The text is a detailed explanation of aerogel, a lightweight, air-filled material that is less dense than a volume of air. It was first invented by Professor Samuel Kissler in 1931, who won a bet with his colleague Charles Learned. The bet revolved around whether it was possible to remove the liquid from a jelly without affecting the solid structure. Kissler solved this problem by using a high-pressure vessel called an autoclave to transform the liquid into a supercritical fluid, which then turned into aerogel.
The video demonstrates the insulating power of aerogel through an experiment involving melting chocolate bunnies. The aerogel setup took longer to melt the chocolate due to its superior thermal insulation. Aerogel is made from a variety of materials, including eggs, rubber, and silica. The process of creating aerogel involves replacing the alcohol in the gel with liquid carbon dioxide, which then transforms into a supercritical fluid when heated.
Aerogel is used for its exceptional thermal insulation properties. It's better than air at insulating heat due to its smaller pore widths, which makes it difficult for hot air molecules to diffuse through it. NASA uses aerogel insulation in their Mars rovers and plans to use it in future missions. It's also used in more exotic applications, such as capturing dust particles from comets.
Although aerogel is currently expensive and not very durable, scientists are working on reducing costs and increasing its durability. There are also ongoing efforts to make aerogel waterproof and hydrophilic. The video ends with a joke about using aerogel for thermal insulation in skyscrapers in Antarctica.
1. Aerogel is the world's lightest solid, with a mass of just 1.22 grams. This is only a few times the mass of the same volume of air .
2. Aerogel is 99.8% air .
3. Some aerogels are so light that if you removed all the air from them, they would be less dense than air .
4. Aerogel was invented by Professor Samuel Kissler in 1931 .
5. Kissler's experiment involved replacing one liquid with another inside a jelly through thorough washing .
6. The jelly was put in a high-pressure vessel called an autoclave, heated to the high temperature and pressure point of the liquid, transforming it into a supercritical fluid .
7. The solid skeleton of the gel remained intact after depressurizing the vessel, except where there was liquid in the pores before, which was now gas .
8. Kissler published his findings in Nature in 1931 .
9. Kissler made aerogels out of various materials, including eggs, rubber, and nitrocellulose .
10. Aerogel is almost impossible to see on a light background due to its transparency, but it appears bluish on a dark background .
11. The bluish color of aerogel is due to Rayleigh scattering of light by its nanoscale structures .
12. Aerogel is a good thermal insulator because its nanoscale pores make it difficult for hot, fast-moving air molecules to diffuse through and transfer heat .
13. NASA has used aerogel insulation on the Mars rovers Sojourner, Spirit, Opportunity, and the Curiosity rover .
14. Aerogel has also been used to catch dust from a comet as part of the Stardust mission .
15. The particles hit the aerogel, entered it, and broke apart the network that makes up the aerogel as they traveled through, losing energy in the process and eventually coming to a stop .
16. The original silica aerogel is hydrophilic, meaning it attracts water .
17. There are currently efforts to make aerogel waterproof and less expensive .