skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Hidden in Plain Sight: Discerning Signal from Noise in the Expanded Laboratory Environment
What happens when disturbances in precision measurement instruments are indecipherable to physicists despite extensive review of the instruments and their outputs? How do physicists parse instrument outputs to discern sought-after signals from noise that originates from the surrounding natural and built environments, either masking or mimicking these desired signals? I argue that given the extreme sensitivity of the laser interferometers used by the Laser Interferometer Gravitational-Wave Observatory (LIGO) to detect minute length deformations caused by gravitational waves, physicists reconceptualized their traditional laboratory spaces to include the surrounding natural and built environments. Discerning signal from noise in instruments operating close to their low noise floors necessitate an epistemic shift that combines the laboratory with the surrounding natural and built environments beyond its walls through the epistemic space of the “expanded laboratory environment.”  more » « less
Award ID(s):
1946555
PAR ID:
10559161
Author(s) / Creator(s):
Publisher / Repository:
Historical Studies in the Natural Sciences, University of California Press
Date Published:
Journal Name:
Historical Studies in the Natural Sciences
Volume:
54
Issue:
3
ISSN:
1939-1811
Page Range / eLocation ID:
335 to 364
Subject(s) / Keyword(s):
gravitational waves laboratory, environment disturbance noise stillness expanded laboratory environment
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Ground-based gravitational-wave (GW) detectors are a frontier large-scale experiment in experimental astrophysics. Given the elusive nature of GWs, the ground-based detectors have complex interacting systems made up of exquisitely sensitive instruments which makes them susceptible to terrestrial noise sources. As these noise transients - termed as glitches - appear in the detector's main data channel, they can mask or mimic real GW signals resulting in false alarms in the detection pipelines. Given their high rate of occurrence compared to astrophysical signals, it is vital to examine these glitches and probe their origin in the detector's environment and instruments in order to possibly eliminate them from the science data. In this paper we present a tensor factorization-based data mining approach to finding witness events to these glitches in the network of heterogeneous sensors that monitor the detectors and build a catalog which can aid human operators in diagnosing the sources of these noise transients. Available from: https://openreview.net/forum?id=O9q0ma6Oh5e 
    more » « less
  2. Electroencephalogram (EEG) signals are often used as an input modality for Brain Computer Interfaces (BCIs). While EEG signals can be beneficial for numerous types of interaction scenarios in the real world, high levels of noise limits their usage to strictly noise-controlled environments such as a research laboratory. Even in a controlled environment, EEG is susceptible to noise, particularly from user motion, making it highly challenging to use EEG, and consequently BCI, as a ubiquitous user interaction modality. In this work, we address the EEG noise/artifact correction problem. Our goal is to detect physiological artifacts in EEG signal and automatically replace the detected artifacts with imputed values to enable robust EEG sensing overall requiring significantly reduced manual effort than is usual. We present a novel EEG state-based imputation model built upon a recurrent neural network, which we call SRI-EEG, and evaluate the proposed method on three publicly available EEG datasets. From quantitative and qualitative comparisons with six conventional and neural network based approaches, we demonstrate that our method achieves comparable performance to the state-of-the-art methods on the EEG artifact correction task. 
    more » « less
  3. Abstract Understanding the noise in gravitational-wave detectors is central to detecting and interpreting gravitational-wave signals. Glitches are transient, non-Gaussian noise features that can have a range of environmental and instrumental origins. The Gravity Spy project uses a machine-learning algorithm to classify glitches based upon their time–frequency morphology. The resulting set of classified glitches can be used as input to detector-characterisation investigations of how to mitigate glitches, or data-analysis studies of how to ameliorate the impact of glitches. Here we present the results of the Gravity Spy analysis of data up to the end of the third observing run of advanced laser interferometric gravitational-wave observatory (LIGO). We classify 233981 glitches from LIGO Hanford and 379805 glitches from LIGO Livingston into morphological classes. We find that the distribution of glitches differs between the two LIGO sites. This highlights the potential need for studies of data quality to be individually tailored to each gravitational-wave observatory. 
    more » « less
  4. Despite being the dominant force of nature on large scales, gravity remains relatively elusive to precision laboratory experiments. Atom interferometers are powerful tools for investigating, for example, Earth’s gravity, the gravitational constant, deviations from Newtonian gravity and general relativity. However, using atoms in free fall limits measurement time to a few seconds, and much less when measuring interactions with a small source mass. Recently, interferometers with atoms suspended for 70 s in an optical-lattice mode filtered by an optical cavity have been demonstrated. However, the optical lattice must balance Earth’s gravity by applying forces that are a billionfold stronger than the putative signals, so even tiny imperfections may generate complex systematic effects. Thus, lattice interferometers have yet to be used for precision tests of gravity. Here we optimize the gravitational sensitivity of a lattice interferometer and use a system of signal inversions to suppress and quantify systematic efects. We measure the attraction of a miniature source mass to be amass = 33.3 ± 5.6stat ± 2.7syst nm s−2, consistent with Newtonian gravity, ruling out ‘screened ffth force’ theories3,15,16 over their natural parameter space. The overall accuracy of 6.2 nm s−2 surpasses by more than a factor of four the best similar measurements with atoms in free fall. Improved atom cooling and tilt-noise suppression may further increase sensitivity for investigating forces at sub-millimetre ranges, compact gravimetry, measuring the gravitational Aharonov–Bohm effect and the gravitational constant, and testing whether the gravitational field has quantum properties. 
    more » « less
  5. Professional engineering demands more than the ability to proficiently carry out engineering calculations. Engineers need to approach problems with a holistic view, make decisions based on evidence, collaborate effectively in teams, and learn from setbacks. Laboratory work plays a crucial role in shaping the professional development of university engineering students, as it enables them to cultivate these essential practices. A successful laboratory task design should provide students opportunities to develop these practices but also needs to adhere to the constraints of the educational environment. In this project, we explore how both virtual (simulation-based) and physical (hands-on) laboratories, based on the same real-world engineering process, prepare students for their future careers. Specifically, we seek to determine whether the virtual and physical laboratory modes foster different yet complementary epistemic practices. Epistemic practices refer to the ways in which group members propose, communicate, justify, assess, and validate knowledge claims in a socially organized and interactionally accomplished manner. To accomplish these objectives, we are conducting a microgenetic analysis of student teams engaging in both the virtual and physical versions of the same laboratory exercise, the Jar Test for Drinking Water Treatment. Jar testing is a standard laboratory procedure used by design engineers and water treatment plant operators to optimize the physical and chemical conditions for the effective removal of particulate contaminants from water through coagulation, flocculation, and settling. The central hypothesis guiding this research is that physical laboratories emphasize social and material epistemic practices, while virtual laboratories highlight social and conceptual epistemic practices. The goal is to gain transferable knowledge about how the laboratory format and instructional design influence students' engagement in epistemic practices. To date we have developed physical and virtual versions of the Jar Test laboratory, each built around the affordances of their respective modes. We have completed two rounds of data collection resulting in data from 21 students (7 groups of 3). The primary data sources have included video recordings and researcher observations of the teams during the laboratory work, semi-structured stimulated recall interviews with students and laboratory instructors, and student work products. Using discourse analysis methods within a sociocultural framework, we are addressing the following research questions: 1. In what ways and to what extent does conducting an experiment in a physical mode to develop a process recommendation influence students’ engineering epistemic practices? 2. In what ways and to what extent does conducting an experiment in a virtual mode to develop a process recommendation influence students’ engineering epistemic practices? 3. How do students in each laboratory mode respond to being “stuck”? Do students’ views on the iterative nature of science/engineering and their tolerance for mistakes depend on the instructional design afforded by the laboratory mode? While this study focuses on a process specific to environmental engineering, its findings have the potential to positively impact teaching and learning practices across all engineering and science disciplines that rely on laboratory investigations in their curriculum. 
    more » « less