It looks like Japanese researchers have figured out how to fit 42GB of information onto a single DVD by changing the way light is reflected off the DVD and thus storing array of bytes instead of 1 single bit.
Not sure how this will affect DVDs in the future but this might be the start of DVD2 era.
Researchers from the Institute of Multidisciplinary Research for Advanced Materials, based in Japan’s Tohoku University, have – according to Google’s translation of a document released by the university department – discovered a way to multiply the amount of data stored on a DVD. The group also claims to be able to replicate the method for CDs.
Essentially, the team states that by changing the shape of the data-storage pits from having a flat bottom to one that’s a V shape, each pit will be able to hold more data. Changing the horizontal orientation of the tip of the valley, alters the way light is reflected by the pit. As a result, pits no longer represent binary 1s and 0s, but a range of values, effectively allowing each to record a byte rather than a bit.