<div dir="ltr">So I <span class="gmail_default" style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)">discussed vacuum balloons with</span> an AI (of course).  :)<br><br>The first <span class="gmail_default" style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)">response</span> was that <span class="gmail_default" style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)">vacuum balloon</span>s are not possible at present.<span class="gmail_default" style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)"> (But I didn't let that deter me).</span><br><br>Answer -<br>No, vacuum balloons are not practically possible with current materials and technology. Here are the key reasons why:<br><br>Buckling is the main issue that prevents vacuum balloons from being feasible. The external atmospheric pressure would cause the vacuum balloon shell to buckle and collapse inward, even for extremely strong materials like diamond. [3] The required material strength-to-density ratio to resist buckling exceeds what is achievable, even with theoretical materials like a diamond shell or honeycomb structures. [3][4]<br><br>The compressive strength calculation alone is insufficient - it disregards the buckling failure mode. Using the formula for critical buckling pressure of a sphere shows that no known material can practically withstand the immense external pressure. [3]<br><br>While some have proposed using a double-walled design with pressurized air between the walls, this would negate any buoyancy benefits as the overall density could not be less than air. [3]<br><br>Despite over 350 years of proposals and attempts, no one has successfully demonstrated a working vacuum balloon prototype due to these fundamental material limitations. [3][4] Vacuum balloons remain an unrealized theoretical concept with current technology.<br><br>Citations:<br>[1] <a href="https://engineering.stackexchange.com/questions/2307/can-vacuum-balloon-become-possible-with-this-idea" target="_blank">https://engineering.stackexchange.com/questions/2307/can-vacuum-balloon-become-possible-with-this-idea</a><br>[2] <a href="https://www.reddit.com/r/theydidthemath/comments/2e6m04/self_could_a_vacuum_balloon_be_possible/" target="_blank">https://www.reddit.com/r/theydidthemath/comments/2e6m04/self_could_a_vacuum_balloon_be_possible/</a><br>[3] <a href="https://en.wikipedia.org/wiki/Vacuum_airship" target="_blank">https://en.wikipedia.org/wiki/Vacuum_airship</a><br>[4] <a href="https://www.mdpi.com/2673-4117/2/4/30" target="_blank">https://www.mdpi.com/2673-4117/2/4/30</a><br><div>[5] <a href="https://science.howstuffworks.com/science-vs-myth/everyday-myths/question194.htm" target="_blank">https://science.howstuffworks.com/science-vs-myth/everyday-myths/question194.htm</a></div><div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">--------------------</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default"><br></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">I didn't give up. As I had inside information, I asked - Is a Los Alamos engineer working on this?</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default"><br></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">Answer -</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">Yes, according to the search results, Miles Beaux, a materials scientist at the Los Alamos National Laboratory, is leading a team working on developing a vacuum balloon or "air-buoyant craft" using ultra-lightweight aerogel materials. [1][2]<br><br>The key points about Beaux's work on vacuum balloons at Los Alamos are:<br><br>- Beaux's goal is to develop an aircraft that floats without heat or helium by creating a hollow sphere containing a vacuum, making it lighter than the surrounding air to stay aloft. [2]<br><br>- They are using polyimide aerogels, which are extremely lightweight yet strong enough to withstand atmospheric pressure and maintain the internal vacuum. [2]<br><br>- They have produced small prototypes ranging from lemon to soccer ball size that can hold a vacuum for up to 12 hours without active pumping. [3]<br><br>- However, these small prototypes are not yet buoyant in air. Beaux estimates they need to build a 1.4-meter diameter sphere for it to generate sufficient lift to float. [2]<br><br>- Beaux and his team have made rapid progress over the past five years, progressing from aerogels 34 times denser than air to within 10 times the density of air, which is close to achieving air buoyancy. [1]<br><br>So in summary, yes, the Los Alamos scientist Miles Beaux is actively working on developing a practical vacuum balloon design using aerogel materials as part of a team at the national laboratory. [1][2][3]<br><br>Citations:<br>[1] <a href="https://www.thomasnet.com/insights/scientists-create-vacuum-balloon-for-air-travel/" target="_blank">https://www.thomasnet.com/insights/scientists-create-vacuum-balloon-for-air-travel/</a><br>[2] <a href="https://discover.lanl.gov/publications/national-security-science/2021-winter/building-a-better-balloon/" target="_blank">https://discover.lanl.gov/publications/national-security-science/2021-winter/building-a-better-balloon/</a><br>[3] <a href="https://www.salon.com/2020/09/27/helium-shortage-vacuum-balloons-science-medicine-party-industry-inventors-engineering/" target="_blank">https://www.salon.com/2020/09/27/helium-shortage-vacuum-balloons-science-medicine-party-industry-inventors-engineering/</a><br>[4] <a href="https://discover.lanl.gov/publications/1663/2021-august/lighter-than-air/" target="_blank">https://discover.lanl.gov/publications/1663/2021-august/lighter-than-air/</a><br>[5] <a href="https://www.osti.gov/servlets/purl/1881814" target="_blank">https://www.osti.gov/servlets/purl/1881814</a></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">----------------------</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default"><br></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">To clarify the problem, I then asked - What are the main challenges faced by the Los Alamos team in developing the vacuum balloon?</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default"><br></div></div><div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">Answer -</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">The main challenges faced by the Los Alamos team in developing the vacuum balloon or "air-buoyant craft" are:<br><br>1. Scaling up the prototypes to a large enough size (around 1.4 meters diameter) to generate sufficient buoyancy to float. So far, they have only produced small prototypes ranging from lemon to soccer ball size that cannot yet hover. [1][5]<br><br>2. Developing aerogel materials with the required combination of ultra-low density (within 10 times the density of air), high strength to withstand atmospheric pressure, and ability to maintain vacuum over long periods. [1][5] <br><br>3. Engineering a vessel design and fabrication process that can create a large, lightweight, vacuum-sealed sphere strong enough to avoid buckling under external air pressure. [5]<br><br>4. Achieving a vacuum level inside the sphere that reduces its overall density below that of air to enable buoyancy. [5]<br><br>5. Integrating a lightweight vacuum pump system to actively maintain the vacuum over extended periods for sustained flight. [5]<br><br>6. Overcoming skepticism and the prevailing view that a practical vacuum balloon is impossible to realize with current materials and technology. [5]<br><br>The Los Alamos team, led by Miles Beaux, has made significant progress by using polyimide aerogels and advancing from prototypes 34 times denser than air to within 10 times air density. However, scaling up to a buoyant full-scale prototype remains a key challenge they are actively working to overcome. [1][5]<br><br>Citations:<br>[1] <a href="https://www.thomasnet.com/insights/scientists-create-vacuum-balloon-for-air-travel/" target="_blank">https://www.thomasnet.com/insights/scientists-create-vacuum-balloon-for-air-travel/</a><br>[2] <a href="https://discover.lanl.gov/publications/1663/2021-august/lighter-than-air/" target="_blank">https://discover.lanl.gov/publications/1663/2021-august/lighter-than-air/</a><br>[3] <a href="https://engineering.stackexchange.com/questions/2307/can-vacuum-balloon-become-possible-with-this-idea" target="_blank">https://engineering.stackexchange.com/questions/2307/can-vacuum-balloon-become-possible-with-this-idea</a><br>[4] <a href="https://www.osti.gov/servlets/purl/1881814" target="_blank">https://www.osti.gov/servlets/purl/1881814</a><br>[5] <a href="https://discover.lanl.gov/publications/national-security-science/2021-winter/building-a-better-balloon/" target="_blank">https://discover.lanl.gov/publications/national-security-science/2021-winter/building-a-better-balloon/</a></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">-----------------------------</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default"><br></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">I note that the  AI mentions the vacuum pump requirement. An airship needs a method of adjusting the buoyancy so that it can ascend and descend as necessary. As well as drive engines. <br></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">Research continues.......</div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default"><br></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default">BillK<br></div><div style="font-family:arial,sans-serif;font-size:small;color:rgb(0,0,0)" class="gmail_default"> <br></div><br></div></div>