Physics News from the AIP No 2, Term 1 2005 s5

Physics News from the AIP Term 2, No 1, 2008

1. Preparing for 2009: VCE Physics Implementation Workshops 2. AIP Physics Photo and Video Clip Contests 3. Switch On To Physics: A free excursion for Year 10 students 4. A Moon Clock Resource 5. Using Dark Matter to teaching Circular Motion and Gravitation ((movie and resources) 6. Forthcoming events for Students a) Two Events about Energy and Climate Change: Free public evening events at BMW Edge, 21st, 28th April. b) New Views of the Universe. Public Lecture series at Swinburne University, Weds in April and May. c) Photonics and Synchrotron Workshops: September 7. Forthcoming Events for Teachers a) Astronomy from the Ground Up!' Teacher Workshop at Parkes, 9 – 11 May, 2008. Special Package for Victorian Teachers b) Teaching Synchrotron Physics, a half day in-service and tour on the day of the GAT, 13th June For details of item a) please see previous “Physics News from the AIP” or check the news section of our website www.vicphysics.org/news/index.html 8. Physics News from the Web a) The Darkest Material Ever Made b) Acoustic Cloaking c) Shattering Viruses

Compiled by the Australian Institute of Physics (Victorian Branch) Education Committee. Check their website www.vicphysics.org for latest resources, events and forum discussions. A list of over 60 items from previous “Physics News from the AIP” that are still of value can be found in the “News” section of the website, as can all the news stories from the “Physics News from the Web”.

This year the AIP Education Committee meets at Camberwell High School normally on the second Tuesday of the month from 5pm – 7pm, the next meeting is on Tuesday, 15th April. If you would like to attend this or any meeting, please contact the chair, Sue Grant at [email protected]

1. VCE Physics Implementation Workshops A series of regional Implementation Workshops to assist teachers in preparing for the new study design starting in 2009. The workshops will be held at 14 locations around the state during the last two weeks in May and one week in June after the Physics exam. There is no cost to attend, but teachers must register with STAV.

The workshops will focus on changes to the Study Design for Units 1 & 2 and for Units 3 & 4 and will include implications for teaching and assessment.

Most of the workshop time will be devoted to activities exploring the following aspects:  A defined set of verbs to specify all the dot points (see pages 47 , 48 of the Study Design),  Challenging concepts and difficult skills: Developing ways to assist students with their learning (examples provided),  Innovative ways of teaching the Detailed Studies at Units 1 & 2 as well as Units 3 & 4,  Strategies to attract and retain students to VCE Physics.

The dates and locations are as follows: A Mon, 19 May 4:00 – 6:00pm Geelong B Tues, 20 May 4:30 – 6:30pm Camberwell C Wed, 21 May 3:30 – 5:30pm Horsham D Thurs, 22 May 1:30 – 3:30pm Ouyen E Mon, 26 May 3:30 – 5:30pm Bendigo F Mon, 26 May 3:30 – 5:30pm Hamilton G Tues, 27 May 4:30 – 6:30pm Ringwood H Wed, 28 May 3:30 – 5:30pm Wangaratta I Wed, 28 May 4:30 – 6:30pm Frankston J Thurs, 29 May 4:30 – 6:30pm West Sunshine K Mon, 16 June 3:30 – 5:30pm Ballarat L Tues, 17 June 3:30 – 5:30pm Sale M Wed, 18 June 4:30 – 6:30pm Northcote N Thurs, 19 June 4:30 – 6:30pm Dandenong

Applications forms are in the latest STAV Contact mail out and on our website at http://www.vicphysics.org/events/forthcomingevents.html . Online registration is available at http://www.sciencevictoria.com.au/VCEPhysicsWorkshops.html

2. AIP Physics Photo and Video Clip Contests A flyer on the Physics Photo and Video Clip Contests should arrive in schools in a few days. Please encourage your students to enter.

The conditions for the Photo Contest have been changed for this year:  The two categories, Natural and Contrived have been combined as the distinction was becoming subtle and confusing to students.  Only students may enter.  Entrants may submit more than one photo, but each entrant can win only one prize.  Entries due by the end of Term 3.  The rule on manipulation of the image has been eased, but a statement of how the image has been modified or manipulated is now required.  The judging will be by a panel. Last year’s entries can be seen at http://vicphysics.blogspot.com/ Further details of this year’s contest can be found at http://www.vicphysics.org/events/photo.html

The Physics Video Clip Contest is open to students and teachers. The video clips should demonstrate physics in action.

Videos must be in MP4 or Quicktime format, or a format suitable for video streaming. The video may not be longer than three minutes in length. Please note: Unsafe practices will not be accepted. An explanation of the Physics in the video should be either on the audio or in a supporting 250 word statement.

Entries will be placed on the AIP website as they are received. They will be available as streamed video.

The best three entries in each category will be selected for judging at the annual Physics Teachers Conference next February. Videos will be evaluated on their suitability for instructional use.

Prize pool: $1000 for each category

Videos will be accepted until the 31st October, 2008. More details about the Contest Rules and Entry Agreement can be found at http://www.vicphysics.org/events/video.html 3. Switch On To Physics: A free excursion for Year 10 students Switch On To Physics (SOTP) is a half day program for Year 10 students held during June at university campuses around Victoria.

In the program each student constructs, uses and keeps a freezer alarm (a one transistor circuit) and a spectrometer. The two tasks are supported by construction and explanatory notes, as well as career information and extension activities.

The event is free in 2008. The cost of the two kits is met by the Federal Government’s National Innovation Awareness Strategy (NIAS) and by the Australian Institute of Physics (AIP).

Details on available dates and bookings can be found at www.vicphysics.org/events/sotp.html . Schools can also book a date by emailing Dan O’Keeffe at [email protected] .

4. A Moon Clock Resource This information is supplied by Dr Susan Feteris of Monash University.

An instrument to tell time by the Moon is available on the internet. It helps to understand the relationship between phases and the positions of Moon and Sun, but it's for the northern hemisphere. http://school.discoveryeducation.com/lessonplans/programs/lightofthemoon/.

The designer, Ted Latham has been asked to put a southern hemisphere version up. In the mean time an adapted version is available on our website at www.vicphysics.org/teachers/astronomy.html .

There's a lesson plan on the discoveryeducation.com site, explaining how to use the clock. It's aimed at 'Grades 6-8', but it has been used with first year uni students.

5. Using Dark Matter to teaching Circular Motion and Gravitation ((movie and resources) The Perimeter Institute http://www.perimeterinstitute.ca/en/Perimeter_Explorations/General/Perimeter_Explorations/ does a number of outreach activities. One of which is the development of classroom material. The address above is about a resource package on using dark matter to teach circular motion and universal gravitation. The package contains a video which can be streamed or downloaded. A teacher’s guide can also be downloaded. A teacher’s kit with the DVD, notes, etc can also be ordered at no cost.

6. Forthcoming events for Students a) Two Events about Energy and Climate Change i) 21st April - Energy and Climate Change: Science and Technology for Australia's future – Renewable Energy – solar, geo thermal, wind Panellists: Professor Andrew Blakers FTSE – ANU, Canberra, an inventor of the sliver cell – Solar Photovoltaics and Solar Thermal,. Dr. Adrian Williams - Former CEO Geodynamics Ltd – Geo Thermal Ms. Dominique La Fontaine - Immediate past CEO Clean Energy Council –Wind, Bio Mass, Tidal and Waves ii) 28th April - Energy and Climate Change: science and technology for Australia's future – Non-Renewable Energy – coal, gas, nuclear. Panellists: Dr Louis Wibberly - Chief Technologist, Energy Technology, CSIRO, Newcastle – Brown Coal and Gas, future utilization. Dr. Peter Cook FTSE – CEO Cooperative Research Centre Greenhouse Gas Technology (C02CRC) – CO2 sequestration Dr. Ziggy Switkowski FTSE - Chair, Australian Nuclear Science and Technology Organisation, Melbourne – Nuclear Energy. Events Moderator: Peter Mares – Presenter ABC Radio National Events Summariser: Professor Graeme Pearman FTSE - Monash University Time: 6:00pm to 7:30pm: entry from 5.30pm Where: BMW Edge, Federation Square, Cnr. Flinders and Swanston Streets, Melbourne FREE ENTRY – NO BOOKINGS b) New Views of the Universe. Public Lecture series at Swinburne University April 23rd: The Extraordinary Accelerating Universe - Cosmology in the 21st Century April 30th : ELTs: The Next Generation of Extremely Large Optical/Infrared Telescopes May 7th : For the Term of its Natural Life: The Siding Spring Observatory 1m Telescope May 14th : From Sticks to Supercomputers Where: AR Building, Swinburne University, Hawthorn. Lectures will occur in the ground floor Virtual Reality Theatre (Room AR104) - the entrance is next to Haddons cafe. When: Wednesdays. Lectures will begin promptly at 6:30pm and will finish ~8:30pm (with an intermission). Please be seated by 6:20pm. Cost: $15/lecture. You can pick and choose which lectures you wish to attend. If you attend all 4 lectures it will only cost you the equivalent of 3 lectures ($45). Reservations: You must reserve a seat for each lecture. Seating is limited in the VR Theatre. Please open this booking sheet, fill in your details, and Fax it to 9214-8797 with "Attention: New Views IV - Carolyn Cliff". Payment is via credit card or cheque only. Check their website for more details http://astronomy.swin.edu.au/outreach/seriesIV c) Photonics and Synchrotron Workshops for Students The AIP Education Committee is organising workshops for students doing two Unit 4 Detailed Studies: “Photonics” and “Synchrotron and its applications”.

The workshops will run from about 3:00pm until 7:30pm sometime during the first two weeks of September, exact dates will be in the next newsletter. The Photonics workshops will be held at Swinburne University, while the synchrotron workshops will be held at Monash University. The program for each workshop will include lectures and extensive hands on practical activities with access to university equipment. The Synchrotron workshop will also include a tour of the Synchrotron. A pizza dinner will be provided. The capacity for both workshops is limited so it is intended to offer a second workshop once the first is fully booked. There will be no cost.

Stay tuned for further news.

7. Forthcoming Events for Teachers b) Teaching Synchrotron Physics, a half day in-service and tour on the day of the GAT The AIP Education Committee will be repeating the half day in-service offered in June last year. The In- service will be held on 13th June at the Monash University from 1:00pm until 4:30pm. The program will include: a tour of the Synchrotron site, hands on practical activities including the microwave Bragg Diffraction kits, teaching advice and a briefing on the operation and uses of the Synchrotron.

To book a place contact Dan O’Keeffe oat [email protected] . 8. Physics News from the Web Items selected from the bulletins of the IOP and the American Institute of Physics. a) The Darkest Material Ever Made b) Acoustic Cloaking c) Shattering Viruses a) The Darkest Material Ever Made Consists of a carpet of vertically oriented carbon nanotubes. The darkness or lightness of any object depends on the fraction of light falling on the object that gets reflected back. The reflectivity of the nanotube array developed by physicists at the Rensselaer Polytechnic Institute (RPI) is only 0.045%, three times smaller than the best previous dark object (see figure at http://www.aip.org/png/2008/296.htm ). Shawn Lin and his colleagues grow the nanotubes on iron nanodots atop a silicon wafer. The resulting mat is thin (10-800 microns) and lightweight (.01-.02 g/cm^3).

Possible applications include the revision of darkness standards, such as are used by photographers. The lowest dark scale defined by NIST right now is for reflectances of about 1.5%. The material might also be useful in astronomical detectors (where you want to soak up stray radiation) or in photovoltaic cells which turn sunlight into electricity. Lin ([email protected]) says that an additional feature of this new material is that it represents a controllably porous substance with an index of refraction (1.02) not very different from that of air. (Yang et al., NanoLetters, 9 January 2008). b) Acoustic Cloaking Computer simulations and the use of wave scattering theory have demonstrated that, contrary to earlier predictions, it should be possible to produce a 3-dimensional material shell which is invisible to sound waves, analogous to “optical cloaking,” the process in which light waves are guided around an object and then refocused on the far side and in the same direction (with no reflected light to betray position) so as to make the object seem invisible. Full optical cloaking has not been achieved yet, but researchers expect to be able to do it.

Can the same thing be done with sound waves? In principle there is no reason why it couldn’t be done. The leader of a group of scientists examining this issue, Steven Cummer at Duke University, says that many of the principles that pertain to the channeling of light waves around an object also apply to sound waves. To be sure, there are differences. Sound waves oscillate in the direction of their motion while the electric and magnetic fields composing light waves oscillate perpendicularly to the wave motion. In the optical case, cloaking will require a material (actually a meta-material) tailored, highly anisotropic (varying widely according to the direction through the material) index of refraction.

In practice, the index of refraction for electromagnetic waves depends on the permittivity, a measure of the material's response to an applied electric field, and permeability, its response to an applied magnetic field (for an account of the demonstration of negative-index materials, see http://www.aip.org/pnu/2000/split/pnu476-1.htm). The acoustic equivalent of these two parameters are the mass density and the bulk modulus (the springiness) of the background fluid (usually air or water) in which the object sits. Cummer (919-660-5256, [email protected]) says that in the short run acoustic cloaking might be more practical than optical cloaking.

A limitation of electromagnetic cloaking, he says, is that it requires portions of the wave to move faster than the speed of light (in full accordance with special relativity); this can be done for very limited frequency ranges but not for wider ranges, limiting the applicability of optical cloaking. This limitation does not apply to sound waves moving through matter. Furthermore, the acoustic properties of most materials means that sound waves might not be absorbed as readily in acoustic cloaking as light waves are absorbed in optical cloaking (in which case the cloaking would be something less than perfect).

Applications of acoustic cloaking come easily to mind: hiding submarines from sonar, for example. Another potential practical application might be in architecture, where acoustic considerations (reducing noise) might not have to be sacrificed in the interest of structural integrity. Among Cummer’s collaborators are David Smith of Duke (one of the early pioneers in the field of negative-index materials) and John Pendry of Imperial College (the early theorist of negative-index studies). c) Shattering Viruses A new study is trying to establish the intrinsic vibration modes of capsids---the protein shells of virus particles that package its genetic material---with a view toward rupturing them and thereby killing the pathogenic virus. If the capsid resonant frequencies could be determined, then possibly light or sound waves might be used to shatter the capsids the way the opera singer Enrico Caruso supposedly shattered wine glasses by sustaining a note at exactly the resonant frequency of the glass. This approach to attacking viruses is alternative to treating them with chemicals, which is not always effective; furthermore, the chemicals can do damage to healthy cells, or the viruses can mutate and defeat chemical defenses. Hence the importance of attempting to undo viruses with mechanical means.

Eric Dykeman and Otto Sankey, physicists at Arizona State University, are modeling capsid vibrations at the atomic level for comparisons with experiments being performed by K.T. Tsen at ASU in which picosecond laser pulses are scattered from capsids. The capsids, which are mostly made of complex protein assemblies, will typically absorb some of the laser light, a process which causes them to vibrate. The rest of the laser beam, its energy somewhat depleted, will be downshifted in frequency. This allows observers to deduce the resonant frequency of the capsids. By staging the short laser pulse in different ways, a whole catalog of capsid resonant frequencies can be made. Sankey ([email protected], 480-965-4334) says that the simulations performed so far suggest that resonant frequencies for their chosen virus, the satellite tobacco necrosis virus (see vibration movie at http://www.aip.org/png/2008/292.htm) are in the vicinity of 60 to 90 GHz.