Podcast Summary: Introducing: The Rest Is Science

Podcast: WW2 Pod: We Have Ways of Making You Talk
Hosts for Segment: Michael Stevens & Professor Hannah Fry
Guest Appearances/Context: Al Murray and James Holland (not present, show channel hosts)
Date: December 1, 2025
Episode Purpose:
This special crossover episode introduces The Rest Is Science, a new science podcast from Goalhanger. Michael Stevens and Professor Hannah Fry invite listeners to explore the hidden logic and unexpected patterns of the world, using the topic of gravity as an intriguing example.

Main Theme

Michael and Hannah use the topic of gravity—a force at once familiar yet deeply mysterious—as a lens to tease the kind of curious, enlightening content their new podcast will offer. They break down how scientists’ understanding of gravity has evolved from Newton's simple law of attraction to Einstein's radical theory of spacetime—peppering the discussion with humor, accessible analogies, and surprising implications.

Key Discussion Points & Insights

1. Gravity for Aliens: The Basic Concept

[01:24 - 02:13]

• Hannah invites Michael to describe gravity to an alien unfamiliar with the concept.

• Michael boils it down: "objects are attracted to each other...if you just have two objects near each other, they will come together, that's it."

  • (Hannah Fry, 01:33)

• They riff on the idea with a playful improvisation involving aliens, defining "object" as "anything with mass."

• Michael notes, "We imagine gravity as though the Earth is pulling us down, but the thing is, we're also pulling the Earth up."

  • (Michael Stevens, 01:54)

2. Everyday Examples and Calculations

[02:13 - 04:37]

• Michael recounts a calculation: Two baseballs in intergalactic space, 1 meter apart, would drift together in 3 days due to gravity.

  • (Michael Stevens, 02:13)

• Fun fact: The gravitational influence of a doctor delivering a baby is stronger than that of a distant constellation, poking fun at astrology.

  • "...the gravitational influence of Pisces on you is less than the gravitational influence of the doctor who delivered you."
    (Michael Stevens, 02:55)

• When a pen is dropped from six feet, it pulls the Earth upwards by "9 trillionths the width of a proton," a minuscule but real effect.

  • "By my calculation, small."
    (Hannah Fry, 04:07)

3. Why Do All Objects Fall the Same?

[04:37 - 05:16]

• Feather vs. hammer: In a vacuum, "they will fall at the same rate," Michael confirms—the difference is only due to air resistance.

4. A History of Gravity: Newton to Einstein

[05:16 - 09:17]

Newtonian Gravity:

• Hannah explains Newton's laws: Gravity as "objects accelerating towards each other."
  • Newton succeeded for centuries, but his model left mysteries, e.g., Mercury’s odd orbit.

The Sun Vanishing Thought Experiment:

• If the sun disappeared, how fast would the gravitational effect be felt? Newton’s theory implies instantly, but that violates relativity and the speed of light.

Einstein’s Breakthrough:

• Michael: "Maybe gravity is just a change in the shape of space time."

  • (Michael Stevens, 09:17)

• Hannah describes Einstein’s discovery: Mass bends the spacetime fabric. If the sun vanished, we’d feel it only after a ripple (gravitational wave) reached us at the speed of light.

• Verified by Einstein’s calculation of Mercury’s orbit—solving what Newton could not.

  • "He absolutely nailed it...he said that he was happy for days after...I've absolutely got it."
    (Hannah Fry, 09:02)

5. Spacetime Analogies and Implications

[09:17 - 11:33]

• Michael’s analogy: Spacetime is like a curtain; if it bunches up or crumples, anything on that surface (us) must go along.

  • "If I crumple the curtain up, they're still stuck on it and they're going over all of these crinkles, but they don't even know it."
    (Michael Stevens, 09:39)

• Time is affected by gravity—stronger gravity means time moves slower.

• Example: In Boulder (high altitude, less gravity), time moves faster than in Greenwich, UK.

  • "The gravitational effect in Boulder is 9.796 meters per second. In Greenwich, it's 9.812...Time travels slower in Greenwich than it does in Boulder. The difference is about 5.6 microseconds a year."
    (Hannah Fry, 11:15-11:33)

Notable Quotes & Memorable Moments

• On Astrology:
  "...the gravitational influence of Pisces on you is less than the gravitational influence of the doctor who delivered you."
  — Michael Stevens [02:55]

• On Newton & Einstein:
  "Everyone...was like, that guy Newton, he's got it made. He's done it for us. That's perfect. But there were still some lingering questions..."
  — Hannah Fry [05:36]

  "...Einstein is like, but what if it's the shape of the canvas that we are on?"
  — Michael Stevens [10:08]

• On Analogies:
  "We need analogies because we're just talking about things that are so out of our normal day to day activities."
  — Michael Stevens [10:25]

Timestamps for Key Segments

• [01:24] — Explaining gravity to an alien
• [02:13] — Baseballs-in-space example; gravitational attraction in everyday life
• [04:37] — Why feather and hammer fall together in a vacuum
• [05:16] — Newton's theory of gravity explained
• [06:35] — The speed of gravity; Newtonian vs. Einsteinian view
• [08:00] — Mercury’s orbit and Newton’s unsolved mystery
• [09:17] — Einstein's big leap: gravity is the shape of spacetime
• [10:46] — Boulder vs. Greenwich: how gravity subtly changes time

Tone and Style

The segment is marked by Michael and Hannah’s easy, humorous banter and knack for breaking down dense topics with vivid analogies and playful asides. Their approach is curious, accessible, and welcoming to listeners with or without a scientific background.

Summary for New Listeners

This episode offers a taste of the intellectual curiosity and accessible expertise listeners can expect from The Rest Is Science. Through the lens of gravity—blending thought experiments, science history, and everyday examples—Michael Stevens and Professor Hannah Fry invite audiences to question the world around them and discover the wonders hiding in plain sight.