3 ms·
The density likely leaves out the weight of the air filling most of the volume, and just represents the mass of the metal divided by the structure's volume. Th
by redthrowaway 15y ago
The density likely leaves out the weight of the air filling most of the volume, and just represents the mass of the metal divided by the structure's volume. This is reasonable, given that the air plays no role in the structure's stability or strength. It could just as easily be in a vacuum, or in some other gas. You can't say the same of the frozen smoke linked in the article, as air forms an integral part of its structure.
- ars 15y agoNot so. You can have frozen smoke with a vacuum in it. There are two types, closed cell and open cell (just like any foam). According to wikipedia the lowest density frozen smoke has a density of 1 mg/cm3 (not including air!), which is just slightly more than this material. The 4 mg/cm3 number in the article is incorrect (I wrote to them to let them know).