High School Mathematics-Physics SMILE Meeting
22 January 2002
Notes Prepared by Porter Johnson
Fred Schaal (Lane Tech HS, Mathematics) Screaming Orange Hat
Fred showed his stylish new hat, produced out of Ten Mile
from Dynamic Textiles, Inc. Phone 718 631 5005 Fax 718 279 4104.
He raised the question of the meaning of the label, which used the
"dominant wavelength between 595 and 605 nm", "excitation purity
not less than 85%", and "luminous factor not less than
40%". The meaning is given in terms of the International
Education Association [IHEA] specifications for "Hunter Orange"
"The IHEA recommends the description of Hunter Orange as "having a
dominant wavelength between 595
and 605 nanometers, a luminance factor of not less than 40% and an
excitation purity of not less than 85%".
Highland guarantees that Ten Mile Cloth, Camo Ten, Easy Ten, and
TenAcious meets these specifications."
Kanner (Lane Tech HS, Physics)200 Puzzling Physics Problems with
hints and solutions by Peter Gnadig, G. Honyek, K. F. Riley
[Cambridge 2001] ISBN 0-521-77480-3
Don found the book interesting and stimulating for the most
felt that some of the problems "needed work":
- Q: A "black box" has two sets of terminals on each
When a battery of voltage V is connected to one side, a voltage V/2 is
across the other side. When the battery is hooked across the other
voltage V is read across the first side What is inside?
A: (But, what about internal resistance of the voltmeter?)
- Q: If you push an object and it goes off the table
[a distance of 1
meter], does it have wheels? A: Yes [Don pushed an
cola bottle off the table to show the absurdity of this question.]
- Q: Why do bubbles in a glass of champagne accelerate
on the way out
of the glass? A: Allegedly, the force of gravity is
balanced by the
buoyant force. But then, why would they accelerate at all?
Here is a review from the website http://www.amazon.com.
The problems are generally at the level of
International Physics Olympiad competitions or higher, and are very
freshman/sophomore honors physics courses. The problems are tough and
very interesting, with many unique and unusual
twists, guaranteed to challenge even the best students preparing for
physics competitions at the senior high school and
undergraduate levels. I would guess that those sitting for PhD
qualifying exams will have difficulties with some of the
problems. The surprise is that the solutions require no more than
elementary calculus, although lots of original critical thinking and
insight are necessary.
Gnadig and Honyek are both leading the Hungarian physics olympiad teams
for many years, while Riley is a Fellow of Clare
College, Cambridge University. Riley had a previous equally interesting
but slightly less difficult problem book called
"Problems for Physics Students," covering quite a few interesting
Cambridge University Natural Sciences Tripos and
entrance exam type questions for the best UK high school students.
If you are a physics buff, you will derive countless hours of enjoyment
(and frustration - if you resist the temptation of
looking at the provided solutions too soon), plus it will bring your
understanding of classical physics to a deeper level.
A few other worthy physics problem books include Thomas & Raine's
"Physics to a Degree" for undergraduates, and Dendy's "Cambridge
Problems in Physics" for high school students aiming for Cambridge
University entrance. The Russian books "Problems in General Physics" by
Irodov and "Problems in Elementary Physics" by Bukhovtsev are very good
too but they may be harder to find. An upcoming excellent (and tough)
classical mechanics problem book is David Morin's Physics 16
course text at Harvard - still in its draft form but downloadable from
Bill Shanks (Joliet Central, Physics, Retired) Various Topics
- Fluorescence of Fred's Hat
Bill used a very bright flashlight to test whether Fred's
hat was appropriately fluorescent. The standard test for fluorescence
of a fabric is to shine an ultra-violet light on the fabric, and not
whether the fabric "glows". Unfortunately, the flashlight
produced too much visible light, so that we could not see the
fluorescent glow. When the room was dark, there was no
phosphorescent glow, either.
- Obituary of ISPP Participant Leo Seren
Leo Seren, 83; Physicist on the Atomic Bomb Who Turned Pacifist. Leo
Seren, 83, a University
of Chicago physicist who called himself a war criminal for the role he
played in the development
of the atomic bomb, died of amyloidosis Jan. 3 at a hospital in
Evanston, Ill. Seren had just
earned his doctorate from the University of Chicago when he went to
work with Enrico Fermi on
the Manhattan Project in 1942. Seren was one of 51 people present in an
abandoned squash court
at the university's Stagg Field on Dec. 2, 1942, when the first nuclear
reactor achieved critical
mass. Seren's job was to measure the density of neutrons in piles of
graphite, uranium and cadmium
control rods used to build the reactor. He worked on nuclear
power until 1960, stopping when
he reached the conclusion that there was no
way to safely dispose of radioactive waste. He began to focus on
renewable energy sources, such
as solar, wind and water power. In a 1982 speech before anti-nuclear
demonstrators at the University
of Chicago, Seren spoke of his regret over his role in the Manhattan
Project, which led to the
devastation of Hiroshima and Nagasaki, Japan, in 1945 and the loss of
tens of thousands of lives.
He said that if he were tried for crimes against humanity, "I'd plead
guilty. And I'd say for
mitigating circumstances that at least I decided that I'd never work on
nuclear weapons again."
- Solar Heating/Cooling (a favorite subject of Leo Seren's)
Bill and others mentioned various matters.
- He suggested using a water reservoir [2 meters in diameter,
of weight about 30 tons]
to store heat energy in the home, to make it warmer in the winter and
cooler in the summer.
These reservoirs, and even smaller ones, are common in the state of
California, where a state
income tax credit for passive solar heating and cooling systems existed
for years. Roy Coleman
said that one friend in California had built an above-ground swimming
pool for this purpose.
- Another plan involved plastic sheeting and piping around a
house, with either pumps or gravity feed.
- A further suggestion involved cold air intakes for fireplaces
and furnaces, as well as dampers that automatically close when not
needed. The cold air intake is a major component in reducing
infiltration of Radon Gas from the ground.
- Solar heating and cooling by blowing air over rocks put
underneath a house.
- Buckminster Fuller's Dymaxion House in Dearborn Michigan
"The Dymaxion's round shape minimized heat loss and the amount of
materials needed, while bestowing the strength to successfully fend off
a 1964 tornado that missed by only a few hundred yards. And the
Dymaxion only weighs about 3000 pounds versus the 150 tons of an
average home!" Source: http://www.thirteen.org/bucky/house.html.
See also http://en.wikipedia.org/wiki/Dymaxion_house.
was some discussion as to whether damage in the tornado is caused
primarily by the wind itself, or by the debris that is carried in the
tornado. Both are obviously important. The first effect was
illustrated some time ago in SMILE by Bill Blunk by
driving a pencil though a sheet of plywood with a CO2
- Q: What is a Monolithic Concrete Dome?
A: (given by Ann S Bosley: http://www.bizjournals.com/birmingham/stories/2000/07/31/focus3.html)
The Monolithic Concrete Dome is a
super-insulated, steel-reinforced concrete structure. David B. South,
president of the Monolithic Dome Institute, and his brothers, Barry and
Randy South, developed an efficient method for building a strong dome
using a continuous spray-in-place process.
In 1976, following years of planning and development, they built the
first Monolithic Dome in Shelley, Idaho.
Since then, Monolithic Domes have been constructed for homes, schools,
gymnasiums, churches, offices and
bulk storage facilities in 45 states and in many foreign countries.
Briefly, here are the steps involved in building
such a dome:
According to the Monolithic Dome Institute, the
advantages of building a Monolithic Concrete Dome include
- The Monolithic Concrete Dome starts as a
concrete ring foundation, reinforced with steel rebar (reinforcing
bars). Vertical steel bars embedded in the ring are later attached to
the steel reinforcing of the dome itself.
- An Airform, fabricated to the proper shape and
size, is attached to the
concrete base. Using fans, the
Airform is inflated, creating the shape of the dome. In fact, the fans
run throughout construction.
- Approximately 3 inches of polyurethane foam
insulation is applied to
the interior surface of the Airform.
entrance into the structure is made through a double-door airlock,
which keeps the air pressure inside at a
- Steel rebar is then attached to the foam using
special hooks embedded
in the foam.
- Shotcrete, a special spray mix of concrete, is
applied to the interior
surface of the dome. The steel rebar is
embedded in the concrete. The fans are shut off after the concrete is
the strength and permanence of the structure, energy efficiency, cost
effectiveness, attractiveness and disaster
See also the website http://www.monolithicdome.com/.
- Solar Radiation
Meteorological winter is defined as the period December 1 - March 1,
because this is the coldest period of the year in the northern
hemisphere. Why? Precisely why is it colder in the winter than in the
summer? Graduating seniors at Harvard a few years ago incorrectly
suggested that the earth is closer to the sun in summer than in
winter. A good physics student might refer to the "glancing
incidence" of sunlight in winter, but does s/he know what that
means? The total solar flux is about 1400 watts per square
meter, as measured for normal incidence. The angle of the sun
with the vertical in Chicago varies from q
42°+23° = 65° in winter to q
42°-23° =19° in summer. As a
consequence, the solar energy delivered to the ground is 1400 ´ cos q Watts/m2,
which varies from 1324 Watts/m2 [summer] to 591
Watts/m2 [winter]. Bill illustrated the role of
the angle of incidence using his bright flashlight and white paper. The
paper was definitely brighter when the light shone directly on
it. In a similar vein, snow cover melts more quickly where it has
a southern exposure, because of the heat absorbed from direct sunlight.
Arlyn Van Ek (Iliana Christian HS) Why are there headrests on
Arlyn put this question on a test recently, expecting students
that they would provide protection from "whip-lash" in rear-end
collisions. However, many students commented that they would also
in front-end collisions, as well. Namely, the occupant's head
forward, bounces off the air bag, and then snaps backward, to be
stopped by the
headrest. Is this correct?
Notes taken by Porter Johnson