StarDate

Degenerate Future


Listen Later

The Sun faces a “degenerate” future. That’s not a value judgment – it’s physics. When the Sun can no longer produce nuclear reactions, its core will collapse. How far it collapses is limited by a type of pressure exerted by its atoms – degeneracy pressure.

Today, the Sun is “fusing” atoms of hydrogen to make helium. When the hydrogen is gone, it’ll fuse the helium to make carbon and oxygen. But the Sun isn’t massive enough to extend that process, so its nuclear furnace will be extinguished.

Fusion releases energy, which balances the pull of gravity. That keeps the Sun puffed up. Right now, it’s big enough to hold a million Earths. When fusion stops, gravity will win out. The core will shrink to the size of Earth itself. But it’ll still be about half as heavy as the present-day Sun. So a chunk the size of a sugar cube would weigh a ton.

The dead core won’t shrink beyond that. That’s because the electrons in the core will exert their own pressure – degeneracy pressure. They can be squeezed only so much before they run out of “elbow room” and halt the collapse. That will leave a white dwarf – a dead cosmic cinder – to cool and fade over the eons.

The galaxy is littered with white dwarfs, but none of them is bright enough to see with the eye alone. The closest one is a companion of Sirius, the brightest star in the night sky, which is low in the southwest as night falls – a star that faces its own “degenerate” future.

Script by Damond Benningfield

...more
View all episodesView all episodes
Download on the App Store

StarDateBy Billy Henry

  • 4.6
  • 4.6
  • 4.6
  • 4.6
  • 4.6

4.6

251 ratings


More shows like StarDate

View all
Radiolab by WNYC Studios

Radiolab

43,967 Listeners

The 365 Days of Astronomy by 365DaysOfAstronomy.org

The 365 Days of Astronomy

349 Listeners

Planetary Radio: Space Exploration, Astronomy and Science by The Planetary Society

Planetary Radio: Space Exploration, Astronomy and Science

1,347 Listeners

SpaceTime with Stuart Gary by Stuart Gary

SpaceTime with Stuart Gary

325 Listeners

BirdNote Daily by BirdNote

BirdNote Daily

1,259 Listeners

Ask a Spaceman! by Paul M. Sutter

Ask a Spaceman!

836 Listeners

Astronomy Cast by Fraser Cain and Dr. Pamela Gay

Astronomy Cast

2,881 Listeners

Universe Today Podcast by Fraser Cain

Universe Today Podcast

570 Listeners

Space Nuts: Astronomy Insights & Cosmic Discoveries by Professor Fred Watson and Andrew Dunkley

Space Nuts: Astronomy Insights & Cosmic Discoveries

234 Listeners

Science Friday by Science Friday and WNYC Studios

Science Friday

6,464 Listeners

Short Wave by NPR

Short Wave

6,564 Listeners

The Supermassive Podcast by The Royal Astronomical Society

The Supermassive Podcast

331 Listeners

NASA's Curious Universe by National Aeronautics and Space Administration (NASA)

NASA's Curious Universe

886 Listeners

Why This Universe? by Dan Hooper, Shalma Wegsman

Why This Universe?

381 Listeners

Crash Course Pods: The Universe by Crash Course Pods, Complexly

Crash Course Pods: The Universe

571 Listeners