Earth – a somewhat bigger
laboratory for school Physics
Grzegorz Karwasz
Andrzej Karbowski
Krzysztof Służewski
Zakład Dydaktyki Fizyki,
Uniwersytet Mikołaja Kopernika w Toruniu
http://dydaktyka.fizyka.umk.pl
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, 2013
G. 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
In other words:
- a starting point 238U
- some „bottle necks”
- an ending point 206Pb
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.
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 Crust
Science 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
Physics and Toys
→ destabilisation of Earth’s axis in 100 mln yrs
„Jakiego kształtu jest kula ziemska?”
What is the shape of Earth’s ball?
Answer: „Geoide” = Earth-like shape
Foto: ESA
= tautology
https://directory.eoportal.org/web/eoportal/satelli
te-missions/content/-/article/goce
Copernicus: Why water does not flow
down from Earth’s ball?
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: Because of gravity
remained: „what is the shape of Earth?”
Newton: Elipsoid
because of the centrifugal force
Centrifugal force from textbooks
waves of kilometric heights would flush down
the 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 m
https://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 vertical
Poziomica, 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?
crust ↔ litosphere
mantello ↔ astenosphere
G. Karwasz, J. Chojnacka, Geografia w Szkole, 2012
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?
Heat flux:
- 238U: 8 TW (1015 W)
- 232Th: 8 TW
- 40K: 4 TW
- cooling: 20 TW
- (electricity production: 10 TW)
Physics World, March 2013
Quarz, olivine etc.
Mg2SiO4
http://webmineral.com/data/Forsterite.shtml#.U6dDmHZcuRM
so, the vertical structure is getting
complex
so, the vertical structure is getting
quite complex...
Nature09401-f1.2.jpg
„Pangea”
Geo-fizyka dla nie-fizyków
300 mln yrs ago
Justyna Chojnacka
Zakład Dydaktyki Fizyki
Wydział Fizyki, Astronomii i Informatyki Stosowanej
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: Japan
Subduction angle: 45º
Dwie kartki papieru
Colliding continents (IIb)
Eastward: Andes
Subduction angle: 15-25º
Colliding continents (III)
Subduction of oceanic plates
Physics World, no 3. (2012)
Ryc. K. Konieczna
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
Illustration of the dynamo mechanism
that creates the Earth's magnetic field
389371aa.eps.2.gif
so, it is getting quite complex
Glatzmaier and Roberts 1995
Atmosphere: Coriolis force
Ω
v
Ω
-2Ω×v
Atmosphere: Coriolis force
Ω
v
Ω
-2Ω×v
Atmosphere: Coriolis force
Atmosphere: Tropics and trade winds
Why Tropics are high pressure regions?
subtropical and polar jet streams
It is dry (descending) air!
Atmosphere: Columbus plan
http://earthguide.ucsd.edu/virtualmuseum/im
ages/ColumbusRoute.html
Seasonal changes in Earth’s axis angle
between September and March (1492/3)
Atmosphere: simple mechanisms, complex
pattern
Atmosphere: vertical motion
Heat of condensation 540 cal/g →
Heating high troposphere
→ augmented air convection
Warm ocean &
Wind-induced
evaporation
http://www.hurricanescience.org/
http://wps.prenhall.com/wps/
media/objects/3312/3392285/blb1801.html
Wind-driven oceanic circulation
Northern hemisphere: clockwise, like Gulf stream, California
Southern hemisphere anti-clockwise: Chile (Humboldt), Kalahari)
antyzegar
In-depth oceanic circulation
Gulf Stream will stop if waters
around Iceland warm up
akwarium
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 day does she vomit forth her waters,
and three 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_Messina
Fontanna Herona, Fala w misce w przewężeniu
3 times a day!
A bigger wave: tsunami
http://crisisreliefjapan.files.wordpress.com/2011/10/tsunami-wave.jpg
http://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!