We also have water vapor, about 0.25% by mass. Significantly easier to get: a chemical reaction not inherently necessary, just filtering (you&#x27;re not <i>combining</i> various elements of the air mixture, just taking one that&#x27;s <i>already there</i>). Thus, no revolutionary breakthrough needed: just iterative optimization of water vapor collection.<p>Of course, the efficiency of this bottle depends on <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Humidity" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Humidity</a> - in a desert, with 0% humidity, there is very little to extract.