Physics Commons^™

Apparatus For Studying Wave Motion And Sound At The University Of Nebraska– Lincoln's “Historical Scientific Instrument Gallery”, Lily M. Wang, M. Eugene Rudd

Lily M Wang

The University of Nebraska–Lincoln's “Historical Scientific Instrument Gallery,'' compiled by the second author in 1998, contains approximately 700 inventoried items and may be visited on-line at http://physics.unl.edu/outreach/histinstr/. Amidst the collection are several acoustical instruments that were used in the early 1900s. These include equipment that demonstrate wave motion (traveling wave machine, mercury ripple dish, vibration microscope), wave interference (interference machine), resonance conditions (Helmholtz resonators, vibrating rods, singing flames, sonometer), and sound generation (Galton's whistles, high-frequency tuning forks, large tuning forks, organ pipes, siren saw). A review of the equipment and the history of their use at the University of Nebraska …

The International Trafficking In Arms Regulations: Precluding Innovation In Academic Spacecraft Engineering — Or Are They?, Jeremy Straub, Joe Vacek

Jeremy Straub

Government regulations and uncertainty about their enforcement can be a significant barrier to innovation. In business, it is undesirable to consume time and other resources developing a product that cannot be sold or which requires navigating significant bureaucracy for each sale. In academ-ia, where limited funding is available prior to the submission of a grant pro-posal and receipt of an award, proposal-stage compliance costs can derail a project long before it begins. This paper reviews the International Traffick-ing in Arms Regulations (ITAR) and their impact on spacecraft research in academia, private research labs and industry. It reviews the exemptions available, …

Formalizing Mission Analysis And Design Techniques For High Altitude Ballooning, Jeremy Straub, Ronald Fevig

Jeremy Straub

High altitude balloon (HAB) missions can be and are used to teach concepts related to spacecraft and satellite design. A HAB mission, however, presents unique characteristics, which must be understood and respected to produce a desirable outcome. Because of this, flying an unaltered satellite design as a HAB payload would be as undesirable as utilizing an unaltered HAB design as a satellite. A well-defined process for HAB mission design is thus needed. The process presented mirrors commonly used space mission design processes to facilitate easy transition between the two. It is also comparatively simple, due to the smaller scale of …

Emp And Geomagnetic Storm Protection Of Critical Infrastructure, George H. Baker Iii

George H Baker

EMP and solar storm wide geographic coverage and ubiquitous system effects beg the question of “Where to begin?” with protection efforts. Thus, in addressing these “wide area electromagnetic (EM) effects,” we must be clever in deciding where to invest limited resources. Based on simple risk analysis, the electric power and communication infrastructures emerge as the highest priority for EM protection. Programs focused on these highest risk infrastructures will go a long way in lessoning societal impact. Given the national scope of the effects, such programs must be coordinated at the national level but implemented at local level. Because wide-area EM …

Risk-Based Critical Infrastructure Priorities For Emp And Solar Storms, George H. Baker Iii

George H Baker

Two electromagnetic phenomena have the potential to create continental-scale disasters. The first, nuclear electromagnetic pulse (EMP), results from a nuclear detonation high above the tropopause. The second, a major solar storm, or "solar tsunami" occurs naturally when an intense wave of charged particles from the sun perturbs the earth's magnetic field. Both phenomena can debilitate electrical and electronic systems necessary for the operation of infrastructure systems and services. One reason why a U.S. protection program has yet to be initiated is that policy makers continue to wrestle with the question of where to begin, given the Department of Homeland Security’s …

Risk-Based Critical Infrastructure Protection Priorities For Emp And Solar Storms, George H. Baker Iii

George H Baker

The Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack has provided a compelling case for protecting civilian infrastructure against the effects of EMP. As with protecting infrastructure against any hazard, it will be important to take a risk-based priority approach for EMP, recognizing that it is fiscally impracticable to protect everything. In this regard, EMP is particularly challenging in that it interferes with electrical and electronic data, control, transmission, and communication systems organic to nearly all infrastructures in a simultaneous and wide-scale manner. And, for nuclear burst altitudes of 100s of kilometers, the exposed geography …

Emp: A Brief Tutorial, George H. Baker Iii

George H Baker

A nuclear detonation at altitudes from about 30 to 500 kilometers generates a strong electromagnetic pulse (EMP) that propagates to points on the ground within the line-of-sight of the burst. For bursts above 100 kilometers, electronics can be affected over continental scale areas. The EMP induces large voltages and currents in antennas and cables of electronic systems that will upset operation or damage circuit components if protection measures are not present. The article provides a brief tutorial on EMP environments, effects and protection.

High Power Electromagnetic Weapons: A Brief Tutorial, George H. Baker Iii

George H Baker

High power electromagnetic weapons, also referred to as high power radiofrequency (HPRF) weapons, are a type of directed energy weapons. The system effects of high power electromagnetic environments are well recognized by world scientific and military communities. Former CIA Director John Deutch has said that, "the electron is the ultimate precision-guided weapon." In the course of the investigation ofnuclear EMP effects on electronics during the Cold War period, it became evident that garden variety, unprotected electronics would malfunction, in some cases burn out, in the presence of electromagnetic fields in the hundreds to thousands of volts per meter. The EMP …

Report Of The Commission To Assess The Threat To The United States From Emp Attack: Critical National Infrastructures, William R. Graham

George H Baker

The physical and social fabric of the United States is sustained by a system of systems; a complex and dynamic network of interlocking and interdependent infrastructures (“critical national infrastructures”) whose harmonious functioning enables the myriad actions, transactions, and information flow that undergird the orderly conduct of civil society in this country. The vulnerability of these frastructures to threats — deliberate, accidental, and acts of nature — is the focus of greatly heightened concern in the current era, a process accelerated by the events of 9/11 and recent hurricanes, including Katrina and Rita. This report presents the results of the Commission’s …

Cascading Infrastructure Failures: Avoidance And Response, George H. Baker, Cheryl J. Elliott

George H Baker

No critical infrastructure is self-sufficient. The complexity inherent in the interdependent nature of infrastructure systems complicates planning and preparedness for system failures. Recent wide-scale disruption of infrastructure on the Gulf Coast due to weather, and in the Northeast due to electric power network failures, dramatically illustrate the problems associated with mitigating cascading effects and responding to cascading infrastructure failures once they have occurred.

The major challenge associated with preparedness for cascading failures is that they transcend system, corporate, and political boundaries and necessitate coordination among multiple, disparate experts and authorities. This symposium brought together concerned communities including government and industry …

Why Magnification Works, Terry L. Smith, Jay S. Huebner

Terry L. Smith

The simplest way to magnify the view of a small object is to bring the object closer to the eye, and of course science teachers know about magnifying glasses, telescopes, and microscopes.But why magnification works seems intuitive and is not usually explained to our students. We present here a few ideas on magnification that we use in our classroom and some general information on vision that we hope will be helpful to other teachers.

Why Magnification Works, Terry L. Smith, Jay S. Huebner

Jay S Huebner

The simplest way to magnify the view of a small object is to bring the object closer to the eye, and of course science teachers know about magnifying glasses, telescopes, and microscopes.But why magnification works seems intuitive and is not usually explained to our students. We present here a few ideas on magnification that we use in our classroom and some general information on vision that we hope will be helpful to other teachers.

Multi-Ball Collisions, Terry L. Smith, Jay S. Huebner

Terry L. Smith

Explanation to use the "double-ball" demonstration as a model for the supernova core bounce.

Nuclear Emp Hardening Approach As The Basis For Unified Electromagnetic Environmental Effects Protection, George H. Baker Iii

George H Baker

Operation DESERT STORM demonstrated the clear military advantage that was provided by our sophisticated electronic C4I and weapons systems. High tech means so dominate the battlefield that the outcome of future conflicts could be decided by electronics attrition rather than human casualties. However, the electromagnetic threat landscape is highly complex. The already formidable list of environments (EMI, lighting, ESD, EMP, HERO, TEMPEST, EW, etc.) is lengthened by emerging threats from high power microwave (HPM) and ultra-wide band (UWB) electromagnetic weapons. Many of these environments overlap in the frequency and amplitude of the electrical stresses they create.

The large number of …

Multi-Ball Collisions, Terry L. Smith, Jay S. Huebner

Jay S Huebner

Explanation to use the "double-ball" demonstration as a model for the supernova core bounce.