# Tag Info

1 vote

### What is an "As-grown crystal"?

Jon Custer's comment is correct. As-grown means the crystals were grown according to a specific recipe, and then were not modified further. Examples of not as-grown would be if you annealed the ...
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### Why are HCP materials brittle while FCC materials are ductile?

Interesting. In my past metal physics thermodynamics lab research work the focus was on yield stress which here characterises the shift from ductile to brittle deformation. Mechanical engineers also ...
• 134

### How do we justify that potential energy in a spring is Galilean invariant (to the extent that Newtonian mechanics holds)?

From this I surmise that the elastic potential energy of a compressed spring can be ultimately reduced down to electromagnetic energy. Well, yes, but you have to use the quantum mechanical rules of ...
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1 vote

• 4,195
1 vote

### Shouldn't length contraction cause friction under certain circumstances?

This question is complicated by using accelerated frames (not just one but two differently accelerated frames, one for the front and one for the back of the train) plus the unintuitive weirdness that ...
• 8,068
Accepted

### What are some reputable databases for the measured values of the physical properties of materials?

The CRC Handbook of Chemistry and Physics is the "industry standard" and should be appropriate for most layman purposes including those listed. Some knowledge of basic physics is assumed. ...

### Which naturally occuring solid material has the lowest refractive index?

If dielectric films are included, North Carolina State University researchers announced "a film made of aluminum oxide that has a refractive index as low as 1.025 but that is mechanically stiff&...
• 1,829
1 vote
Accepted

### Calculating bulk modulus from interatomic potential on cubic lattice

A little bit of pedantry first: NaCl has a face-centered cubic lattice structure with 2 atoms in the basis (1 Na and 1 Cl), which looks like a simple cubic structure only if we ignore that there are ...
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