The E-Reader is the curse of the schoolkid. Give it time and educational books will be carried on a Kindle, thus doing away with the 'carry your books for you?' chat-up line. That one never failed...
Little solace can be found in news that e-readers too get heavier when books are added. A 4GB Kindle only gains the weight of a single strand of DNA when a book is added. When it's completely full it will be a billionth of a billionth of a gram heavier than when it was empty. That's a wrist-snapping 0.000000000000000001g.
Prof John Kubiatowicz a computer scientist at the University of California, Berkeley, said that storing new data involves holding electrons in a fixed place in the device's memory.
Although the electrons are already present, keeping them still rather than allowing them to float around takes up extra energy – about a billionth of a microjoule per bit of data. Using Einstein's E=mc², which states that energy and mass are directly related, Prof Kubiatowicz calculated the above. Just trust him, okay?
The difference in weight is far less than the difference produced by charging the battery, or wiping dust off the screen.
The same scientists explained that e-books could be heavier in summer too, because they would take on more energy from their exposure to sunlight.