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August 31, 2006

Krell metal

I was eight when I first saw the movie Forbidden Planet (1956, Fred M. Wilcox, Director). The plot revolves around an expedition to Altair IV, the fourth planet of the star Altair, a planet once populated by the Krell. The Krell were long extinct, but they left behind many artifacts, including many made from Krell Metal, a nearly indestructible alloy. Krell Metal is not the only fictional, indestructible alloy. Adamantium, a name likely derived from the word adamantine with an -ium ending for chemical affect, has similar properties.

Many years later, when I was at Syracuse University, one of my fellow graduate students synthesized a close cousin to Krell Metal, the intermetallic compound HfPt3. HfPt3 has an enthalpy of formation (∆Hf) of -132 kcal/mole and a melting point of about 2400 K (3850 °F). A closely related compound, ZrPt3, has an enthalpy of formation (∆Hf) of -124 kcal/mole and the same melting point. I've measured the Rockwell-C hardness of HfPt3 to be 65.2. For comparison, hard chrome coatings have a hardness of 60 on the Rockwell-C scale. HfPt3 was so hard, standard metallography techniques could not be used. We needed to treat this metal as if it were a ceramic.

Robbie the Robot was my favorite character in Forbidden_Planet, but in later years I became somewhat partial to Anne Francis. The movie had the first electronic music soundtrack, produced by Louis and Bebe Barron, but the musician's union prevented the Barron's from being credited as "composers." They were credited with "electronic tonalities," instead. Forbidden Planet has been compared to Shakespeare's The Tempest, with the part of Caliban played by Robbie the Robot.

References.
1. V. Srikrishnan and P.J. Ficalora, Metallurgical Transactions 6A (1975), pp. 2095ff.
2. Forbidden Planet on the Internet Movie Database (imdb.com)

August 30, 2006

Women are from Venus, Men are from Cobol

Cobol was a popular name for a fictional planet in science fiction literature. Cobol was the planet where human life originated on the television series, Battlestar Galactica (1978). COBOL is also a computer language (Common Business Oriented Language) developed in the 1950s by a committee that included Honeywell Labs. Honeywell was at one time a computer company, and it was successful to the point that it bought GE's computer operation in 1970. Some Honeywell computers can be found here.

A recent study by scientists at Dalhousie University and Saint Mary's University, both in Halifax, Nova Scotia, Canada, has demonstrated that men and women have different computer programming styles. Fifteen male and fifteen female students with JAVA programming skills were asked to make a small modification to a 300 line program, an emulation of a calculator. Men appeared to use a top-down approach, building a functional model of the program code. Women appeared to use a bottom-up approach, focusing on details such as the names of routines and their positions. The women were identifying program elements that could be used as landmarks in navigating the program structure. The authors of the study note that the male, top-down, programming style is inherently more risky, since it relies on educated guesses. These difference in programming style had no affect on programmer productivity, since both sexes did equally well in completing the programming task.

These results show that men and women navigate code space the same way they navigate real space. Published research in the journal Behavioral Neuroscience (Volume 116, pp. 403-410, 2002) shows that women have difficulty navigating via bearing and distance, something that men do well. Women navigate best using landmarks.

I'll leave you with an example of COBOL code - the notorious Hello World program. Those of you who hate C's semicolons will see that C is just following in the same tradition as COBOL's periods. It is also interesting to note the length of the program. This is likely one reason no one programs in COBOL nowadays.


IDENTIFICATION DIVISION.
Program-Id. Hello-World.
*
ENVIRONMENT DIVISION.
*
DATA DIVISION.
*
PROCEDURE DIVISION.
Para1.
DISPLAY "Hello, world.".
*
Stop Run.

References
1. Mars and Venus in Codespace,Science 313 (21 July 2006), p. 279.
2. Using Sex Differences to Link Spatial Cognition and Program Comprehension.
3. Tell Men Directions, Give Women Landmarks.

August 29, 2006

Where's All the Technetium?

Right in the middle of the transition elements, in between Molybdenum (Mo, element 42) and Ruthenium (Ru, element 44), and just below Manganese (Mn, element 25), lies Technetium (Tc, element 43). Mo, Ru and Mn are common alloying elements, so why isn't Technetium used more often? The reason is simple - Technetium doesn't exist, at least not in nature.

The longest lived isotope of Technetium (98Tc) has a half life of 4.2 million years. If any Technetium existed at the formation of the earth, about five billion years ago, it's long gone by now. The only source of Technetium today is from the fission of uranium-235 in nuclear reactors. The world's supply of Technitium is refined from spent nuclear fuel rods.

Why is Technetium so short lived? It's an accident of the way nuclei assemble themselves. As described by the Nuclear Shell Model, there are certain combinations of neutrons and protons that are more stable than others, and the combinations that would give isotopes of Technetium are far less stable than nearby combinations that give other elements.

It is interesting to note that Tungsten, like Technetium, is unstable. However, its half-life of 2.09 x 1019 years is so long that anything you can make from Tungsten, like a light bulb filament, will still be around for many years to come.

Reference:
Web Elements is a good internet site for viewing the common properties of elements.

August 28, 2006

Perpetual Motion (Continued)

In a previous post, I reviewed the arguments against perpetual motion machines, and I reported on the claim of Steorn, a Dublin, Ireland, company to have invented one that really works. More information about the structure of this machine has been revealed. The most shocking revealation is its reported 285% efficiency. Thermodynamics teaches that any machine must be less than 100% efficient. Although Steorn claims that the machine's efficiency has been confirmed by no less than eight independent investigations, some by people with "multiple PhDs," no diagram of the machine has been released, nor any explanation of its operation. It's been described as an arrangement of four magnets on a rotating wheel that are influenced by another magnet. Steorn has published a full page advertisement in the Economist that asks scientists to form a jury of twelve representatives to verify or falsify its claims. Steorn must be serious - the ad cost £75,000 (about US$140,000).

Since I have experience in several of the fields involved in the operation of this machine, I offer the following reasons why some machines seem to have greater than 100% efficiency, but are not perpetual motion machines:

• They incorporate reactive components that cause input current to lag or lead the input voltage. This leads to an incorrect measurement of the input power, and a resultant error in the efficiency calculation.

• A high impedance voltage source is measured with a low impedance meter.

• A digital multimeter or a computer data acquisition system measures peak voltage or peak current over its sampling interval, rather than the average value expected.

• A voltage or current meter incorrectly averages readings because the input waveform changes rapidly over the measurement interval.

• The device has stored energy that is not considered in the efficiency calculation. Such machines will stop after a time.

References:
[1] Steorn Company Home Page
[2] More on "free energy" company (This web site is blocked by Honeywell - Why? Your guess is as good as mine.)
[3] These men think they're about to change the world

August 25, 2006

Eight is Enough

Until late in the eighteenth century, Earthlings knew only six planets; namely, Mercury, Venus, Earth, Mars, Jupiter, and Saturn. Uranus, which has an orbit farther from the Sun than Saturn, was the first planet discovered in modern times. William Herschel discovered it with a telescope in 1781. At that point, astronomy took a back seat to astrophysics. The orbit of Uranus was not quite what was expected from Newtonian Mechanics, and the gavitational tug of an unknown planet, farther away from the sun, was suspected. Calculations showed where to look, and the German astronomer Johann Gottfried Galle discovered the planet Neptune in 1846. Of course, the little fleas [1] effect was still operational, and it was surmised that the orbit of Neptune was perturbed by a more distant planet. Clyde Tombaugh, observing at the Lowell Observatory in Arizona, discovered the ninth planet, Pluto, in 1930.

From 1930-2006, the Solar System had nine planets. Sure, Pluto was in a highly eccentric orbit that carried it inside the orbit of Neptune, but everyone was happy to call Pluto a planet. Technology, however, has a way of changing things. In 1978, a moon of Pluto, Charon, was discovered. Two smaller moons, Nix and Hydra, were discovered in 2005. The optical image always thought to be Pluto, just a tiny spot when viewed from Earth, was actually a merged image of Pluto and its moons. The immediate affect was a drastic reduction in the estimated size of Pluto, making Pluto very un-planet-like. After many years of deliberation, the International Astronomical Union demoted Pluto to the status of a dwarf planet on August 24, 2006, and made it the first example of an as yet unnamed family of Trans-Neptunian objects.

The careful examination of planetary orbits also led to another great discovery, although not the discovery of a planet. The orbit of Mercury has an anomoly called an advance of perihelion, and some astronomers attributed it to the affect of an unknown planet, Vulcan (Yes, Mr. Spock, there was almost a planet Vulcan). Careful observations of stellar locations by Sir Arthur Eddington during a solar eclipse in 1919 showed that the advance of perihelion was a relativistic affect, overturning Newtonian Mechanics and adding credence to Einstein's General Theory of Relativity.

References:
[1] Big fleas have little fleas,
Upon their backs to bite 'em,
And little fleas have lesser fleas,
and so, ad infinitum.
[2]
Pluto loses planet status
[3] Then there were 8: Pluto isn't a planet

August 24, 2006

Perpetuum Mobile

Since energy prices are rising sharply, it would be really nice to get cheap energy. Better yet, why not free energy? Over the course of history, many inventors have claimed to have made a perpetual motion machine; that is, a mechanism that operates constantly without slowing down, sometimes providing a measure of extra work to external devices.

Currently in the news is a claim by an Irish inventor, Sean McCarthy, to have made a perpetual motion machine. The machine is said to operate by a precise arrangement of permanant magnets. Of course, McCarthy's company, Steorn, values the discovery highly, offering it for sale for $160,000, and patent applications have been filed.

Physicists has always been sceptical about perpetual motion machines, since their hundreds of years experience with Thermodynamics invalidates the work for free concept. Physicists have classified perpetual motion machines as type-1 or type-2 depending on the law of Thermodynamics they would violate:

• First Law: In any process, the total energy of the universe remains constant.

• Second Law: There is no process that, operating in cycle, produces no other effect than the subtraction of a positive amount of heat from a reservoir and the production of an equal amount of work.

All the laws of Thermodynamics can be summarized in a simple expression involving energy (E), temperature (T), entropy (S), pressure (P), and volume (V).

dE - TdS + PdV <= 0

Of course, PdV is the work, and it's that nasty entropy term TdS that says there is no such thing as a free lunch. To underscore this issue, the American Physical Society issued the following statement in 2003:

"The American Physical Society deplores attempts to mislead and defraud the public based on claims of perpetual motion machines or sources of unlimited useful energy, unsubstantiated by experimentally tested established physical principles."

McCarthy has offered to lend out his device for validation, and many scientists have volunteered to do the testing. It is interesting to note that even today, after hundreds of years of evidence, a true scientist is still open minded enough to check his theory just one more time.

Reference:
John Borland, Perpetual Motion Claim Probed, Wired News (August 21, 2006)

August 23, 2006

Math Burn-Out

Henri Poincaré was a preeminent mathematician whose life bridged the nineteenth and twentieth centuries. In 1904, Poincare had a conjecture on topology, known simply as the Poincaré Conjecture, that attained a status as one of the most important unsolved theorems in topology. The conjecture essentially states that the only three dimensional surfaces that can be mapped to a sphere are those with no holes and no boundary (e.g., a coffee cup cannot be mapped to a sphere). This conjecture has been in the news recently since it may have been proved after more than a hundred years. This conjecture is all the more interesting because of the million dollar prize offered for its proof by the Clay Mathematics Institute. And then there's the story of the mathematician who devised the proof and published it as three internet postings in 2002 and 2003 rather than submit it to a journal.

Grigori Perelman, the reclusive and eccentric Russian mathematician who did the proof resigned from the Staklov Institute of Mathematics, Saint Petersburg, and disappeared. The Sunday Telegraph, a British newspaper, reported on August 20, 2006, that it found Perelman living with his mother in St Petersburg. His resignation may have been precipitated by politics, but Perelman seems to suffer from a genuine inferiority complex. In an interview with the Telegraph, Perelman said he was unworthy of all the attention. He refused the award of a Fields Medal, considered the Mathematics equivalent of the Nobel Prize because he has become disillusioned with mathematics. Those who know him say he will refuse the million dollar Clay Matehematics Institute prize.

Perelman's actions are not without precedent. Alexander Grothendieck, a German mathematician, refused to attend the 1966 Fields Medal ceremony in Moscow to protest Soviet militarism, but he accepted his medal later. Grothendieck also became disillusioned with mathematics, left the field, and is thought to be living as a hermit in Andorra, one of the five European Microstates.

References:
1. Russian mathematics genius shuns the spotlight
2. Prestigious Fields Medals for mathematics awarded
3. Maths 'Nobel' prize declined by Russian recluse

August 22, 2006

The More Things Change...

One thing Physics has more of than any other field is constants. Physics is the field of certainty. It's mission has always been to reduce the universe to a single formula. Not long ago it was the Grand Unified Theory. As if that wasn't grand enough, now there's the Theory of Everything. It would be nice to explain everything without the need for measured parameters, which the physical constants indeed are, but until the time of the real theory at the end of the universe, we'll still have our constants.

There are many Physicists involved in getting more accurate values of physical constants. One effort is to replace standards that exist as objects, such as the standard kilogram, with a measurement. The standard kilogram is now a cylinder of a platinum-iridium alloy located at the the Bureau International des Poids et Mesures near Paris. In the US, the National Institute of Standards and Technology is the government body charged with maintaining and improving the accuracy of the physical constants. The US was assigned its own copy of the kilogram cylinder in 1889, and this cylinder is periodically checked with the original. There is research underway to define the kilogram by a magnetic measurement, or to simply redefine it as 1 097 769 238 499 215 084 016 780 676 223 electron mass units. One look at the number confirms that simply may not be the proper term.

By the way, NIST can sell you three, six ounce jars of Peanut Butter (Standard Reference Material No. 2387) for only five hundred dollars.


References:
1. NIST Web Site
2. PDF Chart of latest (2002) values of the constants
3. Peter J. Mohr and Barry N. Taylor, The Fundamental Physical Constanats

August 21, 2006

Art Aids Science

Art has come to the aid of Materials Science in a spintronic material. Spintronics is shorthand for spin-based electronics. Since spintronics is a merger of magnetism and electronics, it is also known as magnetoelectronics. Electrons in solids are responsible for both conduction and magnetism, and changing one property will change the other.

A major barrier to creating spintronic devices is finding magnetic semiconductors that operate at room temperature. The current generation of spintronic materials operates at -200 Celsius. Recently, scientists at the University of Washington have found that a mixture of zinc oxide and cobalt is spintronic at room temperature. Zinc oxide is a semiconductor, and replacing some zinc with cobalt, a magnetic element, does the trick. This bluish-green oxide is known as Rinman's green, or cobalt green. It was first synthesized in 1780 by Swedish chemist Sven Rinman for use as a pigment.

This is not the first pigment found to exhibit interesting properties. BaCuSi2O6, known as Han Purple, was used in China more than 2,000 years ago. Han Purple was likely derived from a variant composition, SrCuSi4O10, known as Egyptian blue, which predates Han Purple by 1,500 years. When exposed to a 23 Tesla magnetic field at three degrees Kelvin, magnetic waves in Han Purple arrange themselves into a Bose Einstein condensate.

References:
1. Pigment formulated 225 years ago could be key in emerging technologies
2. Kevin R. Kittilstved,1 Dana A. Schwartz,1 Allan C. Tuan,2 Steve M. Heald,2 Scott A. Chambers,2 and Daniel R. Gamelin1, Direct Kinetic Correlation of Carriers and Ferromagnetism in Co2+: ZnO, Phys. Rev. Lett. 97, 037203 (2006)
3. Raiders of the lost dimension
4. S. E. Sebastian, N. Harrison, C. D. Batista, L. Balicas, M. Jaime, P. A. Sharma, N. Kawashima and I. R. Fisher, Dimensional reduction at a quantum critical point, Nature 441, 617-620 (1 June 2006).

August 18, 2006

Learning Physics

Sputnik 1, the first artificial satellite, was launched on October 4, 1957, about ten years after my birth. The launch of Sputnik 1 highlighted what was called the missile gap; that is, the disparity of missile technology between the United States and the Soviet Union. The root cause of this gap was perceived to be a lack of capable scientists and engineers in the US, so efforts were made to encourage youngsters to enter these fields.

As one of the target demographic, I was subjected to the New Math as early as seventh grade. There have been many complaints about the New Math, but it taught me the binary number system, a useful tool for computing and digital electronics. My high school Physics course was PSSC Physics, developed by the Physical Sciences Study Committee. The Physical Sciences Study Committee, formed in 1956, was a group of Physicists lead by Jerrold Zacharias and Francis Friedman of MIT, and Philip Morrison of Cornell (later, MIT). Their objective was to bring US Physics education into the Space Age. The PSSC received considerable funding from the National Science Foundation after the launch of Sputnik 1.

Our textbook was Physics (Heath,1960). The textbook's objective was an understanding of concepts, rather than the memorization of facts. Memorization was apparently the staple of earlier Physics education in high schools. The PSSC syllabus included a series of fifty short film clips, some with Morrison doing demonstrations. The laboratory experiments were well conceived, and one particular experiment, a measurement of gravitational acceleration (g), piqued my interest. A falling weight pulled a paper tape through an electrical buzzer assembly that placed a dot on the paper at a calibrated interval - probably ten or twenty times a second. Careful analysis of these data gave a very good value of g. I spent many hours after classes improving the apparatus to get more accurate values of g (9.81 m/s²).

In later years, Morrison described one reason why he became a member of the PSSC.

"I was oppressed by the feeling of the early fifties that science and intellectual reason itself were not being given a fair chance in the schools and in public life."

This still sounds like a valid complaint.

Reference:
1. The AAPT Celebrates PSSC's 50th Birthday

August 17, 2006

The Erdös Number

Paul Erdös (1913 - 1996; pronounced Air-Dish) was a prolific mathematician. He had no possessions other than a suitcase, and he would travel from the home of one mathematician to another, announcing that his "brain was open." He would stay only long enough to solve a single math problem, and then he would move on to the home of another mathematician. His friends in the math community, notably Ron Graham, would collect honoraria for him, pay his bills, and keep him going in this vagabond mathematician lifestyle.

Erdös published about 1,500 mathematical papers with 500 different collaborators. The mathematics community has invented a number, the Erdös number, that specifies the connection between a given mathematician and Paul Erdös . A co-author with Erdös has an Erdös number of 1. Likewise, a co-author of a co-author of Erdös has an Erdös number of 2, etc. Erdös himself has an Erdös number of 0. This is an expression of academic lineage that I touched upon in an earlier posting.

References:
1. Washington Post Obituary of Paul Erdös.
2. The Erdös Number Project .
3. Bruce Schechter, My Brain is Open: The Mathematical Journeys of Paul Erdös, Simon & Schuster (February 28, 2000, ISBN: 0684859807), 224 pages.

August 16, 2006

MIT Energy Technology Initiative

In June of 2005, MIT established an Energy Research Council. A recent Wired news article called it a 'Manhattan Project' for energy. It's also been compared to MIT's Radiation Laboratory that developed radar technology for the US during World War II .

"MIT is stepping into a vacuum, because there is no policy, vision or leadership at the top of our nation," said David Jhirad of the World Resources Institute, and quoted in Wired. "It's uniquely matched. MIT has tremendous strengths across the board -- from science and engineering to management to architecture to the humanities. From that point of view, it's hugely significant."

Here's a list of some MIT projects under the Energy Research Council umbrella:

• Solar cells based on photosynthesis

• Low cost manufacture of silicon for photovoltaic arrays

• Lithium-based batteries for electric cars

• Carbon nanotube supercapacitors for energy storage
(Mildred Dresselhaus, an MIT Physicist, is an authority in this field)

• Computer design of buildings for efficient HVAC

• Ethanol plasma turbocharging for increased fuel efficiency

• Photovoltaic auxiliary power for vehicles.

• Biodiesel derived from effluent from coal-fired power plants

References:
1. Wired News Article.
2. Mildred Dresselhaus MIT Homepage

August 15, 2006

Like Father, Like Son

The expression, "Like father, like son," is as true in Physics as elsewhere.

William Henry Bragg shared the 1915 Nobel Prize in Physics with his son, William Lawrence Bragg for their work on xrays. The exact award citation reads, "For their services in the analysis of crystal structure by means of X-rays."

Likewise, Niels Bohr was awarded the 1922 Physics Nobel, to be followed fifty-three years later by his son, Aage Bohr, who shared the 1975 Nobel Prize in Physics with Ben Mottelson and James Rainwater.

Beyond biological parenthood, there is also an academic parenthood in which students are descendents of their professors. In this respect, I'm in the lineage of William Henry Bragg . My thesis advisor at Syracuse University, Peter J. Ficalora (presently, Professor Emeritus at RPI), took his Ph.D. at Penn State under George W. Brindley. George W. Brindley (1905-1983) received his M.Sc in 1928 under William Henry Bragg at the University of Manchester. Brindley subsequently received a Ph.D. from Leeds University in 1933.

And, yes, I've spent quite a few hours doing X-ray analysis of crystals, following in the tradition of my Great Grandfather.

References:
1. P. J. Ficalora and G. W. Brindley, J. Amer. Ceram. Soc. 50 (1967) p. 662ff.
2. Devlin M. Gualtieri and Peter J. Ficalora, Electron Transfer and Metallic Bonding. The Heats of Reaction of FeAl3-x(Ag; Zn; Pt; Au)x Alloys, High Temperature Science Vol. 7, No. 1 (Mar. 1975) pp. 25-36.

August 14, 2006

Niobium by any other name...

The forty-first element, Niobium, was disvovered by Charles Hatchett in England in 1801. Hatchett named the new element Columbium (Cb), since he extracted it from the mineral Columbite. It is interesting to note that the source of his Columbite was Connecticut, so element 41 could be called a New World Element. Hatchett's work was not well published, so element 41 was 'rediscovered' in 1846 by Heinrich Rose and Jean Charles Galissard de Marignac. They named it Niobium, after Niobe, Queen of Thebes and the daughter of Tantalus. Niobium and Tantalum are chemically similar since they occupy the same column in the Periodic Table.

The controversy over the name of element 41 raged for a hundred years until 1950 when the International Union of Pure and Applied Chemistry (IUPAC) formally certified Niobium as the true and proper name for element 41. This was apparently a compromise that included the naming of element 74. Tungsten was the name for element 74 in North America, and the IUPAC ruled that the name Tungsten would supplant Wolfram, the common European name. In the end, the New World Element was named by the Europeans, and the Old World Element was named by the Americans. To complicate matters, not everyone abides by the IUPAC decision, and the name Columbium is still in common usage by metallurgists.

Reference: Web Elements is a good internet site for viewing the common properties of elements.

August 11, 2006

James A. Van Allen

The launch of Sputnik 1, the first artificial satellite (October 4, 1957), possibly propelled me into a scientific career. I was nearly ten years old at the time, and I kept a space scrapbook. I nearly became a Radio Astronomer, but I was disappointed with the introductory Astronomy course I took as an undergraduate Physics major, so I went into Materials Science instead.

One name I remember well from that era is James A. Van Allen, discoverer of the eponymous radiation belts that circle the earth. James A. Van Allen died August 9, 2006, at the age of 91. It will interest those of you who work with ruggedized components that during World War II van Allen developed vacuum tubes that were mounted in artillery shells, shot from guns, and recovered with a post hole digger. This experience helped him later in life in the development of satellite components.

Van Allen said that watching the Perseid meteor shower in August of each year got him interested in Geophysics. My family enjoys meteor showers, but in a different way.

August 10, 2006

Welcome

I'm Dev Gualtieri, a Senior Principal Scientist with the Honeywell Aerospace Advanced Materials and Devices Laboratory in Morristown, New Jersey.

I've been with Honeywell (a.k.a. Allied Chemical/Allied Corporation/Allied-Signal) since 1977. You can read about my background here.

This blog will feature items relating to Physics and Materials Science, occasionally touching on mathematics, computer science, and science and technology news.

If you haven't tried Wikipedia yet, do it now.