In a computer text book that I had (I think around 1993) the authors made a claim that all the books ever printed could fit on one CD with a diameter (IIRC) of 7 feet.
First of all, has anyone ever heard that statistic or something similar?
Secondly, is that likely to be true at all? It doesn’t seem too likely to me.
Any kind of estimate is going to involve a large fudge factor & lots of variables. For example, is data compression allowed? How about pictures? Does “Where’s Waldo” count as a book? If so, then we’ll have loads of JPGs to store.
A single CD ROM could store about 2000 books. That is assuming 1KB per page, 325 pages per book & no pictures or tables. I don’t see a single disk holding “all the books ever printed” even if it is seven feet across.
I’ve never heard anything like that. Before I’d say it was possible or not, I’d like to know how you define “books.” Does that include bound master’s theses and doctoral dissertations? How about technical manuals? Bound volumes of magazines?
The amount of material we’re talking about will vary greatly depending on how we define the term.
Besides all that, it’s a meaningless statement; there are no CDs with 7 foot diameters, nor would there be a CD-ROM player to put it on if you made one.
If expressed as “All the world’s books would fit on X number of normal-sized CDs” we’d begin to have some idea what we’re talking about.
Martin Gardner, in one of his “Aha!” books, showed how all the world’s books could be recorded with just a scratch on a stick.
Theoretically, anyway. In reality there would be some noteworthy obstacles.
It sounds like the claim about a single 7ft disc (hmmm, practical) rather than X amount of standard discs is going to be based on the assumption that the tracks nearer the edge of the disc (being much longer) could potentially hold a lot more data than the tracks near the middle, but I’m not sure whether current CD technology works in that way, perhaps someone could enlighten me?
I measured a regular CD. The area of the hole thing turns out to be about 17.72 square inches. Take away the area of the non readable center, and you have 15.31 sq inches.
The 7 foot CD has an area of 3339.36 sq inches. Assuming data storage is directly proportional to storage area, the 7 foot disc could hold 361.6 regular CDs, or about 126 Gigabytes.
Is 126GB enough to store every book ever made? Sure beats the hell outta me. I don’t know everything, you know…
the area of the hole thing
Must… preview…
I meant whole, really…
That’s all right, Mikahw. Now we know how many hole things it takes to fill the Albert Hall thing.
The 7 foot CD would have an area of 5539.36 sq in. I read my paper wrong. Everything else should be accurate, though.
Here’s the quote, from Computers by Larry and Nancy Long (1993):
Here’s another quote on the opposite page:
So I guess now we can see if they are correct, if their numbers are wrong or their math is wrong.
BTW, what about a DVD 7 feet in diameter? How much could that hold?
That’s where we get into too many variables. DVDs are not only two sided, but also multi layered.
A CD ROM is good for 650MB of data storage. Since the quote has already made images & text into different categories, I have to assume “250,000 pages of text” means just that- text only. That comes to 2.6KB per page. Depending on lots of goofy stuff like formatting (bold, italics, underlining, colored text, etc), a single page of text can be saved in about 1KB of disk space.
A CD ROM can store the same amount of data as 461 floppy disks. It would take more than three CD ROMs to hold the data from 1500 floppies.
The last number I heard for DVD capacity is 17GB, or about 52,300 books using the numbers from my earlier post.
OK, so one CD can hold 650,000 pages. The seven foot CD can then hold 361.6 times that, or 235,040,000 pages. While that’s a lot, I really doubt that it’s every book ever printed.
*I don’t know what Martin Gardner would think of the following (maybe he would sneer at it), but…
There is a Sufi saying that the meaning of all the sacred texts ever revealed (the Torah, the Psalms, the Gospels, etc.) is contained in the Qur’ân. The meaning of the entire Qur’ân is contained in the first brief chapter, al-Fâtihah. The whole meaning of al-Fâtihah is contained in the first verse, bismillâh al-rahmân al-rahîm (In the name of God, the Compassionate, the Merciful). The whole meaning of that first verse is contained in the first letter bâ’, which has a dot under it. The whole meaning in the letter bâ’ is contained in that itty bitty dot.
Talk about data compression…
That would depend on the type of disk. There’s no way you could fit 1500 full 1.44MB floppies on one CD. However, you could easily put 1500 360K 5.25" floppies on one CD.
I’ve tried every floppy combination possible, and I could never got to exactly 1500. The two closest ones would be the 360K 5.25" floppy and the 720K double density 3.5" floppy. You can fit 1,800 of the 360K discs, while you could only fit 900 of the 720K discs.
As for the 7 foot DVD, a single sided single layer DVD holds 4.7GB, right? You could fit about 1.6TB on the 7 foot version. If you used a double sided double layer disc, you could fit about 4 times as much.
Let’s get real here. The National Geographic Society sells 110 years of their magazine (I am assuming about 1320 issues) on 31 CD-ROMs and that represents an infinitesimal fraction of what is published and has been published in the world. You would need millions of CD-ROMS to record everything ever published.
Yeah, but if you had an infinite number of scanners, and an infinite number of CD burners, then an infinite number of monkeys could…
The National Geographic 31 CD-rom set contains scans of the pages, right? Text files, of course, take up much less room. If you were to settle for text files, you would be able to store much more information.
If we assume that each of those 1320 issues had 100 pages of text, each page of text contains 500 words, and the average word is 6 letters, The entire thing would only take up 396MB.
There is one problem, though. Text alone wouldn’t do National Geographic justice, now would it?
Well, I found another quote from this page that might be slightly more accurate:
http://www.artsci.gmcc.ab.ca/people/sumraini/157/Sstorage.html
Now the fact that this statistic is repeated, but in a different form, leads me to believe that there must be some “master” source of the theory, and if we can find that we can find out what it is based on.
Now this site ( http://itri.loyola.edu/digilibs/02_03.htm ) provides some different statistics:
Is this more accurate?
Upon rereading my last post, I realized that we need to through another variable into this problem: compression.
Text is quite easy to compress. So using todays highest level of compression, can we get closer to our 7 (or 8) foot CD?
Ok, here’s a little more info:
From the Winzip FAQ ( http://www.winzip.com/xgifcomp.htm )
Therefore using the Loyola data, we can put the words of every book ever printed into a text file, and compress it, getting it down to 100 million megabytes.
So who can do the math to find out:
a) How big a CD would need to be to contain that much data (and there are CDs that can hold 800 MB, so that should be taken into consideration)
b) How big would a standard DVD need to be?
c) How about a double sided DVD?