The darwin is not used very much, especially now. An outline is here
It’s basically just a way to compare rates of morphological change in different lineages.
To put things in a little context, there is a non-accidental pattern to the associations in the 19th century and the subsequent naming of units. Questions about universal standards and units for electricity and magnetism were a big issue in physics in the second half of the century. To a certain extent the concepts couldn’t even be systematised until then, but there was also practical pressures from the newly created telegraph industry to establish reliable standards. Kelvin, Weber and Siemens were all central players in the debate about how this should be done, with both Joule and, somewhat later, Hertz also making significant contributions to these arguments. This is a group who, even if they never actually met, were aware of each other, read each others papers and usually corresponded, even as they often took up different positions in that debate. Out of their arguments emerged the definitions and names for the likes of the amp, volt and ohm.
It’s thus hardly surprising that when it came to define the units for thermodynamics and the later electromagnetic ones, these were the sorts of names that were proposed. People have that tendency to honour those whose footsteps they see themselves following in.
And let us not forget the Middle eastern Ernest L. Cubit and his much later English descendent, Bernard Foote.
OK, that makes more sense. The way you phrased it before, it came off as “One unit is equal to 2.718 units”, which doesn’t make much sense, but it seems that it should be better described as “change in a numerical trait by a factor of e per million years”, which is much more reasonable.
Close enough. Specifically, the Henry is defined as the amount of inductance in which a current change of one ampere per second will induce a back EMF of one volt.
Nine and twenty tailors went to catch a snail;
The bravest man among them durst not touch her tail!
She put out her horns like a little Kyloe cow -
Run, tailors, run, or she’ll kill you all e’en now!.
There is the Batman , a unit of weight.
Although now obsolete, I suggest that we now use it as a standard way to measure preparedness.
A few more folks to add to the Six Degrees of Kelvin game…
Wilhelm Rontgen (1845-1923) (rontgen radiation unit)
Samuel Langley (1834-1906) (langley unit of solar radiation)
Max Planck (1858-1947) (planck mass, planck weight, planck scale, etc)
Anders Angstrom (1814-1874) (angstrom unit of length)
Forgive the trickle-posting. I remembered one that doesn’t seem to be mentioned, yet I use it on the job nearly everyday. :smack: Curiously, the unit also seems to be absent from Wikipedia.
Johann Lambert (1728-1777) (the lambert = lumen / cm^2)
The Faraday, a unit of electrical charge. It is equal to about 94.49 kilocoulombs and is defined as the charge carried by one mole of electrons.
To try to keep things managable, I’ve been inclined to ignore the names mentioned where they’re not the main, widely used SI cases. (There are all sorts of units that could be mentioned. Just in the last couple of months, the Bethe was suggested as a unit for supernova energy. Will this catch on? Unlikely.) But Darwin and Planck are worth a mention.
For the most interesting example of an important 19th century scientist who Kelvin didn’t meet is Darwin, despite his prominent role in the post-1859 debate about the geological timescale. However, Darwin’s son George, who became a distinguished physicist in very much the Thomsonian manner, did know him well and collaborated with him.
As for Darwin and Faraday, they also don’t appear to have met, even though the latter was good friends with the likes of Gideon Mantell and Lyell and so was familiar with Darwin’s professional circles. However, there is some evidence that Darwin got John Murray, as his publisher, to send a presentation copy of the first edition of the Origin to Faraday. But that was presumably just because of his status by this stage as the grand old man of British science. Since his mind, and specifically his concentration, was going by then, I doubt Faraday ever read the book.
In fact, I don’t think that Darwin met any of the names mentioned above.
Planck probably didn’t meet Kelvin either, though given that his research was mainly in thermodynamics it’s difficult to believe that he wouldn’t have accepted a chance to meet had one arisen. I suspect he probably knew Hertz, who left Kiel in the same year - 1885 - that he was appointed to the same department and it was a town to which he had prior family connections. Like Hertz, he had professional run-ins with Weber, but I don’t know if they actually met.
The encounter between Planck and one of the names mentioned above that is extremely notable is with Einstein, since it was him who was the established figure in physics who read the first paper on special relativity and, more or less immediately, realised its significance. His follow-up letter he wrote to Bern was the first step in Einstein’s rise to international recognition. They didn’t actually meet until a couple of years later, but they became good friends and later saw a lot of each other in Berlin.
Since it hasn’t been mentioned yet, Gauss and Weber were close colleagues. The monument to them in Göttingen specifically commorates their partnership. But, per the OP, this is a case where it was their joint work on geomagnetism that was partially - though not exclusively - being marked by naming the units after them.
And like the farad and the henry, it’s an inconveniently large unit, and most of use could get by with milliBatmans or even microBatmans.
Hmmm…
It seems to me unlikely that the phot was named after a 9th century bishop who had no apparent scientific bent (he did do a lot of literary writing). Much more likely that it derives from the Greek for “light” (phos; phot- as a prefix). Likewise, I’ll bet cash money that the lumen is derived from the Latin word “lumen” (light) and not the French filmmakers. The Oxford Dictionary of English agrees with me on both of these.
The Dalton is alive and well in biology; the sizes of proteins are generally given in kiloDaltons, not amu’s.
JRB