Maine at . Named Katahdin by the Penobscot Indians, the term means "The Greatest Mountain". Katahdin is the centerpiece of Baxter State Park: a steep, tall mountain formed from underground magma. The flora and fauna on the mountain are typical of those...
, Maine. In addition, he has climbed extensively in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, the Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
and western America where one of his most notable first ascents includes a long and difficult north face route in the Tetons during the formative years of climbing there.
Reppy has said his earliest interest in rock climbing as a very young teenager was related to the re-opening of small open-pit mica mines in eastern Connecticut during World War II in response to increased war-time demand for electronics materials.
Reppy was among the first climbers in the United States to practice so-called "clean climbing
Clean climbing
Clean climbing is a rock climbing term that describes techniques and equipment which climbers use in order to avoid damage to the rock. These techniques date at least in part from the 1920s and earlier in England, but the term itself may have emerged in about 1970 during the widespread and rapid...
" techniques, which he learned in England. While most climbers of the day were hammering their way up the cliffs with pitons, Reppy helped introduce the use of nuts, which at the time consisted of hex nuts from truck wheels, strung with nylon webbing. Unlike pitons, nuts are placed and removed without the use of hammers and save the rock from permanent damage. The technique often makes placements easier and faster to achieve, and thus may make difficult climbs easier to complete. Many advances in rock climbing were made possible by this method. Among a substantial number of others deserving credit for this trend in the U.S. are Yvon Chouinard
Yvon Chouinard
Yvon Chouinard is a rock climber, environmentalist and outdoor industry businessman, noted for his contributions to climbing, climbing equipment and the outdoor gear business. His second company, Patagonia is known for its environmental focus...
and John Stannard.
Scientific contributions
Reppy received a Bachelor's degree in math and physics in 1954 at University of Connecticut and a master's degree from the same school two years later. He completed a Ph.D at Yale University in 1962, where he spent four years as an assistant professor. Reppy joined the Cornell Physics Department in 1966, later becoming the John Wetherill Professor of Physics. He is the recipient of numerous awards and honors, including the Fritz LondonFritz London
Fritz Wolfgang London was a German theoretical physicist. His fundamental contributions to the theories of chemical bonding and of intermolecular forces are today considered classic and are discussed in standard textbooks of physical chemistry.With his brother Heinz, he made a significant...
Memorial Prize in 1981 and the NASA Distinguished Public Service Medal for leadership and support to the NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
microgravity fundamental physics program in 2000. Reppy is also a member of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
.
As physics professor at Cornell University
Cornell University
Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
, he studies quantum properties of superfluids with an emphasis on boundary conditions and phase transitions in systems of reduced dimensionality. His research group has a close association with those of David M. Lee and Robert C. Richardson
Robert Coleman Richardson
Robert Coleman Richardson is an American experimental physicist whose area of research includes sub-millikelvin temperature studies of helium-3...
also of Cornell, who shared the 1996 Nobel Prize in Physics with Douglas D. Osheroff
Douglas D. Osheroff
Douglas Dean Osheroff is an American physicist known for his work in experimental condensed matter physics, in particular for his co-discovery of superfluidity in Helium-3. For his contributions he shared the 1996 Nobel Prize in Physics along with David Lee and Robert C...
for discoveries related to super fluidity in helium-3 ice. Lee, in his Nobel Prize speech, credited Reppy's "extraordinary technical ingenuity" in experiments leading to the discovery. In the speech, Lee made other references to Reppy, noting that his work helped confirm related insights.
Reppy also figured at least on the fringes of the 2001 Nobel Prize for Physics which was awarded to Eric Cornell and Carl Wieman
Carl Wieman
Carl Edwin Wieman is an American physicist at the University of British Columbia and recipient of the Nobel Prize in Physics for the production, in 1995 with Eric Allin Cornell, of the first true Bose–Einstein condensate.-Biography:...
of the Joint Institute for Laboratory Astrophysics, or JILA, in Boulder, Colo., and Wolfgang Ketterle
Wolfgang Ketterle
Wolfgang Ketterle is a German physicist and professor of physics at the Massachusetts Institute of Technology . His research has focused on experiments that trap and cool atoms to temperatures close to absolute zero, and he led one of the first groups to realize Bose-Einstein condensation in these...
of the Massachusetts Institute of Technology. Bose-Einstein condensation was predicted in 1924, and was seen decades ago in liquid helium, according to Ketterle, who acknowledged a controversial earlier claim by Reppy. Ketterle says that Reppy brought this finding to his attention, and that the priority claim was fair. "I think the results appeared conclusive," Ketterle reportedly said. But co-laureate Wieman said that Reppy's claim is "really a stretch" and that Ketterle may have acknowledged the helium experiments merely to appease Reppy. "Ketterle is being gracious," Wieman reportedly said, "and Reppy makes a lot of noise."
Physicists generally agree that the atoms in superfluid
Superfluid
Superfluidity is a state of matter in which the matter behaves like a fluid without viscosity and with extremely high thermal conductivity. The substance, which appears to be a normal liquid, will flow without friction past any surface, which allows it to continue to circulate over obstructions and...
helium-4
Helium-4
Helium-4 is a non-radioactive isotope of helium. It is by far the most abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on earth. Its nucleus is the same as an alpha particle, consisting of two protons and two neutrons. Alpha decay of heavy...
is not a Bose-Einstein condensate in the original sense of the term because its atoms interact too strongly. Reppy studied an exception: tiny amounts of helium trapped in nanometer-sized pores of a spongelike glass called Vycor
Vycor
Vycor is a glass with high temperature and thermal shock resistance, made by Corning Incorporated. Vycor is 96% silica, but unlike pure fused silica it can be readily manufactured in a variety of shapes....
. Even though the pores keep its atoms too far apart to jostle one another much, the helium still behaves like a three-dimensional fluid. In 1983 Reppy and colleagues reported results that suggested the helium was sloshing through the glass as a true Bose-Einstein condensate.
Separately, work from Cornell physics laboratories has been used to test a theory of cosmic strings, hypothetical objects, which may have been important in the formation of galaxies, and may have arisen through "phase transitions" in a fraction of a second after the Big Bang
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
.