# Is the Sun shrinking ?

**URL:** <https://boards.straightdope.com/t/is-the-sun-shrinking/503166>\
**Category:** Factual Questions\
**Created:** [July 15, 2009, 11:12pm UTC](https://boards.straightdope.com/t/is-the-sun-shrinking/503166 "2009-07-15T23:12:40Z")\
**Posts on this page:** 1\
**Page:** 2

<div class="post-metadata">

**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [July 16, 2009, 8:16pm UTC](https://boards.straightdope.com/t/is-the-sun-shrinking/503166/21 "2009-07-16T20:16:49Z")

</div>

> [@](#):
>
> At any given temperature and pressure 2 moles of hydrogen will take up twice as much volume as 1 mole of helium.  
> Now the core of a star is a somewhat extreme environment in which to apply the ideal gas law, but even more complex versions of PV = nRT follow the same general trend linking volume, moles, pressure and temperature.

4 moles of hydrogen to 1 of helium. At those temperatures, everything is monatomic.

[Previous page](https://boards.straightdope.com/t/is-the-sun-shrinking/503166.md?page=1)