StarTalk Radio: Cosmic Queries – Dimensional Leaking
Host: Neil deGrasse Tyson
Release Date: June 13, 2025

Introduction to Cosmic Queries
Duration: 02:02 – 03:44

Neil deGrasse Tyson welcomes listeners to a special edition of StarTalk Radio titled "Cosmic Queries," featuring his co-host Gary and special guest Charles Liu from the Hayden Planetarium. This edition celebrates the 25th anniversary of the Rose Center’s opening and delves into intriguing astrophysical questions submitted by listeners.

1. Gravity: Force vs. Curvature of Spacetime
Duration: 05:13 – 12:24

Listener Question by Tom Stergill (@05:13):
"General relativity tells us that gravity is not a force but a reaction of spacetime to mass. Quantum theory suggests there may be parallel universes influencing our spacetime. Could this affect our understanding of dark energy?"

Discussion Highlights:

• Charles Liu (@06:05):
  "The general theory of relativity supersedes Newton's universal theory of gravity. On small scales like Earth or our solar system, you can't distinguish between acceleration and the curvature of spacetime caused by gravity."

• Graviton Theory:
  Charles explains the search for the graviton, the hypothetical particle that would mediate gravity, paralleling how photons, gluons, and W/Z bosons mediate other fundamental forces.

• Gary's Insight (@08:04):
  "Gravity's unique position in the standard model poses challenges. Unlike other forces, gravity doesn't have an associated particle within the current model, making the detection of gravitons difficult."

• Quantum Mechanics vs. General Relativity:
  The conversation delves into the incompatibility between quantum mechanics and general relativity, highlighting ongoing research to bridge the two theories.

• Charles Liu (@12:24):
  "Gravitational wave detectors provide indirect evidence for gravitons, but detecting them directly remains a significant challenge due to their low energy and high abundance."

Notable Quote:

Charles Liu (@09:15): "All other forces have mediating particles. So gravity should have the graviton, and its detection is crucial for the standard model."

2. Colliding Black Holes and Dimensional Gravity Leaking
Duration: 16:02 – 24:14

Listener Question by Parker Mann (@14:54):
"What happens just prior to the merger of two black holes' event horizons? Could the stress on spacetime increase Hawking radiation or trigger vacuum decay in massive black holes?"

Discussion Highlights:

• Charles Liu (@17:09):
  "As black holes spiral closer, gravitational waves are emitted. The exact interactions and energy releases depend on the geometry and dynamics of the merger."

• Dimensional Leakage Theory:
  Gary introduces the concept that dark matter might be ordinary matter from another universe, with gravity spilling into ours through higher-dimensional spaces, referencing Lisa Randall's "Warped Passages."

• Gary's Explanation (@20:01):
  "In higher dimensions, gravity's strength diminishes faster with distance, potentially explaining dark matter's gravitational effects without invoking new particles."

• Charles Liu (@23:35):
  "Randomld Sundrum's theory suggests that gravity could leak into extra dimensions, offering a possible explanation for dark matter and other cosmic phenomena."

Notable Quote:

Gary (@21:23): "Dark matter in our universe is 5/6 of the source of all gravity expressed here, but it drops off by the third power of distance in a fourth dimension."

3. Supernova Data and Cosmic Time Flow Variations
Duration: 24:15 – 34:25

Listener Question by Matt Koda (@24:15):
"Recent supernova data suggests time flows at different rates throughout space—faster in voids and slower where matter clumps. Could this signal a paradigm shift in our understanding of the cosmos?"

Discussion Highlights:

• Charles Liu (@25:27):
  "While it's tempting to consider this a Copernican revolution, simpler explanations like gravitational lensing might account for the observations without overhauling established theories."

• Gary's Perspective (@27:50):
  "Similar to how Kepler refined Copernicus's model with elliptical orbits, we might need to adjust our cosmological models without discarding foundational principles."

• Charles Liu (@26:25):
  "Einstein knew his theory wasn't complete. If observations require a time-dependent cosmological constant, it suggests areas where our understanding of physics can evolve."

Notable Quote:

Charles Liu (@28:27): "Science is a process of learning what's right and wrong, allowing us to build a more complex and accurate understanding together."

4. Life on Europa and Preventing Cross-Contamination
Duration: 29:00 – 34:25

Listener Question by Trisha Lynch (@29:36):
"If there is life beneath Europa’s ice, how can we observe it without risking cross-contamination?"

Discussion Highlights:

• Charles Liu (@30:03):
  "NASA's Office of Planetary Protection ensures that missions to celestial bodies like Europa avoid contaminating potential ecosystems. This involves secure spacecraft design and disposal strategies."

• Remote Sensing Techniques:
  The panel discusses using ice-penetrating radar and other remote sensing technologies to study subsurface oceans without physical contact, minimizing contamination risks.

• Future Exploration:
  Considerations for how to study potential life forms on Europa responsibly, including the challenges of deploying subsurface probes or submersibles.

Notable Quote:

Charles Liu (@31:15): "Instead of landing and risking contamination, we crash probes into planets like Jupiter and Saturn to ensure they burn up safely in the atmosphere."

5. The Universe in a Time Loop: Isaac Asimov's "The Last Question"
Duration: 43:47 – 47:54

Listener Question by Oleksandr Samulenko (@43:47):
"Could our universe exist in its own time loop, igniting a new universe as the current one dissipates?"

Discussion Highlights:

• Charles Liu (@44:44):
  "Isaac Asimov's short story 'The Last Question' explores this exact concept, pondering whether the universe can reboot itself after reaching a state of entropy."

• Cyclical Universe Theory:
  The panel discusses theoretical physics ideas about the universe cycling through phases of expansion and contraction, potentially leading to successive Big Bangs.

• Vacuum Decay and False Vacua:
  Exploration of the possibility that our universe sits in a false vacuum state, which could eventually tunnel into a true vacuum, triggering a new Big Bang.

• Mathematical Speculations:
  While these ideas are rooted in mathematical theories, they currently lack experimental verification and remain speculative within cosmology.

Notable Quote:

Charles Liu (@47:04): "The idea that our universe could tunnel into a more stable state, igniting a new Big Bang, is a fascinating speculation, but we lack the evidence to confirm it."

6. Parker Solar Probe and the Mystery of the Solar Corona
Duration: 38:00 – 43:38

Listener Question by Lily Rose (@38:00):
"What data can the Parker Solar Probe provide about the sun, and how might it help us understand the corona's inexplicably high temperatures?"

Discussion Highlights:

• Charles Liu (@38:58):
  "One major question is why the sun's corona is millions of degrees hot, much hotter than its surface. The Parker Solar Probe aims to identify the mechanisms transferring energy from the photosphere to the corona."

• Energy Transfer Mechanisms:
  The panel examines theories such as magnetic reconnection and wave heating that could explain the corona's temperature anomalies.

• Practical Implications (@42:40):
  Understanding solar dynamics helps predict space weather, which affects satellite operations and communications on Earth.

• Technical Aspects of the Probe:
  Discussion on how the Parker Solar Probe withstands extreme heat and gathers data through advanced shielding and instrumentation.

Notable Quote:

Charles Liu (@39:56): "If we understand how stars transfer energy outward, it affects everything orbiting them, including our ability to predict space weather."

Conclusion
Duration: 50:35 – 51:37

Neil deGrasse Tyson wraps up the episode by thanking Charles Liu for his insights and encouraging listeners to explore more about the discussed topics. The episode highlights the collaborative nature of scientific inquiry and the ongoing quest to unravel the universe's deepest mysteries.

Notable Quotes Recap:

• Charles Liu (@09:15): "All other forces have mediating particles. So gravity should have the graviton, and its detection is crucial for the standard model."

• Gary (@21:23): "Dark matter in our universe is 5/6 of the source of all gravity expressed here, but it drops off by the third power of distance in a fourth dimension."

• Charles Liu (@28:27): "Science is a process of learning what's right and wrong, allowing us to build a more complex and accurate understanding together."

Final Thoughts

This episode of StarTalk Radio's "Cosmic Queries" delves deep into some of the most profound questions in astrophysics and cosmology. From the enigmatic nature of gravity and dark matter to the tantalizing possibilities of life on Europa and the mysteries of the sun’s corona, Neil deGrasse Tyson and his guests navigate complex theories with clarity and enthusiasm. Whether you're a seasoned science aficionado or a curious newcomer, this discussion offers valuable insights into the ever-expanding frontier of our understanding of the universe.

Keep Looking Up!