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Questions related from Wolfgang R. Dick
The help page on Preprints (https://help.researchgate.net/hc/en-us/articles/14293104044177-Preprints) contains a link to the Copyright section...
21 May 2025 6,085 4 View
The second apparatus used by Gustav Kirchhoff and Robert Bunsen in 1860/61 when they established the foundations of scientific spectroscopy was a 4-prism spectroscope built by Carl August...
29 June 2020 1,150 0 View
This morning (December 2, 2019) at about 6 UTC+1 and at a geographic place of about 52° N 13° E I saw a chain of 12 or more satellites in two groups (5 or more + 7), flying with equal distances in...
03 December 2019 4,653 9 View
Recently a colleague asked how far can I look into the Universe with my amateur telescope (i.e. by the eye, not by photography). I found a (German) source saying that the brightest quasar, 3C 273...
08 November 2019 6,499 5 View
What we see (based on Earth) as a lunar eclipse is a solar eclipse if based on the Moon. Has this been observed already directly? The page https://en.wikipedia.org/wiki/Solar_eclipses_on_the_Moon...
20 January 2019 8,982 12 View
Those who are interested in general questions on how science works, here is an interesting project on the merits and defects of competition in science:...
01 January 1970 3,015 0 View