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## The Sum Total of the World's Knowledge: 250 Exabytes168

arkenian writes "The BBC reports on an article in Science about scientists who calculate that the sum of all the world's stored data is 250 exabytes. Perhaps more interestingly, the total amount of data broadcast is 2 zettabytes (1000 exabytes) annually. In theory this means that the sum of the world's knowledge is broadcast 8 times a year, but I bet mostly that's just a lot of American Idol reruns."
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## The Sum Total of the World's Knowledge: 250 Exabytes

• #### And a lot of it is free (Score:4, Informative)

on Saturday February 12, 2011 @03:39PM (#35188058)

http://en.wikipedia.org/wiki/Free-to-air [wikipedia.org] - "Free-to-air (FTA) describes television (TV) and radio services broadcast in clear (unencrypted) form, allowing any person with the appropriate receiving equipment to receive the signal and view or listen to the content without requiring a subscription (or other ongoing cost)"

http://www.hulu.com/ [hulu.com] (free tv)
http://www.piratebay.org/ [piratebay.org]

• #### Re:And a lot of it is free (Score:4, Insightful)

on Saturday February 12, 2011 @04:10PM (#35188278)
I love how the first thing you see, when you click the link, is that the article says 295 exabytes, not 250.
• #### Re:And a lot of it is free (Score:4, Funny)

on Saturday February 12, 2011 @04:14PM (#35188320) Homepage Journal

How many Library of Congresses is that? I just have no perspective without it being expressed in LOC units.

• #### Re:And a lot of it is free (Score:4, Informative)

<i_have_mental_health_issues@yahoo.com> on Saturday February 12, 2011 @05:16PM (#35188706)

Well, according to the Library of Congress' website [loc.gov], they have collected "over 200 terabytes of data". But since they don't specify an exact number, let's call it at 200 TB.

• #### Just so long as they don't... (Score:2)

Just so long as they don't keep it all in one place.

------

MS Fnd in a Lbry

HAL DRAPER

From: Report of the Commander, Seventh Expeditionary Force,
Andromedan Paleoanthropological Mission

What puzzled our research teams was the suddenness of collapse
and the speed of reversion to barbarism, in this multigalactic
civilization of the biped race. Obvious causes like war, destruction,
plague, or invasion were speedily eliminated. Now the outlines of the
picture emerge, and the answer makes me apprehensive.

Part of the sto

• #### Re:And a lot of it is free (Score:5, Interesting)

on Saturday February 12, 2011 @06:35PM (#35189008)
I swear I read 250 the first time I read the article. I must be getting blind as well as old. My apologies. (Although I grant, one would have hoped the editors would take the trouble to read the article and catch it.)
• #### Something I'd like to know is... (Score:4, Funny)

by Anonymous Coward on Saturday February 12, 2011 @03:42PM (#35188070)

How much of that is pornographic "knowledge"?

• #### Re:Something I'd like to know is... (Score:5, Funny)

on Saturday February 12, 2011 @03:47PM (#35188114)
In UNIX, that's what we used to call the "sticky bits".
• #### Re: (Score:1)

I remember when porn was hard to get. I'd download 4000-color nudie pics or SI Swimsuit scans to my 1985 Amiga, and treasure them like rare gold. (The floppies were hidden with creative names like "Image XXX part 1".)

But now twenty-five years later, there's so much porn I couldn't keep-up even with Viagra.

• #### Re: (Score:2)

Random thinking out loud : : 4000-color Amiga photos were 704x240x5bits per pixel == 845 kilobits. My ZMODEM protocol transferred 2 kbit/s or 7 minutes just to view one photo! I'd forgotten. No wonder I used to leave the computer downloading by itself.

Of course back then you could only fit 8 photos per floppy, so you had to pause the download every hour, change floppies, and then resume.

Good thing the Amiga multitasked (so you could view photos and download at the same time). All. Good times.

• #### Re: (Score:2)

Of course back then you could only fit 8 photos per floppy, so you had to pause the download every hour, change floppies, and then resume.

I suspect there were other reasons you needed to occasionally change floppies.

• #### Re: (Score:2)

I didn't know that that floppy object was replaceable.

• #### Re: (Score:2)

well needless to say, that doesn't include porn. my collection alone is 500 esabytes

• #### Re: (Score:2)

How much of that is pornographic "knowledge"?

approximately 250 sexabytes.

• #### Re: (Score:3)

You mean carnal knowledge?

• #### absolute value? (Score:4, Insightful)

on Saturday February 12, 2011 @03:45PM (#35188102) Homepage
Perhaps some of the knowledge broadcast has a negative value, so the absolute value of the knowledge broadcast is high, but the net information distributed is much smaller?
• #### Re:absolute value? (Score:4, Interesting)

on Saturday February 12, 2011 @07:33PM (#35189300)

Perhaps some of the knowledge broadcast has a negative value, so the absolute value of the knowledge broadcast is high, but the net information distributed is much smaller?

Carl Sagan addressed this in Cosmos. He said there was more data broadcast in TV programs every day than the combined written works of all of history.

But, as he said, "not all bits have equal value."

A quote I had laser engraved on the back of my Nexus One. :)
-Taylor

• #### Re: (Score:2)

Information theory is interesting stuff. I think that the information content can in some way be measured by what the size of the maximum compressed version of the object is. Things get tricky though when you realize that you could compress a tv signal by transmitting just the script and some instructions on how to re-film it. Worse still the average news broadcast repeats the same sentence at least 10 times, so the text ends up 1/10 the size by trivial compression. So we end up with the unfortunate discove

• #### Re: (Score:2)

"I think that the information content can in some way be measured by what the size of the maximum compressed version of the object is"

You just reinvented Kolmogorov complexity.
• #### Re: (Score:2)

It's a good feeling to learn that something I figured out on my own was already invented by someone else and is famous. That's vindication of my thought processes.

I did that with the automatic transmission (I was like 10), the toroidal supercomputer layout used by the early Crays, and variable-bit-rate encoding.

Inventing something already well-known is not a bad thing. It's a very good thing.

• #### "Stored Data" does not equal "Knowledge" (Score:5, Insightful)

on Saturday February 12, 2011 @03:46PM (#35188104)

Nice way to conflate terms for a sensational headline. What a bogus metric. A good chunk of that "stored data" is junk. Probably most of it. Not to mention duplication. (Duplication? I told you not to mention duplication :-)

• #### Re:"Stored Data" does not equal "Knowledge" (Score:4, Funny)

on Saturday February 12, 2011 @03:51PM (#35188142)
How dare you suggest that every byte on /b/, or every "frist psot, I for one, in soviet russia, you insensitive clod" on slashdot isn't knowledge of the first order?
• #### Re: (Score:2)

Wanted to mod that '+1 Knowledge' but then I realized '++Knowledge' might be more accurate. Slashdot provides neither as an option. :(

• #### Re: (Score:3)

Oh, if only you could add to knowledge before you used it.
• #### Re: (Score:2)

Doesn't stop folks from trying...

• #### Re:"Stored Data" does not equal "Knowledge" (Score:5, Funny)

on Saturday February 12, 2011 @04:01PM (#35188214)

Nice way to conflate terms for a sensational headline. What a bogus metric. A good chunk of that "stored data" is junk. Probably most of it. Not to mention duplication. (Duplication? I told you not to mention duplication :-)

Sorry, i'm just increasing world's knowledge database at the moment.

• #### Re: (Score:2)

1) Heh heh... I'm not X, I'm increasing the world knowledge database. Where X = whatever annoying internet trope is being used against us at the moment.

2) And you thought there was no useful purpose for rickrolling.

• #### Re: (Score:2)

Give up rickrolling? Naw, never gonna give that up.
• #### Re: (Score:2)

The world's knowledge is 250 exabytes.

(Checks my own comment)

Wait, now it'll be 250 exabytes + 61 bytes.

(checks again)

Wait, now it'll be 250 exabytes + 61 bytes + 48 bytes.

(checks again)

Wait...

• #### Re: (Score:2)

At this point I'm convinced /. does it on purpose, whether for more hits, or more comments - there is no other reasonable explanation.

From a WoW comic:
[chat] Noob : Hey, how do I get to the blacksmith?
*crickets*
To assist this noob simply give the wrong directions.
[chat] Player A : Take a left by the boat house.
[chat] Players B, C, D : No it's not you idiot, you take a right by the mailbox. What a noob.

Conclusion:
You now have 4 active participants instead of just 1.

• #### a little more filtering needed (Score:2)

And of that "knowledge", how much of it is correct? And of the correct knowledge, how much is relevant. I'd say that 250 exabytes will shrink rapidly if usefulness was taken into account.
• #### Re: (Score:2)

It's all knowledge, and virtually all of it is worthwhile to someone. The subjective value of any piece is just that, subjective. Calling it junk just reveals a bias.

• #### Re: (Score:2)

I ran a little freeware product called "double killer on me Windows partition, there were thousands of individual "dupes" about 3Gigs total.

• #### Re: (Score:2)

Also we have to keep in mind that each unit of storage does not equate to a unit of knowledge. A PDF of about 500KB does not have as much raw knowledge as a 500KB text file. Same as images, videos and compiled programs. I'm not sure if adding up the capacity of every hard drive sold for the past 10-15 years somehow equates to each one being filled with some sort of information or knowledge.
• #### Re: (Score:2)

Well, if we're not deduplicating, I'm sure a billion teaspoons/day of baby batter creams the blogobytes.

• #### Re: (Score:2)

It gets even better.

There is a lot of knowledge that is not stored on any physical media (besides our brains). For instance, I "know" that I went to the grocery store yesterday and spend three minutes looking at candy without buying any. This is something that very few people have knowledge of and I guarantee it was not stored anywhere (until now). However, it does remain knowledge.

There is also a lot of unrecorded meta data associated with stored data. Consider this post. It records the words I type,

• #### So, then, get the backlog done. (Score:5, Interesting)

on Saturday February 12, 2011 @03:46PM (#35188106)

So, then, get the backlog done.

It is about time we have high definition copies of all old texts, like the all hieroglyphs ever documented, all Babylonian texts, all Sanskrit texts, the Dead Sea scrolls, all Medieval hand writings, etc.

I guess all these together could not muster 1% of all the crap that is out there today. I wouldn't be surprised if all the foolish blabber-blobber-blubber on Facebook a single day outcompete all pre-1700 texts combined.

So, back to work. Get the backlog done.

• #### Re: (Score:3)

Much of what you ask for is already on line in one form or another. Often its in the form of on-line books, either from Google or other Libraries.
See this example for Hieroglyphs [archive.org].

The rest is there if you google hard enough, some times in image form, some times translated.

However, TFA is about All the data we have stored, not All the data we have.

The huge amount of bitching that flared up when Google wanted to scan all old books and make them available on line shows that there are deeply entrenched, and lar

• #### What exactly counts as "knowledge"? (Score:2, Insightful)

E=mc^2 represents a lot more knowledge to me than the entire 3,000 episode run of "The View" or similiar programs -- even though it's a lot more concise.

I could take a yottapixel photo of dirt and it sure won't tell me a lot.

• #### Re: (Score:1)

e=mc^2 tells me nothing, its a concept, but it means nothing w/o understanding how many people died from a few pounds of nuclear mineral

• #### Re: (Score:2)

e=mc^2 tells me nothing, its a concept, but it means nothing w/o understanding how many people died from a few pounds of nuclear mineral

A little radiation never hurt anybody.

• #### Re: (Score:2)

A little radiation never hurt anybody.

True, but a lot of it will burn you to a crisp!

• #### Re: (Score:2)

A little radiation never hurt anybody.

True, but a lot of it will burn you to a crisp!

Moderation is the key to all fun, god and clean or bad and nasty.

• #### Re: (Score:2)

Nothing?

"Holy shit, mass and energy are equivalent" doesn't tell you anything?

It should tell you:

Whenever I compress a spring that spring must increase in mass.

A spinning top has more mass than a non-spinning top.

And numerous other amazing implications.

• #### Re: (Score:2)

Yeah but if it were a yottapixel photo of Jessica Alba, I think it'd be a different story.

• #### Re: (Score:3)

You're revealing a pretty heavy bias there. I'd guess a geologist would find the dirt photo much more valuable than either the view or the mc^2, and a bored housewife whose life has been closed down to the point where her only social outlet is tv would find the view more valuable than the other two.

• #### Re: (Score:2)

A yottapixel picture of dirt would tell you a lot. A _lot_.

• #### Editors, please edit (Score:5, Informative)

on Saturday February 12, 2011 @03:49PM (#35188126)
The submitter messed up two of the basic details of this story - the number is actually 295, not 250, and this value is as of 2007, rather than the implied present day. (I know, I must be new here.)
• #### Re: (Score:1)

by Anonymous Coward

Maybe the submitter thought it would be helpful to convert the figure to exibytes and call it exabytes. 295 / 1.024^6 = 255.87... ~= 250.

• #### Re: (Score:2)

What I found much more interesting in the article is that in 2002 we had for the first time more information stored digitally than in other formats, and in 2007, 94% of all information in the world was stored digitally.

• #### Re: (Score:2)

The submitter messed up two of the basic details of this story - the number is actually 295, not 250, and this value is as of 2007, rather than the implied present day.

(I know, I must be new here.)

Maybe it was 250 and after all of the meaningless comments on slashdot about it, it actually increased to 295?

You have my permission to count this as one of the meaningless comments.

• #### Re: (Score:2)

You think either of those numbers is close to the actual value? It's just someone's crude estimate, one could say 400 or 310 or 240 EB and be just as correct.

• #### Re: (Score:2)

Well three actually: Data != Knowledge

Data processed may turn into information.
Information when consumed by an individual may turn into knowledge.

The sum of the world's knowledge is therefore not measurable since it resides in the minds of individuals, not in books or other recorded material.

• #### 295 exabytes (Score:3, Interesting)

on Saturday February 12, 2011 @03:51PM (#35188146) Journal
• #### Re: (Score:2)

that's the total in the linked article as well - the /. headline is wrong.
• #### Re: (Score:2)

But who's really going to notice a difference of 45 exabytes?
• #### Well, its certainly a number. (Score:4, Insightful)

on Saturday February 12, 2011 @04:03PM (#35188230)

...not meaningful in terms of the headline. The number is just addressing storage capacity potential available, not as unique meaningful data. All its saying is that the average person has access to x terrabyes of digital storage. That number is just taking manufacturing numbers for electronic hardware, and dividing by number of people.

It's not addressing the actual complexity generated or used by people. It's not actually addressing any actual people or what they do.

There is, however an interesting deeper meaning behind a number like this - the more this number multiplies, the harder it is going to be to control information, as people have more and more diverse options for storing and transferring data.

This means that even as processing power multiplies - it becomes even more impossible to police all the data of the world for improper uses.

That's the more interesting aspect of this number.

Ryan Fenton

• #### Zero-sum game (Score:3, Funny)

on Saturday February 12, 2011 @04:08PM (#35188264) Homepage Journal
Wrong math. At best what you there have 125 exabytes of knowledge and 125 exabytes of anti-knowledge. Ok, probably the knowledge weights more than the antiknowledge, so for each scientific paper could be a hundred pages on ovnis, a thousand lolcat videos, and. well, hundreds of spam pages, but somewhat we keep going forward.
• #### Wrong! Its infinite! (Score:3)

on Saturday February 12, 2011 @04:11PM (#35188296)
The knowledge of the amount of storage needed to keep all the knowledge increases the amount of storage needed, the knowledge of which increases the amount of knowledge, ad infinitum.
• #### Let me increase that (Score:1)

I just farted. There, let it be said that I have increased the amount of human knowledge on the internet!
• #### 1 zetabyte = 1024 exabytes (Score:1)

not 1000 exabytes

• #### Re:1 zetabyte = 1024 exabytes (Score:4, Informative)

on Saturday February 12, 2011 @04:28PM (#35188404) Journal

Wouldn't that be 1 zebabyte=1024 exbabytes?

*ducks*

• #### Of course (Score:2)

Again the rectal extrusion technique is used to add just a few more bytes to that fantastic number they obtained. I wonder how they classify the 3 dead hard drives sitting in my spares closet. Do they still store data even though I am unable to access it? How did they come up with the algorithm to determine which pieces of paper I left blank, which ones I wrote on both sides, and which ones were printed on one side only. Not to mention the ones I spill coffee on and never end up using. Ahh pseudo-science.
• #### What about brains? (Score:4, Interesting)

on Saturday February 12, 2011 @04:38PM (#35188464)

It's my understanding that each human brain can store roughly 4-5 PentaBytes (entheogen.com [entheogen.com]). So if the human population* is about 6,775,235,741 (Google Public Data [google.com]) then I think this would blow the 250 exabytes estimate out of the water.

*Excluding Gwyneth Paltrow

• #### Re: (Score:2)

'It's my understanding that each human brain can store roughly 4-5 PentaBytes (entheogen.com).'

So, that's like five bytes per brain? Or does this have something to do with diesel engines?

• #### Re: (Score:2)

And you start talking about.. what? "penta"bytes?

It's called _PETA_bytes, dumbass. Go see the fucking SI-prefixes. Then think at least 20 times before ever posting again. This is just too stupid.

Yes, I know the fucking article you're talking is just as dumb, but that doesn't excuse you for being a dimwit.

Sheeez.

• #### ... all of which information takes an area of ... (Score:2)

I learned a while back that for reasons having to do with the event horizon of a black hole and the conservation of entropy/information, a bit does not have mass but it does have area. One bit requires an area of 2 Planck lengths [wikipedia.org] on a side, which is 4 * 16.163e36 m = 6.4652e35 m^2

So 'all the information in the world', multiplied by 1,000, would require an area about 2 femtometers on a side. :D

• #### Re: (Score:2)

Replying to self - yes, I know I'm playing fast and loose with the terminology. IANA physicist. But the concept stands. See black hole entropy.

• #### Gee, thanks Slashdot. (Score:2)

We were all set to record the 250 exabyte mark, and then you posted this story. No one cares about the 250.000000000001st exabyte. Way to spoil things for everyone.
• #### Re: (Score:2)

You're giving Slashdot too much credit. Many submissions here are knowledge neutral - and a fair number appear to remove knowledge from the universe.

• #### But wait! (Score:2)

But wait, now that we know this hasn't the sum of stored knowledge increased? And now that we know it has increased, doesn't that make it increase again? And wait, now that we know it increased again, doesn't that make it increase again? When will it ever end?

• #### Re: (Score:2)

When will it ever end?

When we reach the end of the internet.

• #### Now I can have it all without the internets (Score:2)

Will Britannica be publishing DVD's with all of it? If so, who needs the internets?
• #### "American Idol reruns" (Score:2)

Wouldn't that count as negative information?

Yay!

n/t

• #### Compressed or Uncompressed? (Score:3)

on Saturday February 12, 2011 @07:15PM (#35189212)
I didn't rtfa, but uh, how do you determine the value in bytes of one piece of knowledge?
• #### Pretty narrow definition of "knowledge" (Score:2)

Another good chunk of what would be considered "knowledge" ... my suspicion is "chunk" is woefully inadequate and perhaps this 295 excabytes pales in comparison ... is what humans know but have not committed to another recorded form.

Call me crazy, but "the sum total of the world's knowledge" doesn't imply just "some form" of it; it pretty much states boldly that it's the works.

From TFA:
" ... The researchers calculated the figure by estimating the amount of data held on 60 technologies from PCs and and DVDs

• #### 295? is that all? (Score:2)

I hear Mexico has surpassed 420 Esebytes.
• #### HAH! exabytes, my _ss (Score:2)

Data, not knowledge. big difference. mostly anti-data. distracting from reality. lies. bs (see politicians).
Pure cr_p. un-analyzed photos and movies. pron. dups.
totally bogus figures (see above)

• #### cool number (Score:2)

Nice to see we can fit all of the info on one piece of paper, as a number and say ok, if we need to back up the internet, this is how much space we need.

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