Slashdot Mirror
The Weight of an e-Book
whoever57 writes "According to Prof Kubiatowicz from Berkeley, each time an additional book is downloaded to an e-reader, the mass of the e-reader increases. The effect doesn't really make the devices more difficult to carry: the professor calculates that 4GB of books would increase its weight by a billionth of a billionth of a gram— about the mass of a single virus or DNA molecule."
Really...
So it turns out, pirating is stealing after all?
If my comment didn't sound as good in your head as it did in mine, then I guess we all know who's to blame
A billionth of a billionth of a gram here and there and soon you're carrying around whole bookshelves worth of e-reader!
I want my 30 seconds back ...
From TFA:
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.
No matter whether any bit is currently being used or not, it still has a value. It's not allowed to "float around".
in other news, ipods get heavier as you fill them.
maybe "the singularity" will happen when the internet gets so heavy the Earth collapses into a black hole?
So in the far future 1 x 10^18 GB of data is a gram.
That's interesting?
Also, if the, I guess electrical signals? add mass the earth keeps getting a tiny tiny bit heavier every time new data is made?
Grasping at straws here, people. I think that's vaguely interesting though.
This just in: Whatever...
"billionth of a billionth of a gram" That is painful to read. How about scientific notation? 1*10^-18 grams Or the use of a prefix? 1 atto gram
This just links to a Telegraph article talking about something that was talked about in a New York Times article, with no link to either that or the original source. Come on, Slashdot.
How many Library of Congresses is that?
-AI
For me, it is far better to grasp the Universe as it really is than to persist in delusion
Already found an Ig Noble Awardee for next year...
This should be OBVIOUS, but adding energy increases mass. DUH. By a significant amount? Absolutely not. Think of the way NAND works.
(Why do you think batteries and NAND flash wear out? )
If I delete an e-book off my reader, I actually destroy matter? And no energy is released in its stead?
It seems that E != mc^2 after all!
Ahh - My eye!
The doctor said I'm not supposed to get Slashdot in it!
So, at 21 Grams, how many terabytes would our souls contain? ;)
~ Whence do you come, slayer of men, or where are you going, conqueror of space?
I think I'm missing something here. Is there a state besides 1 and 0 in the memory? A null maybe, or an "I don't care"? Suppose for example that my e-Book's memory is a random jumble. I can query it twice and get the exact same jumble yes? Now I go and publish that jumble, promoting the existing data on my e-Book to information. Does the weight suddenly change?
I thought E=mc^2 was formula for energy/mass transformation. I don't believe it attributes a mass to energy. A photon has an energy but no mass for example.
The fact that the kindle uses more power (note that it's power, not energy) when there is more data stored in it (and I don't even know if that's true) doesn't mean it weighs heavier...
That's why some people call schools, parasite cysts.
Parasites like teachers who have no other job other than stealing peoples money. All in the name of garbage science like string/rope/fur theory.
End the School
This belongs in the Idle section, at best, but probably not at all on /.
He's Probably wrong, since flash memory usually stores new bits by draining *away* charge. So, therefore the newly written bits have negative mass, since they represent a smaller total stored energy for the device. Absolute effect is still insignificant - we don't use flash memory to store energy.
It will get lighter as the battery wears down!
the 21 grams Soul....
Add some stuff written by Bill O'Reilly and all the other usual suspects.
That amount of hot air should easily cancel it out.
Everyone knows that "One" bits are heavier than "Zero" bits. Now Amazon will have to tell us what the ratio of '1' bits to '0' bits is for any given e-book.
Data does weight!
404: sig not found.
The CO2 footprint is, surprisingly, similar (to within one order of magnitude)
When the seagulls follow the trawler, it's because they think sardines will be thrown in to the sea
I'm not sure they're understanding how anything works, it seems like they just figured OH HEY ELECTRONS HAVE MASS I MUST BE SMRT. Here's why.
When you download an E-book from amazon, electrons aren't directly transferred to your tablet, a memory chip is burned, or bits are flipped, to represent the book in memory. (so either a magnetic or optical piece of information is stored by changing the configuration of mass that is already present) This would if anything remove mass from the e-reader, because electrons from the battery that are used to change the configuration of the memory would be lost as heat energy.
now when you charge the battery it might gain a little mass, but electrons don't just hang around once they flow in from the interwebs (that's not how it works :D)
I'm fairly certain some people need to go back to school, and then those people who wrote an article need to go back to journalism school.
Sincerely, your friendly neighborhood rocket engineer :D
Someone really detected and queried about it on MS Forums: http://www.scribd.com/doc/18474538/Microsoft-Answers-Forum
In freshly-cleared flash memory, data starts out as FF bytes, all 1s. Then bits are "programmed" to turn them into zeroes. Then when you need to flip them back again, you erase an entire block of memory to all 1s again, then program new 0s onto it.
So is this just an example of 0s leaving more electrons on the system than 1s would? The only weight difference is due to number of electrons, so this is really small.
Under TFA: "Amazon Kindle review: the e-reader for the mass market"
Well... no, because if i had electrons just "moving" around on my storage, with their varying negative and positive powers of persuasion surely I'd be experiencing data loss?
And I'm not.... therefore I can conlude that both the 0s AND the 1s aren't moving. No weight change
Someone care to explain why I'm not correct? (And do I now get to call myself a Professor too?)
- http://www.milkme.co.uk
For those who didn't TFA, some guy trying to be educational or humorous is reaching to convert energy to mass via e=mc^2 and say that's a significant amount of mass being used to maintain an electron in place to represent a "1" bit.
What about the weight of the energy that was stored in the battery's chemical compound and was used to power the device to download the ebook? Part is dissipated as heat and light emission. So is this scientist assuming a perfect battery, a perfect reversible computational device, and an ESP-driven interface with no visual display? Those photons are heavy too..
What I'm saying is the memory chip is not isolated from its imperfect power source and CPU, and the bits do not magically appear they have to be calculated. Besides which, all this weight is surely dwarfed by the weight of the atoms being rubbed off the device by finger gestures. And lint.
The Kindle is already filled with data. It's just that most of it is meaningless and will get replaced with books.
The value depends for sure on the technology used and the temperature. If you use spins aligned in a weak magnetic field which store information e.g at a transition frequency of 1GHz and accept operation at temperatures of some milliKelvins , then you will find that the same information takes only 2*10^-28g:
octave:20> 6.62e-34*1e9*(4e9*8)/(3e8^2)*1e3
ans = 2.3538e-28
This should not be confused with the fundamental limits which are involved.
But constructing the formula for an applicable system Energies as a function of required reset speed, generated field strength, readout speeds, error rates as a function of temperature and available nonlinearities would be an interesting task for an exercise in a physics course on thermodynamics (and in the limit: quantum mechanics).
say - the weight of a single fingerprint? No need to read TFA - the idea that the weight of the reader would predictably change based on the difference beteween a random pattern of bits compared to the almost-random pattern of a compressed binary file... come on!
[...]"each time an additional book is downloaded to an e-reader, the mass of the e-reader increases. The effect doesn't really make the devices more difficult to carry: the professor calculates that 4GB of books would increase its weight by a billionth of a billionth of a gram— about the mass of a single virus or DNA molecule."
Damn. I'll never be able to take all my biblioteque with me, it would weigh a ton.
"If a boss demands loyalty, give him integrity. But if he demands integrity, give him loyalty." (John Boyd, 1927-1997)
The polish science fiction author Stanislaw Lem describes this (in a humorous fashion) in one of his Ijon Tichy / Professor A. Donda short stories.
Prof. Donda has the theory that information = mass, proceeds to create a new field of study as a pretext to cram the maximum amount of information into the smallest space possible. He succeeds, creating an information singularity that makes all of the fixed, stored information in the universe go kablooie. Tichy and Donda end up somewhere in the jungle, looking at old copies of Playboy magazine.
sig? Oh, that sig...
The results of experiments by DuncanMacDougall, who tried to measure the weight of the departing soul, have been theorized to have a basis in some sort of "information erasure" at the moment of death (though in a tongue-in-cheek fashion it appears): http://en.wikipedia.org/wiki/Duncan_MacDougall_(doctor)
Why would it make a difference how the 1's and 0's are arranged on weight? Are 1's heavier then 0's?
“Although the total number of electrons in the memory does not change as the stored data changes,” Dr. Kubiatowicz said, the trapped ones have a higher energy than the untrapped ones. A conservative estimate of the difference would be 10^(-15) joules per bit.
As the equation E=mc^2 makes clear, this energy is equivalent to mass and will have weight. Assuming that all these bits in an empty four-gigabyte Kindle are in a lower energy state and that half have a higher energy in a full Kindle, this translates to an energy difference of 1.7 times 10^(-5) joules, Dr. Kubiatowicz calculated. Plugging this into Einstein’s equation yields his rough estimate of 10^(-18) grams.
Of course Kubiatowicz also says that:
[10^(-18) grams] is only about one hundred-millionth as much as the estimated fluctuation from charging and discharging the device’s battery.
Which is a far better comparison than the one obtained from The Guardian where Graeme Ackland of Edinburgh University stated:
"If Prof Kubiatowicz is really struggling with the extra weight, he is welcome to come to Edinburgh where it's cooler, and the lack of thermal energy in his Kindle will more than compensate."
Slashdot, home of crowdediting.
wouldn't the outgassing of the plastics that the thing is made of reduce its weight by more than any change in electron configuration?
i'm with you this sounds fishy.
I can see RyanAir and friends using this as an excuse to add a new "eBook reader carrying charge" to all flights.
Sorry, but this isn't significant. And to be honest, it sounds like it should be in the noise. Flash memory is flash memory. The cell can swell based on many environmental factors (air pressure changes, humidity, temperature, etc.), and TFA clearly mentions heat as a possible factor. The fact a downloaded piece of data measured at all could be the cells were heated as the gates were being used to store the data. Who knows. A billionth of a billionth of a gram for 4GB of data just sounds too tiny to be remotely significant, let alone noteworthy outside of an extremely controlled environment.
I'd like to see more data on the experiment itself, to see if the measurements were all taken in a very controlled environment or not. TFA is really lacking any details that would intrigue people who cared.
How do you know the soul is not dark matter?
Not sure if I'm asking a reasonable question or not about dark matter, but as long as we can't qualify the soul, we don't have a way to tell whether it has mass or not.
All we know for sure is that our attempts to measure such mass have been unsuccessful so far. And we really can't expect to get anywhere as long as we don't know what the soul is.
If there truly is no physical "spirit" to the soul, there is still the argument that the soul would be the sum of the information collected as memories, thinking patterns, learned behavior and habits, etc. over the lifetime to the present.
Which brings us back to the question of whether information has mass independent of the medium on which it is stored.
Computer memory is just fancy paper, CPUs just fancy pens with fancy erasers; the 'net is just a fancy backyard fence.
I don't believe that whether a memory location holds a zero or a one has anything to do with it's energy state. Therefore, the contents of memory has no impact on the devices mass.
I work, I pay taxes and when I read such things I am going nuts. WTF???? My tax money goes into some academic pockets so that he can sit for weeks thinking about how much does one ebook weight??? Dammit! I thought such things are over and such debates were finished couple of hundreds years ago! It is like how many devils will fit on the needle tip... gimme a break.
If I have a "blank" unformatted media, wouldn't it naturally have random data on it?
Somewhere close to half the bits in each state?
Then when the data is written, it may bias the data either low or high,however compressing it should again restore it to a near uniform distribution.
At which point half the bits are in each state and it weighs the same again.
The Ig Nobel Prize committee is on line 1.
If Slashdot were chemistry it would look like this:Cadaverine
I believe the guy's analysis is incorrect. I believe there is a mass gain, but most of it is not related to the energy required to "[keep electrons] still rather than allowing them to float around".
Writing a '0' to a flash memory cell involves injecting electrons into a "floating gate", producing a (permanent) net negative charge on the gate. So a flash device which has been written to contains a net surplus of electrons (i.e. an overall negative charge), compared to one that is blank. The increase in mass comes mostly from the fact that you've simply got more electrons in the chip, not from an increased energy level.
He seems to be under the impression that the storage devices have three states: one, zero, and undefined. This is not the case. There is no undefined state, when flash is erased all of the bits are set to one, when it is written some are set to zero. There is no difference in energy state between the a block that is erased and a block that is storing all ones. It is possible that the zero energy state has more mass than the one energy state, but that's not what he is claiming. Expect to see this show up in The Guardian's Bad Science column soon...
I am TheRaven on Soylent News
"...The effect doesn't really make the devices more difficult to carry: the professor calculates that 4GB of books would increase its weight by a billionth of a billionth of a gram— about the mass of a single virus or DNA molecule."
Wow. And just when I thought D.A.R.E. pamphlets held the record for the most useless studies and statistics...
a fresh drive starts out as all "1"s. the "1"s are generated from confined
electrons. writing data is the process of letting some electrons out, producing
"0"s. therefore storing anything will only decrease the number of confined
electrons, and using the logic of tfa, make the e-book lighter.
No wonder I'm gaining weight, it's all those e-books. I knew it!
To offset political mods, replace Flamebait with Insightful.
The mass of a DNA molecule is so incredibly variable (by length) that saying something weighs as much as a DNA molecule makes no sense whatsoever. There is undoubtedly a library of congress reference that would be several orders of magnitude more precise.
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
We must stop this waste now, before Global Warming is increased and life shortened!
I remembered this anecdote from the great book "Expert C Programming" by Peter Van der Linden. See the bottom of page 61, and page 62: google books.
http://cltracker.net -- powerful craigslist multi-city search
Is he assuming that when a book isn't present all the flash cells are set to zero? Because that isn't generally the case.
"The worst tyrannies were the ones where a governance required its own logic on every embedded node." - Vernor Vinge
Most appropriate title to a spam post I've ever seen.
""According to Prof Kubiatowicz from Berkeley, each time an additional book is downloaded to an e-reader, the mass of the e-reader increases. The effect doesn't really make the devices more difficult to carry: the professor calculates that 4GB of books would increase its weight by a billionth of a billionth of a gram— about the mass of a single virus or DNA molecule."
WHO CARES???
After I downloaded 100YB of ebooks my reader was hard to carry.
You might not think a billionth of a billionth of a gram is a lot, but when I catch a small virus, it really weighs me down.
The guy just plugged some number in to an equation, and got an answer. The trick in Modern Physics is to know which law/equation applies in each problem. The mass of an electron is 9.11x10^-31 kg. It does not get heavier. If an electron is traveling near the speed of light, it's "effective mass", m*, increases. Effective mass is lumping gamma (c/sqrt(c^2-v^2)) in with the rest mass m (m* == gamma*rest_mass). Furthermore, both the "1" state and "0" state must be stable for storage, so the higher energy electron would have more potential energy than the lower state. It does not have more mass.
His understanding of NAND flash is a bit better than yours. NAND program and erases must be verified. It is possible to have a state where you can't read it as a 0 or read it as a 1, which is indeed undefined.
It is cleaver though, how you claim there is no difference between an erased block and a block that is storing all ones, since, as you pointed out, these are the same states. Back to what you meant to say, and what most folks would have read...
There is indeed a difference in energy state between a programmed and erased bit. That is exactly how you can tell the difference between the two. In one state you have electrons driven to the floating gate. In the other state you have electrons driven off of the floating gate.
At the end of the day, the only interesting thing about the professor's work is that his paper answering this unimportant question that no one asked can actually get published.
And to the grandparent post, non-volatile memory does not require power to "hold the electrons in position".
This post comes with a double-your-money-back guarantee!
Any offense taken to this post is at your sole discretion.
This reminds me of a supposedly true story about the first manned flights to the moon:
The weight of the rocket was naturally a big issue, and a very efficient bookkeeper was put in charge of keeping track of the weight of everything put on board.
Everything was put on a scale and was rigorously accounted for.
At some point he overheard the hardware developers talking about "software", he did not know what it was, but he figured out that he also needed to take this into account.
He tracked down the software developer in the basement, and he asked about the weight of the software.
The software developer laughed and answered: "nothing".
The bookkeeper was not satisfied with the answer and he replied: "well show me this soft-ware, so I can see it with my own eyes".
The software developer then showed him a stack of punch cards.
"Aha", said the bookkeeper and smiled and reached for his suitcase to get his scale.
"No wait", said the software developer, the software is not the whole punch cards, it is the little holes in the punch cards, that represent the software.
Now the bookkeeper was satisfied and wrote "Software 0 punds" in his litte book.
He is assuming that the flash memory in the e-reader is in a chaotic state and is only ordered when an e-book is written to it. This is not true. By the time you get the e-reader, every cell in the flash memory has probably already been written to at least once (either when the flash memory chip itself was tested post-manufacturing, or when the e-reader software was imaged onto the device). Because it must deterministically return the value written to it, even if the new owner doesn't know what that value was, the e-reader is already "holding stationary" all the electrons in its flash memory gates.
Also, while operating, there is a constant flow of electrons in and out of the device, with energy removed from the electrons and converted to heat (with useful functions a byproduct of this conversion). Since the flow of electrons is not perfectly constant, the mass of the device is constantly changing due to how many electrons are within it at any given moment. This fluctuation is of much greater magnitude than the alleged effect.
5.
Forget the eBooks... Charging the eReader will add more energy ( => some more mass) to the device... much more significant than downloading the books! ... but I am afraid, your finger prints will add larger mass !
Dilbert tells PHB erasing the drive will make it lighter, because 1's are heavier than 0's, or something like that. Not sure I agree with Dilbert. 1 is thinner than 0, so 1 should be lighter.
PPJ.
"E-readers could also become slightly heavier in the summer, because they would take on more energy from their exposure to sunlight, scientists explained."
Yeah,,, but the earth is actually furthest from the sun during the summer and gravity would be less. But because of conservation of momentum, it (and we) would be going faster. And as we all know, going faster (according to the same Einstein theory E = M*C*C), means that we would actually have to shed mass as it is converted to energy.
So there. :) :)
Ok, so I'm not an electrical engineer or a physicist but what I remember from my limited high school and college courses on the subjects is that electrical energy losses efficiency due to heat loss which is energy. If the memory on the device is using energy to hold a state, wouldn't it be loosing the excess energy that is in the form of electrons to heat? Meaning that the weight would stay the same. Also, I though flash memory held a charge for 0's not 1's so that it would by there argument not weigh more but less if a book was downloaded. Also the electrons have to come from somewhere, so I also contend that the electrons are just moving from the battery to the flash memory. So weight isn't added it is just transferred unless one is arguing that the wifi antenna is pulling electrons out of the radio signal and adding them to the device. Basically this whole argument seems flawed to me.
(Monty Python mode ON)
So, if 4GB weighs the same as a virus, it's therefore...
...a virus! BURN!! BUUUURN IT!
(Monty Python mode OFF)
According to Prof Kubiatowicz...
It's fitting that he has a polish name, but surely all this (and more) was discovered ages ago by Professor A. Donda...
So all you have to do next is clean the screen with a wet tissue and wait for water to vaporize :P
I wonder whether they considered the actual microbes, dust particles that get attached\detached to the reader with continued use. I also wonder where they managed to get such precise instruments. But really, a billionth of a billionth of a gram? How on earth will I be able to lift that reader of mine after it's filled...