Naked Science Forum

General Science => General Science => Topic started by: David Freedman on 28/11/2021 01:20:53

Title: mass and entropy
Post by: David Freedman on 28/11/2021 01:20:53
How does the mass of the Earth decrease  over the life of the planet . It seems that all the biosphere that has lived and died over a few billion years would add mass . One tree seed can grow and reproduce millions of seeds over its lifetime . Can you explain entropy.?  My mate Dave has tried his hardest so he is sending question for me . Thanks Jen

Title: Re: mass and entropy
Post by: Origin on 28/11/2021 04:03:23
How does the mass of the Earth decrease  over the life of the planet . It seems that all the biosphere that has lived and died over a few billion years would add mass .
The mass is recycled it doesn't add up.  The molecules and atoms in you are the same ones that were in the dinosaurs.

Entropy can be defined in few ways.  One is the waste heat of a heat engine or any process really.  Another way to define entropy is the tendency for a system to move disorder.
Title: Re: mass and entropy
Post by: evan_au on 28/11/2021 10:16:41
Quote from: OP
the Earth...entropy.
Entropy increases in an isolated system.

However, the Earth is not an isolated system:
- On one side, the Sun pours in about 700 Watts per square meter
- On the other side, heat radiates about 700 Watts per square meter into black space
- In between, Earth's biosphere makes use of this huge energy flow to survive and even thrive

It's a pity that one part of the biosphere (humanity) seems intent on taking over many other parts of the biosphere...
- This is losing a lot of genetic diversity (ie DNA variants which you could describe as "information")
- Loss of information is another description of increasing entropy