Talk:Nat (unit)

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Re: Merger suggestion[edit]

Just delete the other article, and mention the alternative name here if there are references for it. Personally, I've never even heard of a nit. Stanford Goldman calls it a "nepit", a contraction for "neperian [sic] digit". -- 23:31, 11 March 2006 (UTC)

counting in and converting to Nat[edit]

There is a neat summary: One nat corresponds to about 1.44 bits , or 0.434 bans .

But I am still having trouble counting and converting to Nat. What are the digit (Natit) symbols? How many are there? does 1(nat) = e(decimal) What is 2(nat)? help me count to e^3 in nat.

Thanks!--Lbeaumont (talk) 13:53, 18 February 2011 (UTC)

You can count in base e if you want, but you lose some properties of normal bases which you might expect. The biggest one is that there is no canonical representation of a number. To answer your questions: If I remember correctly, sequences of {0,1,2} are sufficient to represent any number base e. 1 is equal to 1 in decimal (1 times e^0), 2 is equal to 2 in decimal. e^3 could be written as 1000.--2003:69:CD03:4301:2E81:58FF:FEFF:8F4B (talk) 21:52, 13 August 2013 (UTC)

Natural unit[edit]

Why is nat the "natural unit" of entropy? — Preceding unsigned comment added by (talk) 13:14, 14 March 2014 (UTC)

Rename article?[edit]

I think this article should be called "Natural Unit of Information". According to the International System of Quantities, the nat is the symbol for this unit, but not its name. Are there sources that say otherwise? Dondervogel 2 (talk) 14:31, 10 August 2014 (UTC)

While I agree with the principle of the name of the article being the same as the name of a unit rather than the symbol, we do not have anything to say that "natural unit of information" is its name, any more than "SI unit of length" is the name of the metre. It would also be atypical in being an extended phrase and thus unlikely to have been nominated by any standards body as the unit name. So I would advocate waiting until someone finds a reference that gives the assigned name of this unit. —Quondum 16:29, 10 August 2014 (UTC)
According to p19 of IEC 80000-13:2008, the name of the unit is natural unit of information (symbol nat), and the first few hits of this Scholar search are relevant. Dondervogel 2 (talk) 16:41, 10 August 2014 (UTC)
The Google scholar hits seem to use the phrase, but otherwise seem to give no direct indication that it is the name. I have no access to the IEC standard, but if as you say, it designates that as the name of the unit (as opposed to just calling it that), then it would be natural to rename the article. If there is no officially designated name, then it would also seem reasonable to do the rename. Along the same lines, Ban (unit) could also be merged into Hartley (unit). —Quondum 18:46, 10 August 2014 (UTC)
The column headed ‘Name’ on p19 lists one, shannon, hartley and natural unit of information, in that order; the next column is headed ‘Symbol’ and has corresponding entries 1, Sh, Hart and nat. I agree about merging hartley and ban as they appear to be synonyms. Dondervogel 2 (talk) 19:21, 10 August 2014 (UTC)
Okay, makes sense. I support a rename (but not with capitals as in your original post), with this article becoming a redirect. —Quondum 21:08, 10 August 2014 (UTC)
I agree the capitals are not appropriate - I guess the name should be "Natural unit of information". I confess I do not know how to rename an article myself though. In any case, perhaps we should wait for 24 hours in case others wish to comment? Dondervogel 2 (talk) 21:28, 10 August 2014 (UTC)
Good call on waiting. Moving is via the "More" tab at the top of the page (then "Move"). After the move you get some clean-up instructions, fairly straightforward to follow. I could do it if you prefer, but you may want to see how it is done. —Quondum 22:27, 10 August 2014 (UTC)
Thanks for the explanation. It seems to work. Dondervogel 2 (talk) 20:37, 11 August 2014 (UTC)
Too bad that I was recovering from Wikimania, and didn't see this discussion until now. I would prefer bit, byte, nat and ban to be used for the names, because they make a set of analogous short similar words, and I think in practice they're what is more usable (and more used) -- so many nats of information, in the same way that we might say so many metres in length. And I do see nat is the analogue of "metre", rather than the analogue of "m." It's perhaps worth noting that throughout the body-text of this article, we use the word "nat" throughout to talk about the quantity, because "natural unit of information" is just too much of a mouthful. And that reflects general usage in the community. So it is simply not correct that "nat" is only used as the symbol.
As for the IEC, what standards bodies say should have "a vote, but not a veto" (as the saying goes) in discussions like this. For example for Gibbs free energy, the IUPAC recommendation is "Gibbs function" or "Gibbs energy", which was considered by the WP community, but in the end the traditional term was preferred, as being more common term, much more widely used, and more expressive, capturing the relatedness to other forms of free energy.
The final point I would make is that "Natural unit of information" sounds like the title of an essay. ('So, Smithers, what is the most natural unit for a measure of information?' -- a question which in fact we don't even answer). On the other hand "nat" has the short crispness that is characteristic of names of units, so conveys much better that this is going to be an article about a unit. Jheald (talk) 08:01, 12 August 2014 (UTC)
I have therefore undone the page move, to allow more time for further consideration. Jheald (talk) 08:10, 12 August 2014 (UTC)
Your undoing the renaming is perhaps peremptory, no? I don't have particularly strong feelings about the name, but I will note that Wikipedia articles do have titles just as essays do, even though we also call it a name, so your argument does not make a clear case. But this is a particularly fuzzy one; perhaps we should solicit more input at Wikipedia talk:WikiProject Science? —Quondum 13:29, 12 August 2014 (UTC)
Or Wikipedia talk:WikiProject Physics. Sure, I have no problem with that. Jheald (talk) 22:48, 12 August 2014 (UTC)
I fail to see the relevance of IUPAC here. And to say that the IEC has a vote but not a veto belittles the International System of Quantities (ISW), because it is an ISQ standard we are talking about, not some capricious IEC invention. It's a bit like saying that Wikipedia has a right to adopt the hellabyte as a unit of information storage. Factually correct, but absurd. Dondervogel 2 (talk) 06:48, 13 August 2014 (UTC)
WP documents how things are used, not how they ought to be used. People talk about so many nats of information, using the word as a name, not just a symbol. WP should reflect that. Jheald (talk) 08:57, 18 August 2014 (UTC)
The article now states that the name of this unit is "commonly" a "nat". Can you support this claim with a reference? Dondervogel 2 (talk) 10:30, 18 August 2014 (UTC)
Searching via Google scholar, JSTOR etc. shows up very little. Searching on "nat" doesn't help, searching on "unit of information" suggests to me that nat is not a common unit of information in either form (i.e. as "nat" or a "natural unit of information") and searching on "natural unit of information" suggests to me that "natural unit of information" is used in a sentence when introducing the concept, e.g.:
  • Brillouin (1960) showed through a number of examples that the minimal energy per natural unit of information is kT
  • It is shown that the minimum energy required to transmit a natural unit of information (nat) over a noisy channel is kT
  • for high excitations the difference between the minimum and the maximum entropies is just one nat (natural unit of information)
  • The minimum amount of energy necessary to transmit one natural unit of information over a channel with statistically independent additive noise satisfies the ... In particular, the minimum energy per nat has been calculated in [5,10] for a broadband one-dimensional photon
In short, claiming a particular case as common usage does not look like a clear-cut conclusion. Word searches are particularly bad for trying to show anything like this. Without a secondary source actually addressing usage, we really don't know, and should claim anything; in particular, I would agree with removing the claim "more commonly called". —Quondum 17:34, 18 August 2014 (UTC)
Well it's not just what's used in introducing the concept, the question is also what's used in the subsequent text -- nat, plural nats, as a name; or nat, no plural, as a symbol. Jheald (talk) 22:01, 18 August 2014 (UTC)
It's not the easiest of things to search, but looking for "Maximum entropy" nats -nat pulls up 168 hits on Google books, and 489 in Google scholar. [1]. Jheald (talk) 22:06, 18 August 2014 (UTC)
"Kullback" -"Maximum entropy" nats -nat gives another 480 hits on Google scholar [2], and 71 results on books. Jheald (talk) 22:12, 18 August 2014 (UTC)
Entropy nats -nat: 2680 hits on Google scholar [3] and 1750 results on Google books. Jheald (talk) 22:14, 18 August 2014 (UTC)
 ;-) I'm not saying you're wrong. All I'm saying is that we do not have anything that fits WP criteria to make a specific claim of this nature. —Quondum 03:16, 19 August 2014 (UTC)
How about

In the International System of Quantities, the natural unit of information (symbol, nat) is bla-bla-bla. This unit is also known by its unit symbol, the "nat".

Dondervogel 2 (talk) 07:06, 19 August 2014 (UTC)
I'm fine with that. It is the "more commonly" that I was objecting to. —Quondum 13:27, 20 August 2014 (UTC)
Done. Dondervogel 2 (talk) 14:19, 20 August 2014 (UTC)