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Posts by muppetry

 The GoPro version is on a 2-axis gimbal, so has full tilt and rotation, and is also rather better stabilized as a result.
 Especially with the new LightBridge dual control and HD FPV link that seems to have a range of at least one mile.
 That might now be possible following the recent ruling that the FAA do not have legal authority to outlaw commercial drone use. They are appealing that decision though.
 No I'm not forgetting that.  Firstly, cell towers can use microwave for backhaul, but even with the trend towards more efficient optical links, it is still much cheaper to run optical fibers to a limited number of cell towers than to run fiber or cable to every property.
 I agree with your hypothesis (2). Cell phone technology now provides a much cheaper route to voice and data in less developed countries than investing in landline infrastructure.
 I think he probably meant that sapphire is homogeneous and isotropic whereas GG is not, rather than that the sapphire would not be part of a laminate.
 (1)  No contest - even with the surface compressive layer of GG, sapphire is much harder and much more scratch resistant. (2)  Assuming that the impact damage of the kind that you describe arises from tensile failure during the dynamic loading with quasi-uniaxial stress, sapphire has the higher ultimate tensile and shear strength, and will survive higher stresses than GG. But note that the induced stresses are also a function of the elastic moduli (the stress/strain...
 On the specific (and undefined) property of "breakability", you completely failed to define how you are trying to break it (bending, impact, penetration etc.), and what  you are considering it to be mechanically attached to. My point was that you appear unaware that each of those responses is controlled by different properties. GG is weaker in every measure of strength, by which we mean that it has lower elastic moduli (bulk compressive, tensile, shear), lower ultimate...
 Where do these bizarre interpretations come from? Scratch resistance correlates purely with surface hardness, not any bulk property. The surface properties of GG just represent a modern version of thermal toughening, using ion exchange instead of thermal expansion to set the outer layer into a permanent state of compressive stress that offsets any externally imposed tensile (crack-opening) stresses. As a secondary effect, increased, not decreased, scratch resistance...
This post epitomizes the confusion that arises every time material science issues are raised. Brittleness and strength are entirely different and relatively independent properties. Strength, itself, refers to multiple properties depending on the stress state in question. Toughness - usually referring to fracture toughness, is just one parameter that falls under the umbrella of "strength". You simply cannot conflate all these terms and then make blanket statements about...
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