Hip-Hop Physics

The Ising and Hubbard models are really clever physical approximations from statistical physics. The Wikipedia page on the Ising model is extensive and every physicist should preform the 1D solution at some point in their life, and for others just taking a look at these models and considering their application to the social sciences is worth considering. Anyways onto Hip-Hop Physics from the American Scientist (by Brian Hayes who also runs the bit-player) which discusses the challenges inherent in solving even these simple mathematical models (I first saw this link on 3QuarksDaily and have shamelessly reproduced it here, but good science writing must be propogated):

Mathematical models and computer simulations usually begin as aids to understanding, introduced when some aspect of natural science proves too knotty for direct analysis. Facing an intractable problem, we strip away all the messy details of the real world and build a toy universe, one simple enough that we can hope to master it. Often, though, even the dumbed-down model defies exact solution or accurate computation. Then the model itself becomes an object of scientific inquiry—a puzzle to be solved.
A good example is the Ising model in solid-state physics, which attempts to explain the nature of magnetism in materials such as iron. (I wrote about the Ising model in an earlier Computing Science column; see “The World in a Spin,” September–October 2000.) The Ising model glosses over all the intricacies of atomic structure, representing a magnet as a simple array of electron “spins” on a plain, gridlike lattice. Even in this abstract form, however, the model presents serious challenges. Only a two-dimensional version has been solved exactly; for the three- dimensional model, getting accurate results requires both algorithmic sophistication and major computer power.

Read on...

Space Exploration Missions

The image above is a link to a huge diagram showing space exploration missions. I have no idea how comprehensive of missions it is. I think the original source was National Geographic so it must be rather complete. Regardless the image is stunning in a visual design sense and it makes a good desktop background. Enjoy.

Wanted

A Dream

In a deserted place in Iran there is a not very tall stone tower that has neither door nor window. In the only room (with a dirt floor and shaped like a circle) there is a wooden table and a bench. In that circular cell, a man who looks like me is writing in letters I cannot understand a long poem about a man who in another circular cell is writing a poem about a man who in another circular cell . . . The process never ends and no one will be able to read what the prisoners write.

A Dream by Jorge Luis Borges (Translated, from the Spanish, by Suzanne Jill Levine.)

En un desierto lugar del Irán hay una no muy alta torre de piedra, sin puerta ni ventana. En la única habitación (cuyo piso es de tierra y que tiene la forma del círculo) hay una mesa de madera y un banco. En esa celda circular, un hombre que se parece a mí escribe en caracteres que no comprendo un largo poema sobre un hombre que en otra celda circular escribe un poema sobre un hombre que en otra celda circular . . . El proceso no tiene fin y nadie podrá leer lo que los prisioneros escriben.
Un Sueño por Jorge Luis Borges

Planck is Alive

Planck Status: Routine Operations (First All-Sky Survey)
Location: in orbit around L2

The Planck satellite after its successful launch a few months ago has first light! I am busy observing at APO (read waiting for the weather to clear) so I don't have time to write more, but I just wanted to drop this news as it breaks.

1/48-scale model of an F-18 aircraft

I stumbled upon Cabinet magazine recently. It is a quarterly print magazine of art and culture. The current issue No. 34 is about testing or sort of the intersection of culture and scientific testing. There is a great article available online (you will have to pick up a physical copy to read the other articles, but I did and it was worth it) about games of chance, but it was the cover image that really caught my attention:

This image shows a plastic 1/48-scale model of an F-18 aircraft inside the "Water Tunnel" more formally known as the NASA Dryden Flow Visualization Facility. Water is pumped through the tunnel in the direction of normal airflow over the aircraft; then, colored dyes are pumped through tubes with needle valves. The dyes flow back along the airframe and over the airfoils highlighting their aerodynamic characteristics. The aircraft can also be moved through its pitch axis to observe airflow disruptions while simulating actual flight at high angles of attack.

The Water Tunnel at NASA's Dryden Flight Research Center, Edwards, CA, became operational in 1983 when Dryden was a Flight Research Facility under the management of the Ames Research Center in Mountain View, CA. As a medium for visualizing fluid flow, water has played a significant role. Its use dates back to Leonardo da Vinci (1452-1519), the Renaissance Italian engineer, architect, painter, and sculptor. In more recent times, water tunnels have assisted the study of complex flows and flow-field interactions on aircraft shapes that generate strong vortex flows. Flow visualization in water tunnels assists in determining the strength of vortices, their location, and possible methods of controlling them.

The design of the Dryden Water Tunnel imitated that of the Northrop Corporation's tunnel in Hawthorne, CA. Called the Flow Visualization Facility, the Dryden tunnel was built to assist researchers in understanding the aerodynamics of aircraft configured in such a way that they create strong vortex flows, particularly at high angles of attack. The tunnel provides results that compare well with data from aircraft in actual flight in another fluid-air. Other uses of the tunnel have included study of how such flight hardware as antennas, probes, pylons, parachutes, and experimental fixtures affect airflow. The facility has also been helpful in finding the best locations for emitting smoke from flight vehicles for flow visualization.

Hubble's New Look

A servicing mission was planned for the 19-year-old Hubble Space Telescope years ago, but after the instrument command and data handling module failed the repair mission was postponed so that an even more comprehensive repair mission could be undertaken. Three months ago the space shuttle Atlantis launched and successfully repaired the telescope. The instruments on the telescope which were repaired or replaced include the Wide Field Camera 3, the Advanced Camera for Surveys, the Cosmic Origins Spectrograph, and the Space Telescope imaging Spectrograph. So NASA is patting its back right now on a job well done and releasing an entire gallery of press images for the publicity, but there are real promises for science to come.

My favorite image is that of Planetary Nebula NGC 6302 (which could easily be called the Butterfly Nebula, but the name is taken), but the comparison of Stephan's Quintet taken by Hubble to the image I took using the Harlan J. Smith Telescope at the McDonald observatory is laughable.

Copenhagen 1941

Copenhagen 1941 ruined everything. It was like the collapse of the wave function. The friendship between Neils Bohr and Werner Heisenberg would never be the same. Their bond began many years previously when the young Heisenberg challenged Bohr during a meeting and Bohr, although taken aback, realized Heisenberg was a promising young mind. They grew together through research and became like family, but in September 1941 Bohr met with Heisenberg in Copenhagen and their bond was broken. There is no complete record of what was said during the meetings, but Bohr was shaken. The history of the Bohr-Heisenberg meeting is now that of legends. Roughly we can see this story as a personal example of the moral implications of science. There was an entire generation of physicists who grew up believing that science would only do good things for the world, but during the war science represented the destruction of people and there was the realization: scientists do not work in a vacuum. I cannot describe the history in its full glory and detail so I defer to this documentary which is worth a watch.

History has a way of gilding itself and so the romanticized Copenhagen meeting has gone on to inspire the play Copenhagen and it continues to resonate with the geek pop culture. My friend has made these awesome shirts. Can you spot the error on them?