Who are Physicists and what do they do?

November 9, 2009

From a “reference frame” article by Michael S. Turner, in the September 2009 issue of Physics Today:

“I have always liked the metaphor of a child watching chess to convey the mission of physics—namely, that we carefully observe Nature to discover her underlying rules. Of course, knowing the rules doesn’t mean you understand the game. That is especially true in complex systems, whether turbulent fluids or living organisms. Understanding complexity and the emergence of large-scale behavior remains a big challenge. ”

This is very true of many pheonmena in Physical Oceanography and Climate Physics.

Another quote from the same article:

“There is an important unity in how physicists approach problems. Physicists use rigorous and quantitative methods; they search for underlying principles and fundamental laws; they begin with simple models and add complexity; and they rely on reductionism and innovative instrumentation. While the name of the activity remains the same, the foci change—so much so that the only robust definition is that physics is what physicists do. Physics has evolved from earthly and celestial mechanics 400 years ago to include electricity, magnetism, and statistical mechanics in the 18th and 19th centuries; and today it encompasses materials, atoms, nuclei, elementary particles, the cosmos, and a growing number of aspects of biology. Its practitioners have invented new tools—mathematical, conceptual, and instrumental—to get at the most urgent questions of their day.”

The full article is at the Physics Today Website at  http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_62/iss_9/8_1.shtml

President Obama modeling the Navier Stokes equations

October 28, 2009
Obama models with the Navier-Stokes equations. Hooray!

President Obama models with the Navier-Stokes equations. Hooray!

Eric Holmes reaches Japan to participate in the Kuroshio Experiment.

October 18, 2009

Graduate Student Eric Holmes has arrived in Tokyo to participate in a scientific experiment. He joins a group of 17 other scientists, led by the Chief Scientist Prof. Takeyoshi Nagai (a post doctoral alumnus of our group) who will be making physical, biological and chemical measurements across the Kuroshio Front. The host institution is the Tokyo University of Marine Science and Technology.

Eric Holmes is now onboard R/V Natsushima with other scientists from Tokyo University of Marine Science and Technology, MIT, and the Woods Hole Oceanographic Institution to make measurements across the Kuroshio Front and fast moving Kuroshio current!

The main objectives of this scientific cruise are to elucidate whether the small scale turbulent dissipation in response to the mesoscale forcing, such as frontogenesis, is ubiquitous and intrinsic feature of the fronts, and to investigate the magnitude and spatial spread of dissipation sites in three-dimensional space near the Kuroshio Front, to investigate horizontal scales of distribution of nitrate across the front, and to investigate the submesoscale contrast in species compositions of zooplankton and phytoplankton across the Kuroshio Front.

The scientific cruise will last from Oct 17th to October 24th 2009 in which five detailed transects across the Kuroshio Front are planned.

Tank Experiments at the Boston Museum of Science

October 18, 2009
Visitors check the surface parabola at the Boston Museum of Science

Visitors check the surface parabola at the Boston Museum of Science

Lodovical Illari (MIT), Amala Mahadevan (BU) and I presented a series of experiments at the Boston Museum of Science during the Earth Sciences Week in October 2009. Amala presented the non-rotating experiments showing the effect of density layering or stratification in setting up the ocean/atmospheric circulation, while I conducted the dye-stirring experiments demonstrating the importance of Earth’s rotation. Lodovica and her student showed the formation of eddies by combining the effects of rotation and stratification by forming eddies in the tank!

Convection Cells in the Tank Experiments

October 18, 2009

Debbie Schwartz sent a picture of convection cells observed in the rotating tank. We did a bunch of dye-stirring experiments for the attendees at the Working Waterfront Festival in NewBedford MA this year. The day was dry and windy, and there was evaporation at the surface of the water. When the water was stirred and the dye introduced we saw the beautiful vertically coherent Taylor curtains. After 15-20 minutes or so though, the water was back to nearly solid body rotation, and evaporation at the surface made the water cold and heavy due to latent heat loss. The dye at the surface made the rotating convection cells visible as in this picture.

 These show convection cells in the rotating Tank. Photo by Grad student Debbie Schwartz

These show convection cells in the rotating Tank. Photo by Grad student Debbie Schwartz