NAME: Galileo Motion Data
TYPE: Measurement
SIZE: 7 observations, 2 variables (both numeric)
5 observations, 2 variables (both numeric)
DESCRIPTIVE ABSTRACT:
This dataset consists of data taken by Galileo in an attempt to model
the path taken by projectiles. The first dataset was obtained in an
experiment in which Galileo rolled a ball down an inclined plane. The
plane was situated above the floor. He recorded the height at which he
released the ball and the distance the ball traveled before landing.
The second dataset was obtained similarly, with the difference that the
ball crossed a horizontal shelf built into the end of the ramp. This
shelf had the effect of cancelling out the downward force vector
operating on the ball before freefall.
SOURCE:
Drake, Stillman (1978), _Galileo at Work_, Chicago: University of
Chicago Press.
VARIABLE DESCRIPTIONS:
Columns
1 - 4 Horizontal distance traveled
6 - 9 Release height above table
SPECIAL NOTES:
The two datasets are separated in the file by a row of zeros. The
variables are the same; only the method of obtaining the data differs.
Both variables are measured in units of punti (points).
STORY BEHIND THE DATA:
Galileo was interested in the physical forces acting on projectiles for
both scientific and military (artillery) reasons. An article in the
_American Scientist_ (Jeffreys and Berger 1992) used the data to
describe the utility of Ockham's razor.
PEDAGOGICAL NOTES:
Information on the pedagogical uses of these data can be found in the
"Datasets and Stories" article "Teaching Statistics With Data of
Historic Significance: Galileo's Gravity and Motion Experiments" in
the _Journal of Statistics Education_ (Dickey and Arnold 1995).
REFERENCES:
Dickey, D.A., and Arnold, J.T. (1995), "Teaching Statistics With Data
of Historic Significance: Galileo's Gravity and Motion Experiments,"
_Journal of Statistics Education_, 3, No. 1.
Jeffreys, W.H., and Berger, J.O. (1992), "Ockham's Razor and Bayesian
Analysis," _American Scientist_, 80, 64-72 (Erratum, p. 116).
SUBMITTED BY:
David A. Dickey
Department of Statistics, Box 8203
North Carolina State University
Raleigh, NC 27695-8203
dickey@stat.ncsu.edu