The Story of Longitude
Chaired by Bruce R. Mehlman
Picture yourself at high noon at the OK Corral. If you knew what time it was
at that moment in London, simple arithmetic would tell you the exact
longitude of Tombstone, Arizona.
Since the problem of longitude reduces to the problem of time, we can
understand why such a large cash prize was offered for the solution:
Longitude is time.
Time is money.
Longitude is money.
QED
The history of the determination of time, and therefore of longitude, falls
neatly into three sections: pre-Harrison, Harrison, and post-Harrison.
Early longitude determination was by dead reckoning. This may have
originally been deduced reckoning, shortened to ded reckoning, then
corrupted to make possible the quip "If you get it wrong, you're dead." Dead
reckoning is based on the fact that if you know where you were, how fast you
went, and in which direction, then you know where you are.
Galileo proposed that the positions of the satellites of Jupiter could be
used to tell the time. This became a reasonable idea after he observed
eclipses of those satellites, which provided a sharper "time tick" than
their mere positions did. This method proved useful only on land, both
because of the difficulty of telescopic observation at sea and because to
determine the longitude of a fixed location only observation of local times
of an eclipse was needed, not prediction of the exact time of eclipses. This
was the method used for the first accurate longitude determination, of Tycho
Brahe's observatory relative to the Paris meridian.
Lunar position was the method suggested by Newton and favored by Nevil
Maskelyne, Harrison's most influential detractor. It never achieved the
accuracy required to be useful.
Harrison built clocks. Dava Sobel tells us all about it.
Nothing significant was gained until the invention of radio, which provided
sub-second accuracy all over the world. Further refinements, such as LORAN
and GPS, are all based on radio. The most recent development in the history
of longitude determination occurred on the first Monday of this month, when
the Department of Defense stopped deliberately reducing the accuracy of
civilian GPS, increasing its accuracy from about a hundred meters to about
ten meters.
Bibliography
William J.H. Andrews (ed), The Quest for Longitude, Harvard, 1993
Dava Sobel and William J.H. Andrews, The Illustrated Longitude, Walker, 1998
Dava Sobel and William J.H. Andrews, Longitude, Walker, 1995
Jonathan Betts, Harrison, National Maritime Museum, Greenwich
Alan Ereira, Longitude: The Hidden Evidence, History Today, January 2000
Reviews of The Quest for Longitude:
Booklist, 1/1/97, p795
Library Journal, 11/1/96, p105
Reviews of Longitude and The Illustrated Longitude:
Science, 10/08/99, p248
Library Journal, Feb 99, p126
Sky and Telescope, Feb 99, p82
New York Times Book Review, 10/20/96, p36
Economist, 10/19/96, p13
New Statesman, 8/9/96, p45
Beaver, Aug/Sep 96, p44 (Canadian Natural History Society)
Sky & Telescope, July 96, p60
People, 2/19/96, p31
School Library Journal, Feb 96, p135
Christian Science Monitor, 1/31/96, p13
New York Times, 11/2/95, pC21
Library Journal, 9/15/95
Webliography
http://easyweb.easynet.co.uk/~robodyne/inventors-world/iwharris.htm
A brief biography of Harrison by Jonathan Betts, Curator of Horology at the
National Maritime Museum, Greenwich.
http://www.bhi.co.uk/ The British Horological Institute
http://www-groups.dcs.st-and.ac.uk/%7Ehistory/HistTopics/Longitude1.html
http://www-groups.dcs.st-and.ac.uk/%7Ehistory/HistTopics/Longitude2.html
University of Saint Andrews online article on Harrison's work
http://es.rice.edu/ES/humsoc/Galileo/Things/longitude.html
From The Galileo Project, Rice University
The History of the History of the Universe
Chaired by Nancy Cox
We all know that the most accepted theory of the beginning of the Universe
is the Big Bang. How did scientists figure this out and come to this
conclusion? And, what is the history of the Universe? What were things
like way back then, when all was energy?
The first part of this afternoon's session will discuss the history of the
history of the universe - the figures involved, the twists and turns in this
story, the missed opportunities - from first figuring out the immense size
of the universe (back to the great distances to the stars - parallaxes in
Halley's time, then to the vast distances, through the discovery of Cepheid
variables, to other island universes (galaxies) to figuring out the age
of
the universe (from stellar evolution to geology). Then to the startling
discovery of the expanding universe, redshifts (Edwin Hubble and Milton
Humason, 1920s and '30s). The fathers of cosmology, such as Einstein,
deSitter, A. Friedman, Fred Hoyle; and the kinds of universes - open,
closed, or steady state. discoveries regarding the atom, and the amounts of
nucleosynthesis of the chemical elements: Rutherford, Eddington, Gamow, and
Fowler.
Then on to the conclusion that the universe began in a big explosion, from a
small seed. The father of the Big Bang, Lemaître (1931) and the primæval
atom. George Gamow: first detailed model of the Big Bang itself, 1940s.
This model stood the test of time. At that time the age of the universe and
the stars were not reconciled. April 1, 1948: famous first paper on the
Big Bang model by Alpher, Bethe and Gamow (a great scientific pun).
Irony: who coined the term Big Bang? Hint: it's that steady-state
guy.
Then the story of the detection of the cosmic microwave background
radiation, the embers of creation. The story of missed opportunities:
Gamow published his prediction but despite the beginning of radio astronomy,
no one searched for it. The story of Arno Penzias and Robert Wilson at Bell
Labs who detected the cosmic microwave background in 1964 at 2.7 Kelvins
before Robert Dicke of Princeton, who predicted it. And as frequently
happens in science, there were others before Dicke, who also calculated but
went unheralded.
Who got the Nobel Prize?
The Cosmic Fireball and the Standard Model
On to present-day cosmologists such as P. J. E. Peebles, Martin Rees, and
Stephen Hawking, and observations such as COBE - seeing the wrinkles in
time - small perturbations/ fluctuations in the early universe. The
latest
measurements were just released this month.
In the second part - the History of the Universe - we will discuss way back
when, when the universe was particle soup - a quark/gluon plasma (and modern
experiments to recreate it), inflation, the formation of the first
particles, atoms, light elements, in the first few seconds and minutes - a
timetable for the early universe. Back to a certain time it's speculative
and has not been directly observed yet.
The formation of the first stars; galaxies. Recent HST findings/images of
primitive galaxies. The future of the universe (if we have time) -
acceleration, missing mass, the Big Crunch, etc.
A Short Bibliography
John Gribbin, In Search of the Big Bang (paperback) Penguin, 1998 edition.
Gives a good historical outline of all the major figures involved in the
discoveries of the life and death of the universe, as well as the theory.
Steven Weinberg, The First Three Minutes - a Modern view of the Origin of
the Universe, Basic Books/HarperCollins, 1997 edition. The best popular
account of the Standard Model of the Hot Big Bang from the first hundredth
of a second to the end of nucleosynthesis.
Joseph Silk, The Big Bang, W. H. Freeman, 1980. A good introduction for
serious students.
George Gamow, The Creation of the Universe, Viking, 1952. Readable account
of what became the Big Bang model of cosmology. It predicts the cosmic
background radiation of a few Kelvins.
David Filkin, Stephen Hawking's Universe - the Universe Explained. Basic
Books, 1997. Companion guide to the PBS series. A popular account of the
beginnings of the universe, spacetime, etc., including historical people and
many illustrations.
Stephen Webb, Measuring the Universe - the Cosmological Distance Ladder,
Springer Praxis, 1999. A good outline of the history of the universe.
Some others, for which I have incomplete information:
George Gamow, The New Mr. Tompkins, 1999. Explores the worlds of
relativity, cosmology, and the new physics.
All Things in Heaven and Earth - a Celebration of Physics at the Millennium,
Springer/APS. Includes chapters on cosmology topics such as the microwave
background.
George Smoot, Wrinkles in Time, about the COBE observations.
Don Goldsmith, The Runaway Universe - just published - about the future of
the universe.
For an alternative theory, check:
Halton Arp, Redshifts, Quasars and Controversies, 1970s, or his newer one,
Seeing Red (1998 or 1999)
Berkeley MAXIMA Website: http://cfpa.berkeley.edu/group/cmb/