Talk:Jan Peter Toennies

message: Multiple user accounts with the subject's name or initials have edited this page over several years. JesseRafe (talk) 14:18, 19 January 2023 (UTC)
thread_title:  COI tag (January 2023) 

message: Dear wiki-editors. Peter Toennies has brough to my attention that his biographical wiki page is in bad shape. It indeed is. He has understood from the communication with some of the editors, that the person is not supposed to create and edit the page themselves and therefore asked for my advice. The only way I see is that another person knowledgeable and interested would do it, but I'm not a frequent Wikipedia contributor and don't know what the rules are. 
My connection with J. Peter Toennies is that he served as supervisor of my PhD thesis, which I have submitted back in 2004. Currently I'm working as a department head at the Max-Born-Institute in Berlin and do not have much scientific overlap with Peter anymore, we do communicate occasionally. Would it be fine for me to improve the page or shall it be done by a person with even more remote connection?
I have prepared a tentative updated based on some material, which Peter sent me and which I proofread and confirm its correctness (to the best of my knowledge). I have added references to several external sources confirming the information and can improve it further if the answer to the question above is positive. 
Here is the updated version, which provide a more detailed and correct information about Toennies:
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Jan Peter Toennies (born 3 May 1930) is a German scientist of American decent [1]. His main scientific works are in the fields of molecular beam, ion-molecule collisions, atom-atom van der Waals interactions and spectroscopy of liquid helium droplets. He is the author of more than 900 scientific publication. The h-index is 96 [2].
Early life and education
J. Peter Toennies was born in Philadelphia, Pennsylvania to German immigrant parents. He is the son of the biochemist Gerrit Toennies and the grandson of sociologist Ferdinand Tönnies. He graduated from Lower Merion High School, outside of Philadelphia in 1948, from Amherst college, with a B.A. in 1952, and from Brown University, with a Ph.D. in Chemistry in 1957 [3]. During graduate school he was a Fulbright student in Göttingen 1953 – 1954. After graduation in 1957 he moved to the Physics Department of the University of Bonn where he was a post-doc with Wolfgang Paul (Nobel Prize 1986). He obtained the Habilitation (the right to teach at a German university) in 1965 and then became a Dozent (assistant professor). From 1965 – 1974 he was a guest professor in the Department of Physical Chemistry at the Gothenburg University.
In 1969 he became director at the Max-Planck Institut für Strömungsforschung (Fluid Research) in Göttingen and established the division of molecular physics [4]. From 1971 he was also professor in Göttingen and honorary professor at the University of Bonn. He retired officially in 1998, but was acting director until 2004. 2004 – 2005 Peter Toennies was Miller Professor at the University of California in Berkeley.
Scientific Work
As a postdoc in Bonn he was the first to report crossed beam elastic and inelastic scattering experiments with quantum-state-to-state resolution.  He studied both rotational transitions in molecule-atom/molecule collisions and vibrational excitation in ion-molecule collisions. In Göttingen his group continued their study of elastic, inelastic and reactive collisions in crossed molecular beams. These experiments led to the development of a new widely cited analytical model for the van der Waals interaction, called the Tang-Toennies potential [5]. His group also observed that in helium free jet gas expansions at high backing pressures instead of the usual broad velocity distributions the helium atom beams had very sharp velocity distributions. These nearly monoenergetic helium atom beams have found widespread application. The Toennies group exploited the sharp velocity helium atom beams for exploring the structures and the surface phonon dispersion curves of clean and adsorbate covered solid crystals. They studied over 200 different surfaces by inelastic helium scattering (HAS) [6]. This led to a much more profound knowledge of interatomic forces at surfaces and how atoms and molecules interact with metal surfaces, which is of basic importance for understanding many surface phenomenon such a corrosion, friction and catalysis.  Later his group succeeded in detecting non-destructively very fragile helium clusters HeN up to about N = 20 by utilizing the matter-wave duality in the diffraction from transmission gratings [7]. From the diffraction intensities the size (52 Å) and binding energy (~ - 1.5 mK) of the dimer could be  determined.
In the 1990’s the Toennies group discovered that small helium nanodroplets could be doped with other atoms and molecules either singly or in pure or mixed clusters of predetermined sizes. The surprisingly sharp spectral features of an embedded molecule indicated that the molecule was practically  unaffected by the helium environment and could rotate freely as if it were in a vacuum. From the resolved rotational spectrum the temperature of the droplets was found to be 0.37 K. Subsequent spectroscopic experiments revealed that the free rotations were related to the superfluidity of the helium  droplets. This is the first evidence that superfluidity occurs in a finite-sized system. Also the superfluidity of small numbers of hydrogen molecules could be found [8].
[1] Bretislav Friedrich a and Dudley Herschbach, “Jan Peter Toennies: an ebullient serendipitous adventurer”, Phys. Chem. Chem. Phys., 2021, 23, 7525
[2] Google Scholar, J. Peter Toennies
[3] https://www.leopoldina.org/mitgliederverzeichnis/mitglieder/member/Member/show/j-peter-toennies/
[4] https://www.ds.mpg.de/2740044/150513_toennies_jan
[5] https://pubs.aip.org/aip/jcp/article/80/8/3726/90054/An-improved-simple-model-for-the-van-der-Waals
[6] Giorgio Benedek , Jan Peter Toennies, Atomic Scale Dynamics at Surfaces, Springer 2018
[7] https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.95.063002
[8] https://onlinelibrary.wiley.com/doi/10.1002/anie.200300611
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Thanks for your advice. Kappuzin (talk) 17:56, 13 December 2023 (UTC)
replies: text: , please reformat your references as inline references with complete bibliographic details. Bare URLs are sub-optimal, as are references clumped at the end, instead of being placed at appropriate points throughout the body of the article. If the references are formatted properly, then the software will number them and automatically create a reference list. You do not need to assign reference numbers. Please read Referencing for beginners. Cullen328 (talk) 19:41, 21 December 2023 (UTC)
replies: text: OK, thanks. Will work on this. Best, Kappuzin (talk) 11:40, 22 December 2023 (UTC)
thread_title:  Extensive update to the page of J. Peter Toennies