Bath interferometer (common path)

Article summary

Karl-Ludwig Bath patented 5 designs of common path interferometers in 1973. Bath interferometers can be used to test telescope mirrors of any size. A Common path interferometer has the test and reference beams traveling over effectively the same path which has the advantage that you can use an inexpensive semiconducting laser pointer with low coherence versus other interferometers which need a high coherence laser (typically a He Ne laser). Bath also published an article about his favorite variation in June of 1973. Before the patent there was a functionally identical Right Angle Bath interferometer described and published in the journal Optical Engineering (the article was received by the journal on July 23, 1973).

Key claims

1. publication date: 1973 — source: Wikipedia · confidence 0.95
2. publication date: 1973-07-23 — source: Wikipedia · confidence 0.95

Discussion questions

1. Summarise the article in your own words. Which single claim would you verify first, and why?
2. The record states that the publication date is "1973". What evidence would count against this claim?
3. The record states that the publication date is "1973-07-23". What evidence would count against this claim?
4. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
5. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

Bibliography

1. Wikipedia https://en.wikipedia.org/w/index.php?oldid=1109578834