Wave Machine Labs

[Spencer Prather]

TheShive wave machine consists of a series of horizontal metal rods 1.25 cm apart coupled by a torsion wire. A pulse can be sent down the machine by displacing the end rods (when doing this by hand, pull down on more than one rod as the connections are delicate and do break). The far end can be lamped for rigid termination to show reflections, or damped using a pair of dashpots which absorbs the energy and prevents reflections. There are three attaching units, one having 46cm long rods, one with 23cm rods, and an 'impedance matching' section with intermediate lengths. The 23cm rod section has a wave propagation velocity three times that of the 46cm section.

The wave machine is mounted on its own foldable base. The tips of the rods on our machine are coated with fluorescent paint; with the hall lights down and a 4ft black light placed in front and below the rod level, only the tips can are visible, making the wave motion beautifully clear. The dashpots 1 are attached to the last rod in the line (how far down the length of the rod for best damping takes a bit of experimenting). The driver attaches by an alligator clip to a taped loop over the first rod.

The Shive wave machine was developed at Bell Labs by John Shive. His handbook (see Reference) is a good accompaniment. Our Shive wave machine is from Pasco Scientific (SE-9600); Cenco have a similar machine (32694). The 46cm section is usually used alone.

As a managed service, Lab Services gives you automatic provisioning and management of your lab's infrastructure. Just prepare the right lab experience for your users and the service will handle the rest, rolling out and scaling your lab to hundreds of virtual machines.

The new version of Lab Services replaces the lab account concept with the lab plan concept. Both are used for controlling the configuration and settings for the labs. Learn about the new improvements.

Lab plan offers many benefits compared to a lab account when creating labs in the service. Also, lab accounts will be retired on September 30, 2024. Any labs created with a lab account will stop working at that time. Learn more about a lab plan and how to use them to create labs.

"Factoids," "Kirt's Cogitations," and"Tech Topics Smorgasbord" are all manifestations of my ranting on various subjects relevant (usually) to the overall RF Cafe theme. All may be accessed on these pages:

Sometime around 1985, I was enrolled in a second-semester physics class (AACC) while working on earning my BSEE. Along with covering topics like electricity, magnetism, heat conduction, optics, etc., my professor, a moonlighting oceanography instructor from the nearby U.S. Naval Academy, conducted a laboratory exercise wherein he wanted to demonstrate the action of sea waves breaking against the shore and underwater shelf discontinuities. He used an impressive contraption that was comprised of coplanar parallel metal rods that were attached in their centers to a spring steel bar for torsional continuity. The tips of the rods were painted white so that when the end bar was perturbed with a vertical impulse, a sinewave shape could be seen propagating along the length of the device - both an incident and, eventually, a reflected wave.

Depending on whether the last bar at the far end of the device, which I now know is called a Shive Wave Machine, is free to move or held rigidly, the reflected wave would be either in phase or out of phase with the incident wave. He then attached to the far end a smaller Shive Wave Machine to demonstrate what happens when something between an open and shorted connection terminates the larger machine. Finally, he inserted a Shive Wave Machine section between the large and small machines that had rods that tapered linearly from the large to the small size. That addition caused the reflections in the initial section to nearly (but not totally) disappear.

Upon watching the action of the Shive Wave Machine, I immediately recognized the parallel between its mechanical motions and those of electromagnetic signals on a transmission line (and in free space for that matter). The professor confirmed my assertion and noted that with his dedication to the mechanical aspects, he had not thought to relate it to electrical waves during a demonstration, although he certainly was aware it. I have written about this guy in the past, regarding him as being one of the more inspirational instructors I have had in all my engineering classes. He could work out any problem in my physics book (Halliday & Resnick), whether it be on gravitational forces, electric fields, black body radiation, or relativity.

I have thought about the Shive Wave Machine often over the years, but never knew its name until I ran across a video of it on YouTube. I honestly cannot recall the website where I saw it posted or I would give credit to the author of the article for reminding me of it. The video is embedded below.Dr. John N. Shive, of Bell Telephone Laboratories, was the inventor. He also invented thephototransistor.

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

John N. Shive was born in Baltimore, Maryland, on February 22, 1913,[2] and grew up in New Jersey.[3] Shive graduated from Rutgers University with a BS in physics and chemistry in 1934. He also earned a PhD from Johns Hopkins University, submitting a dissertation Practice and theory of the modulation of Geiger counters in 1939.[4] Shive became a fellow of the American Physical Society, a member of the American Association for the Advancement of Science, and was a member of the Phi Beta Kappa and Sigma Xi fraternities.[2]

John N. Shive joined Bell Telephone Laboratories in 1939.[2] Shive worked initially on physical research and device development, and later on education and training.[3] After retirement from industry, he worked as an adjunct professor of physics at Georgian Court University.[5] The spherical sundial on campus, in front of the bookstore and next to the library, is dedicated to his memory.[6]

Shive was a gifted lecturer, and became Director of Education and Training at Bell Telephone Laboratories.[12][13] He was responsible for curriculum and administration of educational programs provided to employees of Bell Laboratories.[3]

In this new role, he invented the Shive wave machine (also known as the Shive wave generator). The wave generator illustrates wave motion using a series of steel rods joined by a thin torsion wire which transmits energy from one rod to the next. The high moment of inertia of each rod ensures the wave takes several seconds to traverse the entire series of rods, making the dynamics easily visible. The motion is analogous to high-frequency waves that are invisible to the human eye, such as electromagnetic waves on a transmission line. The wave generator could illustrate wave reflection, standing waves, resonance, partial reflection, and impedance matching. Shive made two educational films in which he demonstrated the machine, Simple Waves[14] and Similarities in Wave Behavior,[1] and wrote a book with the same name as the latter.[15]

Shive held several patents including Selenium rectifier and method of making it,[17] Directly heated thermocouple,[18] Photoresistive translating device,[19] Selenium rectifier including tellurium and method of making it,[20] Apparatus for and method of treating selenium rectifiers,[21] Semiconductor photoelectric device,[22] Conditioning of semiconductor translators,[23] Semiconductor amplifier,[24] and Alternating gate current.[25]

Shive authored three books during his career, beginning with The Properties, Physics, and Design of Semiconductor Devices (1959), a book about semiconductor devices.[26] This was followed by Similarities of Wave Behavior (1961), a book designed to help college professors teach students about waves using the machine he invented.[1] His last book, Similarities in Physics (1982), was coauthored with Robert L. Weber.[15] He was also one of the editors of Transistor Technology, Volume 1.[27]

John N. Shive was a fellow of the American Physical Society and a Senior Member of the Institute of Electrical and Electronics Engineers. He was also a chairman of the Advisory Committee on the Pre-College Physics Project of the American Institute of Physics.[3]

Shive was married to Helen Conner, and the two were the parents of Peter, Jonathan, and Elaine. From 1974 to 1984 Shive was faculty lecturer in physics at Georgian Court College of Lakewood, New Jersey. He died on 3 June 1984 at the Riverview Medical Center in Red Bank, New Jersey.[28][26]

The lab is also connected with a number of facilities and centers that provide a wide variety of research and prototyping capabilities, including the Stevens MakerCenter, a collaborative a design hub where students and researchers conceptualize and build prototypes to turn ideas into reality.

Located in the Davidson Laboratory's primary research facility, our unique high-speed towing tank is 320 feet long, 16 feet wide, and can support a variable water depth of up to 8 feet. It is one of the highest speed towing tanks in the world with a monorail supported, cable-driven carriage capable of speeds of up to 100 feet per second with speed control of .01 feet per second.

The tank contains an articulated, double-flap, programmable wave maker capable of generating monochromatic and random wave fields, as well as several types of wave spectra. This wave maker generates both regular waves and pseudorandom waves and can be programmed to produce nontraditional wave forms such as wave pulses, complex periodic waves and dual and triple wave trains. The wave maker can be used to generate both regular and irregular waves with heights up to 18 inches.

3a8082e126