Header add

Thursday, February 21, 2008

Alien Grave Site

4 comments:

Bob Johnson said...

The concern I have with this is aliens even more then a hundread years ago would have something far in advance of aluminum for their crafts, yes?

Marica said...

Perhaps. Or, could it have been the only metal that could be used to describe what they saw at that time.

Something to think about:
Aluminium is a soft, lightweight, malleable metal with appearance ranging from silvery to dull gray, depending on the surface roughness. Aluminium is nontoxic, nonmagnetic, and nonsparking. It is also insoluble in alcohol, though it can be soluble in water only in certain forms. The yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa.[2] Aluminium has about one-third the density and stiffness of steel. It is ductile, and easily machined, cast, and extruded.

Corrosion resistance is excellent due to a thin surface layer of aluminium oxide that forms when the metal is exposed to air, effectively preventing further oxidation. The strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper.

Aluminium atoms are arranged in an face-centered cubic (FCC) structure. Aluminium has a high stacking-fault energy of approximately 200 mJ/m².

Aluminium is one of the few metals that retain full silvery reflectance in finely powdered form, making it an important component of silver paints. Aluminium mirror finish has the highest reflectance of any metal in the 200–400 nm (UV) and the 3000–10000 nm (far IR) regions, while in the 400–700 nm visible range it is slightly outdone by tin and silver and in the 700–3000 (near IR) by silver, gold, and copper.

Aluminium is a good thermal and electrical conductor, by weight better than copper. Aluminium is capable of being a superconductor, with a superconducting critical temperature of 1.2 kelvins.

Anonymous said...

It's an important note that the descriptive detail of the time would necessarily be colored by the limitations of their own knowledge. In particular, during a time striving toward modernity and wanting to be less inclined to offer "magical" or "mythical" origins for unknown happenings.

Marica said...

True, thanks gl