The Skeptics' Guide to the Universe

The Skeptics Guide #1053 - Sep 13 2025

September 13, 2025

Key Takeaways Copied to clipboard!

  • NASA's Mars sample return mission faces significant funding cuts, potentially jeopardizing the confirmation of biosignatures found by the Perseverance rover. 
  • New research suggests that the apparent correlation between acetaminophen use during pregnancy and neurodevelopmental disorders in children is likely due to confounding familial factors, not a direct causal link. 
  • As people age, their musical tastes tend to narrow, focusing more on nostalgic music from their youth, which presents a challenge for music streaming services in recommending new, relevant content. 
  • The Alter Ego wearable device allows silent communication by interpreting sub-vocalized thoughts through muscle signals, offering potential benefits for individuals with speech disorders and other niche applications. 
  • Recent NAEP results show a significant decline in science scores for eighth graders nationwide, with only 31% scoring proficient and a widening gender gap, highlighting concerns about science education in America. 
  • The 'word is mightier than the sword' phrase has ancient origins, with its earliest written substantiation found in Egyptian folklore from the 5th century BCE, predating the more common 'pen is mightier' iteration. 

Segments

Mars Biosignatures & Funding Cuts
Copied to clipboard!
(00:00:03)
  • Key Takeaway: NASA’s Mars sample return mission faces significant funding cuts, potentially jeopardizing the confirmation of biosignatures found by the Perseverance rover.
  • Summary: The hosts discuss NASA’s announcement of possible biosignatures on Mars, noting the discovery of minerals that can be created by microbes. However, they emphasize that these minerals can also form abiotically and confirmation requires sample return to Earth. The conversation then shifts to the severe funding cuts and potential cancellation of the Mars sample return mission, with a mention of NASA administrator Nikki Fox’s quote about being close to discovering ancient life.
Earth’s Quasi-Moon Discovery
Copied to clipboard!
(00:04:28)
  • Key Takeaway: A new quasi-moon, designated 2025 PN7, has been confirmed to be co-orbital with Earth for 60 years and is expected to remain so for another 60 years before transitioning to a horseshoe orbit.
  • Summary: Evan Bernstein introduces Earth’s newest quasi-moon, 2025 PN7, which is a small asteroid (19 meters in diameter) that has been co-orbital with Earth for 60 years and will remain so for another 60. The discussion touches on the concept of mini-moons and horseshoe orbits, clarifying that quasi-moons are temporarily captured asteroids, distinct from stable dust clouds like Kordylewski clouds.
Controlling Microscopic Robots
Copied to clipboard!
(00:09:30)
  • Key Takeaway: Researchers have developed a method called ‘artificial space-times’ to control microscopic robots by projecting patterns of light, enabling complex navigation without onboard intelligence.
  • Summary: Jay discusses research from the University of Pennsylvania on controlling microscopic robots using projected light patterns. This method, termed ‘artificial space-times,’ allows robots with photovoltaic panels to move in specific directions based on light intensity, enabling them to navigate mazes and sort themselves without onboard processors. The researchers draw parallels to general relativity and optics for designing these light fields, highlighting the potential for scalable control of swarms of microbots.
Tylenol and Autism Link Debunked
Copied to clipboard!
(00:21:36)
  • Key Takeaway: Recent high-quality studies, including a large Swedish database analysis with sibling controls, have debunked the alleged link between acetaminophen (Tylenol) use during pregnancy and autism or other neurodevelopmental disorders.
  • Summary: Steve Novella addresses Robert F. Kennedy Jr.’s predicted announcement linking Tylenol use in pregnancy to autism. He explains that while preliminary observational studies might show a correlation, robust follow-up research, including a large Swedish study with sibling controls and a lack of dose-response relationship, has found no causal link. The hosts emphasize the importance of Tylenol as a safe fever reducer during pregnancy and warn against fear-mongering that could harm pregnant individuals.
Aging and Music Taste
Copied to clipboard!
(00:37:33)
  • Key Takeaway: As people age, their musical tastes become more unique and focused on nostalgic music from their youth, making it harder to discover new music that resonates.
  • Summary: Kara Santa Maria leads a discussion on how musical tastes change with age, citing a study using Last.fm data. The findings suggest that while younger people explore novelty, older individuals prefer a balance of new and familiar, with a strong inclination towards music from their youth. The hosts share personal anecdotes about their listening habits and discuss the challenges of discovering new music as one gets older, as well as the potential for music services to better cater to these evolving preferences.
Mind-Reading Wearables
Copied to clipboard!
(00:56:19)
  • Key Takeaway: The Alter Ego device uses non-invasive sensors to detect subtle muscle signals from sub-vocalized thoughts, translating them into natural language for communication with AI or other people.
  • Summary: This segment introduces Alter Ego, a startup from MIT developing a wearable device that allows silent communication through thought interpretation. The technology works by sensing weak neural signals in the face and neck associated with internal speech, which an AI then deciphers. The device also uses bone conduction to deliver silent audio responses. The discussion touches on the neurological basis for these signals, the device’s non-invasive nature compared to other brain interfaces, and its potential applications, including assisting individuals with speech disorders.
Declining Science Scores
Copied to clipboard!
(01:10:14)
  • Key Takeaway: Eighth-grade science scores have dropped significantly, erasing gains made since 2009 and indicating that two-thirds of middle schoolers lack a solid grasp of fundamental science concepts.
  • Summary: This segment reports on the latest National Assessment of Education Progress (NAEP) results for science, revealing a four-point drop in eighth-grade scores since 2009. The discussion highlights that only 31% of students are proficient, and a concerning number score below basic levels. The segment also notes a decline in student interest and enjoyment of science, as well as widening equity gaps, particularly for girls. The impact of the pandemic is considered a potential factor, and the need for better resources and support for teachers is emphasized.
Gravitational Wave Science
Copied to clipboard!
(01:28:03)
  • Key Takeaway: Gravitational wave detectors, like LIGO, are the most precise measuring instruments in science, capable of detecting disturbances on the scale of ten-thousandths the diameter of a proton, surpassing atomic clocks in relative uncertainty.
  • Summary: This segment features a ‘Science or Fiction’ game focused on gravitational waves, celebrating the 10th anniversary of LIGO’s operation. The participants guess which of three statements about gravitational waves is false. The discussion clarifies that LIGO is indeed the most precise instrument, followed by atomic clocks, and that the smallest detectable events are mergers of two neutron stars. It also confirms that LIGO detections have helped confirm Stephen Hawking’s theorem regarding black hole event horizons.
Ancient Wisdom and Etymology
Copied to clipboard!
(01:42:38)
  • Key Takeaway: The phrase ’the word is mightier than the sword’ has ancient roots, originating from the Assyrian sage Ahikar and appearing in Egyptian folklore from the 5th century BCE, predating the more common ‘pen is mightier’ version.
  • Summary: This segment delves into the etymology of the phrase ’the pen is mightier than the sword,’ tracing its origins back much further than commonly believed. The discussion reveals that the earliest iteration is ’the word is mightier than the sword,’ attributed to the Assyrian sage Ahikar and found in folklore dating back to the 5th century BCE in Egypt. The hosts reflect on the broader meaning of ‘word’ encompassing spoken language, ideas, and intellect, contrasting it with physical force.