Talk:Orders of magnitude (data)
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[edit] Uninformative Entries
This article seems to have a very large number of entries describing the names of the numbers (eg. 8,000,000 = 8 kilobits) and relatively few entries that actually give you an idea of how large that number is. For example, in the entry for 10^15 bits, there are five entries - four of which are names. Are all these names really relevant? Furthermore there is notable redundancy in the names - for example there is the heading "10^18 bits – One exabit" and then the first entry is "1,000,000,000,000,000,000 bits (1018 bits, 125 petaoctets) – One exabit" which is really not very informative - yes there is some information there but most readers will find it irrelevant. Cornflake pirate
[edit] Powers of ten or powers of two
I created this with a list of powers of ten to match the other order of magnitude charts. But perhaps it would make more sense to go with powers of two (and sectionalizing accordingly by prefixes)? Fredrik 16:01, 19 May 2004 (UTC)
- Stick with the powers of 10. Wikipedia defines an order of magnitude as a power of 10 and you don't want to generalize that (at least I wouldn't). Sectionalize by SI prefixes (kilobit, megabit etc.) but mention binary prefixes (kibibit, mebibit etc.).
- Because the byte is (more?) frequently used as unit of data, kibibyte, mebibyte etc. should also be included. And of course, byte should really be octet… This should yield some delightfully complicated fun!
- —Herbee 22:45, 2004 May 22 (UTC)
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- Seems good to me then. Thanks for contributing :) -- Fredrik 12:33, 23 May 2004 (UTC)
- Kilobyte could refer to either, and many other sizes as well; it is therefore not used in this list.
The point has already been made (in the article) that kilo always means 1000, and never 1024. Seen in that light, the above statement might actually reinforce the confusion we're trying to avoid.
—Herbee 16:45, 2004 May 23 (UTC)
- I guess I should've added "In casual use...". But I'm fine with it removed too. Fredrik 16:48, 23 May 2004 (UTC)
- .4 × 109 bits – Size of the human genome, 3.2 billion base pairs
and later:
- 1.28 × 1010 bits – Capacity of the human genome, 3.2 billion base pairs
At 3.2 billion base pairs, wouldn't the potential information content be 1.28 × 1010 bits? Transcription from DNA runs in one direction down one strand and can see any of four states at each basepair (A,T,C,G); not just that the pair was one of two (AT,GC) possible pairs. Nor do complementary Codons code for the same amino acid.
- Ah, but binary numbers have the wonderful ability to encode four states in just two bits. Explicitly, one might encode the AT base pair as 00, CG as 01, GC as 10 and TA as 11. So it's actually 2 bits per base pair. Accordingly, I'm changing the size of the human genome to 6.4 gigabits.
- —Herbee 22:23, 2005 Apr 21 (UTC)
That said, the amino acid translation for codons is more-than-one-to-one (in fact it's about four-to-one), thus reducing that potential back to around 3 × 109 post-translation. But even after that, the human genome doesn't come close to saturating its potential information content, since about 97% is Junk DNA. And that brings us to a content of about 9 × 107 useful bits -- a small stack of floppies. Mimirzero 07:25, 7 Jan 2005 (UTC)
I changed to page to use "Capacity" instead of "Size of Genome" to satisfy my second complaint without getting extra obscure on the page.
- The meaning of size is perfectly clear while capacity is not. Moreover, the article is about size and not about 'amount of content'. For instance, the 'total amount of printed material in the world' is listed, and that certainly includes a lot of junk and redundancy. Accordingly, I'm changing back to the size of the human genome.
- —Herbee 22:23, 2005 Apr 21 (UTC)
[edit] At a glance?
The article claims that 150 megabits is the approximate amount of data the human eye can "capture at a glance". That sounds pretty cool, but what does it mean? I'm pretty sure nowhere near that much actually makes its way to any useful bit of the brain on a brief glance at a scene. It's not too different from the number of photoreceptors in the human retina; is that what's meant? I'm willing (just barely!) to believe that there may be a useful sense in which the figure is right, but stated so baldly it seems more like a factoid than a fact. Gareth McCaughan 21:56, 2005 Apr 21 (UTC)
- The retina article claims an information rate of 0.6 megabits/sec through each optic nerve, so each "glance" would take about two minutes. The 150 megabits seem a factor 100 too high, at least.
- —Herbee 22:46, 2005 Apr 21 (UTC)
[edit] Phonebook
This is so stoopid:
104bits
- 22,500 bits – Amount of information in a typical non-fiction book.
- 27,000 bits – Amount of information in a typical phone book.
- 42,000 bits – Amount of information in a typical reference book.
Reality check: a phone book has on the order of 1000 pages, which would amount to 27 bits or less than 4 bytes per page. Stoopid! My own phone book (2005/2006 edition for the Arnhem-Zevenaar region, the Netherlands) has 704 pages, 4 columns per page, 129 lines per column, and on average 35 characters per line, for a total of about 100 megabits. Ads have a lower information density, so I estimate that my phone book contains 80 ± 20 megabits of information. The other two entries make no sense either—what is a "typical non-fiction book"?
As a fix, I removed these three entries and created a new one for the phone book.
—Herbee July 3, 2005 23:05 (UTC)
[edit] Binary prefixes like kibibyte
A vote has been started on whether Wikipedia should use these prefixes all the time, only in highly technical contexts, or never. - Omegatron 14:57, July 12, 2005 (UTC)
[edit] Octet vs Byte
Byte is a far more common term... shouldn't we use that instead of octet? SigmaEpsilon → ΣΕ 03:31, 15 May 2006 (UTC)
- I tend to agree, Bytes would be useful on this page as they are more common and much easier for most people to understand.--Hibernian 19:32, 16 August 2006 (UTC)
