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Scientists Turn Gold Into Foam That's Nearly As Light As Air (www.ethz.ch)
Zothecula writes: Along with its use in jewelry, gold also has numerous applications in fields such as electronics and scientific research. It's a handy material, but – of course – it's also expensive. That's why researchers at ETH Zurich have developed a new way of making a small amount of gold go a long way. They've created a gold foam that looks much like solid gold, but is actually 98 parts air and two parts solid material (abstract). As an added bonus, the aerogel-type foam can also be made in non-gold colors such as dark red.
The idea of creating a material that is mostly air isn't particularly impressive. The technique of actually doing it is where it gets clever, and the technique used here to make this gold foam is not the same as the techniques used to create the familiar aerogels. FTA:
"The method chosen, in which the gold particles are crystallised directly during manufacture of the aerogel protein structure (and not, for example, added to an existing scaffold) is new. The method's biggest advantage is that it makes it easy to obtain a homogeneous gold aerogel, perfectly mimicking gold alloys."
Nope.... Iron is less dense than gold. It wouldn't weigh enough. In fact, that was how Archimedes detected the forgery.
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A pound of gold. A pound of gold would be 12 troy ounces, which totals to a little bit less than the 16 avoirdupois ounces that would make up a pound of feathers.
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Nope.... Iron is less dense than gold. It wouldn't weigh enough. In fact, that was how Archimedes detected the forgery.
Color mark-t Informative.
Iron has a density of 7.87 g/cm^3, whereas gold has a density of 19.32 g/cm^2.
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Actually if radiation is aligned with a crystal lattice it interacts even more with the material and the radiation length (the distance travelled before 1/e of the particles interact on average) gets shorter. However this only happens if the radiation is aligned to within a few milli-radians of the symmetry axis of the crystal (and most metal you encounter is not a single crystal). I actually measured this effect as part of my PhD thesis for an application in the main particle physics experiment I was working on.
So no, this material will probably be no more effective than the same mass of gold in a thin, but solid, sheet. Radiation shielding with matter is a statistical affair and the fewer nuclei you have the less shielding you get. I'm also surprised that they suggest a use in jewelry since they also describe it as easily malleable, far more so than solid gold. Still it is interesting.