Cosmic Gold Mining - Shreya Anand - 04/19/2024

Most of the elements that we interact with on a regular basis were originally synthesized inside stars or during their explosions. What were these conditions like and how often does this happen? Join us for a 30-minute lecture discussing the origin of the elements, followed by a panel Q&A consisting of several astrophysicists to answer your questions about astrophysics and space science. Timestamps below:
00:00 Announcements
5:58 Intro to Cosmic Gold Mining Presentation
7:15 Cosmic Gold Mining Presentation
42:15 Q&A for Cosmic Gold Mining Presentation
42:25 "Is gold's abundance on Earth's surface representative of its cosmic abundance?"
45:10 "What are optimal conditions for following up on a transient detection?"
47:31 "When does the s-process occur?"
48:18 "Can one observe heavier elements than uranium in supernovae?"
51:15 Intermission
57:55 Q&A Panel Introductions
1:00:23 "Can you explain more about the r-process?"
1:02:26 "Tell us more about beta decay?"
1:06:24 "How does the value of gold on earth relate to this study?"
1:09:15 "How do we extract gold from extraterrestrial sources?"
1:10:39 "Where did the stuff in our solar system come from?"
1:16:32 "How close do 2 neutron stars have to be to merge?"
1:19:50 "Why didn't we get heavy element production in the Big Bang?"
1:22:18 "When a neutron star merges with a black hole, do you create heavier elements?"
1:25:47 "Why is there a 3-5 solar mass threshold for black holes in your presentation?"
1:29:33 "How did the supermassive black hole in our galaxy form?"
1:34:26 "When you lack precision to measure underlying physics, what to do?"
1:37:36 "Do certain elements have different formation pathways?"
1:39:47 "Is gold's abundance on Earth's surface representative of its cosmic abundance?"
1:43:53 "What is the difference between a collapsar and a supernova?"
1:45:49 "What is the heaviest element that can be produced through the s-process?"
1:51:22 "Have we seen naturally-occurring technicium, neptunium, or unobtainium?"
1:52:42 "How did the heavy elements find their way into planets?"
1:55:37 "What distinguishes a nova, kilonova, supernova, and hypernova?"
2:00:46 Concluding Remarks
Title: Cosmic Gold Mining
Lecturer: Shreya Anand
Abstract:
Most of the elements that we interact with on a regular basis were originally synthesized inside stars or during their explosions. The heaviest of elements, such as gold, platinum, and uranium are thought to be primarily produced in extremely dense, neutron-rich, energetic explosions such as the mergers of neutron stars. In this talk, I will share a few different possible origin stories for how these rare, heavy elements came to populate the Earth and our Universe using clues from galactic archaeology, geochemistry, and rapid astronomical observations.
Image Credit: Tohoku University

[@zapfanzapfan]

I saw the eclipse in France in 1999. Definitely planning on driving to the ones in 2026 and 2027. Galicia and then Gibraltar. Modern version of pilgrimage to Santiago de Compostela 🙂

[@CaltechAstro]

Maybe we'll see you there!

[@zapfanzapfan]

@@CaltechAstro That'd be cool! Or very hot since it is in Spain in August 🔥

[@jasonodell79er]

Firmament. Flat. Motionless.

[@deepblue2250]

It turns out free proton lives about 15 min, I wonder what makes it unstable?

[@CaltechAstro]

I misspoke when I said the half-life of a free neutron was very long. It's only about 15 minutes as you say. A free proton's half life is extremely long, like much longer than the age of the universe. I do not know why neutrons are intrinsically unstable.

[@swenic]

7:20 Beginning

[@CaltechAstro]

There are timestamps already included for what it's worth.