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Archive for December, 2010

Reid Nixon

S. Reed Nixon, nuclear engineer

On Nov. 30, I had the privilege of interviewing S. Reed Nixon, who lives not far from where I do in Orem, Utah. I met him through my wife, who has known the Nixons for several years. Over the summer, we went to visit them and Reed told me of some of his experiences as a nuclear engineer on Admiral Hyman Rickover’s staff during the 1950s. I couldn’t pass up such an opportunity, so I arranged to bring over my video equipment and interview him on camera.

Reed got into nuclear engineering by chance. He started out by receiving a B.S. in electrical engineering from Caltech in Pasadena (where he had Linus Pauling as a chemistry professor – according to Reed, Dr. Pauling would nervously pace up and down the chemistry lab during his lectures, turning the Bunsen burner gas stopcocks on and off). This was in the late 1940s, after Reed had served two years in the Navy. At the time, Robert Millikan was Chancellor and would have the seniors and their parents over for tea each year. He told how gracious Dr. Millikan was to his mother at the tea party.

Upon graduation, he moved to Provo, Utah where he taught math part-time at Brigham Young University and then started working for Telluride Power Company, which ran the power utilities for southern Utah at that time before it was bought out by Utah Power and Light. Telluride Power Company originated in Telluride, Colorado when the mines there began to have trouble with ground water. The Nunn brothers bought out a number of mines, then contracted with George Westinghouse to design a hydroelectric power system based on alternating current as conceived by Nikola Tesla. This was the world’s first commercial AC system, which supplied power to the mines for pumps that kept the water at bay. Reed had some interesting stories about this original power system, including how it was difficult and dangerous to shut off. When the mines in the Tintic Mining District around Eureka, Utah began to have the same trouble with flooding, the Nunns built a hydroelectric plant in Provo Canyon (now the site of Nunn Park) and transmitted electricity about 40 miles across the valley to Eureka.

USS Nautilus

USS Nautilus, SSN 571

After a few years with Telluride Power, Reed heard of a new laboratory being built in Arco, Idaho to process spent nuclear reactor fuel rods. They needed an electrical engineer. This was about 1951, and nuclear reactors for generating power were a brand new invention. As Uranium-235 splits, it releases free neutrons, which in turn split other atoms. The fission byproducts, such as Barium-141 and Krypton-92 (among other isotopes), are themselves mostly radioactive. Some byproducts, however, are not, and they act as neutron sponges, so that of the three neutrons given off by a single U-235 atom, only about 2.5 are available to continue the reaction. Eventually these products poison the reaction, to where fission will no longer occur spontaneously. The Arco facility (now the Idaho National Laboratory) was built to take the “poisoned” fuel rods and remove the impurities, so that the remaining U-235 could be re-used in reactors. It also was the training facility for the prototype reactor for the USS Nautilus.

After a year or two at INL, Reed applied to receive training in nuclear engineering at Oak Ridge National Laboratory, which was the primary source of U-235 enrichment at the time. It was such a new field that only one textbook had been written, and he could see an opportunity to get in on the ground floor of a whole new technology. Hyman Rickover (later an Admiral) had recently been put in charge of developing nuclear reactors for the navy, and was sending his people to Oak Ridge as well. While there, Reed got to know the navy personnel and also finished as one of the top engineers in his class. His job at INL had meanwhile been eliminated, so he decided to take a chance and apply to be on Rickover’s staff.

Hyman Rickover

Admiral Hyman Rickover, father of the nuclear navy

Rickover was infamous for being a hard-driven workaholic. He was also abusive, profane, and intolerant of anything less than perfection in his subordinates and in the contractors (such as General Dynamics) who were building the first nuclear submarines. He personally selected his staff members and all officers in nuclear vessels until his retirement in 1983. His recruiting interviews were legendary; he was known for being so confrontational during the interviews that several candidates tried to attack him physically, and so he usually had his director of personnel in the room as well for protection. He would push a candidate to the edge – he already knew their technical qualifications or they wouldn’t have been there in the first place. What Rickover wanted to know is how much abuse the person could take.

USS Nautilus

USS Nautilus, SSN 571

Reed Nixon’s interview was probably the easiest one that Rickover ever gave. After Reed was accepted, his job was to act as a liaison with the contractors as they built the USS Nautilus (SSN 571) and USS Seawolf (SSN 575), making sure that all the specifications were followed exactly, even down to inspecting each weld on the reactor vessels with X-rays. Rickover was a demon for quality assurance, and would insist that contractors tear a system apart and start over if there was even the slightest flaw. Reed was a part of Rickover’s staff through the launch of both vessels.

Using nuclear reactors to power naval vessels has many advantages, especially for aircraft carriers and submarines. The power plant can operate for many years without refueling, so there is no need for tankers to follow along and act as targets for enemy torpedoes. Also, the old diesel subs during World War II were noisy and fairly easy to locate, since they had to run close to the surface in order to pull in air and discharge exhaust from the diesel motors. Nuclear reactors run quietly (no moving parts except the propellers) and have no exhaust, so they can run silent and run deep. Our “boomer” subs (those with nuclear weapons) are said to “hide with pride.” Nuclear carriers, such as the USS Enterprise (“nuclear wessels” anyone?) and the USS Nimitz, employ at least four separate reactors. They don’t need to take up a major portion of the ship with diesel tanks, so they can hold more planes and ordnance.

The Nautilus was the world’s first nuclear powered vessel, which used what is now a standard design of saturated water cooling. It was launched in 1954, and was used to test the feasibility of nuclear reactors on ocean vessels. Two of its first accomplishments were to sail under the North Pole (Operation Sunshine) and to sail all the way around the world underwater, thereby living up to its namesake by going more than 20,000 leagues under the sea. It was decommissioned in 1980 and is now a museum in Groton, Connecticut.

USS Seawolf

USS Seawolf, SSN 575

The Seawolf used a more advanced superheated water system with liquid sodium metal as the primary coolant. The sodium, however, was corrosive and difficult to maintain and the pre-heaters for the superheated steam rarely operated at top output. The Seawolf was known as the “Blue Haze” because of a sodium leak that occurred during the original reactor fitting. It was eventually refitted for a standard reactor in 1959. The liquid sodium reactor was sealed in a steal container and towed out to sea on a barge, then sunk 120 miles east of Maryland. The Navy has not been able to relocate the container. Originally launched in 1955, the Seawolf stayed in service until it was decommissioned in 1987 after a long and distinguished career.

Admiral Rickover’s insistence on perfect quality has led to our nuclear navy now having over 5400 reactor years and over 200 million miles sailed without a single accident or even a safety incident related to the nuclear reactors. This perfect operational record should convince the general public just how safe and reliable nuclear power can be, but unfortunately it’s a fact that often goes overlooked.

Reed Nixon worked in Rickover’s office for about two years. One memory he shared of his time there was a memo that Reed wrote to a contractor in which he said that, “we desire that you do the following . . . .“ Rickover wrote a caustic correction in the margin of the memo saying, “We’re the Navy! We don’t desire anything! We demand it!” Reed eventually left Rickover’s staff to work in the private sector as a consultant, promoting the use of nuclear power in industry. Rickover wasn’t at all happy for him to leave.

The Nixons

The Nixons

Our interview ranged over many subjects, from Nikola Tesla to nuclear reactions and the disposal of nuclear waste, such as the radioactive byproducts that had been removed from fuel rods at INL. Reed Nixon was very generous with his time, and it was a pleasure to hear these stories of the dawn of the nuclear age.

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Gay eyeballs

Making gak eyeballs at Walden School

This last week was our final week of Fall Semester at Walden School, and for their final test my chemistry students planned, practiced, and presented chemistry demonstrations to their peers and to Walden’s elementary classes. Altogether five groups of students presented to the elementary school on Wednesday, Dec. 15 and the rest of the student teams presented on Friday, Dec. 17.

I’ve discussed my rationale for doing this in previous posts: that this is an excellent method for generating excitement about STEM in elementary students as they see their older siblings and high school students working with and presenting science. Certainly the younger students were very excited and attentive; they were eager to participate and asked good questions.

Raising hands

Students at Walden School participating in chemistry demonstrations

For me, though, the real reason for doing anything in my classes is always how it will benefit my students. Taking 3-4 days out of our curriculum to practice and present these demonstrations is hard to justify unless it has strong pedagogical advantages. The justification is this: as my students write up their demonstration scripts and outlines, as they practice talking about the science they are presenting, and as they prepare to answer questions from the audience they are thoroughly learning the chemistry behind their demonstrations. They are going beyond hands-on labs to share what they have learned, and that learning will be indelible.

Karlie and Sofia

Karlie and Sofia demonstrate hand warmers

The topics of the demonstrations had to related to the individual element/materials research project of one of the group members, which they are continuing to work on. Here’s what was presented:

Sofia, Karlie, and Jerry demonstrated the principles behind hand warmers by showing the rapid crystallization of sodium thiosulfate crystals that had been heated and then cooled down. They also talked about crystals in general.

Making gak

Mari and Casey help students make gak

Ryan and Casey, with help from Chelise, Lindsey, and Mari, demonstrated how to make gak (a polymer made out of white glue and borax powder). This is an old standby demonstration, and the kids really enjoyed it.

Copper demonstration group

Genny, Rachel, Jared, and Morgan demonstrate copper's properties

Genny, Rachel, Morgan, and Jared demonstrated aspects of copper chemistry. They handed around samples of copper ore (Rachel’s uncle is an engineer at Rio Tinto’s Bingham Canyon Mine in Utah) and showed a methanol version of a flame test (including copper salts). Jared demonstrated the alchemist’s dream reaction: turning copper into gold (actually brass).

Kinesthetic activity

Sid and Sam use a kinesthetic activity to demonstrate magnetic induction

Sam and Sid, with help from Josh, presented the idea of magnetic induction and discussed how modern electrical generators work. Sam actually built her own alternator and induction coil, and Sid presented on his research about the use of wind power to generate electricity. They also created a fun kinesthetic activity to show induction.

Burning magnesium

Karl and Nicona demonstrate burning magnesium

Karl, Nicona, and Tanner presented on the properties of the elements; they did a flame test as well, and demonstrated what magnesium ribbon looks like when burned and how fireworks get their colors. They also had sparklers for each of the students to try out.

Cabbage pH

Sonora, Dallas, and Morgan demonstrate cabbage pH

In class on Friday, the other groups presented their demonstrations. Sonora, Morgan, and Dallas presented the red cabbage pH demonstration that is one of my favorites.

Untarnishing silver

Mari and Holly demonstrate how to un-tarnish silverware

Courtney, Holly, and Mari showed how to untarnish silver using baking soda and aluminum foil. They even included a correctly balanced chemical equation, although we won’t be learning about those until we return in January.

Dry ice group

Libby, Lindsey, and Chelise demonstrate the properties of carbon dioxide

Chelise, Lindsey, and Libby presented the properties of carbon dioxide gas and dry ice. They showed how regular matches go out in carbon dioxide, but that magnesium burns even brighter when placed in carbon dioxide.

Olivia and Jace

Jace and Olivia explain the ingredients of gunpowder

Jace and Olivia talked about gunpowder, how it is made, and why it is dangerous. Jace has experience working with black powder (he has his own muzzle loader – this is Utah, after all) and he created some raw gunpowder, which he burn outside. They also demonstrated the “fire writing” demonstration of drawing on a piece of paper with a saturated solution of potassium nitrate, then touching a wooden splint to the edges of the writing to see it burn letters through the paper.

Josh and Jess

Josh and Jess demonstrate the principle of density with salt solutions

Josh and Jess presented on salt solutions and how they can be used to determine the density of objects. They showed how an egg will sink in pure water but will float in salt water.

We also videotaped as much of the presentations as we could and took quite a few photos; those students that weren’t helping present helped with the photography.

Burning gunpowder

Burning gunpowder

When their demonstrations were done on Wednesday and Friday, my students were excited about what they had done and the feedback they’d gotten from the younger students. They still have to learn some showmanship and presentation skills (which we’ll continue to work on), but based on what I saw and what the elementary teachers reported, the science content was excellent. They and their peers filled out evaluation forms (and I will as well) so that they can improve on their presentations for the next round in January.

Golden pennies

Golden pennies

It was a lot of work to prepare for this. Now my lab room is a mess and I’ll need to take a day during Christmas break to clean up and re-organize (and I think I forgot to throw out the leftover red cabbage pulp that’s in my trash can, so I’d better go clean up tomorrow). But despite the work and the lost time, I’d say these demonstrations were well worth it. As we go through the second semester, the students will present at least twice more, including a final time at a back-to-school night for their parents. We’ll polish the delivery, add more science explanations, create slide shows and videos to supplement their demonstrations, and by the end of the year these will be incredibly well done.

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Schrodinger illustration

Erwin Schrodinger

My students will tell you that I am a massive Star Trek fan; in fact, I have most of the episodes of all of the series on VHS tapes or DVDs. A number of years ago, an episode of The Next Generation featured Data trying to learn what humor is. He went to the holodeck and asked the computer who the funniest stand-up comedian of all time was, and got the answer that it was a 21st century comedian whose subject was quantum mechanics.

This intrigued me. Could one actually make a good stand-up routine about quantum mechanics? While teaching at Provo Canyon School, my students weren’t able to do most standard chemistry labs due to the circumstances, so I taught a course that was more theoretical. For an extra credit question on our test on quantum mechanics and atomic physics, I asked them to come up with a joke or pun that involved terms and ideas from these subjects. The students took more time on that one question than all the rest of the test combined, and the results eventually mutated into a stand-up routine by a cartoon character called Boson the Clown. I’ve described him in a previous post (The Atomic Comic Club).

This last week, my chemistry students came to their test on the same subjects and I asked the same question. Here are samples of their jokes:

So Heisenberg was driving one day when he was pulled over by the police. The officer asked him, “Sir, do you know how fast you were going?” Heisenberg replied, “No, but I know where I am!”

There were three men named Mark, Larry, and Alphonso who were at a wrestling match. The match was between Mark’s grandma and a rabid grizzly bear. All the odds were against her and she was feeling rather down. Mark was trying to cheer her up while Larry took bets outside. Suddenly, Larry burst into the room yelling, “Alpha’s  beta on your Gamma!”

 

 

Fractal image of p and s orbitals

Fractal image similar to p and s-orbitals

 

Why did the electron cross the road? He never did – because he was quantized, he was already on both sides at once but never in the road.

There was a cat named Schrödinger;
In a box is where he hid.
When poisoned with lead,
Old Erwin said,
“The cat is both alive and dead!”

 

The vet at the particle zoo had a problem with beryllium. He only had two options – to curium or to barium. He had a dentist to boron the beryllium’s tooth. I’d give a nickel to see what happened when the beryllium woke up; now the vet and the dentist argon.

Did one particle in the particle accelerator like the other? Yes, they had a “smashing” good time!

 

 

 

Fractal image of f-orbital

Fractal image similar to the shape of an f-orbital

 

An electron walks into a bar and the bartender says, “Why so negative?” The electron says, “My girlfriend just met this photon and moved out on me.” The bartender says, “Well, that’s too bad. But do you see that young particle over there? She’s dying to interact with you.” The electron thinks, “Maybe this is my lucky day!” and swaggers over to meet her. He asks her name. “Positron,” she says. “Nice to meet you!” he says and shakes her hand. Boom! It was annihilating love at first sight. Now they have a bunch of baby quarks.

A boson checks into a hotel in Neutrino City. He asks the neutrino at the front desk how much it costs to attend services at the local religious shrine. The neutrino replies, “There’s no charge, but I’m afraid we don’t offer mass.”

Some of them are actually pretty good as jokes and even better as evidence of an understanding of atomic physics.

We are now studying quantum mechanics and I have prepared a Keynote/Powerpoint presentation on quantum numbers and electron configurations. I am including it here in case anyone out there could use it; please feel free to make use of it however you like, just give me credit (consider this to have a Creative Commons 3.0 Attribution Only license).

Powerpoint File: Quantum_Numbers

PDF File: Quantum_Numbers

Standing waves at Goat Island

Standing waves near Goat Island, Hawaii

I’m struck, as always, by our inability as humans to adequately visualize subatomic properties. We think of these “objects” inside the atom as either being particles (like small, hard balls) or as waves, constantly in motion. Our models are the solar system of planets orbiting in nearly circular orbits around the Sun, and waves of water in the ocean producing a nice sin wave pattern as they wash up on a beach. It turns out both of these models are partially true; subatomic particles sometimes behave as particles (as in Einstein’s paper on the photoelectric effect) and sometimes as waves (such as Louis de Broglie’s experiments). The truth is, subatomic particles are really neither of these things – they are what they are, but we have a hard time coming up with models that describe them well. On the other hand, the quantum mechanical equations of Schrödinger, Heisenberg, and others describe the electrons so perfectly that we can create such amazing devices as Magnetic Resonance Imagers and iPads. The mathematics is very accurate; our visual models are the only things that need work.

I like to think of electrons as standing wave patterns. The example I give my students is the waves near Goat Island, Hawaii. This is a small island located just off shore to the northeast of Oahu. As waves break around the island, they are bent in two directions as they pass between the islands, coming in at about 90 degree angles. As they meet, the crests of the waves reinforce each other to create large humps at regular intervals. These are standing waves that slowly move toward shore. You can actually float on top of them and ride them for a few seconds. Between these humps, there are no waves at all and the water is very calm where the waves interfere with each other and cancel each other out.

Waves near Goat Island

Waves bending around Goat Island

According to the quantum numbers, electrons are standing waves as well with only certain energy combinations that are stable (where the waves add up). This is why the principle quantum number n is always a positive integer; any non-integer solution tends to cancel itself out, like a wavelength of 3.5 bent around the nucleus would completely interfere with itself. This is why Planck saw the quanta as being fixed energy levels where electrons could be found, but never in between.

Frozen energy s-orbitals

The s-orbital electrons create a spherical shape based on probability

Another way of looking at subatomic particles (and all matter for that matter) is that they are crystallized or frozen energy; chaotic energy patterns are trapped in a lattice or matrix of quantum numbers. I am again reminded of the patterns I see in fractal math or chaotic geometry. The atoms freeze the energy patterns, but using particle accelerators, we force the particles into phase transitions and release the trapped energy, which soon re-freezes into other particles. The more energy we can add through our collider, the more massive the subsequent collision debris will be. The dance of energy at the heart of matter is elegant and beautiful.

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