Download Incandescent Lamp

Incandescent Lamp
Background reading (web links)
Wikipedia: Incandescent ligh bulb, http://en.wikipedia.org/wiki/Incandescent_light_bulb
Wikipedia: Light bulb, http://en.wikipedia.org/wiki/Light_bulb
Wikipedia: Black body, http://en.wikipedia.org/wiki/Black_body
Wikipedia: Color temperature, http://en.wikipedia.org/wiki/Color_temperature
How Stuff Works: light bulb, http://home.howstuffworks.com/light-bulb.htm
D. MacIsaac, G. Kanner, and G. Anderson. Basic physics of the incandescent lamp (lightbulb.) Phys.
Teach. 37, 9, 520-525 (1999), http://www.cce.ufes.br/jair/web/TPTDec99Filament.pdf
Lawrence D. Woolf. Seeing the light: The physics and materials science of the incandescent light bulb
(GA Sciences Education Foundation, Feb. 20, 2002), http://www.sci-edga.org/modules/materialscience/light/index.html
Kevin Cunningham. Light sources, http://www.mindspring.com/~smskjc/lightk.htm
Resistance and temperature, http://tap.iop.org/electricity/resistance/index.html
Edward J. Covington's Early Incandescent Lamps. http://home.frognet.net/~ejcov/
Light source spectra (Cornell University, 2001),
http://www.graphics.cornell.edu/online/measurements/source-spectra/index.html
Background reading (periodicals)
John W. Dewdney. Energy loss from the filament of an incandescent lamp. Am. J. Phys. 28, 2, 89-91
(1960)
Harvey S. Leff. Illuminating physics with light bulbs. Phys. Teach. 28, 30–35 (1990)
D. C. Agrawal, H. S. Leff, and V. J. Menon. Efficiency and efficacy of incandescent lamps. Am. J.
Phys. 64, 649-654 (1966)
John M. Anderson and John S. Saby. The electric lamp: 100 years of applied physics. Phys. Today,
32-40 (Oct. 1979)
B. Denardo. Temperature of a lightbulb filament. Phys. Teach. 40, 101–105 (2002)
V. J. Menon and D. C. Agrawal. Lifetimes of Incandescent Bulbs. Phys. Teach. 41, 100 (2003)
D. C. Agrawal and V. J. Menon. Lightbulb exponent-rules for the classroom. IEEE Trans. Educ. 43,
262–265 (2000)
D. C. Agrawal and V. J. Menon. Life-time and temperature of incandescent lamps. Phys. Educ. 33,
55–58 (1998)
W. S. Wagner. Temperature and colour of incandescent lamps. Phys. Teach. 29, 176–177 (1991)
Paul Gluck and John King. Physics of incandescent lamp burnout. Phys. Teach. 46, 29 (2008)
D. A. Clauss, R. M. Ralich, and R. D. Ramsier. Hysteresis in a light bulb: Connecting electricity and
thermodynamics with simple experiments and simulations. Euro. J. Phys 22, 385 (2001)
H. Richard Crane. Making light bulbs last forever. Phys. Teach. 21, 606–607 (1983)
I. R. Edmonds. Stefan-Boltzmann law in the laboratory. Am. J. Phys. 36, 845 (1968)
B. S. N. Prasad and R. Mascarenhas. A laboratory experiment on the application of Stefan's law to
tungsten filament electric lamps. Am. J. Phys. 46, 420 (April 1978)
I. Cooper. Physics with a car headlamp and a computer. Phys. Educ. 32, 197 (May 1997)
A. James Mallmann. Lamp lifetimes. Phys. Teach. 46, 196 (2008)
Bruce Denardo. Temperature of a lightbulb filament. Phys. Teach. 40, 2, 101-105 (2002)
Biswajit Ray. Don't zap that light bulb! Phys. Teach. 44, 374 (2006)
Key questions
 How does the ratio between thermal and light energies evolve over time, when the lamp is
switched on?
 Is there a way to directly measure the temperature of the filament and other elements of the lamp?
Is it possible to measure or calculate the radiation intensity?
 What physical parameters of the system may be relevant? (voltage provided by the power supply?
resistance of the filament as a function of temperature? inductance of the filament? heat
conductivity of contact wires and the gas? surface properties of the filament?)
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What is the radiation spectrum of the lamp and does it evolve over time? Are the Planck’s law
and the black body approximation relevant?
The filament in a “used” lamp is possibly thinner and more likely to burn out. How does it
influence on ratio between energies in question?
In the end, what are the overall energy losses via radiation and via heat transfer?
What amount of heat is leaving through contact wires and through gas and glass?
What are the time scales for these energy losses?
Bright Waves
Background reading (Web links)
Jearl Walker. Shadows cast on the bottom of a pool are not like other shadows. why? In: Amateur
Scientist, Sci. Am. 259, 116-119 (July 1988),
http://optica.machorro.net/Optica/SciAm/PoolShadows/1988-07-fs.html
Kim Cois. Physics of ripple tanks. (ehow.com, July 5, 2011),
http://www.ehow.com/info_8689182_physics-ripple-tanks.html
Water Waves (physicstutorials.org), http://www.physicstutorials.org/home/waves/water-waves
Andrew Kirk. Trout and optical catastrophes (atopics.co.uk), http://www.atoptics.co.uk/fz535.htm
M. V. Berry and J. F. Nye. Fine structure in caustic junctions. Nature 267, 5606, 34-36 (1977),
http://www.phy.bris.ac.uk/people/berry_mv/the_papers/Berry056.pdf
Michael Berry. Beyond rainbows. In: Waves and Symmetry (Raman Centenary Symposium,
Bangalore, Dec. 1988), http://www.phy.bris.ac.uk/people/berry_mv/the_papers/Berry213.pdf
Mark Watt. Light-water interaction using backward beam tracing. Computer Graphics 24, 4, 377-385
(1990), http://www.naturewizard.com/papers/caustics%20-%20p377-watt.pdf
Musawir Shah and Sumanta Pattanaik. Caustics Mapping: An Image-space Technique for Real-time
Caustics. IEEE Trans. Visualization and Computer Graphics 13, 2, 272-280 (2007),
http://graphics.cs.ucf.edu/caustics/caustics.pdf
Mojca Čepič. Why underwater caustic network appears on the vertical walls?,
https://www.ffri.hr/GE2/download/65_underwater_final.pdf
D. K. Lynch, W. C. Livingston. Color and light in nature (Cambridge University Press, 2001),
http://books.google.com/books?id=4Abp5FdhskAC
Background reading (periodicals)
Cyrus Adler. Shadow-sausage effect. Am. J. Phys. 35, 8, 774-776 (1967)
Michael J. Smith. Comment on: Shadow-sausage effect. Am. J. Phys. 36, 10, 912-914 (1968)
C. Upstill. Light caustics from rippling water. Proc. Royal Soc. Lon. A 365, 1720, 95-104 (1979)
Janet Shields. Swimming pool optics. Optics and Photonics News 1, 9, 37-37 (1990)
Runcai Miao, Zongli Yang and Jingtao Zhu. Critical light reflection from curved liquid surface.
Optics Communications 218, 4-6, 199-203 (2003)
James A. Lock, Charles L. Adler, Diana Ekelman, Jonathan Mulholland, and Brian Keating. Analysis
of the shadow-sausage effect caustic. Applied Optics 42, 3, 418-428 (2003)
P. Ferraro. What breaks the shadow of the tube? Phys. Teacher 36, 542-543 (1998)
Key questions
 What types of patterns can appear on the bottom? Can they be classified into distinct categories?
Are they macroscopic only, or a microscopic, fine structure might exist? (a fractal-like pattern?)
 What is a caustic and how relevant this concept is to the problem?
 How exactly do the patterns change over time? What features are not time-dependant? Can these
changes be described quantitatively?
 Can the effects be explained in terms of geometrical optics only? Is there room for wave
phenomena, such as diffraction? Is there any light scattering involved?
 How to describe the waves on water? Are they capillary or gravitational? What of their properties
are the most relevant? (amplitude? wavelength? speed of propagation? modes of oscillations?
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frequency? overall, the time-dependant 3D profile of the water surface?) How relevant are the
parameters of the waves and on the parameters of the container (depth? size? shape?)
Are there any essential effects not related to the 3D surface shape, e.g. changes in the optical path
length? How does the phenomenon depend on the optical parameters of the fluid? optical
properties of the container?
Are there threshold values for the amplitude of the waves and the depth of the container for the
bright patterns to be visible?
The observed pattern changes rapidly. How to build an experimental setup to study the dynamic
system in a reproducible, reliable manner?
How to record the visible patterns?
What information about the system can be extracted from the observed patterns?
How relevant is an approach involving a model system, e.g. by creating a stationary meniscus? Is
such an approach applicable and appropriate?
How does the pattern depend on the illumination and the position of the light sources?
What changes if we illuminate the largest possible area or the smallest possible area?
Is it possible to describe the patterns in case of a randomly undulating surface?
The phenomenon would be typically observed from above of the surface. Can this disturb the
measurements?
Is every pattern unique for a particular physical system, so that a reverse problem can be solved:
restoring the 3D surface shape from the intensity distribution on the bottom?
Above all, what is your conclusion on the problem?
Flotation
Thee are numerous websites describing how this experiment can be set up. A Google search on raisins,
vinegar, bicarb and science will generate many examples. Other possibilities include raisins, soda and
science. Sometimes the experiment can be done with small pieces of chocolate instead of raisins.
However it is difficult to find detailed research on the topic.
Key Questions
 What is the basic phenomenon? What can you measure about it?
 What factors could be varied that might have an impact on the various aspects that you measure?
 Does the phenomenon change over time?
 Does the choice of equipment have an impact?