morley: Michelson Speed of Light Data

Description

A classical data of Michelson (but not this one with Morley) on measurements done in 1879 on the speed of light. The data consists of five experiments, each consisting of 20 consecutive runs. The response is the speed of light measurement, suitably coded (km/sec, with 299000 subtracted).

Usage

morley

Arguments

source

A. J. Weekes (1986) A Genstat Primer. London: Edward Arnold.

S. M. Stigler (1977) Do robust estimators work with real data? Annals of Statistics 5, 1055--1098. (See Table 6.)

A. A. Michelson (1882) Experimental determination of the velocity of light made at the United States Naval Academy, Annapolis. Astronomic Papers 1 135--8. U.S. Nautical Almanac Office. (See Table 24.)

Details

The data is here viewed as a randomized block experiment with experiment and run as the factors. run may also be considered a quantitative variate to account for linear (or polynomial) changes in the measurement over the course of a single experiment.

Examples

Run this code

require(stats); require(graphics)
michelson <- transform(morley,
                       Expt = factor(Expt), Run = factor(Run))
xtabs(~ Expt + Run, data = michelson)  # 5 x 20 balanced (two-way)
plot(Speed ~ Expt, data = michelson,
     main = "Speed of Light Data", xlab = "Experiment No.")
fm <- aov(Speed ~ Run + Expt, data = michelson)
summary(fm)
fm0 <- update(fm, . ~ . - Run)
anova(fm0, fm)