AI Summary
5 min readIn 200 milliseconds, two black holes colliding 1.3 billion light years away released as much energy as every star in the universe does in the same amount of time. When that gravitational wave reached Earth, the entire planet squished and squeezed by about the width of a dozen protons. We didn't feel a thing.
That fact opens a surprisingly rich set of questions about what we can and cannot sense, what we have left in orbit, and what a single volcanic rock can tell us about the entire human story. This episode of The Rest Is Science weaves together three distinct threads — gravitational waves, space debris, and obsidian — each one a different way of thinking about what is invisible, what is dangerous, and what connects us to forces far larger than ourselves.
What It Would Actually Feel Like to Be Near a Black Hole Collision
The question from listener Ben is deceptively simple: if you were floating near a pair of colliding black holes, would you feel the gravitational wave pass through you? The answer is yes — but only under very specific conditions, and the sensation would be nothing like what you might imagine.
Continue reading the full summary in the app — free to try.
Read Full Summary →Free • No credit card required
Never miss an episode of The Rest Is Science
Get every new episode summarized in your inbox — free, ~5 minutes to read.
No spam. Unsubscribe anytime.
What you'll learn
- 1 (03:16) **Mailbag: Feeling Gravitational Waves** - Ben asks if you could feel a gravitational wave from a black hole collision pass through you.
- 2 (15:54) **Mailbag: Why Can't We See Space Junk in Photos?** - Dan asks why space junk isn't visible in photos from the ISS.
- 3 (27:10) **Mailbag: Escalators vs. Stairs** - Lawrence asks if it takes more effort to walk up an escalator than stairs.
- 4 (33:23) **Field Notes: The Sharpest Object in the Universe** - Hannah reveals her object: a polished obsidian sphere.
- 5 (47:10) **Obsidian as a Record of Human History** - The unique chemical fingerprint of each volcano allows archaeologists to trace obsidian trade routes.
- 6 Standout Quotes
- 7 (05:13) "I was 14 years old and I was in a science class at school and honestly this existential dread lasted for I would say about ten days. I was like not sleeping at night. I was really... I think it was a before time and after time, you know, before that realisation, happy and free. And then after." — Michael on realizing cosmic insignificance
+ Full timestamped outline available in the app
Show Notes
When you think of dangerous geological specimens, does your mind jump straight to radioactive uranium, toxic heavy metals, or even asbestos? What if one of the most dangerous items sitting on a shelf is actually a polished, perfectly ordinary-looking piece of black onyx?
Professor Hannah Fry and Michael Stevens dive into the surprisingly treacherous geology and chemistry of onyx.
Hannah brings an onyx from her personal rock collection to explain exactly why this specific piece of material holds the title of the most dangerous rock she owns, unpicking the fascinating physical properties of the stone and exploring how its conchoidal fracture pattern can easily create edges sharper than a modern surgical scalpel.
-------------------
For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit https://cancerresearchuk.org/restisscience
Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ.
-------------------
Find The Rest Is Science all over the internet by clicking here.
-------------------
Video Producer: Adam Thornton + Oli Oakley + Jack Meek
Animator: Sam Benson
Video & Social: Bex Tyrrell
Assistant Producer: Lucy Lipscombe
Producer: Simona Rata
Senior Producer: Lauren Armstrong-Carter
Head Of Digital: Samuel Oakley
Exec Producer: Neil Fearn
Learn more about your ad choices. Visit podcastchoices.com/adchoices
More from this podcast
The Rest Is Science →