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Teachinghttp://www.marinewatchnsw.com/library/images/harrison4.jpghttp://www.marinewatchnsw.com/library/images/harrison4.jpg Science from a Science Perspective

Introduction to basic units

Educational Philosophy:

The normal approach to teaching Energy and Force goes along the ideas of "Proximal Development" (ZPD) and concept teaching strategies.

Fundamentally this requires the student to leverage past experience and make common sense steps to grow in understanding. It is possible to get students to replicate the teacher's common sense, received wisdom which often contain some common widely held flaws in thinking. They are

1) confusion between Mass and Matter / Weight and Mass

2) Believe that atoms are largely empty space (no supported by Quantum Mechanics)

3) The belief objects can not occupy the same region of space  (no supported by Quantum Mechanics)

It is common to see the use of the 

1) Drude model

2) The Bohr Atom

3) The Bohr liquid drop nucleus (as opposed to the Woods - Saxon Potential)

4) Requirement for wave particle duality (as opposed to a full quantum mechanical treatment)
5) The classical point electron

In short education technique has driven the propagation of bad science. People are simply not aware of the scope or seriousness of the situation. They have become comfortable with a network of misconceptions and don't perceive there is any long term problem that "can be fixed, for those luck one's who go on to study it seriously.

Scientific literature away of quality control by direct editorial intervention or by general reduction in citation, Education has a far more folk lore approach. Once an error is published it generates a cohort that propagates the misconception.

In an unusual move, it has been decided to teach Energy rather than the constructive concepts of Force,  Motion and Mass. This means we have to explore the concepts in Energy from a factual rather than a constructive frame work.

The Origin of the Second

1 second is defined to be  9192631770  (approximately 9 billion) pendulum periods of a metal gas Cesium.  Your microwave oven works at about 2 450 000 000 cycles per second.

To avoid doubt, it is Cesium with 133 protons and neutrons in the nucleus. The gas is stationary, and at absolute zero.

The pendulum swing is with microwave resonating with the swing of the Cesium.

In reality millions of atoms are held in a laser light cursible and thrown up much like a tennis serve.
Imagine the microwaves like a tennis racket, and if timed right they hit the atoms and get them to change shape.  The atoms on return (about 1 second ie about the height you throw a tennis ball) the number hit is scored.  High score means the right microwave.

The idea of a clock is analogous to flipping a coin in a sound wave and checking the frequency has hit the resonance of the coin

So it is not the rise and fall of the coin or atom but rather this is acting as a target that is only hit at a specific frequency.  Therefore time.

In the United States, the standard of time is regulated by the US Naval Observatory's Master Clock (USNO) which checks a fleet of atomic clocks circling the earth, that then keep time on all GPS and ATM

Here is an article on GPS atomic clock use http://www.gps.gov/applications/timing/

It is interesting it is used in the Hollywood film slates.

The internet references state that the electrons in the atoms "Jump" from one quantum state to another.  This is a common lose description. In our space electrons have a large physical extent typically > 1/20 nm. However they have distinct resonant shapes, and if the energy of these shapes are plotted they correspond to a single point tagged by their quantum numbers.  The microwave does cause the electron to move to new points absorbing or adding to the microwave energy. But they do not vanish only the energy levels get shifted by the radiation and the electron deforms in harmony.

Here is a picture of it happening

What happens in terms of radiation is that the Magnetic field vector which is normally in sync with the Electric field vector shifts pi/4 and the light gets trapped in the atom. It is important to remember that the stationary wave states are for the atom unperturbed by the EM radiation.

It is interesting that Australia was discovered as a Science bonus for the transit of Venus

Now for this Cook needed a very accurate clock. The greater the time difference of transit between London and Tahiti, the greater the parallax so the closer one is to the Sun.

Having an accurate clock meant basically a GPS for Cook.

The second red journey was with Harrisons watch number 4 the size of a bread and butter plate and kept accurate to seconds in a year.  The cost of this clock was several million dollars in todays terms.  To set the clocks ships would anchor in the Themes to see the "time ball" drop a 1 pm

"Shannon the Cannon was replace by Harrision the Garrison" Though out the british empire the gun rang out at o'oclock"

The French are kept in the dark about Cooks longitude work.

Odd facts about Cook

His Chronometer the K1 was a ripoff of the H4 a real Rolex story

He took his prized Goat on his voyage of discovery to Australia the first female to circumnavigate the earth

The use of the plate size watch sent him to scour the pacific for the great southern land, Australia wasn't it and not worth a second visit.  There is a new accuracy of his voyage with this.

Music is the answer

Phythagoras - Universal music, Planets, People and Instruments but we discovered the music of atoms.

Interesting Insects and Spiders

This spider caught my attention. It had three brilliant metallic gold marking on its back.
Soon after this shot it adopted a hunting position directed at me.

... and jumped directly 20 cm onto the camera.  At 5mm length it was larger than any other jumping spider.

This a metalic bettle that looks like a Christmas Borble (Green) . Our bower bird polished off the body before I could photograph it. The hook claws are interesting an lack of jaws

Glenbrook 2.0

View DrHillTeach in a larger map

First Computer Games

I will start reporting more on Australia forgotten computer science history.  In this 1956 article the use of CIRAC to play games is mention. Geoffrey Hill is attributed as the creator of the first computer music in 1948 -52, and this article shows he was working early on computer games,

Charlemagne

I have just read a very readable history of Charlemagne.  It was by a 1970's Christian historian, so it was a popular easy read.

I was interest in this era, as learning was going backwards as politics got out of hand.  Today it is heresy to say some aspects of education are lost in politics.

I found the following things interesting:

1) Dark ages society was an interwoven mix of Gallo Roman classical life,  Barbarian (Goth) and first wave administrators, and layers of subsequent barbarians (the Franks)

2) Monastic architecture with cloisters were essentially derived from Roman villas, and the structure with monks and more worldly abbots, reflected Roman house holds with the Freemen and Slaves.

3) Kings in 600 quickly lost power to Nobles and Mayors as they pursued the Kings life and handed over the running of the country.

4) Pepin a mayor got Rome to reboot the king process by making him King of the Franks, this was enabled by the "cutting the hair" of the old king, and him being thrown aloft on his shield three times.  This was a mix of Christianity and Heathen cultures.

5) The Saxons had a "Pillar of the world" around which they horded treasure

6) The Huns had treasure held in a Nine ring defence

7) Charlemagne killed 4500 Saxon men, and started a Saxon up rising.

9) The German practice of making all sons inherit a divided kingdom,  kept things small and easy to administer.  The practice of having more than one wife (Teutonic) and concubines (eastern) lead to an explosion of heirs.

More on Black Bodies

What we strictly have to cover in the Syllabus

8.5.3.2.1  That is focus area 5 column 2 point 1

define the relationship between the 
temperature of a body and the
dominant wavelength of the radiation
emitted from that body 

On the most basic level a body is an object of more than a few hundred atoms, and the hotter it is the more blue it is.

Blackbodies are a class of bodies that were theoretically discussed in 1860 by a scientist call Kirchoff,
Simply put anylight falling on them get absorbed so that any light coming from them has been generated by the body. Now for the next 40 years scientist fooled around making blackbody radiators, then taking spectra. Finally they got black body spectra and Planck modeled it and this lead to Modern Physics, but that is another story

 1900 was close enough to make do calculations. 2009 we are getting close but we are still not there, light goes in and never comes out, only the heat light comming from the body.  So far "blackbody" only really turns up next year in the HSC Astrophysics Option.

So the modern defintion of a Blackbody radiator is

A blackbody allows all incident radiation to pass into it (no reflected energy) and internally absorbs all the incident radiation (no energy transmitted through the body). This is true of radiation for all wavelengths and for all angles of incidence. Hence the blackbody is a perfect absorber for all incident radiation

Siegel, Robert; Howell, John R. (2002). Thermal Radiation Heat Transfer; Volume 1 (4th ed.). Taylor & Francis. p. 7. ISBN 1-56032-839-8. http://books.google.com/books?id=O389yQ0-fecC&pg=PA7.

So here is my summary from the point of view of a spectroscophist, baring in mind

Most things coffee cups and stars, are good black body radiators in the visible, perfect in the infrared, and to varying degrees poor in the UV. So if you use the black body Weins law that looks at the peak wavelength, you get a good temperature, if you use an infrared bolometer that looks at the curve in the IR you get a great reading, and UV you get a more or less view of the structure of what you are looking at.  That is how different it is from a little Pt box with carbon nano tubes in it.

This is a plot of how badly stars deviate from the BBR curve (black) in the UV which people dont use to determine temperature, because the curve is not valid there.  Basically the is not a fix surface for a surface temperture.  Stars get hotter in the inside, and so there is no defined temperature.  Supergiants have colder outer layers to the UV escape surface is higher. The curves above  represent UV deficit

More in depth is given in this web text http://cseligman.com/text/sun/blackbody.htm

This is from, http://homepages.wmich.edu/~korista/sun-images/solar_specbb.jpg  as you can see

1. IR good
2. Peak fair
3. UV lousy

I would interpret this as the UV light powering, more visible light from the sun but this is an observation not a published piece of science.

Planck's Vision

How to understand Electrons

1. Metals are regular 3D array of positive nuclei (example Mg++ nuclei)
2. Electrons(example e- and e- from the Mg++) swim around the nuclei

2.1 Here is a realistic picture of electrons swimming around a metal, They are not "classical electrons" but actually give bulk to the metal (dont worry until you do Quantum Mechanics at UNI)

3. Electrons are like trout in a tank, the walls are like the WORK FUNCTION

4. There are three ways to get electrons out of a metal

4.1 Fire an ion from a low pressure gas (throw a rock in the trout pond and trout will jump out)

4.2 Heat up the metal called THERMIONIC EMISSION (Heat it up Elmo?)

4.3 Hit out the electrons with UV light PHOTOELECTRIC effect (Laser)





Is there a relationship between metal lattice distances and resistivity?

What a great site Web Elements is !
The red ones are the d block standard metals.
Copper, silver gold are in a line copper silver gold
Iron is dark grey, mercury light grey.
The last period is has many null values

What do you think? Does a large r (top) lead to low resistivity (bottom)?