Daniel and Kelly's Extraordinary Universe
Hosted by Daniel Whiteson and Kelly Weinersmith
Written by a model from the transcript; not yet reviewed.
In this listener questions episode of Daniel and Kelly's Extraordinary Universe, hosts Daniel White and Kelly Wiener-Smith address complex listener inquiries about physics and biology. The first question, from Lincoln in Florida, tackles special relativity and whether photons near a black hole appear to slow down and stop at the event horizon. Daniel explains why velocity for distant objects is not well-defined in curved space and why that apparent slowdown is an observational artifact rather than a real physical event. Next, responding to a question from Yarthvar about life forms evolving to eat plastic, Kelly breaks down how certain bacteria, fungi, and wax worms utilize modified enzymes like PETase to break down polymer chains. Finally, Sebastian asks about the block universe theory and how special relativity affects the concept of the future being unwritten. Daniel clarifies that while special relativity shows there is no global universal now, it does not mean the future is fully predetermined or incompatible with quantum mechanics.
The episode opens with a brief iHeart introduction followed by multiple sponsor advertisements from United Healthcare, Granger, Chase, and other brands.
Daniel and Kelly welcome listeners, explain the episode’s focus on answering listener questions, and set the tone for the discussion.
The hosts summarize key takeaways, thank listeners, and sign off, concluding the episode’s Q&A session.
Daniel explains how light’s speed is constant in flat space, why this breaks down near massive objects, and why velocity is ill‑defined in curved spacetime.
Yarthvar the True inquires about organisms that digest plastic; Kelly and Daniel discuss PETase, bacterial evolution, and potential recycling applications.
The hosts promote the Chase Freedom Flex credit card, highlighting its cash‑back rewards and special Halloween bonuses.
A brief advertisement for Pepperidge Farm cookies, encouraging listeners to enjoy a treat while relaxing.
A dramatic mock emergency call about a potential murder hornet outbreak in Nashville, used as a comedic interlude.
The hosts introduce Sebastian’s question about the block universe, setting up a discussion on relativity and determinism.
The hosts explain how special relativity eliminates a universal present, using the train‑flashlight thought experiment.
Discussion of how relativity can reorder causally disconnected events but preserves causality for connected events.
Explanation of the block universe concept, treating past, present, and future as fixed within a 4‑dimensional spacetime.
Kelly recommends an AI podcast called Last Humans in the Loop hosted by her husband Zach Weiner-Smith and Marty Weiner, featuring humorous segments like Kermit the Frog reading The Odyssey.
Relativity Near Black Holesinsight
Daniel explains that light always moves at the speed of light in local flat neighborhoods, but velocity in curved space near black holes cannot be strictly defined for distant objects.
Kelly shares that bacteria discovered in a Japanese recycling plant produce an enzyme called PETase, which breaks down PET plastics into smaller carbon chains and ingredients used to make new plastic.
Block Universe and Free Willinsight
Sebastian asks whether the block universe theory means the future is completely determined. Daniel explains that special relativity means now is local, but the universe being quantum mechanical means the future is not fully predetermined.
“If you have a flashlight and you click it on, light is zooming out of your flashlight at the speed of light.”
“We produce 360 million tons of plastic waste each year.”
“This bacteria was producing an enzyme that has been named PETase.”
“You have something which does a different job and you randomly evolved to do something new, which unlocks an enormous new food source, since you can see why that would help those populations survive.”
“Special relativity can reorder events, but only ones that are causally disconnected.”
“You can still have a universe where the laws are probabilistic, for example, like quantum mechanical, right?”
“Special relativity says that the past, the present and the future are different for everybody.”
Daniel and Kelly answer listener questions about special relativity, organisms that eat plastic, and whether the future is already determined. See omnystudio.com/listener https://omnystudio.com/listener for privacy information.
12,256 words · 8 speakers
Speaker names marked are inferred from speaking time and the show’s known hosts — they are not voice-verified.
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