A nuclear physicist, inventor and entrepreneur, Dr. Cranberg’s career spanned seven decades, but the wonder and beauty of science was always on his mind.

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In Memory of Lawrence Cranberg, 1917-2011

Lawrence M. Cranberg PhD, 94, passed away on November 21, 2011 surrounded by his loving family.  Cancer was the cause of death.  Lawrence, a true patriot, was born on the 4th of July in 1917 in Bronx, New York, the eldest child of Fanny Rubenstein and Hyman Cranberg – Polish and Russian immigrants.

Lawrence Cranberg

Lawrence married Charlotte Mount on October 31, 1953 in New Mexico at the Old Santa Fe Courthouse.

A nuclear physicist, inventor and entrepreneur, Dr. Cranberg’s career spanned seven decades, but the wonder and beauty of science was always on his mind.

After graduating from Townsend Harris High School at age 16, he matriculated from the City College of New York, Harvard University, and The University of Pennsylvania. His career in science began in 1940 at the Signal Corps Engineering Labs where he was a Senior Physicist. Dr. Cranberg developed systems of target detection and location-based use of infra-red radiation, a precursor technology to today’s autofocus cameras. He later joined the Los Alamos National Laboratory where he became a fellow of the Atomic Energy Commission.

At Los Alamos, he was a protégé of Hans Bethe, and conducted groundbreaking research on high energy neutrons.  Dr. Cranberg was appointed to the US delegation to the First International Conference on the Peaceful Uses of Atomic Energy at Geneva in 1955 where he reported on his work.  Among his many widely-cited publications were papers in The Scientific American and Physics Today.  Dr. Cranberg also generously shared his intuitive insights with colleagues; one such insight directly led to the discovery of the neutrino.  Dr. Cranberg was elected a Fellow of the American Physical Society in 1958 – his nomination made by 1995 Nobelist and neutrino pioneer Frederick Reines and J.M.B. Kellogg. Once introduced as “Mr. Nanosecond” by Sir Denys Wilkinson to a London physics conference, Dr. Cranberg developed the means to measure a billionth of a second before “nanotechnology” was a word; his “time-of-flight” method of measuring neutron spectra became the foundation for neutron spectrometry.

Following a Guggenheim fellowship in 1962, Dr. Cranberg was instrumental in securing a large federal grant to the University of Virginia to build and to become founding director of its Physics Accelerator Laboratory. He was a devoted scientist and teacher.  Thirty years later, one of his grateful graduate students would endow a scholarship and faculty research in his name at George Mason University, remarking that Dr. Cranberg inspired him by exemplifying the work ethic of American scientists.

Dr. Cranberg didn’t hesitate to fight for justice whether it be the case of his own academic freedom, or his involvement in the lawsuit that eventually forced UVA to accept women into its formerly all-male undergraduate school.  In 1971, after winning an AAUP hearing that declared his academic freedom had been invaded, Dr. Cranberg moved to Austin where he joined a small high-tech company, eventually starting his own firm to develop fast-neutron techniques for the treatment of cancer.  He was always grateful for the welcome arms of the private sector and of Texas, calling it “The Land of Milk and Honey”.

In 1975, Dr. Cranberg applied the laws of physics to fire-building and invented the Texas Fireframe grate. Later dubbed “The Physicist’s Fire” by Time magazine, his invention was featured in news stories on CBS and BBC. His company is now run by his daughter.

An advocate for social causes throughout his life, Dr. Cranberg fought for racial equality in Virginia (he also recruited the first black graduate physics student at UVA), for the freedom of Russian physicist Andrei Sakharov and for scientists and inventors not properly credited for their work.  He wrote incisively about topics from the ethical problems of scientists to the pseudoscientific basis of Marxism.  Dr. Cranberg’s candidacy for the U.S. Senate from Texas was inspired by his desire for science to better inform decisions in and of the law.  Dr. Cranberg’s capacity for indignation at injustice was matched only by his optimistic belief in his ability to fight for change and to make a difference.

Dr. Cranberg was a loving, devoted husband, father and grandfather: his last words were “I’m the richest man in the world”.  His enthusiasm, generosity, sense of humor and his quest for knowledge, truth, and justice are just a few of the qualities that his family, friends and colleagues will always remember him for.

Dr. Cranberg is survived by Charlotte, wife of 58 years; son Alex of Austin, Texas; daughter Nicole and husband Giff Crosby of Cos Cob, Connecticut; and grandchildren Jacob, Hannah and Clare.  Other surviving family members include brother, Gilbert Cranberg of Sarasota, Florida and sister, Sylvia Troy of Beverly Shores, Indiana.

In lieu of flowers, the family asks that memorial donations be made to the Niels Bohr Physics Library Center for History of Physics at http://donate.aip.org. Please type “In Honor of Lawrence Cranberg” in the comments box. A memorial service will be held by the family at a later date.

Lawrence Cranberg

To share memories, please visit http://tinyurl.com/d7p849e

Introduction to The Initiation of Electrical Breakdown in Vacuum

THE phenomenon of electrical conduction between metal electrodes in high vacuum has been ob- served and studied for many years. The conduction is of two kinds: cathodic electron emission, which is very sensitive to the cathodic gradient and occurs only at . very high gradient (of the order of megavolts/cm) j and a low gradient, heavy current arc in which vapors of the electrode materials playa role. The only method by which the second type of conduction has been ob- tained has been by application of progressively higher voltage. The onset of the arc limits the practical useful- ness of vacuum as electrical insulation and is therefore referred to as breakdown. In 1928, with the formulation of the Fowler-Nord-heiml theory of cold electron-emission from metals, a theoretical basis was provided for the interpretation of the first phenomenon. The comprehensive analysis of Stern, Gosling, and Fowler2 showed substantial agree- ment of theory and experiment, and the Fowler-Nord- heim theory has been regarded as reasonably well es- tablished, at least in the domain of low voltage and high gradient.
The initiation of breakdown, which is the concern of this paper, is a matter of much less theoretical interest, but of great practical importance for the design of high voltage vacuum apparatus; and about this there is much less agreement. Up to 1936, with the work of Hull and Burger,3 Snoddy,4 Beams,5 and Ahearn,6 it ap- peared to be fairly well established that breakdown was initiated by cold electron-emission from points on the cathode, these electrons producing intense localized heating of the anode. The conditions studied by these workers were those of uniform and cylindrical fields, with high cathode gradient, but low (less than 30 kv) total voltage. Even in this work, however, the evidence has not been entirely concordant: viz., Ahearn’s observation of the effect on breakdown of the glass walls surrounding the electrodes, and Beam’s calculation that the measured breakdown gradient from a pool of mercury, fitted into the Fowler-Nordheim relation, gives less than 1 electron/cm2/sec as the initiating current density.
In 1935, with the work of Anderson,1 who used the segmented-tube technique suggested by Van de Graaff to obtain high voltage in vacuum, it became clear that the explanation in terms of cathode gradient, though possibly applicable to some cases, could not explain satisfactorily the results obtained with high voltage gaps. His work, together with data taken subsequently with the same or similar apparatus by Trump and Van de Graaff,8 showed breakdown to be associated with progressively lower cathode gradient as the gap distance and voltage were increased, and this has been denoted the “total-voltage” effect. Because of the great sensitivity of emitted current to cathode gradient in the Fowler-Nordheim relation, these results cannot be reconciled with an initiation hypothesis which depends on heating of the anode to some critical temperature by field-emitted electrons.
This difficulty has led Anderson and Trump and Van de Graaff to postulate that positive ions as well as electrons playa role, one particle producing the other at opposite electrodes, breakdown resulting when the product of positive-ion yield per bombarding electron at the anode, and electron-yield per positive ion at the cathode exceeds unity. Experimental determinations-lo of these yield functions, however, have given results too small by several orders of magnitude, particularly for the positive-ion yield per electron.
Very low gradient current-loading phenomena ob- served in Van de Graaff accelerator tubes have led to the postulation by Blewettll of a “Malter-layer” effect, and by McKibben and BoyerlO of a positive-ion-nega-tive-ion chain-reaction. This loading may be so severe that with power supplies of limited regulation, no break- down can be observed. The relationship of these phe- nomena, and the mechanisms postulated to explain them, to breakdown itself it is not clear. In the case of the results obtained by McKibben and Boyer at least, it appears that loading and breakdown are due to different mechanisms, so that when the former is cleared up the latter has a chance to assert itself. This situation seem analogous to that with very short gaps, where ordinary field-emission is apparent, and the attainment of breakdown depends on sufficiently lower- ing the resistance of the power-supply, or clearing up the field emission by the smoothing of roughened sur- faces. In what follows an attempt will be made to interpret the breakdown phenomenon for both long and short gaps in common terms, and in this picture the loading is incidental.

Dr. Cranberg

 

Raves from Time magazine, USA Today, The New York Times

Raves from Time magazine, USA Today, The New York Times and many others helped put the Texas Fireframe® Grate on the map. Dr. Cranberg’s breakthrough invention even made the news – at both CBS and the BBC. In the years since it was introduced, his high efficiency fireplace grate has become a classic, with homeowners all over America enjoying the warmth and ease of the “Physicist’s Fire.”

And the praise continues. The Texas FireFrame® Grate is featured in the just-released Handbook to Practical Disaster Preparedness for the Family, written by NASA robotics engineer Arthur T. Bradley.

Some press quotes are highlighted below. Complete articles available upon request.

Money magazine – “I call your attention to one of the greatest finds of my personal energy-saving crusade – the Texas Fireframe [grate]. This specially designed grate turns a fireplace into a real heating plant…I was so excited I ordered another [Texas Fireframe grate] for my other fireplace. Result: furnace on only an hour or hour and a half on the coldest days.”

The New York Times — “Easy lighting is only a side benefit of this grate arrangement; the big advantage is the slow burning, steady fire that results and the way the fire burns. The arrangement of logs creates a cavity that keeps the fire confined to the inside of the slot and, as well, forces the fire to radiate a very high percentage of its heat out into the room. Thus it is insured that more B.T.U.’s will be used to heat people in front of the fire, rather than heating masonry or flowing up the chimney.”

Time magazine — “Dr Lawrence Cranberg…has designed a fireplace grate that forces a fire not only to burn better, but to send more of its heat out into the room.”

Scientific American – “Cranberg’s conception of the radiation pattern from his log holder is correct…little of the radiated heat was lost upward to the overhang or the chimney…nearly all of it must have been coming out into the room. The burning was slower with this arrangement…and required no rotation or stirring of the logs.”

USA Today – “With a ‘physicist fire’ under the hood,” Cranberg says, ‘the fireplace delivers about five kilowatts of radiant power. Multiply that by all of America’s fireplaces,’ he says ‘and you have more power output than all its nuclear power plants combined.’”

Better Homes and Gardens – “It channels an amazing amount of heat from a fireplace directly into the room, without using any moving parts.”

Dallas Morning News – “An Austin physicist, Dr. Lawrence Cranberg, has received sudden national and international attention…for achieving a scientific breakthrough…Throughout the world, scientists are at work trying to get more heat from solar, thermal, nuclear and other energy sources. They are sophisticated and long-range sources. Dr. Cranberg took a more direct route. He learned how to get more room heat from a log fireplace. In so doing, he seems to have achieved what has eluded man almost since the discovery of fire.”

Austin American-Statesman — “ the Cranberg device creates a slot for the hottest part of the fire to escape out into the room rather than up the chimney, thereby increasing the efficiency of the primitive heater.”

Dayton Daily News -  “The most dramatic discovery was the amount of heat produced. ”

 

Alex Cranberg – Will seek additional informative, detailed data

On Feb. 12, Gene Powell, the chairman of the University of Texas System Board of Regents, sent a note to Francisco G. Cigarroa, chancellor of the U.T. System, about the newest regents appointed by Gov. Rick Perry. The new members “all have extensive experience in higher education and all of them are hard core conservatives. And none of them are shy. We will see no ‘break in’ period from these individuals,” he wrote.

Bob Daemmrich for The Texas Tribune

“If I read some of the stuff about me that I read in the paper, I’d be against me,” said Alex Cranberg, regent of the University of Texas System.

It was an early hint of the changes afoot at the U.T. board and the tense months — some of the most tumultuous in institutional memory, with the regents seemingly pitted against the flagship university in a highly public spat — that lay ahead. Of that new crop of board members, none have received more scrutiny than Alex Cranberg.

Sitting in the student center at the University of Texas campus in Austin in early June, Mr. Cranberg, the 56-year-old chairman of Aspect Holdings, a lucrative energy company based in Denver, said the time had come to “push a reset button” on the relationship between the regents and the leadership of the university.

Individuals who encountered Mr. Cranberg as an undergraduate student at U.T. — he received a degree in petroleum engineering in 1977 — remember him as a spirited debater who enjoyed challenging others and being challenged in return.

And it may not be what he expected, but he has certainly been challenged lately.

Suspicion has surrounded Mr. Cranberg from Day 1. First, there was the speed with which he became a regent — one of the most prestigious appointments a governor can bestow upon a Texan. Mr. Cranberg received the nod just two weeks after registering to vote in the state following a move from Colorado for personal reasons.

“Frankly, I’ve got a lot going on and would not have moved specifically for this job,” he said.

Then there were his associations. Mr. Cranberg is a longtime friend of Jeff Sandefer, the Austin energy investor who wrote a controversial set of seven proposals for changing higher education and has promoted them with Mr. Perry’s aid. “I don’t expect anybody to tell me what to do and have me do it,” Mr. Cranberg said.

Of all the regents, Mr. Cranberg was the one closest to Rick O’Donnell, a fellow former Coloradoan and an associate of Mr. Sandefer who had publicly questioned the value of academic research. The U.T. System’s hiring of Mr. O’Donnell as a special adviser to the board was one of the sparks that lit the statewide controversy. (Mr. O’Donnell’s employment was terminated after 49 days, during which he was “unfairly attacked,” Mr. Cranberg said.)

At the height of the debate, Mr. Cranberg was widely considered by critics in the Legislature and the academic community to be the ringleader of a bloc of regents who were influenced by Mr. Sandefer and others aiming to, among other things, stage an attack on academic research and coordinate an ouster of U.T.’s president, William Powers Jr. Most recently, after a request for extensive data on all the faculty members in the system, Mr. Cranberg was accused by the same groups of trying to micromanage the universities.

“If I read some of the stuff about me that I read in the paper, I’d be against me,” said Mr. Cranberg, who denied all the details of what he called a “caricature.”

When Mr. Cranberg heard that his data request was overwhelming the small staff at the University of Texas-Pan American, he asked the university’s president, Robert S. Nelsen, to write a grant proposal for him to personally finance. “It surprised me very much,” Mr. Nelsen said. “It was a very generous offer on his part.”

When asked if other universities shared concerns publicly expressed by many in Austin about the data, Mr. Nelsen said: “I know my faculty are concerned and my staff are concerned. We’re not worried, but we would like a better idea of what the data will be used for.”

Mr. Cranberg said that his grant offer, which ultimately was not accepted, was as symbolic as it was sincere. “I want to show that I’m willing to share the sacrifice,” he said. “I expect it to be symbolically understood that I’m not asking for stuff out of some arrogant desire to be given whatever I want.”

Mr. Cranberg has a long history of investing in causes he cares about. In Colorado, when a school voucher initiative he backed failed, he joined with others to create the Alliance for Choice in Education, a nonprofit group that provides scholarships to schoolchildren. An advocate of expanding pathways to citizenship for immigrants, Mr. Cranberg paid $10,000 to conduct a poll in his Colorado district just to confirm his belief that he was not an anomaly in the Republican Party.

“I’ve got two kinds of energy,” he said. “I’ve got my own personal energy inside my body, and I’ve got this stored energy that’s called financial resources or cash. I intend to use both up as fully as humanly possible by the time I die.”

Mr. Cranberg, the son of a prominent physicist, grew up in the world of academia, which he said influenced him greatly, as did work toward an M.B.A. from Stanford University. His stint on the Board of Trustees of the Metropolitan State College of Denver, from 2002 to 2007, informs much of his behavior as a regent.

“I saw some things there that I wish I’d done differently, and I don’t like to ever look back on something I did and wish I’d done things better,” he said.

On the Denver board, he said, he learned of the “critical importance” of data, especially granular information that one can “slice and dice” different ways.

“That’s not micromanagement,” he said. “That’s just good analysis.”

His requests for data are not likely to subside, despite the complaints. He said he intended to ask for detailed data on faculty peer reviews. He anticipates that the request could be “burdensome,” but also informative.

Of a controversial, widely publicized study by Richard Vedder, an economist at Ohio University, which used unverified data to allege that U.T. functions inefficiently, Mr. Cranberg called the analysis “simplistic.”

Still, while the criticisms of the report resonate with him, so do Mr. Vedder’s concerns. Mr. Cranberg said he hoped to “win the hearts and minds” of those who still had reservations about his intentions as he sought to address those concerns. That the Legislature created a new higher-education oversight committee in response to the continuing controversy might indicate that he has a long way to go.

Mr. Cranberg said he welcomed the new oversight committee, which some conservative bloggers have strongly criticized, and said he believed that most of its members were aligned with his vision.

“I’m the one that’s been arguing for transparency,” he said, “so why should I argue about going before some legislative committee?”

The most important issue moving forward, Mr. Cranberg said, is which groups will rally together “post reset” to embrace the changes that he believes must happen. He added, though, that he and the other regents would not relinquish their responsibilities “just because they’re being critical, especially if they’re being critical of something we don’t even recognize as our position.”

Read more http://alexcranberg.wordpress.com/2011/06/11/alex-cranberg-interviewed-seen-in-new-york-times/

Mr. Nanosecond

Once introduced as “Mr. Nanosecond” by Sir Denys Wilkinson to a London Physics Conference, Dr. Cranberg developed the means to measure a billionth of a second – the precursor to what we today call “nanotechnology.”

From Wikipedia

Nanotechnology (sometimes shortened to “nanotech“) is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with structures sized between 1 to 100 nanometre in at least one dimension, and involves developing materials or devices possessing at least one dimension within that size. Quantum mechanical effects are very important at this scale, which is in the quantum realm.

Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale.

There is much debate on the future implications of nanotechnology. Nanotechnology may be able to create many new materials and devices with a vast range of applications, such as in medicine, electronics, biomaterials and energy production. On the other hand, nanotechnology raises many of the same issues as any new technology, including concerns about the toxicity and environmental impact of nanomaterials,[1] and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted.

Ethical Code for Scientists

Many researchers maintained high ethical standards for themselves and took great care to pass these ideals on to their students. Nonetheless, the larger community of research scientists formulated few statements of ethical norms for their work. Despite two articles in Science that argued the need for an ethical code for scientists, little was done by professional societies to address the need for guidelines for research conduct until the mid-1980s or later. For example, it was not until 1991 that the American Physical Society issued their first statement of ethical guidelines, (and those guidelines dealt exclusively with matters of research ethics.) see reference http://www.onlineethics.org/Topics/RespResearch/ResEssays/cw1.aspx

Dr. Cranberg wrote an article titled “Ethical Code for Scientists” where he discusses evidence of scientists, engineers, and the public in the ethical aspects of the relationships of scientists and engineers to society and to one another.

Click Here For Article on Ethics

The Texas Fireframe® grate – order one today.

The Texas Fireframe® grate is made of hot rolled steel, welded bars, and includes slip-on, height-adjustable, friction-locking arms. Fully-assembled. Instructions included.It comes in three sizes; the U-25 unit fits almost all fireplaces. Select the size that fits your fireplace. The depth of your fireplace should be at least three inches greater than the depth of the unit you choose.

To order click here http://www.texasfireframe.com/fireplace-grate-store.html

Click to enlarge fireplace grates:

17 inch - Efficient Fireplace Grate
U-17
25 inch - Hotter Fire Grate
U-25
33 inch -  Fireplace Grate
U-33

Customers’ Grate Reviews

The steady flow of letters and e-mails we’ve received from satisfied customers over the past 35 years warms our hearts nearly as much as the Texas Fireframe® grate warms the hearth. To our customers, we say thank you for all the wonderful messages you’ve sent to us. Below is just a sampling. (Could you blame us for leading off with one from the governor of Texas?)

Gov Perry note to Texas FireFrame Grate

Domestic Fire and its Improvement: Qualitative Insights

American Journal of Physics, Vol. 49, No. 6 (June, 1983): 596-599.

Evidence of domestic wood fires have been found in caves occupied by Peking Man, and are estimated to be about half a million years old, so that fire-making with wood must be considered among man’s oldest inventions.  Perhaps the most remarkable fact about this particular invention, however, is that the technique of making and maintaining a wood fire may have changed very little in the vast stretch of time since Peking Man, in contrast with the striking evolution characterizing all of man’s other early inventions, such as tools, clothes, and language.

Click Here For Article on Domestic Fire and its Improvements

Plotting particles of diverse energies in a two-dimensional array

If you count particles as a function of energy, your methods, instruments and purposes can differ greatly depending on whether you are looking for emissions, absorptions or scatterings.  Neutron counting started with Chadwich and has become variegated science.

Problem of Spectrometry are by definition those of plotting particles of diverse energies in a two-dimensional array that shows numbers of particles as a function of energy. The prototype was discovered and solved in the 17th century by Isaac Newton when he accomplished the decomposition of white light into a spectrum with a refracting prism. The 19th century brought extension of the problem to electrically charged particles, and it was solved by exploiting the energy and momentum dependence of charged-particle motions in electric and magnetic fields. James Chadwick’s discovery of the neutron in 1932 presented the problem in still another form,in which the particles are, like photons, electrically neutral, but,unlike photons, they interact only with the nuclear constituents of matter. It is not surprising, therefore, that the problems of neutron spectrometry exhibit distinctive peculiarities and difficulties.

 

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