News and Events
Although high-speed turbulent jets have been studied since the 1950s, predicting the sound they produce remains a challenging problem in physics. In the BYU Physics and Aerospace Student-Centered Acoustics Laboratory (PASCAL), we investigate aircraft and rocket noise, asking age-old questions important to both physics and philosophy: Where does it come from? What makes it unique? Where is it going? Why does it matter?
In this presentation, I’ll discuss recent PASCAL research on rocket noise, including cases when things go right (launch noise and sonic booms) and when they don’t (explosions). We’ll talk about how these sounds affect structures, humans, and wildlife. I’ll also share lessons from measurement successes and failures, as well as from engaging with government officials, the media, and local communities.
| Temp: | 64 °F | N2 Boiling: | 76.0 K |
| Humidity: | 87% | H2O Boiling: | 368.6 K |
| Pressure: | 86 kPa | Sunrise: | 7:10 AM |
| Wind: | 1 m/s | Sunset: | 7:31 PM |
| Precip: | 6 mm | Sunlight: | 0 W/m² |
Selected Publications
The Extended Murphy Good (EMG) mathematical theory proposed by Richard G. Forbes for Large Area Field Emitters is applied to Patterned As-Grown Carbon Nanotube field emitters as well as existing research for comparison. Patterned As-Grown Carbon Nanotubes (developed by Brigham Young University in collaboration with Varex Imaging) were transferred to titanium substrates by means of a precise thermal process which creates a unique titanium carbide nanostructure as an adhesion mechanism for Patterned As-Grown Carbon Nanotubes. This deposition process is called the VanDyke Deposition Method. Field emission IV curve data was measured from 10 mA to 100 mA and was placed in the EMG calculator. As the EMG data more correctly estimates the vertical axis intercept the EMG results show that As-grown CNTs adhered to titanium can have Formal Emission Areas of 318.9u2 & 684.5u2 .
The shapes and densities of midsized and large trans-Neptunian objects (TNOs) are pivotal for understanding a variety of important aspects of planet formation. In this work, we present a Bayesian shape modeling method that combines constraints from rotational light curves and satellite orbits to construct three-dimensional shape models of TNOs. We use it to reanalyze three stellar occultations of the TNOs (229762) G!kún∣∣’hòmdímà (2007 UK126), (136108) Haumea, and (174567) Varda. By assuming that their satellites (or rings) orbit in their respective equatorial planes, we are able to derive unique shape models for both G!kún∣∣’hòmdímà and Haumea. Our derived shape for G!kún∣∣’hòmdímà is spheroidal with km and km, with a system density kg m−3. For Haumea, we find km, km, and km, providing kg m−3. For Varda, after updating its mutual orbit with its satellite Ilmarë, we find that currently published data are unable to fully constrain its three-dimensional shape. Intriguingly, Varda’s elongated limb appears to point toward its satellite at the time of the occultation. With a ∼2% chance of such an alignment happening randomly, this may be suggestive of a frozen-in tidal and/or rotational bulge. Our work emphasizes the importance of how external constraints can improve occultation analyses. With continued observations of rotational light curves, stellar occultations, and satellite orbits, these—and other—TNOs can have their shapes and densities further refined.
On November 19, 2024, Space-X launched the sixth test flight of their Starship rocket. Measurements were made by Brigham Young University at 21 different locations around the launch pad, including two 3-meter-radius vector probes located roughly 2 km north and 2 km south of the pad. There was also an array of measurement stations near the coast ranging from 3 km south of the pad to 27 km north. Using a broadband time-correlation technique, the direction of the sound source can be determined from the vector probes. Having two vector probes potentially allows the measurement of the trajectory of the rocket as it lifts off. It was found that the small distance between the two probes limited the accuracy of the position determination when the rocket was downrange. On this launch, the super-heavy booster did not return to the launch site but was instead diverted to the Gulf of Mexico. There were two transient events that occurred after the launch which were associated with the booster-return and the hot-staging ring reentry. These sonic booms were poorly localized by the intensity probes, but well localized by the arrival times of the booms at the array of other stations.
We present You Only Stack Once (YOSO), an automated pipeline designed to detect faint, slow-moving solar system objects in wide-field astronomical surveys. The pipeline integrates a novel Gaussian motion filter (GMoF) that operates at the pixel level to enhance the signal-to-noise ratio for objects exhibiting a range of apparent rates of motion. Unlike conventional shift-and-stack methods, which rely on discrete velocity trials, GMoF amplifies trails while suppressing random noise and static background features. Applied to a subset of DEEP observations from the Dark Energy Camera, YOSO discovered 45 out of 73 previously detected objects, as well as 11 new trans-Neptunian objects. It also discovered 216 objects in the near solar system. Although alternative shift-and-stack methods are sensitive to objects about 0.88 mag fainter, YOSO’s false-positive rate is extremely low, since it detects only sources that exhibit a trail and are consistent with a point source when shifted at the right rate. We show how this method can be deployed on large surveys like LSST, and be adapted for other domains that require motion-based signal enhancement, including exoplanet imaging through angular differential imaging and near-Earth object (NEO) detection for missions like the NEO Surveyor. YOSO thus provides a versatile, scalable approach for extracting faint, motion-dependent signals in the era of data-intensive astronomy.
Glycosylation is the most common post-translational modification in the human proteome, with over half of all human proteins bearing covalently attached glycans. These glycan structures direct protein folding through ER quality control machinery, shield polypeptides from proteolytic degradation, regulate circulatory half-life via the asialoglycoprotein receptor, and serve as molecular signals for immune recognition and intracellular trafficking. For biopharmaceuticals, which constitute a rapidly growing share of approved drugs, glycan profiles are critical quality attributes that directly determine clinical efficacy and safety. Yet achieving the correct glycosylation on a therapeutic protein remains one of the field’s central challenges, as glycan biosynthesis is non-template-driven and highly sensitive to expression system and manufacturing conditions. This review connects the biological functions of glycosylation to the practical strategies of glycoengineering, examining how sequence design, expression system selection, and downstream enzymatic remodeling are used to optimize therapeutic glycoproteins. Clinical case studies spanning monoclonal antibodies, cytokines, and enzyme replacement therapies illustrate how glycan engineering translates into improved patient outcomes. We conclude by surveying emerging technologies poised to make precisely glycosylated therapeutics more accessible.
Rocket launches generate acoustic environments that impact nearby communities, motivating the need for tools to predict launch noise at the community level. RUMBLE is a computational rocket noise prediction model that produces spatial predictions of acoustic metrics but offers limited temporal resolution, complicating direct comparison with field measurements. This paper tests whether RUMBLE-predicted unweighted maximum sound levels (Lmax) agree with community-level measurements from nine Falcon 9 Block 5 launch events recorded near Cape Canaveral, Florida. Field measurements were obtained using Larson–Davis sound level meters deployed at residential distances of approximately 20–25 km from active launch pads. Because RUMBLE outputs only scalar metrics without time histories, a rolling Lmax analysis using Z-weighting and slow exponential time weighting was developed to enable direct comparison. Across nine launch events, RUMBLE-predicted Lmax values agreed with measured community levels within 5 dB, with mean absolute differences of 3.5 dB for Space Launch Complex 40 operations and 2.8 dB for Launch Complex 39A operations. These results demonstrate that Lmax is an effective scalar metric for validation of RUMBLE predictions at community locations. While the absence of time-domain and spectral outputs limits more detailed comparisons, the results provide a foundation for future model development and monitoring efforts.