Mark Morris
Department of Physics & Astronomy, University of California, Los Angeles, CA 90095-1547,
USA
E-mail: morris@astro.ucla.edu
Abstract. The magnetic field within a few hundred parsecs of the center of the Galaxy is
an essential component of any description of that region. The field has several pronounced
observational manifestations: 1) morphological structures such as nonthermal radio filaments
(NTFs) – magnetic flux tubes illuminated by synchrotron emission from relativistic electrons
– and a remarkable, large-scale, helically wound structure, 2) relatively strong polarization of
thermal dust emission from molecular clouds, presumably resulting from magnetic alignment of
the rotating dust grains, and 3) synchrotron emission from cosmic rays. Because most of the
NTFs are roughly perpendicular to the Galactic plane, the implied large-scale geometry of the
magnetic field is dipolar. Estimates of the mean field strength vary from tens of microgauss to
∼ a milligauss. The merits and weaknesses of the various estimations are discussed here. If the
field strength is comparable to a milligauss, then the magnetic field is able to exert a strong
influence on the dynamics of molecular clouds, on the collimation of a Galactic wind, and on
the lifetimes and bulk motions of relativistic particles. Related to the question of field strength
is the question of whether the field is pervasive throughout the central zone of the Galaxy, or
whether its manifestations are predominantly localized phenomena. Current evidence favors the
pervasive model.
http://arxiv.org/pdf/astro-ph/0701050.pdf
Friday, 22 October 2010
The Galactic Center Magnetosphere
Monday, 18 October 2010
Balloons in Liquid Nitrogen
MIT Physics Demo
This demonstrates the ideal gas law (PV=nRT) which states that a drop in temperature with fixed mass and external pressure will result in a smaller volume, and vice versa.
Source:
MIT Department of Physics
Thursday, 14 October 2010
Sekolah Pendidikan Robotika Indonesia
"Murid yang dipersenjatai dengan informasi Akan selalu memenangkan pertempuran"
(Meladee McCarty)
Participants who are interested in submitting or being featured in a video must register before November 12th in order for a submitted video to be eligible. Once participants have received notification that they have been officially registered, participants will have till December 31st to submit a video entry to the website. NASA will screen each video submission for content and will notify the participant if their submission is accepted for inclusion in the contest. Videos will be available for public viewing throughout the submission period, but voting will not be accepted until the specified voting period. Voting will open on December 31st, 2010 and remain open through January 31st, 2011. The top 5 videos in each grade category (grades 3-5 and grades 6-8) will then be evaluated and ranked by NASA based on the criteria below. The winner(s) will be notified by February 28th, 2011.
NASA Spinoff Technologies
Did you know that space technology is all around you? The heart defibrillator your grandparents might have or the memory foam mattress you sleep on at night, or even the purified water you drink at your house are all technologies developed by NASA engineers, scientists and innovators. NASA is required to share its technologies with the public. The public then can take these technologies and make them into something that you can use around your house, at school or even on the road. These are known as spinoffs.
In 1976, NASA wanted to put all these great stories about spinoffs in a book that the public could read about. Since then, over 1,600 stories have been written about spinoffs. If you want to read more about these stories, the history of spinoffs and the impact space technology has made on you, please visit Spinoff.
Pilihan Teknologi
Autobots
Voices:
- Peter Cullen voices Optimus Prime leader of the Autobots
- Darius McCrary voices Jazz
- Jess Harnell voices Ironhide
- Robert Foxworth voices Ratchet
Engineering
Dengan Perkembangan Ilmu Pengetahuan dan Teknologi yang semakin pesat, hemat saya sekitar 100 tahun Kedepan FIKSI-ILMIAH Transformers dapat diwujudkan semoga!.
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