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Professor of Physics
Professor of Physics
New
York Times,
To the Editor:
If President Clinton is shocked that two-thirds of the energy used to produce electricity is "squandered" as waste heat (Week in Review, Oct. 26), he shouldn't be. And we can reduce that "waste" without repealing the laws of thermodynamics only by moving to generation methods that aren't based on heat, like solar photovoltaics and fuel cells.
However, those who promote hydrogen use as alternative "fuel" for fuel cells are misguided. Since there are no hydrogen wells, it must be extracted from traditional fuels like natural gas, ethanol or petroleum.
We must generate and use energy more efficiently and with fewer emissions, but our laws must comply with Nature's, because She is immune to lobbying.
Roger
G. Tobin
Background:
In an article criticizing a proposal to erect a cellular
phone tower, the author criticized the description of an electrical
generator
that is part of the project: "The spokesman incorrectly
referred to the size of the generator as
130 watts. Generator power levels are measured in KW Hrs. (Kilowatt
Hours), not
watts."
To the Editor:
I have no stake either way in the controversy over the proposed Cellular One tower, but as a physicist I feel compelled to clarify Paul Marzocchi's comments about the appropriate units for measuring generator capacity ("Cellular One tower deal is another case of Belmont government as usual," June 17, 1999).
Power, which is a rate of energy production or use, is measured in watts, kilowatts (thousand watts) or megawatts (million watts). I presume the Cellular One representative misspoke in saying the proposed generator would have a capacity of 130 watts, since that's barely enough for two light bulbs. More likely the proposed capacity is 130 kilowatts or 130,000 watts. The number was probably wrong, but the unit was right.
The kilowatt-hour (kWh) is a unit of energy, not power. A 100-kilowatt generator running for one hour will generate 100 kWh of energy. But that's not a measure of the capacity of the generator. A 1 kilowatt generator could produce that same amount of energy; it would just take 100 hours to do it.
Roger
G. Tobin
Associate Professor of
To the Editor:
Much
of the wonderful work on K–8
science education reported by Ramon E. Lopez and Ted Schultz (Physics
Today,
September 2001, page 44) will be wasted, I’m afraid, unless greater
emphasis is
placed on training and supporting teachers.
Not
long ago, in an affluent
suburb known for its excellent schools, I helped my son's fourth-grade
class
with a unit on pulleys. The students were to measure the weight
required to
lift a standard load and the distance the load rose,
using one, two, and three pulleys. It sounded straightforward. But the
pulleys
had a lot of friction and were not light compared to the load. Neither
the
students nor the teacher realized that the distance needed to be
measured from
the load's initial height, not from the floor; and no effort was made
to keep
the strings close to vertical. With attention to these details and
judicious
use of WD-40®, we were able to get reasonable
results, and had a
good discussion about what they meant. Apparently that had never
happened
before. When another teacher saw the results on the blackboard, she was
astonished to see patterns that actually made some sense. I can only
imagine
the impression of science that this unit had left on previous classes.
In
other subjects, these talented
and experienced teachers had no trouble improvising, identifying and
solving
problems on the fly, and helping students understand what they were
doing. But
in science they were adrift, and the kids could feel their discomfort.
Teachers
need help. At a minimum, every elementary school should have a
full-time
science specialist. In my son's school, that position had been
eliminated to
fund a computer room.
Roger
G. Tobin
New
York Times,
To the Editor:
Re "Computers Help Math Learning, Study Finds" (news article, Sept. 30): The big problem with computers in elementary schools isn't their minimal educational value but the fact that they often replace science in the budget and curriculum. In my son's school the science room was replaced by the computer room. The Parent Teacher Association is throwing away science equipment as fervently as it raises money for more computers.
I use computers extensively in the college physics classes I teach, so I appreciate their value in communications and advanced computation. But in elementary schools, too much is being sacrificed so that children can have all those pricey beige boxes.
Roger
G. Tobin
New
York Times
Magazine,
(The sentence in italics was deleted by the editors from the published version.)
Background:
This was a response to an article about
"child-free" activists who protest the benefits that they feel are
lavished on people with children at the expense of those without; one
letter in
response argued that "People choose to have children yet expect society
to
subsidize their choice".
To the Editor:
Contrary to Mitchell McConnell's May 24 letter ("Missing point in debate"), it is the "child-free" activists quoted in Scot Lehigh's May 21 Focus article ("No kidding!") who are missing the point.
Societies
provide support for families with children because children are a
social good - not only for the private joy they bring their parents,
not even
only for their future economic productivity, but also in ways that
transcend
the cramped language of individual choice and responsibility.
Children's need
for care, for guidance, and for love brings us together in our shared
need for
community and solidarity. All societies recognize the social value of
children,
yet among industrialized countries the
Surely we can work together without rancor - those with children and those without - for a more humane society. We were all children once.
Roger
G. Tobin
Linda M. Blum
New York Times,
To the Editor:
I applaud the President's Information Technology Advisory Committee for reminding us that today's research is the basis of prosperity in future decades (Business Day, Feb. 24). But its recommendations, which are focused on software, telecommunications and high-end computing, are much too narrowly drawn.
History is not encouraging to those who would predict the future of innovation. The transistor emerged from fundamental research in the physics of solids, and the Internet was invented by high-energy physicists. Future breakthroughs in information technology may well come from research in optics, polymer chemistry or biology. Without a crystal ball, the best we can do is support the research and training of talented people in a wide range of fields.
Roger
G. Tobin