Like all great researchers, we love spending time learning about the latest breakthroughs across science and technology. Here's what we found this week.
A new method can provide explanations for the decisions made by self-driving cars.
MIT | Adam Zewe. Working with technicians at an autonomous vehicle technology company, researchers developed the Concept-Wrapper Network, which provides easy-to-understand explanations of the reasoning process in a self-driving car's AI system. CW-Net provides real-time feedback that engineers can use to troubleshoot inexplicable decisions made by these systems, thereby improving safety. (More)
> Used to verify that you're human on websites, CAPTCHA puzzles provide training data for the algorithms in self-driving cars.
> ... and some of these algorithms make decisions based on data collected by lasers.
A galaxy's chemical evolution may be traced through light from certain elements.
Ohio State University | Tatyana Woodall. Because stars form certain heavy elements when they explode, the elements' increasing abundances across successive generations of stars can be used as "cosmological clocks" of a galaxy's life. Researchers predict that certain elements, such as manganese, are particularly sensitive to changes in temperature and density, making their emission spectra useful for analyzing supernova remnants and large molecular clouds. (More)
> Watch a video explainer of why every element emits a unique light signature.
> By mass, more than 90% of the elements in the human body were forged in stars.
Evidence suggests that sea spray does not increase exposure to forever chemicals.
York University | Sandra McLean. Previous international studies involving modeling and lab work suggested that sea spray is a significant source of per- and polyfluoroalkyl substances. However, fieldwork in areas affected by sea spray from the Atlantic Ocean found no major contribution, with findings suggesting that the detected PFAS originated from atmospheric precursor compounds. (More)
> Slow to break down, forever chemicals have been used since the 1940s.
> Explore an interactive map of forever chemical testing results in public water systems.
Novel speakers create sound that is audible only to a specific person.
Pohang University of Science & Technology | Staff. Traditionally, directional audio systems rely on arrays of tens to hundreds of ultrasonic emitters, with interactions between these inaudible sound waves generating audible sound in a specific direction. Instead of these complex, costly systems, scientists integrated two types of metamaterials into a single ultrasonic emitter, which behaved like a lens for sound and produced a laser-like audio beam that did not leak out from the sides. (More)
> View how every sound imaginable can be created by overlapping sound waves.
> The human auditory system, which includes the three smallest bones in the human body, prevents airborne ultrasound from being audible.
