I've found the on-line only sites to have better news than the `real journalists'. The advantage that the media had in the past was that they got the news *first*. With the internet, that isn't true anymore. (As an example, I was able to read the Finding of Fact before there was even a single news story written about it in the on-line press.)
I think what the poster was really asking wasn't `Why is holographic storage better than CD's?', but `Why is holographic storage, better than storing a 3D image of the actual data you're encoding?' The answer to the first question is obvious, but its not clear why we should use holographic. I know of a San Diego company that is *not* using holography, but stores data like multilayer CD's. You should get the same amount of data, the only difference is the representation of it. I think the main advantage of a holographic memory is that is less sensative to defects in the media. The data is stored as a grating (redundantly throughout the whole media), so you can't just point to a spot and say that's the bit I just wrote. This comes at a cost, though because then you have to do holography. This is a no-brainer if you have 10K to spend on an optical table, but doing it on everyone's desktop is much harder. I don't know if it will ever be commercially feasible.
I think that write speed was also a big problem for holographic memory and that hasn't been addressed. The writing process is typically done using a photorefractive material and this means you shine light on it, set up an electric field and let the excited electrons diffuse trap states in the `dark' regions. This results in an index change that can be `read out' later. The problem is the diffusion time. I don't see how they can make that a very fast process, so while you'll get great read times, the writes are slow. Last time I, speed was more important to most people that size.
I think part of the problem is that Apple does not have a *client* to view Quicktime with that runs under Linux. Right now, there isn't a solution for viewing on Linux.
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I've found the on-line only sites to have better news than the `real journalists'. The advantage that the media had in the past was that they got the news *first*. With the internet, that isn't true anymore. (As an example, I was able to read the Finding of Fact before there was even a single news story written about it in the on-line press.)
I think what the poster was really asking wasn't `Why is holographic storage better than CD's?', but `Why is holographic storage, better than storing a 3D image of the actual data you're encoding?' The answer to the first question is obvious, but its not clear why we should use holographic. I know of a San Diego company that is *not* using holography, but stores data like multilayer CD's. You should get the same amount of data, the only difference is the representation of it. I think the main advantage of a holographic memory is that is less sensative to defects in the media. The data is stored as a grating (redundantly throughout the whole media), so you can't just point to a spot and say that's the bit I just wrote. This comes at a cost, though because then you have to do holography. This is a no-brainer if you have 10K to spend on an optical table, but doing it on everyone's desktop is much harder. I don't know if it will ever be commercially feasible.
I think that write speed was also a big problem for holographic memory and that hasn't been addressed. The writing process is typically done using a photorefractive material and this means you shine light on it, set up an electric field and let the excited electrons diffuse trap states in the `dark' regions. This results in an index change that can be `read out' later. The problem is the diffusion time. I don't see how they can make that a very fast process, so while you'll get great read times, the writes are slow. Last time I, speed was more important to most people that size.
I think part of the problem is that Apple does not have a *client* to view Quicktime with that runs under Linux. Right now, there isn't a solution for viewing on Linux.