# The sun must be stopped - with seawater! **URL:** \ **Category:** Factual Questions\ **Created:** [March 15, 2011, 6:23am UTC](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756 "2011-03-15T06:23:44Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [March 15, 2011, 5:54pm UTC](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756/21 "2011-03-15T17:54:48Z")
> [@Autolycus](#): > > Let us assume for the sake of argument that there is an infinite supply of seawater. Then the answer is easy: All of it. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [March 15, 2011, 9:11pm UTC](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756/22 "2011-03-15T21:11:18Z")
> [@Chronos](#): > > Quoth **AndrewL** :You certainly could. When the Sun eventually dies a natural death, it’ll still have about 90% of its original hydrogen remaining. The dying is triggered by having too much waste helium, not by having not enough hydrogen. And anything more massive than helium will work even better. My guess is that by adding water to the Sun, you’re doing more to quench it with the oxygen than you are to fuel it with the hydrogen. And it’s seawater at that. So there are heavier elements there, too. ---
**Author:** ![DHMO](https://avatars.discourse-cdn.com/v4/letter/d/ecc23a/32.png) [@DHMO](https://boards.straightdope.com/u/DHMO)\ **Post date:** [March 15, 2011, 10:47pm UTC](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756/23 "2011-03-15T22:47:16Z")
> [@Chronos](#): > > You certainly could. When the Sun eventually dies a natural death, it’ll still have about 90% of its original hydrogen remaining. The dying is triggered by having too much waste helium, not by having not enough hydrogen. And anything more massive than helium will work even better. My guess is that by adding water to the Sun, you’re doing more to quench it with the oxygen than you are to fuel it with the hydrogen. It would be hard (or impossible) to “quench” the solar furnace with Oxygen, since Oxygen is one of the steps in the [CNO cycle](http://en.wikipedia.org/wiki/CNO_cycle) of stellar fusion, and acts as a catalyst to the fusion reaction. The basic equation is: four Hydrogen atoms fuse to form one Helium nucleus, with the concomittant release of enormous energy. In stars of approximately the mass of our Sun, the [proton-proton](http://en.wikipedia.org/wiki/Proton-proton_chain) reaction predominates. At a mass of about 1.3 Solar masses or more, the CNO cycle is dominant. If you add enough water to theoretically “quench” the fusion reaction at the Sun’s core, you have added a sufficient amount of matter to easily increase the Sun’s mass to the tipping point where CNO predominates, mostly by adding a lot of Hydrogen fuel, and enough extra Oxygen to speed the reaction. This will quench the Solar furnace about as well as throwing gasoline on a burning house. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [March 15, 2011, 11:46pm UTC](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756/24 "2011-03-15T23:46:28Z")
OK, then. None of it. ---
**Author:** ![Canadjun](https://avatars.discourse-cdn.com/v4/letter/c/76d3ee/32.png) [@Canadjun](https://boards.straightdope.com/u/Canadjun)\ **Post date:** [March 16, 2011, 12:00am UTC](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756/25 "2011-03-16T00:00:19Z")
> [@Chessic\_Sense](#): > > But the water would displace the hydrogen and helium at the core. If you used iron, wouldn’t the iron sink to the center of the star and stop fusion at some point _before_ the star would be so massive that it could fuse iron? Wouldn’t the hydrogen float on top of the iron and continue fusing? ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [March 16, 2011, 12:03am UTC](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756/26 "2011-03-16T00:03:28Z")
> [@Canadjun](#): > > Wouldn’t the hydrogen float on top of the iron and continue fusing? At those temperatures, iron would be an incandescent plasma. [Previous page](https://boards.straightdope.com/t/the-sun-must-be-stopped-with-seawater/574756.md?page=1)