How much does [electronic] data weigh?

[ChrisBooth12]

Hard drives store data by having positive and negative charges. Of course they weigh different depending on the charge the earth will pull it more

[WarmNPrickly]

@njtt

I do not know much about how flash memory works, but I question whether it is in fact the case that a 1 (I take it you actually mean the electrons representing a 1) is in a higher energy state than a 0. I am fairly sure that this is not the case in ordinary dynamic RAM. It is not the state of the electrons that matters but, literally, where they are in the circuit: which gate is being clamped open. If flash memory relied on keeping some electrons in a higher than ground energy state, surely the information would be subject to quite rapid decay, which is just the opposite of what is wanted from a flash drive.

As for information having mass, well, I can’t claim to understand that, but even if it does, is it actually the case that drive containing, say, a lot of JPEGS actually contains objectively more information than one where every bit is set to 0? (The former contains more useful information, from a human perspective, but that is not the same thing as objectively more.)

It’s pretty complicated, and the only reason I know so much is because I finally had to eat my words last time this came up. I’m fully prepared to do the same again, but I think I have a pretty good grasp on the subject now.

Flash memory works by pushing electrons into the floating gate. The floating gate changes the gate voltage of the transistor. The stored electrons are in an energy well that is higher than the ground state because they are separated from the positive charge. I believe that the electrons are capacitively stored. Since the floating gate is not conductively connected to the circuit, they stay there until another voltage is applied to either raise their energy or lower the barrier enough for them to escape.

@ChrisBooth12

Hard drives store data by having positive and negative charges. Of course they weigh different depending on the charge the earth will pull it more

Hard drives do not store data this way.

[Saint_Cad]

@iamnotbatman

I’ve heard something like this before, but I don’t understand it, on conservation-of-energy grounds. If I put a HD of mass X with information Y into a hermetically sealed container, and have the HD set to self-destruct, then presumably information Y would be destroyed. And yet by conservation of energy, the closed system must remain the same mass.

I think there is a paper resolving the Maxwell’s devil paradox that deals with entropy and information and that the energy used in forgetting something like the state of the piston is more than the energy gained.

I’ve probably messed it up a bit and I have no clue if this has anything to do with the OP.

[Markxxx]

This was the subject of a Dilbert cartoon

The pointy-haired boss was complaining that his laptop weighed too much. Dilbert told him to delete some of the files off of it.

[ChrisBooth12]

How do they store data then?

[Ludovic]

@Chairman_Pow

is it possible that the electrons, or whatever, add up to a measurable weight?

Those two words are key to the whole pickle. We all had better hope that they do not add up to a measurable weight. Because if they did, we could annihilate the laptop with a massive explosion, instantly rending the hard drive to shreds and destroying the information. It would then be released in the form of energy per the equation E=mc2 :eek:

[WarmNPrickly]

@ChrisBooth12

How do they store data then?

Well, Flash memory works by the first thing I said. Other memory works other ways, but none of it involves adding and subtracting charge in such a way to leave the device anything but neutral.

[TimeWinder]

@ChrisBooth12

How do they store data then?

Magnetic disks, you mean? Changing the alignment of the magnetic fields on the disk: basically like moving iron filings around with a magnet, but smaller.

[ChrisBooth12]

A typical HDD design consists of a spindle that holds flat circular disks called platters, onto which the data are recorded. The platters are made from a non-magnetic material, usually aluminum alloy or glass, and are coated with a shallow layer of magnetic material, typically 10–20 nm in depth—for reference, standard copy paper is 0.07–0.18 millimetre (70,000–180,000 nm)[7]—with an outer layer of carbon for protection. Older disks used iron(III) oxide as the magnetic material, but current disks use a cobalt-based alloy

The platters are spun at very high speeds. Information is written to, and read from a platter as it rotates past devices called read-and-write heads that operate very close (tens of nanometers in new drives) over the magnetic surface. The read-and-write head is used to detect and modify the magnetization of the material immediately under it.
From wiki it sounds like they are magnetic and the earth does have a magnetic charge right?

[WarmNPrickly]

So with magnetic memory, which “weighs” more, a “1” or a “0”?

[Chairman_Pow]

@CookingWithGas

Don’t stop with a flash drive–think big. How much does the Internet weigh?

Fascinating. Thanks. The comments in the linked article linked to in there has a lot of interesting info.

[Chronos]

From wiki it sounds like they are magnetic and the earth does have a magnetic charge right?

There is no object known in the Universe that has a magnetic charge. And even if you meant the Earth’s magnetic dipole moment, that has nothing whatsoever to do with weight.

[Nehemiah_Samedi]

Perhaps I have an arcane or fundamentally flawed concept of data storage, but i would imagine nothing. I envision data to be like many many switches either in the on or off position, creating the data patterns. If you have a row of switches “00000” there is no weight added to set them in a specific way such as, “011001” but a different message is thereby encoded.

[WarmNPrickly]

Mostly, you are right, but it’s not necessarily the case that the two states are equal. I’m fairly certain that what I assume to be the “on” state in flash memory is in a higher energy state than the “off” state. In that case, there is a minuscule mass difference simply because energy and mass are equivalent.

[psychonaut]

I thought I might briefly revive this thread to mention that this question was recently addressed in the mainstream news. Apparently there was a New York Times article on the subject last week, but because of its paywall it cannot be shared. Fortunately, less antisocial newspapers such as the Telegraph have summarized the original report:

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.

[Senegoid]

@psychonaut

I thought I might briefly revive this thread to mention that this question was recently addressed in the mainstream news. Apparently there was a New York Times article on the subject last week, but because of its paywall it cannot be shared. Fortunately, less antisocial newspapers such as the Telegraph have summarized the original report:

There is also another current thread nearby on this board with a discussion of this.

ETA: Sorry, I haven’t learned yet how to create a link in a post, to another post or another thread. (Can somebody enlighten me? Although, actually, I think our brains get heavier, not lighter, as we learn more things.)

[tangent]
BTW: I have been reading stuff on NYT freely at will without any apparent limit, and without subscribing or otherwise paying up, and I haven’t encountered any paywall. Why am I able to do this? My WAG: Because I habitually run by browser with JavaScript disabled, they are not able to keep track of how many articles I have read, and so cannot tell when I have read my quota of free articles.
[/tangent]

[Half_Man_Half_Wit]

@Napier

As I understand it, information actually does have mass, on the order of something like 10^-65 kg per bit.

Where does that number come from? The minimum energy needed to erase a bit is kTln(2) Joule, where k is Boltzman’s constant and T is the temperature, about 2.9 * 10[sup]-21[/sup] J in numbers, equal to a mass of 3.2 * 10[sup]-38[/sup] kg, if I did the numbers right.

[Really_Not_All_That_Bright]

@Senegoid

Sorry, I haven’t learned yet how to create a link in a post, to another post or another thread. (Can somebody enlighten me? Although, actually, I think our brains get heavier, not lighter, as we learn more things.)

If you click on the post number in the top right hand corner of a post (it’s next to the “report post” button) you’ll get that post by itself in a new tab or window. The URL of the post will be “universal” (ie., it doesn’t matter if anyone else clicking it isn’t logged in as you, or whatever), so you can copy and paste it wherever you like.

Here is a link to your post in this thread.

In that link, if you click on the link back thread title in the full bar at the top (after “view single post”) it will take you back to the full thread with your browser displaying that particular post. That link is universal too.

Welcome to the SDMB!

[Kenm]

@TimeWinder

Off for most of them, because it’s down, and closer to the gravitational center of the earth.

Except in the U.K., where off is up, which explains why the North Atlantic filled the English Channel.

[DaveBfd]

When they say information can not be destroyed, they are not (as far as I understand it) talking about information on flash drives, or information gained by humans for any means.

Information is more of a physical term for certain things in the universe. The two are unrelated when asking if the flash drive weighs more, are they not?