I think Twitter is a bit faster than that. Twitter users in Japan seem to respond really fast when they feel any moderate level of shaking; at times, if you follow enough Japanese people on Twitter, your entire timeline gets filled with people saying "oh hey, something's shaking" or "it's rocking" or "boobs!". So yes, you will get advanced warning if there are people closer to the epicentre than you posting on Twitter (and as long as they are not using a certain phone provider which got overloaded during the big earthquake/tsunami last year while all the other providers were fine). And yes, this obviously doesn't work if the earthquake knocks out all the cell phone infrastructure in the areas between you and the epicentre.
Amusingly enough, I was watching a UStream broadcast run by some Japanese guy and people from a different area of Japan told him that they just had an earthquake, and he replied saying he didn't get any info here. Then, several seconds later, the earthquake alarm went off in the broadcast. So, I think Twitter isn't going to be very far off in terms of speed and definitely should be able to inform you about an ongoing earthquake as long as it's not a super short one and you're like next to the epicentre.
This new lens is not just a diffraction grating since it uses sub-wavelength structures to alter the apparent optical density (refractive index) of the material, i.e. metamaterials.
The analogy kind of works and kind of doesn't. A parallax barrier has an image layer and a fixed mask layer. What these guys did was to allow for multiple layers with time-varying patterns and optimize the pattern on each layer so as to create a better image. So it's more like "this is to integral what parallax on crack is to lenticular."
The company website is scant on details of their technology, but it's obvious that a different implementation is used and my guess from what they do say is that it's a lenticular device that only generates horizontal parallax. In that case, try tilting your head 90 degrees to the side and you'll lose depth perception, whereas this wouldn't be the case for the tensor display mentioned in the article. It might not be that important of an issue, until you want to lie down on a couch and watch a 3D program on TV...
Oh interesting, so they finally gave it a name. I remember coming across the 2-layer version of the display sometime ago. Looks like they also have an interesting theoretical foundation to go with it; the abstract of the first paper from Gordon Wetzstein's page gives a nice overview.
What essentially is going on is that you can model (at least when talking about things much larger than the wavelength of light) light as a four-dimensional function (i.e. intensity of light along all the possible rays that fill space), which is referred to in this research area as a "light field." Putting a mask somewhere in space will mask out a 2D-extrusion of the mask shape in 4D space. Putting multiple masks at different planes will mask out the product of this 2D-extrusions (and the extrusion angle varies as a function of depth). Hence, what they are doing is attempting to piece together the original 4D function by piecing together unmasked portions at each time frame.
For a more simplified view, you can think of this as trying to create a 2D picture through a sequence of special single-color 2D pictures created by placing stripe patterns oriented at a fixed set of angles on top of a light panel.
If you've taken linear algebra, it is somewhat like decomposing a matrix into a sum of rank-one matrices, except here each component needs to be positive (masks cannot create "negative" light).
Well, Adobe isn't exactly complaining or crying about it since Adobe didn't write the lines quoted in the summary; the writer over at Security Week did. It seems the only thing we got out of Adobe so far is that now they're working on it.
This is clearly another case of too many mad scientists, and not enough hunchbacks.