APS March Meeting 2012
Volume 57, Number 1
Monday–Friday, February 27–March 2 2012;
Boston, Massachusetts
Session Q19: Invited Session: The Scientific Legacy of Edward Purcell (1912-2012)
11:15 AM–2:15 PM,
Wednesday, February 29, 2012
Room: 253AB
Sponsoring
Unit:
FHP
Chair: Gerald Holton, Harvard University
Abstract ID: BAPS.2012.MAR.Q19.2
Abstract: Q19.00002 : Purcell and the Development of Radioastronomy
11:51 AM–12:27 PM
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Abstract
Author:
Doc Ewen
(Special Projects Team, LLC)
``Join me for a ride on an electron, as we fly through electric and
magnetic fields.'' With those words, Ed Purcell began a course in
Electromagnetic Theory. I had a front row seat. Ken Bainbridge recommended I
take the course and get to know Ed. Ed's wisdom and lucidity of thought soon
gave the course, and Ed, a special place in my learning experience. I did
not take notes in class. I was in awe at Ed's ability to present the subject
with such clarity and simplicity.
Ed's broad scope of interests and ability to present simple
solutions to complex issues quickly led to my identification of Ed as the
supreme mentor on any and all subjects.
While working with Norman Ramsey to obtain an external beam from the
Harvard Cyclotron, I consulted with Ed on the subject of available options.
He suggested I scatter the beam off a target that could be remotely
positioned, and catch it in a tunnel shielded from the magnetic field of the
Cyclotron. When I had a problem with implementation I would, `` Ask Ed.''
During a visit to the Lab by Fermi, he commented on the simplicity of the
solution. He was not surprised to learn that Purcell provided critical
guidance.
When I suggested Meteorology as a subject for my Oral Test, Purcell
said it was not a science and I should pick another subject. I argued it was
a science. Ed asked that I loan him some books on the subject and the Oral
would be in two weeks. When I walked into the room for the Oral, I noticed
that Ed had invited all seven authors of the books I had loaned to him. A
simple Purcell answer to a problem.
When I asked about his recommendations concerning doctorate
dissertation topics, he said the selection must be based on my interests not
his. I provided a brief summary: Mathematics, Quantum Mechanics,
Meteorology, and Astronomy. Within two weeks, Ed proposed I look into the
Hydrogen Line. After a joint review of the papers by Van deHulst and
Shklovski we concluded that: van de Hulst had clearly shown the line was
undetectable, Shklovski had claimed the line was detectable, however, there
was an error in his calculations. We noted, however, that the topic fit my
interests. Purcell had a simple solution. I would proceed with a ``negative
thesis,'' the goal to measure the level of non-detectability. As with all
other joint ventures, Ed was always there when I needed help. His guidance
was always simple and embarrassingly obvious.
For my doctorate oral exam, Ed invited Van deHulst as the only other
participant. Purcell began by asking if I had any questions. I asked Van
deHulst why the line was detectable. Purcell then announced that I had my
doctorate and could leave at any time, while he and Van deHulst worked on
the answer to my question.
Many of us became terribly alone on March 7, 1997, when we learned
we could no longer ``Ask Ed.''
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.MAR.Q19.2