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Perspectives of the NSF Assistant Director for Mathematical and Physical Sciences

Dr. F. Fleming Crim, NSF Assistant Director for Mathematical and Physical Sciences, shares his thoughts on emerging ideas, frontier research areas, and national needs.

Reliable Science: The Path to Robust Research Results

LIGO close up

September 8, 2015

These days, much discussion about the reproducibility of scientific results seems driven by critiques of research in biomedicine and psychology. Most recently, an article in Science concluded that 60 percent of a collection of studies were not replicable. This result along with similar analyses of cancer research results have stimulated strong commentary. For example, the New York Times print edition headline about the Science article was “Psychology’s Fears Confirmed: Rechecked Studies Don’t Hold Up,” coverage that prompted a strong op-ed rebuttal titled, “Psychology Is Not in Crisis.”

Issues that arise with human subjects or with other complex living systems do not plague physical science to the same degree. However, the notion of measuring the same value of a physical quantity or the same behavior of a physical system in different laboratories at different times is central to our concept of a valid scientific result. Often the approach is not simply to replicate an experiment, but rather to get at the same quantity via different paths. For example, we can measure the gravitational constant, G, with approaches ranging from a torsional pendulum to atom interferometry.


Advanced LIGO dedicated: Anticipation for observing gravitational waves grows

LIGO close up

May 19, 2015

One has to wonder if Einstein dreamt of a tool like Advanced LIGO arriving to test the ideas about ripples in the fabric of space and time predicted by General Relativity. Today's celebration at the Laser Interferometer Gravitational Wave Observatory (LIGO) in Richland, Washington brings the world a step closer to testing those ideas as never before.

The Advanced LIGO project is the next stage of the LIGO search for gravitational waves. The California Institute of Technology and Massachusetts Institute of Technology designed and operate the NSF-funded facilities in Washington and Louisiana that are intended to observe these phenomena directly for the first time. The goal is a creation of a gravitational wave observatory that is analogous to familiar optical and radio observatories.


The excitement behind a renewed agreement

Globe at Night

May 7, 2015

One of the great pleasures of leading the Mathematical and Physical Sciences Directorate at NSF is the chance to witness events that influence the course of science for many years. Today at the White House, the United States signed a new agreement with the European Organization for Nuclear Research, better known as CERN. This agreement renews our nation's partnership in one of the world's preeminent research institutions and its centerpiece, the large hadron collider (LHC). Scientists at the LHC first confirmed the Higgs particle's existence, and now they intend to learn about additional exotic particles, dark matter, and other fundamental aspects of our universe.

While today's signing involved relatively few people - mostly from the National Science Foundation, Department of Energy, the Department of State, the White House Office of Science and Technology Policy, and CERN itself - its potential impact is enormous. Just last month, the LHC began its second phase of operations during which it will collide particles at nearly twice the energy of its first run in 2008, continuing the search for physics beyond the "standard model."

NSF's role in better understanding our universe

The United States signed its first CERN agreement in 1997, with the Department of Energy taking the lead and with NSF playing a key scientific and financial role. Since that time, NSF has contributed $281 million toward the construction and operations of the ATLAS and CMS detectors, representing the lion's share of its involvement at CERN. These detectors allow researchers to examine and identify the byproducts of collision between particles moving near the speed of light to understand the very smallest parts of our universe.


Nobel Prize shines light on optics, photonics past, present, future

November 18, 2014

Last month, the Nobel Prize in chemistry went to Eric Betzig, Stefan W. Hell and W.E. Moerner for discoveries that have transformed optical microscopy. Their accomplishments are a compelling story of innovative, brilliant work that carries imaging of microscopic objects beyond the limit imposed by diffraction of light. Along the way, it illustrates some of the opportunities that are emerging in both optics and photonics. Conventional optical imaging can resolve objects as small as the wavelength of light, a few hundred nanometers. The work of this year's laureates meets the challenge of "going beyond the diffraction limit" to even smaller objects.

A fundamental connection among the techniques that Betzig, Hell and Moerner invented is using laser light to manipulate molecules to emit on demand. The key to detecting light from individual molecules is to excite only a few of them. One way to accomplish this goal is to work with very dilute samples as Moerner first did with a small number of emitting molecules embedded in a sample of non-emitting molecules. These experiments began the era of "single molecule dynamics" where chemists could study matter one molecule at a time. However, there are many important samples, such as biological structures, where a host of emitters are near each other. Further manipulation of samples with light is the key to overcoming that problem.

Laser 'light switches'

A central aspect to these new microscopies is labeling the biomolecule with an efficient emitter such as a dye molecule or variant of green fluorescent protein (GFP). (GFP's discovery is another piece of NSF-funded, Nobel-winning basic research that has transformed fields in unimagined ways.) Using pulses of laser light to turn off most emitters in a sample reduces the number of potential targets to a very few, making the sample artificially dilute. Repeating that process many times with different emitters turned on builds up an image with previously unobtainable resolution, as the accompanying picture from the Nobel website illustrates.

Lysosomal membranes in a section for a COS-7 cell show the value of single-molecule microscopy. A offers a view with conventional microscopy; B demonstrates super resolution and C and D  with higher magnification views. Photo credit: Eric Betzig, Harald Hess, Janelia Research Campus/HHMI

Lysosomal membranes in a section for a COS-7 cell show the value of single-molecule microscopy. "A" offers a view with conventional microscopy; "B" demonstrates super resolution and "C" and "D" with higher magnification views. Photo credit: Eric Betzig, Harald Hess, Janelia Research Campus/HHMI


LSST: A new era for astronomy

LSST Vista

October 7, 2014

"We find them smaller and fainter, in constantly increasing numbers, and we know that we are reaching into space, farther and farther, until, with the faintest nebulae that can be detected with the greatest telescopes, we arrive at the frontier of the known universe."
-- Edwin Hubble

Astronomy and astrophysics turned a corner when Edwin Hubble discovered nebulae beyond the Milky Way and proved the existence of galaxies besides our own and comparable in scale. Using the 100-inch Hooker Telescope at Mount Wilson Observatory, he opened a door to a breadth of previously unimaginable possibilities for researchers and stargazers everywhere. Ever larger and more powerful telescopes continue to push our view and understanding of the universe to new limits.


Thinking beyond the Quadrant

August 7, 2014

Ideas from the 1997 book by Donald Stokes, Pasteur's Quadrant, have become a popular means of describing the landscape of research and innovation. A key insight in the book was that scientific discovery is not a linear continuum that leads from basic science to applied science to transformative applications. Rather, Stokes invoked a two-dimensional picture along the axes of "quest for fundamental understanding" and "consideration of use," as illustrated in the figure.

Quadrant Graphic

He identified three of the quadrants with icons of discovery: Bohr for pure basic research; Edison for pure applied research; and Pasteur for use-inspired basic research. (A friend refers to the fourth quadrant as the "chia pet" quadrant because, like the chia pet, this section is for discoveries that have neither fundamental import nor practical application.)


The Underpinnings of Quantum Information Science in MPS

July 28, 2014

John Markoff's recent New York Times article on Microsoft's investment in quantum computing describes a topic that has been on our radar at the National Science Foundation for a good while. Fifteen years ago, the Foundation led an interagency working group on the best approach to realizing the promise of quantum information science, and the Foundation has continued to fund research at this frontier. The Directorate of Mathematical and Physical Sciences (MPS) is one part of NSF that supports the fundamental research that underpins quantum information science and associated technologies.

Quantum information science draws on one of the spookier parts of quantum mechanics, popularized in the image of Schrodinger's cat, neither alive nor dead but rather in a superposition of those two states. Quantum information science rests on those intriguing and non-intuitive ideas about entanglement and measurement in quantum systems.


New 'Perspectives' to Share News, Comments and Insights

May 16, 2014

One benefit of leading the NSF Directorate of Mathematical and Physical Sciences is that I hear about new science and fresh insights coming out of MPS-funded research almost every day. Because many of these developments will interest people outside the agency, we are launching a new feature on the NSF MPS web page: Perspectives. These periodic posts will highlight news about NSF-funded facilities and projects, share thoughts about topics such as budget, funding, and merit review, describe results of NSF-funded activities, and provide some perspective on issues that affect the MPS community.

One example of the sort of activity I want to write about comes from our Physics of Living Systems program in the Physics Division. They recently sponsored a three-day workshop in partnership with the Division of Behavioral and Cognitive Sciences in the Social, Behavioral, and Economic Sciences (SBE) Directorate. The topic of the workshop, "Quantitative Theories of Learning, Memory and Prediction," draws heavily on . . . More