Podcast Summary: The Rest Is Science

Episode: Why Erdős Was The Original Kevin Bacon

Date: January 15, 2026
Hosts: Professor Hannah Fry & Michael Stevens (Vsauce)

Episode Overview

Hannah Fry and Michael Stevens embark on a characteristically quirky journey through science and mathematics, anchored by unusual personalities, the interconnectedness of academic and pop culture networks (Erdős and Bacon numbers), and the mind-bending concept of left vs. right in the universe. The episode closes with Hannah sharing her prized prop: a quantum computer chandelier from the sci-fi series 'Devs', segwaying into a accessible primer on quantum computing.
Tone: Playful, nerdy, insightful, and filled with the energy of two science enthusiasts who are as entertained by the quirks of scientists as by the science itself.

Key Discussion Points & Insights

1. Peculiar Scientists: Who Wins the Prize?

[03:29-12:39]

• Listener Q: "Who is the scientist with the most peculiar personality?"
• Hannah discusses mathematicians as especially "peculiar," singling out Paul Erdős—iconic for his wanderer lifestyle, mathematical output, and unique habits.
  • Cantor was mentioned for his wild ideas about infinity and his personal eccentricities (e.g., once believing he could cause rain by stirring his own urine) [04:13].
  • Historical odd beliefs: Newton predicting the end of the world, D.H. Lawrence claiming the moon produces its own light.
• Michael: "You have to be peculiar to... well, we're all peculiar in some way" [03:47].
• Erdős as "the six degrees of Kevin Bacon mathematician," respected not just for math, but for his remarkable collaborative life [05:06].

Notable Erdős Stories:

• Lifestyle: Erdős lived out of a suitcase, couch-surfed at mathematicians’ homes, and had no fixed residence.
  • He would let hosts feed and clothe him, then co-write papers with them—leading to an enormous web of collaborations [05:14].
  • He famously discarded clothes rather than launder them—not because he was rich, simply because he didn’t care [05:14].
• Collaborations & the Erdős Number:
  • Erdős Number: Your "distance" in co-publishing from Erdős himself. Hannah’s number is 5; her Bacon number is 3. "I've got an Erdős Bacon number of five. Two." [07:44].
  • Discussion about Daniel Kleitman, who has the rare, enviable Erdős Bacon number of 3 [08:23].
  • Michael: "Records that can't be broken, Michael, one of your favorite subjects" [09:32].
• Funny/Strange Habits:
  • Erdős was highly dependent on amphetamines, and upon being challenged to abstain for a month by Ron Graham (with a $500 bet), he succeeded, only to remark:

    "What you've proved is you proved that I'm not an addict... What you've done here is you've set mathematics back by a month." – Hannah Fry, [10:46].

  • Erdős' domestic incompetence: couldn’t make a sandwich, stabbed a carton of tomato juice open, left a mess for his host [11:42].
  • Attributed small misfortunes to "the Supreme Fascist" (God), but praised beautiful proofs as coming from "the Book" of perfect solutions [12:16].

2. The Six Degrees: Erdős vs Bacon Numbers

[06:24-09:38]

• Erdős Number:
  • How many steps are you from co-authoring a math paper with Paul Erdős?
  • Hannah recounts hers as 5; Michael contemplates how collaboration could reduce his.
• Bacon Number:
  • Used in Hollywood: Number of links (co-appearances) between an actor and Kevin Bacon.
  • Michael: "Is there a way to find out?" [07:37].
• Erdős-Bacon Number:
  • Sum of both your Erdős and Bacon numbers; legendary among nerds.
  • Daniel Kleitman holds a 3 (co-authored with Erdős, extra in Good Will Hunting with Bacon connections).
  • "Pathetic. I need to hunt down Kevin Bacon immediately." – Hannah Fry [08:53].
• Records and Impossibility:
  • Discussion about how, with Erdős deceased and Bacon alive, some records can only be tied, never beaten [09:32].

3. Physics of 'Left' and 'Right': Communicating With Aliens

[12:39-19:53]

• Listener Q: How could you explain "left vs right" to a symmetric, humanoid alien via words only—no visual reference?
• Michael references Martin Gardner's Ambidextrous Universe and the Wu experiment.
  • Three of the four fundamental forces (gravity, electromagnetism, and the strong force) are left-right symmetric.
  • Only the weak force breaks this rule—specifically, in the direction of electron emission in cobalt-60 decay (Wu experiment).
  • This allows for a universal, physically grounded definition of "left" and "right", though highly impractical:

    "If you’re willing to do a lot of work, I [the weak force] can help." – Michael Stevens [18:01].

• Thought experiments involving mugs, handles, and communicating right-handedness.
• The right-hand rule and magnetism are dismissed as circular, since you’d need to agree on “north” first [19:18].
• Hannah: "I would say it doesn't matter if they print it on the left hand. I think it'd probably be all right." [17:22]
• Michael jokes about wanting a Father's Day mug labeled with a comically high number to reflect realistic rankings, not "#1 Dad" [19:59].

4. Quantum Computing: The Ultimate Nerd Trophy

[23:20-36:32]

• Hannah presents her favorite, most ridiculous possession: the ten-foot-tall quantum computer prop from the TV series Devs (created by Alex Garland).
  • Describes its visual presence: a dazzling, gold-wired chandelier-like structure [25:30].
  • Prop dropped into her life via Adam Rutherford, after museums declined (“wasn’t a real quantum computer”) [28:42].
• Real vs. Prop Quantum Computers:
  • Real ones look similar: gold wiring, complex structures for cooling and connections; see IBM’s System Two [29:16].
  • Real quantum computers are “just fancy fridges”—delicate, ultra-cold, with lavishly expensive gold wiring for conductance [30:38].
  • Despite technological sophistication, they're still connected using outdated USB 2.0 ports—"Even the most amazing places in the world, once you peer under the surface, it's all still gaff tape and WD-40." – Hannah Fry [30:22].
• Michael admits: “I actually know basically nothing about quantum computing. I have to attack the things I’m interested in one at a time.” [30:49].
• Quantum Computing 101 by Hannah Fry [31:09]:
  • Classical computer: bits are ones and zeroes, deterministic, always repeatable.
  • Quantum computer: qubits, exist in “probability distributions,” can process many possibilities at once—“like pouring water through every path in a maze simultaneously.”
  • They’re not "better" at everything, but they’re uniquely suitable for problems involving vast numbers of possibilities (e.g., modeling atoms, breaking encryption).
  • Potential to revolutionize fields like drug discovery and battery technology.
  • Hannah: “There are things traditional computers do that quantum computers are rubbish at. But vice versa is true as well.” [34:28].
  • The field is progressing rapidly: “There’s sort of a joke…quantum computing’s always been 30 years away. A bit like fusion. But I think that we’re really starting to see genuine progress.” [35:46].
  • Cautionary sci-fi: The Devs computer in the show does not bode well for humanity—be careful what you wish for! [35:59].

Memorable Quotes & Moments

• On Mathematicians’ Quirks:

  "Mathematicians...there's Cantor who discovered infinities can be different sizes. I mean, that in itself is a wild idea. But he at one point thought that he was causing the rain by stirring his own urine."
  — Hannah Fry, [04:13]

• On Erdős’ Academic Nomadism:

  "He didn't have a house. He didn't have a kind of traditional life. What he would do is rock up at different mathematicians' houses...and sleep on their couch where they would take on the responsibility for cleaning him, feeding him, laundering his—actually, he didn't do laundry, he chucked his clothes away once he'd worn them."
  — Hannah Fry, [05:14]

• On Erdős and Drugs:

  "What you've done here is you've set mathematics back by a month."
  — Hannah Fry, recounting Erdős' comeback after abstaining from amphetamines, [10:46]

• On “The Book”:

  "When he found a really beautiful mathematical proof...he said, 'That came from the Book.' And the Book was the Supreme Fascist's little handbook of perfect Mathematical proofs that could only have been created by God." — Hannah Fry, [12:16]

• Left/Right Problem:

  "Three of the four fundamental forces, we knew made no difference when mirror reversed, left and right didn't matter... But the weak force was hypothesized to not have that same symmetry."
  — Michael Stevens, [15:27] "If you're willing to do a lot of work, I [the weak force] can help."
  — Michael Stevens [18:01]

• Quantum Chandelier:

  "Every time someone—the postman comes in, you can see it from inside the front door. They wonder what it is because it sort of looks like a spaceship."
  — Hannah Fry, [27:25]

• Quantum Computer, Practically:

  "Basically what you're looking at here—the guts of quantum computer—is just a fancy fridge."
  — Hannah Fry, [30:38] "Even the most amazing places in the world, once you peer under the surface, it's all still gaff tape and WD-40."
  — Hannah Fry, [30:22]

• On Quantum Computing Potential:

  "Imagine how different the world would be if we could design better batteries. This is another one on the list for quantum computers...I do think it is coming."
  — Hannah Fry, [35:14]

Timestamps for Essential Segments

• [03:29-12:39] — Eccentric scientists and the story of Paul Erdős
• [06:24-09:38] — Explaining Erdős number, Bacon number, and the pursuit of records
• [12:39-19:53] — The physics and philosophy of 'left' vs 'right', the Wu experiment and communicating with aliens
• [23:20-36:32] — Show-and-tell: Hannah’s Devs quantum computer, what real quantum computers are like, and a primer for beginners

Conclusion

This episode offers a delightful and enlightening tour through mathematical folklore, the strange beauty of human (and scientific) interconnectedness, the odd facts at the boundaries of physics, and an accessible glimpse into the quantum future—delivered with laughter, humility, and genuine awe about the mysteries around us.

For the science-curious, “Why Erdős Was The Original Kevin Bacon” is both a celebration of strange geniuses and a primer on some of the most fascinating ideas in mathematics and physics.