Wednesday, August 29, 2012

Satellite launch

Excellent look at the whole process of assembling the satellite launcher and launching. Features the space centre in French Guiana. A 1 hour program.

The Higgs particle


The more-or-less confirmed discovery of the Higgs particle must be noted as it is of major significance to Physics. See BBC reports here and here. While this development is not a surprise it provides major confirmation of the standard theory of matter (in terms of sub-atomic particles anyway), provides new insights and will lead to new progress in the years to come.
It might be compared somewhat with Rutherford's experiment which confirmed the existence of the atomic nucleus and stimulated many further developments.
I will not attempt to explain what the Higgs particle is - try the above reports for that. But be warned that there is no simple description!

Sunday, May 13, 2012

Online electronics course from MITx


MIT has long been in the forefront of online education and open learning. They have now, with Harvard University, launched MITx with a free online course on electronics. See this report.
It looks to be of great value to those living where there are no accessible local equivalents. It is a university level course and hard work will be required! Definitely of interest to those doing Physics at A-level or university.

Sunday, April 1, 2012

Physics free textbooks online


Given the current high costs of university textbooks I decided it would be useful to see what was available online in a open format. In this first post four general texts are considered which might be suitable for the first year or two at our University at least as supplementary material. These texts were found in these two lists of free texts:

http://www.e-booksdirectory.com/physics.php - a useful long list of some 200 free books and lecture notes, mostly university level
http://www.freebookcentre.net/Physics/Physics-Books-Online.html - many books categorised by topic, quite a few are also on the above list

The four texts are not easily compared as the styles are different as is the coverage. Some have additional downloads of teaching materials, some include exercises in the text. I have tried to give brief details of each and have included snapshot of their summary of Maxwell's Equations, if covered, to give an idea of the style. Also included at the end is one from Wikipedia for comparison.

In addition to these there are many collections of lecture notes, lecture videos etc which are difficult to assess.

Calculus-Based Physics by Jeffrey W. Schnick, Ph.D. of Saint Anselm College - mechanics, waves, fluids, heat, E&M, optics (no electronics or modern physics) split into two sections plus various other materials. 300+ pages. Creative Commons license. Multiple formats, PDF ~2 Mb per section. Dated 2008.


Essential Physics by Emeritus Professor Frank Firk of Yale University - intensive introduction to classical and special relativity, Newtonian dynamics and gravitation, Einsteinian dynamics and gravitation and wave motion, all in one file. ~210 pages. No copyright notice. PDF only 1Mb.
Note: does not cover Maxwell's Equations. Dated 2000.


Simple Nature by Benjamin Crowell, Ph.D. of Fullerton College - "calculus-based physics textbook meant for the type of freshman survey course taken by engineering and physical science majors", covers the topics usual for this level of Physics, split into 18 sections. ~900 pages total. Creative Commons license. Online and PDF 5 Mb per section. Dated 2012.


Modern Physics - A series of online books covering Waves, Mechanics, Special Relativity, Quantum Mechanics, Gravity, Electromagnetism, Thermodynamics and Nuclear Physics. Wikibooks


And here is the summary from Wikipedia (note the similarity to the Wikibooks text):


Thursday, March 22, 2012

Faster CT scans


CT scanners are a key medical physics application and figure prominently in A-level syllabuses so this report should be of interest. After years of work by GE and Intel new software has been developed which speeds up the processing of an "image from a low-dose CT scan down from 100 hours per image to less than 1 hour" - a remarkable achievement. There are important safety implications since low-dose scans become more practical as a result. Also of interest is the use of parallel processing.

"It takes lots of time, and huge amounts of computing power, to turn the smaller dataset from a low-dose scan into a usable medical image. We're talking not hours but four to five days of computing time on mainframe-equivalent computers to come up with a workable image. For many doctors and hospitals, both the computer power needed and the long delay to get an image have made low-dose scans impractical."

"The joint team ultimately developed an accelerator based on 28 Xeon processors totaling 112 cores and a dramatically improved algorithm. We reduced the compute time to around an hour, delivering superior medical images and reducing the X-ray power by up to 90 percent."

Friday, March 9, 2012

Faster-than-light neutrinos - mistake?

It seems there may have been problems with the equipment - see this BBC report. Further results are expected in May. This underlines the need for scrupulous testing and for independent confirmation especially for research using equipment as complex as that used in this case.

Saturday, February 18, 2012

Experiments in weighlessness on the ISS


One of NASA's astronauts has been doing some instructive and interesting experiments on the International Space Station described here.

"NASA and the American Physical Society (APS) have partnered to share unique videos from the International Space Station with students, educators and science fans from around the world. NASA astronaut Don Pettit will use everyday objects from Earth to demonstrate physics..."