Earth – a somewhat bigger laboratory for school Physics

Grzegorz Karwasz

Andrzej Karbowski

Krzysztof Służewski

http://dydaktyka.fizyka.umk.pl

Zakład Dydaktyki Fizyki, Uniwersytet Mikołaja Kopernika w Toruniu

Rationale (I): Polish National Curriculum Base (2007)

Rationale (II): XXI Century Science

XXI Century Science

XIV: Structure and evolution of Earth

• Litosphere

• Hydroshere

• Atmosphere

• (Crysphere)

• Biosphere

XV: Structure and evolution of Solar System

Didactical/ heurestic goal

• Bring together Physics & Geography• Illustrate, possibly experimentally, phenomena• Choose the minimum knowledge requirements• Make the whole package attractive

Didactical theory context: -neo-realism (show as much as you can,

and even more), -hyper- constructivism (make student construct his/ her knowledge from apparently nothing, i.e. pre-existing knowledge in his/her mind)

G. Karwasz, Problemy Wczesnego Nauczania, 2013G. Karwasz, GIREP Conference 2012

Case examples:

- radioactivity → the age of Earth

- two-body mechanics → Earth and Moon

- gravity and rotation → shape of Earth

- convection and radioactivity → shield tectonics

- electromagnetic induction → magnetic field

- Coriolis force → general dynamics of atmosphere

- Coriolis force → dynamics of oceanic currents

- latent heat & convection → tropical storms

Three heurestic functions of an interactive/multimedia object

- Child: that’s so funny!

- Pupil: that’s so easy!

- Scientist: that’s so complex!

G. Karwasz, J. Kruk, Idee i realizacje dydaktyki interaktywnej, Wyd. Nauk. UMK, 2012

Radioactive series

rad - 1600 lat, gaz radon - 3,8 dnia, polon - 3 minuty, ołów - 27 minut (ten rozpada się przez proces β); bizmut - 20 minut; w kolejnym rozpadzie β powstaje ponownie polon, ale inny izotop, żyjący zaledwie 0,16 milisekundy, itd.

In other words:- a starting point 238U- some „bottle necks”- an ending point 206Pb

What is the age of Earth/Solar system?

What is the age of Earth?

Science 321, 1828 (2008); Jonathan O'Neil, et al. Neodymium-142 Evidence for Hadean Mafic CrustScience 309, 576 (2005); M. Boyet, et al. Silicate Earth 142Nd Evidence for Early (>4.53 Ga) Global Differentiation of the Silicate Earth

What is the age of Universe?

Planck mission (March 2013): 13.67 bilion yrs

Moon – a companion from (almost) ever

http://en.wikipedia.org/wiki/Lunar_eclipse

4.567 bln yrs + ~100 mln yrs ago

„Satelite” = body guard

G. Karwasz, M. Więcek, Toruński po-ręcznik. Fizyka współczesna, ZDF UMK 2012

„Satelite” = orbit stabilizer

→ destabilisation of Earth’s axis in 100 mln yrs

Physics and Toys

„Jakiego kształtu jest kula ziemska?”What is the shape of Earth’s ball?Answer: „Geoide” = Earth-like shape

= tautologyFoto: ESA

https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/goce

Copernicus: Why water does not flow down from Earth’s ball?

remained: „what is the shape of Earth?”

Newton: Because of gravity

Także i wody morskie układają się do postaci kulistej [...]

jako ląd i woda wspierają się na jednym środku ciężkości Ziemi, który jest zarazem środkiem jej objętości.

Newton: Elipsoid

because of the centrifugal force

Centrifugal force from textbooks

waves of kilometric heights would flush downthe globe!

Elipsoid is perpendicular to the effective gravity force

„flatness” 1/297

Parabole is perpendicular to the effective gravity force

Springs in mountains flow perpendicularly to iso-height lines

In physics we call these lines - equi-potential lines:the gravity force is perpendicular to potential lines

Ellipsoid vs. geoid

i.e. geometry vs. physics

Geoid – constant (gravitational + centrifugal) potential surface

GOCE: equipotential lines

https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/goce

Earth’s shape: equipotential surface

± 100 mhttps://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/goce

Earth’s shape: equipotential surface

Geoid is lower than elipsoid in the Himalaya mountains!

Potential formula: V=GM/r2

Lower mass → lower r

Himalaya are ligth (calcite) rocks

What is the shape of Earth?

The one, shown by the lever (libella)

and this is perpendicular to the verticalPoziomica, pion

Earth’s shape: horizontal water

because water level is always horizontal, like Copernicus said

What is the Earth’s internal structure?

S-wave in iron: 3,24 km/s

P-wave in iron: 5,95 km/s

Sprężyny, stukot

What is the Earth’s structure?

What is the Earth’s structure?

G. Karwasz, J. Chojnacka, Geografia w Szkole, 2012

crust ↔ litospheremantello ↔ astenosphere

How old is Europe?

M. Grad, T. Tirra, and ESC Working Group, The Moho depth map of the European Plate, Geophys. J. Int. 176 (2009), str. 279.

What is the Earth’s crust?

Lampa Lava

Why this vertical movement?

Physics World, March 2013

Heat flux:

- 238U: 8 TW (1015 W)- 232Th: 8 TW- 40K: 4 TW- cooling: 20 TW

- (electricity production: 10 TW)

Quarz, olivine etc.

http://webmineral.com/data/Forsterite.shtml#.U6dDmHZcuRM

Mg2SiO4

so, the vertical structure is getting complex

so, the vertical structure is getting quite complex...

Nature09401-f1.2.jpg

Geo-fizyka dla nie-fizyków

Justyna ChojnackaZakład Dydaktyki Fizyki

Wydział Fizyki, Astronomii i Informatyki Stosowanej

300 mln yrs ago

„Pangea”

and the surface structure?

some 500 mln yrs ago

Moving continents

+ 50 mln yrs (?)

wosk

Colliding continents (I)

John Nábelek, et al. Science 325, 1371 (2009); Foto: J. Karwowski, M. Karwasz, M. Visintainer

Colliding continents (IIa)

Westward: JapanSubduction angle: 45º

Dwie kartki papieru

Colliding continents (IIb)

Eastward: AndesSubduction angle: 15-25º

Colliding continents (III)Subduction of oceanic plates

Ryc. K. Konieczna

Physics World, no 3. (2012)

IV Continents drifting away

Foto M. Karwasz

IVa Continents drifting away

Foto M. Karwasz

Earth’s magnetic field

Dynamo model

Magnetic nigthingales

Auto-generated electric super-currents →auto-generated magnetic fields

389371aa.eps.2.gifIllustration of the dynamo mechanism that creates the Earth's magnetic field

Glatzmaier and Roberts 1995

so, it is getting quite complex

Atmosphere: Coriolis force

Ω

v

-2Ω×vΩ

Atmosphere: Coriolis forceΩ

v

-2Ω×vΩ

Atmosphere: Coriolis force

Atmosphere: Tropics and trade winds

Why Tropics are high pressure regions?

It is dry (descending) air!

subtropical and polar jet streams

Atmosphere: Columbus plan

Seasonal changes in Earth’s axis anglebetween September and March (1492/3)

http://earthguide.ucsd.edu/virtualmuseum/images/ColumbusRoute.html

Atmosphere: simple mechanisms, complex pattern

http://wps.prenhall.com/wps/media/objects/3312/3392285/blb1801.html

Atmosphere: vertical motion

http://www.hurricanescience.org/

Heat of condensation 540 cal/g →Heating high troposphere→ augmented air convection Warm ocean &Wind-induced evaporation

Wind-driven oceanic circulation

Northern hemisphere: clockwise, like Gulf stream, California Southern hemisphere anti-clockwise: Chile (Humboldt), Kalahari)

antyzegar

In-depth oceanic circulation

akwarium

Gulf Stream will stop if waters around Iceland warm up

Time-dependent patterns: Fourier components

Atmosphere (II): Fourier components

Interdisciplinary search

• You will find the other rocks lie lower, but they are so close together that there is not more than a bowshot between them. [A large fig tree in full leaf grows upon it], and under it lies the sucking whirlpool of Charybdis. Three times in the dayThree times in the day does she vomit forth her waters, and three times she sucks them down againthree times she sucks them down again; see that you be not there when she is sucking, for if you are, Neptune himself could not save you; you must hug the Scylla side and drive ship by as fast as you can, for you

had better lose six men than your whole crew

Homer, Ulysses

Homer: Scilla & Charybdis

In-between Scilla and Charybdis

http://dydaktyka.fizyka.umk.pl/Publikacje_2014/GwSzk1_2014.pdf

Messina Strait

http://it.wikipedia.org/wiki/Stretto_di_MessinaFontanna Herona, Fala w misce w przewężeniu

3 times a day!

A bigger wave: tsunami

http://crisisreliefjapan.files.wordpress.com/2011/10/tsunami-wave.jpghttp://cksimpsonwx.blogspot.com/2013/03/throwback-tohoku-earthquake-and-tsunami.html

Geophysics cardinal points

• Earth’s age: 4,567 mln yrs• Moon: 1/4 of Earth’s diameter• Shape: almost spherical 1/297 ± 100m• Tectonics: colliding every some 300 mln yrs• Cryosphere: bistable system, ~40k yrs• Atmosphere: Coriolis force + 7 days synoptic

Fourier component• Oceans: wind-driven (clock or anti-clock)• Significant human impact

Conclusions: Need for interdisciplinary Science teaching

- Physics with Geography- Physics with Chemistry

- Geography with Literature-...

- Biology with Philosphy- ...

Thank you very much!