Observatory (LIGO) in Livingston, LA.
Image credit: LIGO Laboratory
Interferometers are investigative tools used in many fields in science and engineering. They work by merging two or more sources of light or other waves to create an interference pattern, which can be precisely measured and analyzed. Interferometers are making possible significant advances in scientific research. One of these advances is in astronomy, where laser interferometers are opening a new era in the exploration of the universe.
In 1972, a young Massachusetts Institute of Technology physics professor, Rainer Weiss, drew up a teaching exercise using a basic concept for an interferometer to detect gravitational waves. This work later became the blueprint for the Laser Interferometer Gravitational-Wave Observatory (LIGO), a national facility for gravitational wave research. LIGO is funded by the National Science Foundation and other public and private institutions.
Image credit: Mathematics and
Statistics at ScholarWorks @UMass
Amherst (Open Access)
In 1834, naval engineer John Scott Russell was riding his horse along the Union Canal in the Scottish countryside when he made a mathematical discovery. As he subsequently described it in his “Report on Waves,” presented at a meeting of the British Association for the Advancement of Science in 1844, Russell noticed a boat had stopped abruptly in the canal leaving the water in a state of violent agitation. A large solitary wave emerged from the front of the boat and rolled forward at about eight miles per hour without changing its shape or speed. He continued on his horse to follow the wave down the canal for nearly two miles until the wave became lost in the winding channel. Russell called this beautiful phenomenon the “wave of translation,” and it has become known as a solitary wave, or soliton.
James Van Allen’s space instrumentation innovations and his advocacy for Earth satellite planetary missions ensured his place among the early leaders of space exploration. After World War II, Van Allen begin his atmospheric research at the Johns Hopkins University Applied Physics Laboratory and Brookhaven National Laboratory. He went on to become the Regent Distinguished Professor and head of the University of Iowa (UI) Department of Physics and Astronomy. Drawing on his many talents, Van Allen made tremendous contributions to the field of planetary science throughout his career.
Van Allen used V-2 and Aerobee rockets to conduct high-altitude experiments, but the lift was limited. He devised a ‘rockoon,’ a rocket lifted by hot air balloons into the upper atmosphere where it was separated from the balloons and ignited to conduct cosmic-ray experiments. The rockoon, shown with Van Allen in the image above, achieved a higher altitude at a lower cost than ground-launched rockets. This research helped determine that energetic charged particles from the magnetosphere are a prime driver of auroras.
Thorium (232Th), the chemical element named after the Norse god of thunder, has a history that is as colorful as its namesake. Although discovered in 1828 by the Swedish chemist Jöns Jakob Berzelius, thorium had no known useful applications until 1885, when it was used in gas mantles to light up the streets across Europe and North America. Then in 1898, physicist Marie Curie and chemist Gerhard Schmidt observed thorium to be radioactive, and subsequent applications for thorium declined due to safety and environmental concerns. The scientific community would later find that the element thorium held promise for the planet to have clean, safe, cheap, and plentiful nuclear power as an alternative fuel to plutonium-based nuclear power plants.
One of the research programs managed by the Department of Energy (DOE) is the Atmospheric Radiation Measurement (ARM) Program, created in 1989 to address scientific uncertainties related to global climate change. ARM's Climate Research Facility, a DOE scientific user facility, provides the world's most comprehensive 24/7 observational capabilities to obtain atmospheric data specifically for climate change research. The ARM facility includes fixed, mobile, and aerial sites that gather continuous measurements used to study the effects and interactions of sunlight, radiant energy, clouds, and aerosols and their impacts on the global climate system. The ARM program serves as a model and a knowledge base for climate change research endeavors across the globe.