Why We Have Heavy Elements on Earth

  • Context: Graduate 
  • Thread starter Thread starter paweld
  • Start date Start date
  • Tags Tags
    Earth Elements
Click For Summary

Discussion Overview

The discussion revolves around the presence of heavy elements, such as uranium and lead, on Earth, particularly questioning their origins if they were not produced during the Big Bang or through stellar nucleosynthesis processes that typically yield elements only up to iron and nickel.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions the existence of heavy elements on Earth, suggesting a lack of understanding of their origins if not from the Big Bang or stellar nucleosynthesis.
  • Another participant asserts that heavy elements are produced in supernova explosions, referencing the "S-process" and "R-process" in stellar nucleosynthesis as mechanisms for their creation.
  • A participant inquires about the proximity of supernovae to Earth, indicating a curiosity about the relevance of nearby supernovae to the presence of heavy elements.
  • It is noted that supernovae create shock waves that disperse material throughout the galaxy, with a historical context provided about the frequency of supernovae in the Milky Way and their contribution to the interstellar medium from which the solar system formed.
  • A later reply confirms the understanding of the topic, indicating a shift in clarity regarding the origins of heavy elements.
  • Another participant emphasizes that numerous supernovae contributed to the material in the proto cloud from which the solar system formed, particularly noting the timeframe of 6-9 billion years ago.

Areas of Agreement / Disagreement

Participants generally agree on the role of supernovae in producing heavy elements, but there is an initial uncertainty about their origins that is addressed through the discussion. The conversation reflects a mix of exploratory questioning and technical explanation without any explicit consensus on all aspects.

Contextual Notes

The discussion does not resolve the initial question about the origins of heavy elements beyond the assertion of supernova contributions, leaving some assumptions about the processes and their implications unexamined.

Who May Find This Useful

This discussion may be of interest to those exploring astrophysics, stellar nucleosynthesis, or the formation of elements in the universe.

paweld
Messages
253
Reaction score
0
Why we have (although very little) on Earth heavy elemnents such
as uranium, lead, ... if they weren't created in Big Bang or stellar nucleosynthesis
(these proceses don't produce elements heavier than iron and nickel).
Any guesses?
 
Astronomy news on Phys.org
No need to guess - these processes are well understood. Elements heavier than iron are produced primarily in supernova explosions, where there is a flood of neutrons which builds up the heavier elements. Look up the "S-process" and the "R-process" in stellar nucleosynthesis.
 
But is there any supernove near Earth?
 
Supernovae create massive shock waves which blow material out into the host galaxy. A galaxy like the Milky Way has on the order of about 1 supernova per century. Since the Milky Way was in existence for billions of years before the sun formed, there were millions of prior supernovae within the Milky Way, all churning up the interstellar material. So, when the solar system formed, there was an ample supply of heavy elements from supernovae with which to build the planets. As the song goes, "...we are stardust..."
 
Yes, it's now clear.
Thanks.
 
Numerous supernova contributed matter to the proto cloud from which the solar system formed. Mostly from 6-9 billion years ago.
 

Similar threads

  • · Replies 28 ·
Replies
28
Views
4K
  • · Replies 34 ·
2
Replies
34
Views
7K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
0
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
6K
  • · Replies 4 ·
Replies
4
Views
3K