 # File:Michelsonmorley-boxplot.svg

## Summary

This data is not from the Michelson-Morley experiment but from Michelson's measurement of the speed of light. See MICHELSON, A. A. (1882).Experimental determination of the velocity of light made at the United States Naval Academy, Annapolis. Astronomic Papers 1 pp. 109-145 U.S. Nau- tical Almanac Office or S. M. Stigler (1977) Do robust estimators work with real data? Annals of Statistics 5, 1055–1098.

Boxplot representing Michelson and Morley's data on the speed of light. It consists of five experiments, each made of 20 consecutive runs.

This image is similar to Image:R-speed of light boxplot.png, but is stored in vectorial format instead of bitmap.

Note that the oblique line is incorrect, and probably due to a bug in the Mediawiki software/SVG converter.

The graphic was created by User:Schutz for Wikipedia on 28 December 2006, using the R statistical project. The program that generated the graphic is given below; the data and the idea are from the R help page for the morley dataset (see help(morley)). The graph was exported in postscript format, converted to SVG using the pstoedit command, and the layout was slightly modified using Inkscape before upload.

```
data(morley)
morley\$Expt <- factor(morley\$Expt)
morley\$Run <- factor(morley\$Run)
attach(morley)

postscript("Michelsonmorley-boxplot.ps", paper="special", height=6, width=6,
horizontal=F)
par(las=1)
par(mar=c(5.1, 5.1, 2.1, 2.1))
par(font=2)
par(font.axis=2)
boxplot(Speed ~ Expt, xlab = "Experiment No.", ylab="Speed of light (km/s minus 299,000)")
abline(h=792.458, lty=3)
dev.off()

```

Boxplot representing Michelson and Morley's data on the speed of light. It consists of five experiments, each made of 20 consecutive runs.

The graphic was originally created by User:Schutz for Wikipedia on 28 December 2006, using the R statistical project. The program that generated the graphic is given below; the data and the idea are from the R help page for the morley dataset (see help(morley)). The graph was exported in PDF format, converted to SVG using Adobe Illustrator, and the layout was slightly modified using Vim before upload.

```data(morley)
morley\$Expt <- factor(morley\$Expt)

pdf("Michelsonmorley-boxplot.pdf", height=6, width=6)
par(las=1, mar=c(5.1, 5.1, 2.1, 2.1))
boxplot(Speed ~ Expt, morley, xlab = "Experiment No.",
ylab="Speed of light (km/s minus 299,000)")
abline(h=792.458, col="red")
text(3,792.458,"true\nspeed")
dev.off()
```

## Licensing I, the copyright holder of this work, release this work into the public domain. This applies worldwide.In some countries this may not be legally possible; if so:I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

The creator and uploader also believes that this graphic is a trivial work which does not qualify for copyright.

## Reference

• A. J. Weekes (1986) A Genstat Primer. London: Edward Arnold. This chart was created with R.

The following pages on Schools Wikipedia link to this image (list may be incomplete):