Wave-like modulations with non-lattice periodicities accompany a variety of important physical phenomena (e.g. magnetism and superconductivity). Though such a material is not properly crystalline in three dimensions, it does have a regular crystal lattice in a higher dimensional superspace. The superspace symmetry groups in (3+1), (3+2) and (3+3) dimensions have now been exhaustively tabulated, which will make it easier to solve modulated structure and understand their properties.
This image was secured just after the end of evening twilight on a clear April night from the West Mountain Observatory. The view is looking west past the domes housing the two smaller research telescopes at the observatory. The thin crescent Moon is also illuminated by reflected light from the Earth that is known as earthshine. Higher in the sky, the bright 'star' is actually the planet Venus. In between the two, the 'V' shaped group of stars in the constellation of Taurus is in reality the nearby open cluster known as the Hyades. Photo credit: Dr. Michael D. Joner
The anisotropic x-ray diffuse scattering pattern surrounding this Bragg reflection from La1.8Sr2.2Mn2O7 at 125 K provides evidence that Jahn-Teller polarons (football-shaped lattice distortions that follow hopping electrons from site to site) play a role in this material's exotic phase transition from paramagnetic insulator to ferromagnetic metal. This data was used to perform a quantitative three-dimensional structural analysis of transient polaronic distortions.
This image from the BYU 0.9-m telescope looks out along the plane of our Milky Way Galaxy toward the constellation Cygnus the Swan. Called the Tulip Nebula, the glowing cloud of interstellar gas and dust is also listed in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. This nebula is about 8,000 light-years away from the solar system. The nebula shown here is a composite image that maps emission from sulfur, hydrogen, and oxygen atoms into red, green, and blue colors. Energy from the hot O-type star HDE 227018 ionizes atoms in this region so that we see a faint glow from the Tulip Nebula. HDE 227018 is seen near the blue arc at center of the image. This appeared as the NASA Astronomy Picture of the Day on July 26, 2012. Image Credit & Copyright: Michael Joner, David Laney (West Mountain Observatory, BYU); Processing - Robert Gendler
This photograph from university photographer, Mark Philbrick shows the BYU 0.9-meter Reflector at the West Mountain Observatory focused on a field near the galactic center during the summer of 2016. The stars of the constellation Scorpius are visible through the lower center portion of the dome slit with the planets Mars (on the right side) and Saturn (just off the left edge) visible. The computer controlled telescope was funded through an NSF grant; AST 0618209.
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Kent Gee, Traci Neilsen, and Mylan Cook et al. recently published an article titled "Characterization of Supersonic Laboratory-Scale Jet Noise with Vector Acoustic Intensity" in 23rd AIAA/CEAS Aeroacoustics Conference, (Denver, CO, June 2017), AIAA AVIATION Forum, (AIAA 2017-3519). Click on the image above to read it.
Perseid by the Sea: Just after moonrise on August 12 this grain of cosmic sand fell by the sea, its momentary flash part of the annual Perseid Meteor Shower. To create the Perseid meteors, dust along the orbit of periodic comet Swift-Tuttle is swept up by planet Earth....
This photograph and Description come from NASA's Astronomy Picture of the Day web site.