Variables:
Michelson: A data frame with 100 observations on the following variable, given in time order of data collection

velocity

a numeric vector
MichelsonSets: A 20 x 5 matrix, with format int [1:20, 1:5] 850 850 1000 810 960 800 830 830 880 720 ...  attr(*, "dimnames")=List of 2 ..$ : NULL ..$ : chr [1:5] "ds12" "ds13" "ds14" "ds15" ...
Details
The "true" value is taken to be 734.5, arrived at by taking the "true" speed of light in a vacuum to be 299,792.5 km/sec, and adjusting for the velocity in air.
The data values are recorded in order, and so may also be taken as a time series.