Peter Lu
Encyclopedia
Peter James Lu, PhD is a post-doctoral research fellow in the Department of Physics and the School of Engineering and Applied Sciences
Harvard School of Engineering and Applied Sciences
The Harvard School of Engineering and Applied Science , a school within Harvard University's Faculty of Arts and Sciences , serves as the connector and integrator of Harvard's teaching and research efforts in engineering, applied sciences, and technology.Engineering and applied sciences at Harvard...

 at Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

 in Cambridge, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

. He has been recognized
for his discoveries of girih tiles
Girih tiles
Girih tiles are a set of five tiles that were used in the creation of tiling patterns for decoration of buildings in Islamic architecture...

, quasicrystal
Quasicrystal
A quasiperiodic crystal, or, in short, quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry...

 patterns in medieval Islamic architecture
Islamic architecture
Islamic architecture encompasses a wide range of both secular and religious styles from the foundation of Islam to the present day, influencing the design and construction of buildings and structures in Islamic culture....

, early precision compound machines in ancient China, and man's first use of diamond
Diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

 in neolithic
Neolithic
The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

 China.

Early life and education

Lu was born in Cleveland, Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...


and grew up in the Philadelphia suburb of West Chester, Pennsylvania
West Chester, Pennsylvania
The Borough of West Chester is the county seat of Chester County, Pennsylvania, United States. The population was 18,461 at the 2010 census.Valley Forge, the Brandywine Battlefield, Longwood Gardens, Marsh Creek State Park, and other historical attractions are near West Chester...

. His early childhood interest in rockhounding
Rockhounding
Amateur geology is the recreational study and hobby of collecting rocks and mineral specimens from their natural environment.-Collecting:...


led to his winning national gold medals in the "Rocks, Minerals, and Fossils" event at four National Science Olympiad
Science Olympiad
Science Olympiad is an American elementary, middle, or high school team competition which tests knowledge of various science topics and engineering ability. Over 6,200 teams from 49 U.S. states compete each year. Most teams compete in three levels of competition: regionals, states, and nationals...

 tournaments. Lu graduated from B. Reed Henderson high school in West Chester in 1996.

Lu matriculated at Princeton University
Princeton University
Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....

 in September, 1996, and was advised in his first year by geology professor Kenneth S. Deffeyes
Kenneth S. Deffeyes
Kenneth S. Deffeyes is a geologist who worked with M. King Hubbert, the creator of the Hubbert peak theory, at the Shell Oil Company research laboratory in Houston, Texas. Deffeyes holds a B.S. in petroleum geology from the Colorado School of Mines and a Ph.D. in geology from Princeton University,...

. He studied organic chemistry with Maitland Jones, Jr., with whom Lu published his first paper on his freshman summer research project about carbenes.
As an undergraduate physics major, he wrote his fourth-year senior thesis with Prof. Paul J. Steinhardt
Paul Steinhardt
Paul J. Steinhardt is the Albert Einstein Professor of Science at Princeton University and a professor of theoretical physics. He received his B.S. at the California Institute of Technology and his Ph.D. in Physics at Harvard University...

 on the search for natural quasicrystals, later published in Physical Review Letters
Physical Review Letters
Physical Review Letters , established in 1958, is a peer reviewed, scientific journal that is published 52 times per year by the American Physical Society...

.
Lu graduated from Princeton summa cum laude and Phi Beta Kappa with an A.B. in physics from Princeton in June, 2000. In September, 2000, he began his graduate studies at Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

, receiving an A. M. in physics in 2002. In 2005, Lu presented a set of lectures in Turkmenistan.
Since 2007, Lu has served on the national advisory committee of the Science Olympiad
Science Olympiad
Science Olympiad is an American elementary, middle, or high school team competition which tests knowledge of various science topics and engineering ability. Over 6,200 teams from 49 U.S. states compete each year. Most teams compete in three levels of competition: regionals, states, and nationals...

. Lu completed his Ph.D. in physics in 2008.

Girih tiles and quasicrystals in medieval Islamic architecture

Lu's most widely-publicized work involves his discovery of the girih tiles
Girih tiles
Girih tiles are a set of five tiles that were used in the creation of tiling patterns for decoration of buildings in Islamic architecture...

, a set of fundamental geometric tiles used to create a wide range of patterns in medieval Islamic architecture. In collaboration with Paul Steinhardt
Paul Steinhardt
Paul J. Steinhardt is the Albert Einstein Professor of Science at Princeton University and a professor of theoretical physics. He received his B.S. at the California Institute of Technology and his Ph.D. in Physics at Harvard University...

, he demonstrated their use to create quasicrystal
Quasicrystal
A quasiperiodic crystal, or, in short, quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry...

 tilings on the walls of Darb-i Imam
Darb-i Imam
The shrine of Darb-e Imam, located in the Dardasht quarter of Isfahan, Iran, is a funerary complex, with a cemetery, shrine structures, and courtyards belonging to different construction periods and styles...

 shrine (1453 A.D.) in Isfahan, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

.

The finding was considered a significant breakthrough by demonstrating a simple and straightforward method that could have been used by common workers to create extremely complicated patterns using girih tiles
Girih tiles
Girih tiles are a set of five tiles that were used in the creation of tiling patterns for decoration of buildings in Islamic architecture...

, and by identifying a medieval example of quasicrystal
Quasicrystal
A quasiperiodic crystal, or, in short, quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry...

line patterns, which were not widely known to or understood by the West until the discovery of Penrose tiling
Penrose tiling
A Penrose tiling is a non-periodic tiling generated by an aperiodic set of prototiles named after Sir Roger Penrose, who investigated these sets in the 1970s. The aperiodicity of the Penrose prototiles implies that a shifted copy of a Penrose tiling will never match the original...

s by Roger Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...

 in the 1970s. For its timely scientific and political implications, Lu and Steinhardt's work on medieval Islamic architectural tilings received substantial worldwide coverage on the front pages
of a number of major newspapers,
on the radio, and in magazines;
the finding was identified as among the top 100 scientific discoveries of 2007 by Discover magazine.

Earliest precision compound machines

In 2004, Lu presented evidence in a single-author paper in Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....

 that ancient Chinese craftsmen during the Spring and Autumn Period used precision compound machines to craft spiral grooves on Chinese jade
Chinese jade
Chinese jade is any of the carved-jade objects produced in China from the Neolithic Period onward. The Chinese regarded carved-jade objects as intrinsically valuable...

 burial rings;
Lu had been introduced earlier to the grooved rings by Prof. Jenny So at the Smithsonian Institution.
Lu discovered that these grooves follow the exact mathematical form of the Archimedes spiral, demonstrating the ability of ancient craftsmen to interconvert two types of motion precisely, in order to fashion the jade rings. The close conformity to this mathematical form confirmed that these craftsmen must have had a precision compound machine (as opposed to a simple machine
Simple machine
A simple machine is a mechanical device that changes the direction or magnitude of a force.In general, they can be defined as the simplest mechanisms that use mechanical advantage to multiply force. A simple machine uses a single applied force to do work against a single load force...

) in 550 BC, predating Archimedes by several centuries; prior to this paper, the earliest compound machines were thought to be of Greek origin (e.g., Archimedes' screw
Archimedes' screw
The Archimedes' screw, also called the Archimedean screw or screwpump, is a machine historically used for transferring water from a low-lying body of water into irrigation ditches...

).
Lu's discovery of the earliest precision compound machines was included in the Encyclopædia Britannica.

Man's first use of diamond

Lu continued his interdisciplinary combination of art history and physics with his discovery, with a group of collaborators,
of man's first use of diamond, in neolithic
Neolithic
The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

 China. Prior to this work, evidence for man's first use of diamond
Diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

 was known primarily from Indian texts dating to the latter half of the first millennium BC, and there was no reported evidence for its use in prehistoric times. In 2005, Lu and collaborators reported strong evidence that the ancient Chinese used diamonds to polish ceremonial stone burial axes as early as 2500 BC, placing the earliest known use of diamond two thousand years before the mineral is known to have been used elsewhere. These stone axes, made predominantly of the mineral corundum (sapphire and ruby in its colorful gem forms) were fashioned as early as 4000 BC, so that they represent the earliest use of the mineral corundum
Corundum
Corundum is a crystalline form of aluminium oxide with traces of iron, titanium and chromium. It is a rock-forming mineral. It is one of the naturally clear transparent materials, but can have different colors when impurities are present. Transparent specimens are used as gems, called ruby if red...

, as well. The finding's media coverage
included a front-page article in China's largest English-language newspaper, the China Daily
China Daily
The China Daily is an English language daily newspaper published in the People's Republic of China.- Overview :China Daily was established in June 1981 and has the widest print circulation of any English-language newspaper in the country...

.

Other contributions

Lu's interests in geology-related phenemena also include paleontology
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...

, which lead to collaboration with his college and grad-school roommate Motohiro Yogo and Prof. Charles Marshall. Leveraging vector autoregression analysis upon an established marine fossil record, Lu, Yogo and Marshall found that a "speed limit," which was previously thought to restrict the reemergence of biodiversity following a mass extinction, may be an artifact of the incompleteness of the fossil record.
According to paleontologist Douglas Erwin of the National Museum of Natural History
National Museum of Natural History
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. Admission is free and the museum is open 364 days a year....

 in Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....

, "This is the battle line for the next decade in paleontology."
Lu's research in the group of Prof. David A. Weitz focused on the behavior of attractive colloidal particles in the laboratory and in the microgravity environment of the International Space Station
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...

. In 2008, Lu, Weitz and collaborators in Rome combined experiment and computer simulations to demonstrate that the onset of colloidal gelation is triggered by a form of phase separation known as spinodal decomposition,
resolving a long-standing debate within the soft condensed-matter physics community on the origins of this mechanism. Lu's colloid work has also led to the development of new techniques for observing real-time, three-dimensional behavior of colloidal particles, and freely-moving biological cells, with active target-locking in real-time confocal microscopy.
Lu also wrote the opening chapter, on confocal microscopy and nanotechnology, of the Handbook of Microscopy for Nanotechnology, edited by Nan Yao.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK