E-readers get heavier with each book

[n2doc]

4:30PM GMT 30 Oct 2011
The weight difference is unlikely to make much difference to holidaymakers' baggage allowances, however, because each new tome is about as heavy as a single molecule of DNA.

Filling a 4GB Kindle to its storage limit would increase its weight by a billionth of a billionth of a gram

Prof John Kubiatowicz a computer scientist at the University of California, Berkeley, explained in the New York Times last week that storing new data involves holding electrons in a fixed place in the device's memory.

Although the electrons were 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 formula, which states that energy and mass are directly related, Prof Kubiatowicz calculated that filling a 4GB Kindle to its storage limit would increase its weight by a billionth of a billionth of a gram, or 0.000000000000000001g.

This is roughly equivalent to the weight of a small virus, while the equivalent number of books – about 3,500 – would weigh approximately two tons.

http://www.telegraph.co.uk/science/science-news/8858355/E-readers-get-heavier-with-each-book.html

[rucky]

1. This crosses the line from geeky to nerdy. n/t

[virgogal]

2. And from nerdy to irrelevant.

[Rabblevox]

3. Southwest Airlines will be charging extra for Kindle-book weight soon...

:sarcasm:

Seriously, I'm just enough of a scientist nerd to think that that is worth thinking about, and smart enough to know however long I think, I will never understand the math.

Cool story, thanks for the share!

[drm604]

4. This doesn't sound right to me.

Isn't the value of a given bit retained regardless of whether or not it's indexed as containing useful information?

[pokerfan]

6. I gave it some thought

and what they're talking about is the mass of the electrons sitting on the floating gate of the cmos device which is what allows it to be non-volatile storage. A '1' means no electrons and a '0' means a bunch (thousands?). So a block erased section of flash memory would have fewer electrons sitting on those gates.

Flash is unlike magnetic media where coding is used that ensures that there's never a string of 'physical' ones or zeros because that screws with the overall magnetic field which can mess with adjacent memory cells.

[Odin2005]

5. Nerdgasm!

[caraher]

7. I'd imagine a MUCH bigger effect on mass would be

how much energy is in the battery.