text:
Talk:Difference engine

Additional extension for the display of DE2
I don't have a written source, but a senior docent working at the Mountain View Computer History Museum said today that Nathan Myhrvold is extending his loan of the DE2 again (to the end of 2010). Should I change the article now, or wait for the museum to update its site? Seijihyouronka (talk) 04:28, 10 January 2010 (UTC)

Novel?
In the novel, did they assume that difference engines took over or analytical engines? A world full of difference engines wouldn't be too exciting I'm afraid.

I don't have a copy with me, but I believe it was various Babbage engines, from difference engines to analytical engines and beyond. --The Cunctator

Plans?
Does anyone know where I might find plans of either engines?

BrentB

Adding and subtracting?
The example of the polynomial is not correct. It states: 'A difference engine only needs to be able to subtract'. Though, the Difference Engine could only add. What's wrong is that the differences in the second column (column of 1st difference) are not subtracted correctly and need a minus sign. SvenPB 19:24, 6 August 2005 (UTC) (edit Jan'09: fixed, thanks Dickguertin)

I would also like to add that transcendental functions can only be approximated by polynomials. And thus in those cases you'll not find the constant value at the end. In those cases you can only do so good as the number of columns in the difference engine. For example a sine on the difference engine can only be calculated to about PI/2 or so. After that it will just disapear into plus or minus infinity. SvenPB (talk) 15:06, 11 May 2008 (UTC)

 * That is not correct. It is possible to produce appropriate polynomial approximations for any portion of the domain of the sine functions.  However, a single approximation will not be suitable for the entire domain.  That is true for many other transcendental functions as well, including logarithms.  This was well-known in Babbage's time; even with the Difference Engine it still would have been necessary for mathematicians to derive the appropriate polynomial approximations for various portions of the domain, and use each polynomial for only a portion of the tables being generated.  --Brouhaha (talk) 20:01, 12 May 2008 (UTC)

 * That is exactly the same. As the second difference of a simple x^2 is a constant being 2, this function can be calculated without error. For trancendental functions, you'll not find such a beautiful constant and you're dependent on the number of columns: the lesser columns the sooner major deviations occur. Then you'll have to recalculate your differences and reprogram the column to expand your domain. Reprogramming needs human intervention and is a manual job. SvenPB (talk) 14:12, 11 January 2009 (UTC)

The difference engine could both add and substract, using the trick of adding negative numbers. The engine has no signs for numbers so you have to express them in arithmetical nine's complement (e.g. -6 would be 999999999999994).

Example:

You want to calculate the height of a rock being thrown. For simplicity, asume the engine has only 4 digits per number.
 * Display Column = 0000 (initial height, floor level)
 * First D.Column = 0005 (initial speed, upwards
 * Second D. Column= 9998 (acceleration = -2)

This yields this:

0005 0005 9998

0005 0003 9998

0008 0003 9998

0008 0001 9998

0009 0001 9998

0009 9999 9998

0008 9999 9998

0008 9996 9998

...and so on. The final list would be 0 5 8 9 8 5 0 -7 etc. RedNifre (talk) 21:22, 26 June 2008 (UTC)

 * Yes ok, but the mechanism is an adder and the subtraction is a trick. Then you're not using 9's complement, but 10's. Which is in fact 9's complement plus 1 (e.g. -0029 = 9970 + 0001 = 9971). Finaly, there's no mechanism in the difference engine to convert negative numbers to something readable. If printed, the difference engine would print 9971 instead of -(0028 + 0001) = 0029 SvenPB (talk) 14:52, 11 January 2009 (UTC)

But can it run "Crysis"? —Preceding unsigned comment added by 76.174.19.121 (talk) 02:25, 7 June 2010 (UTC)

Method of differences?
This 'method of differences' looks a bit like differential calculus to me. Is that wrong? E.g.: the first column is the function; the 2nd is the 1st derivative, and the 3rd is the 2nd derivative. Note that the third column of a 2nd-degree polynomial is constant, like the 2nd derivative. --Taejo 12:52, 27 August 2005 (UTC)

 * The "method of differences" uses difference equations; "differential calculus" uses differential equations. They are very similar, except the first uses finite steps and the second infinitesimal steps. -- RTC 20:07, 7 September 2005 (UTC)

Historical information?
I'm not a computer science major, an engineer or anything of that sort, but this article seems terribly incomplete to me. There's no historical information (when was it designed, why wasn't it built), there's no discussion of the engineering principles. Cansomeone please work on this? Zaklog 03:01, 12 February 2006 (UTC)

I've gone through the history section and added a paragraph on Babbage's work on the development of the Difference engine. It is brief but should explain the basics of Babbage's efforts. As a result I also re-wrote the other parts of the section to improve the flow. I added a note about how his work on the Analytical engine helped improve the design of Difference engine #2. I also edited the part of the history section where it talked about the printer on the Difference engine #2 that was built in 1991. Wanted to make it clear that at the time Babbage created his design, humans were also doing the calculations for the tables but that the article was correct that the real concern was errors in printing. Japenfold (talk) 02:51, 25 October 2011 (UTC)

student
im doing a power point on this topic i was wondering if anyone could plz add the history of the people's live's involved with the machine? thnx

-- Be BOLD. :-)

 * Ha ha. I have an assignment due, I was wondering if anyone could plz do it for me? Thnx --Be EXCELLENT coz I need an A to pass.154.5.40.122 (talk) 13:16, 10 December 2011 (UTC)

Now there are two
http://www.computerweekly.com/Articles/2008/03/31/230058/babbages-vintage-supercomputer-heads-to-us.htm http://www.electronicsweekly.com/Articles/2008/04/01/43442/babbages-difference-engine-heads-for-california.htm http://www.wired.com/gadgets/miscellaneous/multimedia/2008/04/gallery_babbage Conrad T. Pino (talk) 02:51, 10 April 2008 (UTC)

Rather than add drum one to two, then two to three, and so on - "only a 25 per cent use of the machine", said Swade, all the odds are simultaneously added to the evens on one half cycle, then all the evens are added to the odds on the other half cycle. See Wikipedia for a more detailed description.
 * Nice to see someone reads us. --Petri Krohn (talk) 19:20, 11 January 2009 (UTC)

Intentional Error
Is there any documented evidence of the notion that the errors found in Babbage's plans were intentional mistakes--a sort of insurance against patent theft? And if so, should the article reflect that in its coverage of the errors? I've heard this idea from many a good mind, but no one has offered evidence. O0drogue0o (talk) 09:38, 17 September 2008 (UTC)

No, so far as I know there isn't, except the beliefs of the team who made the reproduction. There are other potential explanations, but they would be personal opinions, and therefore not appropriate for Wikipedia. Also one could argue that the team who made the reproduction are better qualified to comment on Babbage's personality than anyone else - they lived and breathed Babbage-mechanics for a long period! It is a question of Babbage's work-habits whether he would deliberately obfuscate the drawings to avoid competition, or whether the "errors" are actually that the design on paper couldn't keep up with Babbage's ideas in his head, so the drawings contain inconsistencies through their not all being prepared on exactly the same day. Drawing 1 contains features based on Babbages's thoughts on day 1, drawing 2 contains features based on his newer ideas from day 2, which require changes in the drawings from day 1, which never got redrawn, because by day 3, he was already onto further improvements. As I say, this is random conjecture not appropriate for an encyclopedia 149.155.219.44 (talk) 16:15, 15 December 2014 (UTC)

Pipeline Method
I have removed the folowing section from the article and restored my original text in section Difference engine. I have done this for two reasons:
 * 1) This is not encyclopedic, it tryes to "demonstrate these concepts" through the use of examples.
 * 2) I do not understand any of it.

-- Petri Krohn (talk) 20:50, 11 January 2009 (UTC)

P.S. - Searching for "Pipeline Method" "Difference engine" -wikipedia produces no results. -- Petri Krohn (talk) 22:10, 11 January 2009 (UTC)

Initial values and Pipeline Method
The Babbage Difference Engine is designed to calculate a new result using a "pipeline method" which requires an initial setup involving "staggered steps". To demonstrate these concepts, consider the following polymomial:

R = X3 -2X2 + 1

Compute the first N+1 results (R) where N is the highest exponent in the polynomial, starting at any value of X. In this case, we'll start at X = 1 and calculate four consecutive results:

X    Result    Diff1    Diff2   Diff3 1      0         1        8       6 2       1         9       14       6 3      10        23 4      33

This table also shows the differences between consecutive values in a column written into the column to its right. Thus, Diff1(n) = Result(n+1) - Result(n), Diff2(n) = Diff1(n+1) - Diff1(n), and Diff3(n) = Diff2(n+1) - Diff2(n). For a third-order polymonial, Diff3 is a constant, which can be propagated down that column.

The initial values for a pipeline are Result(2), Diff1(2), Diff2(1), and Diff3(1). These values are highlighted in bold in the table above. Aligning them in a straight line, and applying a four-step Babbage cycle:

Step Result    Diff1    Diff2   Diff3 1       9        8       6       Initial values for this cycle. 1   c 0        0      c 4       0       Add Diff1 to Result, Diff3 to Diff2, c=carry 2    10        9       14       6       Propagate carries, restore Diff1 & Diff3. 3     0     c 13        0       6       Send Result to printer, add Diff2 to Diff1 4    10       23       14       6       Propagate carry, restore Result & Diff2

Several carries can occur in any add, but in this example, only one occurs for any number. In Step 1, 9+1 = 0 with a carry, and, 6+8 = 4 with a carry. Step 2 increments the next higher digit for each carry, yielding 10 and 14. Note that applying a carry can cause another carry on the incremented value, as when 9 becomes 0 with a carry. That's why the carry mechanism is a spiral, to pass generated carries up to higher levels. The carry for Diff1 on Step 3 is from 4+9 = 3. The 1 from 14 becomes the 1 in 13. When step 4 occurs, the carry is applied to the 1, and it becomes 2, so 13 becomes 23.

At the end of the four steps, we have a new set of staggered steps, which are shown in italic in the calculation table. Repeat the four steps beginning with 10, 23, 14, 6 replacing 1, 9, 8, 6. You'll get: 33, 43, 20, 6, with 33 and 43 on the X=4 level, 20 and 6 on X=3 level. Every repetition of these four steps obtains and prints another Result.

Photos from of version 2 from computer history
I have a set of photos that I would be happy to contribute to the article if people would like to add them. The set is here: http://www.flickr.com/photos/0x0000org/sets/72157605376240530/

The photos are of the Difference Engine No. 2 exhibit at the Computer History Museum. —Preceding unsigned comment added by Wikiwikimoore (talk • contribs) 23:57, 17 January 2009 (UTC)

Curve fitting
I don't understand this paragraph. The polynomials for the functions that Babbage was planning to use were perfectly known in his time. The paragraph is talking about statistical correlation or something. SvenPB (talk) 11:39, 6 February 2009 (UTC)
 * No. -- Petri Krohn (talk) 14:25, 7 May 2009 (UTC)

Method of Differences Table Incorrect
The column headers in the table are incorrect. p(x) for x=0 is indeed 2.00 but p(x+1) is 1.00 (i.e., 2^2 - 3 + 2). The column headers should instead read p(x+0.1) not p(x+1). Ross Fraser (talk) 22:40, 5 April 2009 (UTC)

Incorrect claim
The sentence: Functions that are not polynomial functions but are infinitely differentiable can be expressed as power series, for example as a Taylor series. is wrong as an example of function e-1/x 2 fox x> 0 and 0 for x <= 0 shows. —Preceding unsigned comment added by 4.143.95.100 (talk) 12:10, 14 June 2009 (UTC)

Manufacturing tolerances.
Look at a Holtzapffel lathe and the high precision work possible with one. Late 18th (first lathe sold by the company June 31st, 1795) and 19th century equipment was capable of very precise tolerances. It was mostly a lack of funding and inability to envision what the thing would be useful for by those in positions to provide the funding, which prevented Babbage from getting his engines built. Bizzybody (talk) 05:57, 30 August 2010 (UTC)

Babbage built a small model of the difference engine (although it was too small to produce tables) so the precision needed for manufacture was possible. Campbell-Kelly and Aspray (in Computer: A History of Information Machine) suggest it was telling potential fund raisers that after building the difference engine he should be funded to build the Analytical Engine and this undermined confidence in the project. — Preceding unsigned comment added by Japenfold (talk • contribs) 00:55, 21 September 2011 (UTC)

Performance?
I'd be very curious to see some performance and timing data. Thanks! --Brian Fenton (talk) 21:12, 16 October 2010 (UTC)

Converging polynomials
All polynomials of finite order "converge" so I don't really understand to what the caption of the first photo is referring when it uses the phrase "converging polynomials." Is there some specific technical meaning that the author of this caption intended or is it merely pedantry? Shall I delete the word "converging?"154.5.40.122 (talk) 06:42, 4 December 2011 (UTC)

Method of differences
In the table: p(x) = 2x^2 − 3x + 2  when x=2,  P(2)=4  not 12920 88.104.128.60 (talk) 14:44, 4 April 2012 (UTC)

Why is there no mention of Ada Lovelace in this article? — Preceding unsigned comment added by Cet3091 (talk • contribs) 19:26, 21 October 2013 (UTC)

 * I am wondering as well Harrmas (talk) 18:14, 27 March 2023 (UTC)

May be worth noting as a weblink
Maybe worth noting in the article:

http://acarol.woz.org/difference_engine.html

I think it's hilarious... — Preceding unsigned comment added by 84.135.18.129 (talk) 15:59, 17 May 2014 (UTC)

Please make this article inclusive
Hello. I am not a Wikipedia editor. I am however a professional teacher who came to find out what the Difference Engine is. The introduction to the article is written to a level more suited to the preamble to a PhD dissertation. I haven't the faintest idea what it means. I came here looking for knowledge and you guys simply can't keep your big words in your pants for even an introduction. Congratulations - you understand it. The people you supposedly wrote it for haven't got a clue.... Please sort this out before you disappear up your own internal affairs. Off to consult Britannica. THIS IS AN ENCYLOPEDIA for people to learn from, not for you to show how clever you are!!!!

As no reply was given to this very serious request i am afraid that I decided to vandalise the article for which I apologise. The vandalism took the form of the following paragraph placed at the beginning of the article:

"This first paragraph is an anonymous and deliberate "vandalisation". The following article is incomprehensible to users of Wikipedia who do not have exceedingly high levels of Mathematical Knowledge on which to build further learning. Despite a request on the Talk Page for months, no reply has been received and no work done to resolve this matter. The author of this regrettable vandalisation notwithstanding requests that there be at least an introduction to this article that explains in plain English what the purposes and functions of the Difference Engine are so that the Wikipedia user can continue deeper into the article with some sort of awareness of the system and its purposes. The author regrets the vandalism." — Preceding unsigned comment added by 217.44.205.7 (talk) 08:12, 20 July 2015 (UTC)

Photo requests of the Difference Engine
I'm arranging a visit to photograph the Difference Engine at Intellectual Ventures in Bellevue, Washington in conjunction with Wikinews. Does anyone have specific parts of the machine I should try to photograph, particularity those we haven't seen or are not normally visible to the public? --Dennis Bratland (talk) 23:09, 15 February 2016 (UTC)
 * The photos --most of them -- are up: . I have a couple more uploads to add. --Dennis Bratland (talk) 16:05, 25 February 2016 (UTC)

Turing completeness?
Is the difference engine Turing complete? More to the point, is there a source that specifies whether or not it is, and would someone please be so kind as to add it into the article? Mattman00000 (talk) 23:57, 28 March 2017 (UTC)
 * DE isn't programmable (beside setting initial values to the columns.), so it's most likely not Turing complete. — Preceding unsigned comment added by 89.25.210.104 (talk) 19:35, 8 May 2018 (UTC)
 * Well, I will try to prove it not to. A Turing machine must have the ability to create a loop(Just like Brainfuck), but there is no evidence that it can create a loop. Also, it is in a mechanical sequence, so it can never implement all of the Turing-machines. The sequences are already built-in, so we can't program it(without putting values inside, and there is no way here explained to do that). So, the difference machine is not Turing-complete. Also, if the above doesn't work, a Turing-machine must have the ability to halt(in at least some way), but it never halts. Also, it said that the columns are marked from 1 to N, so the columns are obviously limited in size, which is not infinite, as in the Turing-machine.

External links video proposition
--89.25.210.104 (talk) 01:25, 16 February 2018 (UTC)
 * Video of Martin Wibergs difference engine

Title spelling
Why Difference engine, but Analytical Engine? Smeagol 17 (talk) 19:04, 6 November 2019 (UTC)

Suggest to replace photo with clean, unedited one
The photo used in the box is really badly "photoshopped", presumably to clone out people's faces for privacy or whatever reason. Looks pretty bad in the article, it is visually distracting and the edit obscures parts of the exhibit. I suggest replacing it with a one from Commons (if the license permits, I think it should so), or a newer one if available. Technicality nitpicker (talk) 16:50, 15 January 2023 (UTC)

title: Talk:Difference engine


text:
Draupnir

In Norse mythology, Draupnir (Old Norse:, "the dripper" ) is a gold ring possessed by the god Odin with the ability to multiply itself: Every ninth night, eight new rings 'drip' from Draupnir, each one of the same size and weight as the original.

Draupnir was forged by the dwarven brothers Brokkr and Eitri (or Sindri). Brokkr and Eitri made this ring as one of a set of three gifts which included Mjöllnir and Gullinbursti. They made these gifts in accordance with a bet Loki made saying that Brokkr and Eitri could not make better gifts than the three made by the Sons of Ivaldi. In the end, Mjöllnir, Thor's hammer, won the contest for Brokkr and Eitri. Loki used a loophole to get out of the wager for his head (the wager was for Loki's head only, but he argued that, to remove his head, they would have to injure his neck, which was not in the bargain) and Brokkr punished him by sealing his lips shut with wire.

The ring was placed by Odin on the funeral pyre of his son Baldr: Odin laid upon the pyre the gold ring called Draupnir; this quality attended it: that every ninth night there fell from it eight gold rings of equal weight. (from the Gylfaginning).

The ring was subsequently retrieved by Hermóðr. It was offered as a gift by Freyr's servant Skírnir in the wooing of Gerðr, which is described in the poem Skírnismál.

In popular culture
The ring appears in the 2022 video game God of War Ragnarök, where it is used as a base for creating the new weapon of Kratos. The ability of replicating itself is instead used to create spears that can be thrown and explode on command.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Draupnir


text:
Divergence

In vector calculus, divergence is a vector operator that operates on a vector field, producing a scalar field giving the quantity of the vector field's source at each point. More technically, the divergence represents the volume density of the outward flux of a vector field from an infinitesimal volume around a given point.

As an example, consider air as it is heated or cooled. The velocity of the air at each point defines a vector field. While air is heated in a region, it expands in all directions, and thus the velocity field points outward from that region. The divergence of the velocity field in that region would thus have a positive value. While the air is cooled and thus contracting, the divergence of the velocity has a negative value.

Physical interpretation of divergence
In physical terms, the divergence of a vector field is the extent to which the vector field flux behaves like a source at a given point. It is a local measure of its "outgoingness" – the extent to which there are more of the field vectors exiting from an infinitesimal region of space than entering it. A point at which the flux is outgoing has positive divergence, and is often called a "source" of the field. A point at which the flux is directed inward has negative divergence, and is often called a "sink" of the field. The greater the flux of field through a small surface enclosing a given point, the greater the value of divergence at that point. A point at which there is zero flux through an enclosing surface has zero divergence.

The divergence of a vector field is often illustrated using the simple example of the velocity field of a fluid, a liquid or gas. A moving gas has a velocity, a speed and direction at each point, which can be represented by a vector, so the velocity of the gas forms a vector field. If a gas is heated, it will expand. This will cause a net motion of gas particles outward in all directions. Any closed surface in the gas will enclose gas which is expanding, so there will be an outward flux of gas through the surface. So the velocity field will have positive divergence everywhere. Similarly, if the gas is cooled, it will contract. There will be more room for gas particles in any volume, so the external pressure of the fluid will cause a net flow of gas volume inward through any closed surface. Therefore the velocity field has negative divergence everywhere. In contrast, in a gas at a constant temperature and pressure, the net flux of gas out of any closed surface is zero. The gas may be moving, but the volume rate of gas flowing into any closed surface must equal the volume rate flowing out, so the net flux is zero. Thus the gas velocity has zero divergence everywhere. A field which has zero divergence everywhere is called solenoidal.

If the gas is heated only at one point or small region, or a small tube is introduced which supplies a source of additional gas at one point, the gas there will expand, pushing fluid particles around it outward in all directions. This will cause an outward velocity field throughout the gas, centered on the heated point. Any closed surface enclosing the heated point will have a flux of gas particles passing out of it, so there is positive divergence at that point. However any closed surface not enclosing the point will have a constant density of gas inside, so just as many fluid particles are entering as leaving the volume, thus the net flux out of the volume is zero. Therefore the divergence at any other point is zero.

Definition

The divergence of a vector field $x$ at a point $S_{i}$ is defined as the limit of the ratio of the surface integral of $V_{1}, V_{2}, V_{3}, …$ out of the closed surface of a volume $x$ enclosing $F(x)$ to the volume of $x_{0}$, as $F$ shrinks to zero where $V$ is the volume of $x_{0}$, $V$ is the boundary of $V$, and $$\mathbf{\hat n}$$ is the outward unit normal to that surface. It can be shown that the above limit always converges to the same value for any sequence of volumes that contain $|V|$ and approach zero volume. The result, $V$, is a scalar function of $S(V)$.

Since this definition is coordinate-free, it shows that the divergence is the same in any coordinate system. However it is not often used practically to calculate divergence; when the vector field is given in a coordinate system the coordinate definitions below are much simpler to use.

A vector field with zero divergence everywhere is called solenoidal – in which case any closed surface has no net flux across it.

Cartesian coordinates
In three-dimensional Cartesian coordinates, the divergence of a continuously differentiable vector field $$\mathbf{F} = F_x\mathbf{i} + F_y\mathbf{j} + F_z\mathbf{k}$$ is defined as the scalar-valued function:

 * $$\operatorname{div} \mathbf{F} = \nabla\cdot\mathbf{F} = \left(\frac{\partial}{\partial x}, \frac{\partial}{\partial y}, \frac{\partial}{\partial z} \right) \cdot (F_x,F_y,F_z) = \frac{\partial F_x}{\partial x}+\frac{\partial F_y}{\partial y}+\frac{\partial F_z}{\partial z}.$$

Although expressed in terms of coordinates, the result is invariant under rotations, as the physical interpretation suggests. This is because the trace of the Jacobian matrix of an $V$-dimensional vector field $x_{0}$ in $N$-dimensional space is invariant under any invertible linear transformation.

The common notation for the divergence $div F$ is a convenient mnemonic, where the dot denotes an operation reminiscent of the dot product: take the components of the $x$ operator (see del), apply them to the corresponding components of $N$, and sum the results. Because applying an operator is different from multiplying the components, this is considered an abuse of notation.

Cylindrical coordinates
For a vector expressed in local unit cylindrical coordinates as
 * $$\mathbf{F}= \mathbf{e}_r F_r + \mathbf{e}_\theta F_\theta + \mathbf{e}_z F_z,$$

where $F$ is the unit vector in direction $∇ · F$, the divergence is
 * $$\operatorname{div} \mathbf F = \nabla \cdot \mathbf{F} = \frac{1}{r} \frac{\partial}{\partial r} \left(r F_r\right) + \frac1r \frac{\partial F_\theta}{\partial\theta} + \frac{\partial F_z}{\partial z}.

$$

The use of local coordinates is vital for the validity of the expression. If we consider $∇$ the position vector and the functions $F$, $e_{a}$, and $a$, which assign the corresponding global cylindrical coordinate to a vector, in general $$r(\mathbf{F}(\mathbf{x}))\neq F_r(\mathbf{x})$$, $$\theta(\mathbf{F}(\mathbf{x}))\neq F_{\theta}(\mathbf{x})$$, and $$z(\mathbf{F}(\mathbf{x}))\neq F_z(\mathbf{x})$$. In particular, if we consider the identity function $x$, we find that:

 * $$\theta(\mathbf{F}(\mathbf{x})) = \theta \neq F_{\theta}(\mathbf{x}) = 0$$.

Spherical coordinates
In spherical coordinates, with $θ$ the angle with the $z$ axis and $φ$ the rotation around the $z$ axis, and $r(x)$ again written in local unit coordinates, the divergence is
 * $$\operatorname{div}\mathbf{F} = \nabla \cdot \mathbf{F} = \frac1{r^2} \frac{\partial}{\partial r}\left(r^2 F_r\right) + \frac1{r\sin\theta} \frac{\partial}{\partial \theta} (\sin\theta\, F_\theta) + \frac1{r\sin\theta} \frac{\partial F_\varphi}{\partial \varphi}.$$

Tensor field
Let $θ(x)$ be continuously differentiable second-order tensor field defined as follows:

 * $$\mathbf{A} = \begin{bmatrix}

A_{11} & A_{12} & A_{13} \\ A_{21} & A_{22} & A_{23} \\ A_{31} & A_{32} & A_{33} \end{bmatrix}$$

the divergence in cartesian coordinate system is a first-order tensor field and can be defined in two ways:

 * $$\operatorname{div} (\mathbf{A})

= \cfrac{\partial A_{ik}}{\partial x_k}~\mathbf{e}_i = A_{ik,k}~\mathbf{e}_i = \begin{bmatrix} \dfrac{\partial A_{11}}{\partial x_1} +\dfrac{\partial A_{12}}{\partial x_2} +\dfrac{\partial A_{13}}{\partial x_3} \\ \dfrac{\partial A_{21}}{\partial x_1} +\dfrac{\partial A_{22}}{\partial x_2} +\dfrac{\partial A_{23}}{\partial x_3} \\ \dfrac{\partial A_{31}}{\partial x_1} +\dfrac{\partial A_{32}}{\partial x_2} +\dfrac{\partial A_{33}}{\partial x_3} \end{bmatrix}$$

and

\nabla\cdot \mathbf A = \cfrac{\partial A_{ki}}{\partial x_k}~\mathbf{e}_i = A_{ki,k}~\mathbf{e}_i = \begin{bmatrix} \dfrac{\partial A_{11}}{\partial x_1} + \dfrac{\partial A_{21}}{\partial x_2} + \dfrac{\partial A_{31}}{\partial x_3} \\ \dfrac{\partial A_{12}}{\partial x_1} + \dfrac{\partial A_{22}}{\partial x_2} + \dfrac{\partial A_{32}}{\partial x_3} \\ \dfrac{\partial A_{13}}{\partial x_1} + \dfrac{\partial A_{23}}{\partial x_2} + \dfrac{\partial A_{33}}{\partial x_3} \\ \end{bmatrix} $$

We have

 * $$\operatorname{div} (\mathbf{A^T}) = \nabla\cdot\mathbf A$$

If tensor is symmetric $z(x)$ then $$\operatorname{div} (\mathbf{A}) = \nabla\cdot\mathbf A$$. Because of this, often in the literature the two definitions (and symbols $F(x) = x$ and $$\nabla\cdot$$) are used interchangeably (especially in mechanics equations where tensor symmetry is assumed).

Expressions of $$\nabla\cdot\mathbf A$$ in cylindrical and spherical coordinates are given in the article del in cylindrical and spherical coordinates.

General coordinates
Using Einstein notation we can consider the divergence in general coordinates, which we write as $F$, where $n$ is the number of dimensions of the domain. Here, the upper index refers to the number of the coordinate or component, so $A$ refers to the second component, and not the quantity $x$ squared. The index variable $i$ is used to refer to an arbitrary component, such as $A_{ij} = A_{ji}$. The divergence can then be written via the Voss-Weyl formula, as:

 * $$\operatorname{div}(\mathbf{F}) = \frac{1}{\rho} \frac{\partial \left(\rho\, F^i\right)}{\partial x^i},$$

where $$\rho$$ is the local coefficient of the volume element and $div$ are the components of $\mathbf{F}=F^i\mathbf{e}_i$ with respect to the local unnormalized covariant basis (sometimes written as $\mathbf{e}_i = \partial\mathbf{x} / \partial x^i$). The Einstein notation implies summation over $i$, since it appears as both an upper and lower index.

The volume coefficient $ρ$ is a function of position which depends on the coordinate system. In Cartesian, cylindrical and spherical coordinates, using the same conventions as before, we have $x^{1}, …, x^{i}, …, x^{n}$, $x^{2}$ and $x^{i}$, respectively. The volume can also be expressed as $\rho = \sqrt{\left|\det g_{ab}\right|}$, where $F^{i}$ is the metric tensor. The determinant appears because it provides the appropriate invariant definition of the volume, given a set of vectors. Since the determinant is a scalar quantity which doesn't depend on the indices, these can be suppressed, writing $\rho=\sqrt{\left|\det g\right|}$. The absolute value is taken in order to handle the general case where the determinant might be negative, such as in pseudo-Riemannian spaces. The reason for the square-root is a bit subtle: it effectively avoids double-counting as one goes from curved to Cartesian coordinates, and back. The volume (the determinant) can also be understood as the Jacobian of the transformation from Cartesian to curvilinear coordinates, which for $ρ = 1$ gives $\rho = \left

Some conventions expect all local basis elements to be normalized to unit length, as was done in the previous sections. If we write $$\hat{\mathbf{e}}_i$$ for the normalized basis, and $$\hat{F}^i$$ for the components of $ρ = r$ with respect to it, we have that
 * $$\mathbf{F}=F^i \mathbf{e}_i =

F^i \|{\mathbf{e}_i }\| \frac{\mathbf{e}_i}{\| \mathbf{e}_i \|} = F^i \sqrt{g_{ii}} \, \hat{\mathbf{e}}_i = \hat{F}^i \hat{\mathbf{e}}_i,$$ using one of the properties of the metric tensor. By dotting both sides of the last equality with the contravariant element $$\hat{\mathbf{e}}^i$$, we can conclude that $F^i = \hat{F}^i / \sqrt{g_{ii}}$. After substituting, the formula becomes:

 * $$\operatorname{div}(\mathbf{F}) = \frac 1{\rho} \frac{\partial \left(\frac{\rho}{\sqrt{g_{ii}}}\hat{F}^i\right)}{\partial x^i} =

\frac 1{\sqrt{\det g}} \frac{\partial \left(\sqrt{\frac{\det g}{g_{ii}}}\,\hat{F}^i\right)}{\partial x^i}.$$

See  for further discussion.

Properties
The following properties can all be derived from the ordinary differentiation rules of calculus. Most importantly, the divergence is a linear operator, i.e.,

 * $$\operatorname{div}(a\mathbf{F} + b\mathbf{G}) = a \operatorname{div} \mathbf{F} + b \operatorname{div} \mathbf{G}$$

for all vector fields $ρ = r^{2} sin θ$ and $g_{ab}$ and all real numbers $n = 3$ and $F$.

There is a product rule of the following type: if $φ$ is a scalar-valued function and $F$ is a vector field, then

 * $$\operatorname{div}(\varphi \mathbf{F}) = \operatorname{grad} \varphi \cdot \mathbf{F} + \varphi \operatorname{div} \mathbf{F},$$

or in more suggestive notation

 * $$\nabla\cdot(\varphi \mathbf{F}) = (\nabla\varphi) \cdot \mathbf{F} + \varphi (\nabla\cdot\mathbf{F}).$$

Another product rule for the cross product of two vector fields $G$ and $a$ in three dimensions involves the curl and reads as follows:

 * $$\operatorname{div}(\mathbf{F}\times\mathbf{G}) = \operatorname{curl} \mathbf{F} \cdot\mathbf{G} - \mathbf{F} \cdot \operatorname{curl} \mathbf{G},$$

or

 * $$\nabla\cdot(\mathbf{F}\times\mathbf{G}) = (\nabla\times\mathbf{F})\cdot\mathbf{G} - \mathbf{F}\cdot(\nabla\times\mathbf{G}).$$

The Laplacian of a scalar field is the divergence of the field's gradient:
 * $$\operatorname{div}(\operatorname{grad}\varphi) = \Delta\varphi.$$

The divergence of the curl of any vector field (in three dimensions) is equal to zero:
 * $$\nabla\cdot(\nabla\times\mathbf{F})=0.$$

If a vector field $b$ with zero divergence is defined on a ball in $F$, then there exists some vector field $F$ on the ball with $G$. For regions in $F$ more topologically complicated than this, the latter statement might be false (see Poincaré lemma). The degree of failure of the truth of the statement, measured by the homology of the chain complex

 * $$\{ \text{scalar fields on } U \} ~ \overset{\operatorname{grad}}{\rarr} ~ \{ \text{vector fields on } U \} ~ \overset{\operatorname{curl}}{\rarr} ~ \{ \text{vector fields on } U \} ~ \overset{\operatorname{div}}{\rarr} ~ \{ \text{scalar fields on } U \}$$

serves as a nice quantification of the complicatedness of the underlying region $R^{3}$. These are the beginnings and main motivations of de Rham cohomology.

Decomposition theorem
It can be shown that any stationary flux $G$ that is twice continuously differentiable in $F = curl G$ and vanishes sufficiently fast for $R^{3}$ can be decomposed uniquely into an irrotational part $U$ and a source-free part $v(r)$. Moreover, these parts are explicitly determined by the respective source densities (see above) and circulation densities (see the article Curl):

For the irrotational part one has

 * $$\mathbf E=-\nabla \Phi(\mathbf r),$$

with
 * $$\Phi (\mathbf{r})=\int_{\mathbb R^3}\,d^3\mathbf r'\;\frac{\operatorname{div} \mathbf{v}(\mathbf{r}')}{4\pi\left|\mathbf{r}-\mathbf{r}'\right|}.$$

The source-free part, $R^{3}$, can be similarly written: one only has to replace the scalar potential $|r| → ∞$ by a vector potential $E(r)$ and the terms $B(r)$ by $B$, and the source density $Φ(r)$ by the circulation density $A(r)$.

This "decomposition theorem" is a by-product of the stationary case of electrodynamics. It is a special case of the more general Helmholtz decomposition, which works in dimensions greater than three as well.

In arbitrary finite dimensions
The divergence of a vector field can be defined in any finite number $$n$$ of dimensions. If
 * $$\mathbf{F} = (F_1, F_2 , \ldots F_n) ,$$

in a Euclidean coordinate system with coordinates $−∇Φ$, define

 * $$\operatorname{div} \mathbf{F} = \nabla\cdot\mathbf{F} = \frac{\partial F_1}{\partial x_1} + \frac{\partial F_2}{\partial x_2} + \cdots + \frac{\partial F_n}{\partial x_n}.$$

In the 1D case, $+∇ × A$ reduces to a regular function, and the divergence reduces to the derivative.

For any $div v$, the divergence is a linear operator, and it satisfies the "product rule"

 * $$\nabla\cdot(\varphi \mathbf{F}) = (\nabla\varphi) \cdot \mathbf{F} + \varphi (\nabla\cdot\mathbf{F})$$

for any scalar-valued function $φ$.

Relation to the exterior derivative
One can express the divergence as a particular case of the exterior derivative, which takes a 2-form to a 3-form in $∇ × v$. Define the current two-form as
 * $$j = F_1 \, dy \wedge dz + F_2 \, dz \wedge dx + F_3 \, dx \wedge dy .$$

It measures the amount of "stuff" flowing through a surface per unit time in a "stuff fluid" of density $x_{1}, x_{2}, ..., x_{n}$ moving with local velocity $F$. Its exterior derivative $n$ is then given by
 * $$dj = \left(\frac{\partial F_1}{\partial x} +\frac{\partial F_2}{\partial y} +\frac{\partial F_3}{\partial z} \right) dx \wedge dy \wedge dz = (\nabla \cdot {\mathbf F}) \rho $$

where $$\wedge$$ is the wedge product.

Thus, the divergence of the vector field $R^{3}$ can be expressed as:
 * $$\nabla \cdot {\mathbf F} = {\star} d{\star} \big({\mathbf F}^\flat \big) .$$

Here the superscript ♭ is one of the two musical isomorphisms, and $ρ = 1 dx ∧ dy ∧ dz$ is the Hodge star operator. When the divergence is written in this way, the operator $${\star} d{\star}$$ is referred to as the codifferential. Working with the current two-form and the exterior derivative is usually easier than working with the vector field and divergence, because unlike the divergence, the exterior derivative commutes with a change of (curvilinear) coordinate system.

In curvilinear coordinates
The appropriate expression is more complicated in curvilinear coordinates. The divergence of a vector field extends naturally to any differentiable manifold of dimension $F$ that has a volume form (or density) $μ$, e.g. a Riemannian or Lorentzian manifold. Generalising the construction of a two-form for a vector field on $dj$, on such a manifold a vector field $F$ defines an $⋆$-form $n$ obtained by contracting $R^{3}$ with $μ$. The divergence is then the function defined by

 * $$dj = (\operatorname{div} X) \mu .$$

The divergence can be defined in terms of the Lie derivative as

 * $${\mathcal L}_X \mu = (\operatorname{div} X) \mu .$$

This means that the divergence measures the rate of expansion of a unit of volume (a volume element) as it flows with the vector field.

On a pseudo-Riemannian manifold, the divergence with respect to the volume can be expressed in terms of the Levi-Civita connection $X$:

 * $$\operatorname{div} X = \nabla \cdot X = {X^a}_{;a} ,$$

where the second expression is the contraction of the vector field valued 1-form $(n − 1)$ with itself and the last expression is the traditional coordinate expression from Ricci calculus.

An equivalent expression without using a connection is

 * $$\operatorname{div}(X) = \frac{1}{\sqrt{\left|\det g \right|}} \, \partial_a \left(\sqrt{\left|\det g \right|} \, X^a\right),$$

where $g$ is the metric and $$\partial_a$$ denotes the partial derivative with respect to coordinate $j = i_{X} μ$. The square-root of the (absolute value of the determinant of the) metric appears because the divergence must be written with the correct conception of the volume. In curvilinear coordinates, the basis vectors are no longer orthonormal; the determinant encodes the correct idea of volume in this case. It appears twice, here, once, so that the $$X^a$$ can be transformed into "flat space" (where coordinates are actually orthonormal), and once again so that $$\partial_a$$ is also transformed into "flat space", so that finally, the "ordinary" divergence can be written with the "ordinary" concept of volume in flat space (i.e. unit volume, i.e. one, i.e. not written down). The square-root appears in the denominator, because the derivative transforms in the opposite way (contravariantly) to the vector (which is covariant). This idea of getting to a "flat coordinate system" where local computations can be done in a conventional way is called a vielbein. A different way to see this is to note that the divergence is the codifferential in disguise. That is, the divergence corresponds to the expression $$\star d\star$$ with $$d$$ the differential and $$\star$$ the Hodge star. The Hodge star, by its construction, causes the volume form to appear in all of the right places.

The divergence of tensors
Divergence can also be generalised to tensors. In Einstein notation, the divergence of a contravariant vector $F$ is given by

 * $$\nabla \cdot \mathbf{F} = \nabla_\mu F^\mu ,$$

where $X$ denotes the covariant derivative. In this general setting, the correct formulation of the divergence is to recognize that it is a codifferential; the appropriate properties follow from there.

Equivalently, some authors define the divergence of a mixed tensor by using the musical isomorphism ♯: if $∇$ is a $∇X$-tensor ($x$ for the contravariant vector and $∇_{μ}$ for the covariant one), then we define the divergence of $T$ to be the $T$-tensor

 * $$(\operatorname{div} T) (Y_1, \ldots , Y_{q-1}) = {\operatorname{trace}} \Big(X \mapsto \sharp (\nabla T) (X , \cdot , Y_1 , \ldots , Y_{q-1}) \Big);$$

that is, we take the trace over the first two covariant indices of the covariant derivative. The $$\sharp$$ symbol refers to the musical isomorphism.

title: Divergence


text:
Talk:Drug of abuse

Restructuring
I have some plans for restructuring based on proper organization of drugs into their proper respective groups and subgroups. There are three main groups of drugs which intersect and overlap -- Stimulants, Depressants and Hallucinogens. (A fourth, smaller separate group would be the Antipsychotics.)

In the Stimulant group would be a Psychomotor Stimulants subgroup (cocaine and amphetamines), and lesser stimulants would fall outside that group (i.e. caffeine, nicotine, etc).

In the Depressant group would be a Sedative Hypnotics subgroup (alcohol and barbituates paired up, and Ativan, Valium, Xanax, etc grouped up), as well as a Narcotic Analgesics subgroup (opium, codeine, morphine, heroin, etc). Other depressants would fall outside these groups (GHB).

In the Hallucinogens group, there would be a Dissociatives subgroup (ketamine, DXM, PCP, nitrous oxide, salvinorum), a Deliriants subgroup (muscimol, atropine, inhalants), and a Psychedelics subgroup (MDMA, mescaline, LSD, psilocybin, AMT, DMT, Ibogaine, etc).

Marijuana would fall just about dead center between the three main intersecting groups, since it possesses properties of each, but doesn't really belong to any of the categories. It is only a hallucinogen in very high doses (for some people), and many different substances can cause hallucinations in high doses.

--Thoric 16:08, 10 Nov 2004 (UTC)

Someone should add the FDA's definition of a "drug" to this entry because I think it would be pertinent and informative.

--User:Remember 18:05, 27 July 2005

Drug of Abuse
The categorization is sloppy and unorganized, here are the new categories I propose: stimulants, narcotics (opiates & opiods), hallucinogens, depressants, cannabis/hashish, herbs, other chemicals, common otc medications

The last two need actual names but it's a start and a big improvement. --Petrock 23:02, 27 Feb 2004 (UTC)

Why the hell somedoby removed painkillers ? --Taw

All painkillers are used as recreational drugs. And yes, Acetaminophen is also abused in drug-mixes.

I'm moving the War on Drugs section here because it lacks a neutral tone and has bad spelling and questionable grammar. I have replaced it with one of my own bias, which I hope is more neutral. I'm admittedly pretty avidly anti-drug so please feel free to correct the article where needed. -- BryceHarrington

(BTW, The War on Drugs is an abomination. This is fact, not opinion. --Thoric)

War on Drugs
Unfortunately regulating efforts changed into war against drug-users in many countries since 1960s-1980s. Effects of War os Drugs are many bilions dollars wasted many every year, milions of innocent people

put into prisons, spreading of HIV/AIDS and hepatitis, rise of criminal organizations in many countries and reduction of civil liberties. And War on Drugs had very little effect on drug usage, accessibility or prices.

It is widely believed that, as War on Drugs failed to reduce drugs usage, safer and less adictive drugs (like Marijuana and Methadon) should be legalized for adults. Legalization of Marijuana in Netherlands proved legalization doesn't cause any social problems. Therefore many European countries partially legalized private Marijuana usage.

Probably the most tragic effect of War on Drugs is that patients hving glaucoma and sclerosis are being denied Marijuana that could help them.

At the very least we should call drug prohibition 'drug prohibition' rather than 'war on drugs'. It is not the business of an encyclopedia to endorse propaganda terms.

'War on drugs' is much more popular term than 'drug prohibition'.

(Only in the USA, and occasionally in other countries when having a laugh at the USA, notwithstanding similar stupidity elsewhere. 'drug prohibition' would be the normal term in several English speaking countries.)
 * (I've heard the Australian media use the term completely seriously -- Simon J Kissane).

And some aspects of it, like ban on medical marijuana usage, have nothing to do with 'drug prohibition'.

If marijuana is a drug, and it is prohibited, then that is drug prohibition. 'Drug prohibition' is the descriptive term for what is being discussed - the prohibition of drugs. Calling the prohibition of drugs something else is misleading, especially if the term that is used is a politically-loaded catchphrase. The term 'drug war' was adopted because it served the interests of prohibitionists; it's strange that opponents of prohibition would accede in its use. - Tim

So let it be `Drug Prohibitiuon (also known as `War on Drugs')'. While both prohibitionists and opponents use the same term, prohibitionists think about `war against drugs' and opponents about `war against drug users'. --Taw

Well, I can't see any bias in my version. It contains only facts. Your version contains many false claims and you removed important things like Medical Marijuana usage.

As much as I am a dedicated libertarian, and believe strongly that the war on drugs is a national disgrace, abject failure, and morally reprehensible, I have to agree that the next is biased and doesn't belong here as is. I may agree with every word of it--and it may even be strictly factual--but even facts can be presented in a clearly biased way, and this text is a good example of that. We probably should have an article that examines drug laws by country, and the likely effects thereof, but this isn't it. --LDC

 * Societies have long sought to control the use of drugs within their culture.

Yeah, since 19 century.

 * Such substances and the behaviors of their users can run counter to principles and behaviors that the society wishes to promote for itself.  For example, it is accepted that use of alcohol while driving a vehicle can lead to death of innocent individuals; addiction to alcohol can make the individual unable to support himself  financially and thus become a burden on society.
 * Within the last century, as a wide variety of socially unacceptable drugs have become increasingly more and more easily available, national governments have become heavily involved in enforcing controls on them.

The only drug-related principle that society is against is fun. The only reason why US government banned drugs was WASP racism and later lobying by medical corporations which sell legal psychoactive substances.

 * But unlike alcohol, which had a history of socially accepted use prior to Prohibition, there is a question whether our society could ever wish to allow uncontrolled use of any of these substances.

Marijuana, mushrooms, optiates, amphetamine and cocaine were socially acceptable before War on Drugs. Oh ? You mean society == White Anglo-Saxons Puritans ? Then maybe not ... --Taw

Societies have long sought to control the use of drugs within their culture. Such substances and the behaviors of their users can run counter to principles and behaviors that the society wishes to promote for itself. For example, it is accepted that use of alcohol while driving a vehicle can lead to death of innocent individuals; addiction to alcohol can make the individual unable to support himself financially and thus become a burden on society. Within the last century, as a wide variety of socially unacceptable drugs have become increasingly more and more easily available, national governments have become heavily involved in enforcing controls on them. Unfortunately, as is not atypical with reliance on government intervention in social affairs, there have been a variety of consequences; an oft cited example is the 1920s Prohibition Act, that illegalized alcohol and thereby inadvertantly spawned an explosion in organized crime and did little to actually solve the problems as intended, and it was ultimately reversed. Since the 1960s, the U.S. and other governments have been pursuing a similar course of action against other controlled substances, with similar consequences in terms of increased violent crime and corruption, health issues, impingement of civil rights, and forth. Meanwhile, illegal drug use has not abated and shows little sign of doing so soon, which leads some to wonder if the War on Drugs, like Prohibition, is worth the consequences it has brought. But unlike alcohol, which had a history of socially accepted use prior to Prohibition, there is a question whether our society could ever wish to allow uncontrolled use of any of these substances.

Y'know, if youse would simply rechannel your debating energies to the article itself, drug would contain more than the five sentences (count 'em) it now contains. Yes, it's a fascinating topic, but is Wikipedia a talk forum or is it an encyclopedia? :-) --LMS

Some things in life are more important than others. The depravity of 2 million American citizens in jail, most of whom have harmed no one in any way, and the complacency of American politicians and public to the tragedy is a subject that demands attention. It is a topic that should be covered, and this forum has shown that it can cover controversial subjects and do a pretty good job coming up with factual, minimally biased reportage on them. That's a worthy goal. Along the way, I'm sure we'll throw in a few medical facts about the drugs themselves, but frankly, that information is already easily available to anyone. It should wind up here as well, but I don't for a moment apologize for spending my time and energy on something much more important, like reporting and helping to end the national disgrace that is drug prohibition. --LDC

You're missing my point, Lee. I don't see lots of reporting on the legalization camp's arguments to end drug prohibition. I see five sentences. :-) --LMS

Yes, because we haven't had enough discussion to find the basic points of contention and the appropriate advocates yet. I strongly suspect there will be several more pages of discussion before we get a few more good sentences. Look at Capitalism, for example; that took weeks, and large amounts of discussion, but it's a great article. That will happen here too, and encouraging off-line discussion, not denigrating it, will make it happen faster. --LDC

I think the arguments for legalization got moved: talk:Cannabis

Well, that's reasonable, Lee. I don't at all mean to discourage discussion that actually is aimed at creating encyclopedia articles, but the above doesn't look like that to me. It looks like discussion for its own sake. I have a similar objection to the talk:Abortion page proceedings. I could be totally wrong in my judgment, of course! Maybe we should encourage as much partisan bickering, or "discussion for its own sake," as possible, on the theory that it will actually result in better articles. Personally, I don't think so, but I could easily be convinced otherwise.

So there are two issues here: on the one hand, whether what looks like partisan wrangling is actually aimed at producing articles; on the other hand, whether partisan wrangling, regardless of its explicit aim, is desireable (because it helps produce better articles). --LMS

If not the first then certainly the second case. MHO. --Koyaanis Qatsi

OK, but why? --LMS

Well, simply because I think it does help produce better articles because I also think that it generally does cause people to rethink their positions. And yes, I've done some of this myself, though it's probably not obvious. :-) --Koyaanis Qatsi

Why somebody changed average world laws into US laws ? --Taw

There's no such thing as "average" laws. US law is typical of international law--some contries are better, some are worse. But now the laws in the article are actually verifiable facts, rather than just an overall impression. --LDC

Listing Marijuana as `prohibited even for medical use' is very US-centric. Laws of EU countries, US, Canada, and other 1st world countries should be considered. --Taw If it's too dificult to consider them all, European laws should be presented as US laws are much more radical than world average.

Why are painkillers listed separately from medicinal drugs? Also is there somewhere that anabolic steriods are merely regulated and not prohibited for non-medical use? -rmhermen

Because most painkillers are used as recreational drugs and are addictive. --Taw

Just because they are addictive or abused doesn't make them not primarily medicinal drugs. People use tranquilizers and other classes of drugs as recreation but they are still medicinal. I would imagine some drugs must be addictive although not painkillers. (can't think of any yet.) ---rmhermen

 * Seriously? The most obvious is the most addictive drug in common use today: nicotine.

There is no difference between medical and non-medical drugs. Majority of abused drugs have significant medical use. All (at least, I don't know single exception yet) enhancing drugs have some medical use. Marijuana have significant medical use. Methadone, morphine and acetaminophen have significant medical use. Does it mean that only halucinogens, alcohol, nicotine and more obscure derivatives will be left on this page? Of course, you should write something about medical use if you feel it's neccessary. --Taw

Why did somebody moved most of article into a subpage ? And why does title of subpage has nothing to do with content (the only type of drugs that has something to do with narcosis, and guess what ? - those are left on main page).

"Narcotic" is mainly prohibitionist propaganda term, they use it to group many completely unrelated substances. I don't think we should use this term. --Taw

- I just took marijauna out of "hallucinogenic" (and left it under general mood altering stuff). It is occasionally claimed to be hallucinogenic, but this is way too controversial to be stated as fact here in the encyclopedia. In fact, it is not hallucinogenic except perhaps in very rare cases, and most of those probably involve use with other drugs, or a pre-existing psycosis, or both. Basically, the "marijuana is hallicinogenic" is a piece of propoganda bullshit put out by lunatic fringe prohibitionists. Of cause, we can't say that in the encyclopedia either. But neither can we repeat their bullshit as fact.

This is certainly NOT true. Cannabis IS a hallucinogen, and that is accepted in the medical and scientific community. You can proove it yourself, just take enough of it. Alkohol, e.g., is clearly not hallucinogenic, because when you take too much, it'll cause a narcosis and perhaps, you'll die.

"no medical uses currently known" was clearly wrong: in Switzerland both drugs were used in the 90s in psychotherapy research with (once again) very promising results. The therapeutical use has been stopped again due to political reasons - not medical ones. AFAIK both drugs are used by psychotherapists these days also in the US, where as has been written before, the laws are very strict. These US therapists do not have a licence to do so, because they probably wouldn't get one, but they certainly know how to help their patients best. -- DA, MD.

Cannabis really should not be classified as a hallucinogen. In many systems, I see Cannabis and Hashish classified in their own category, appropriately named cannabis. I wanted to stick Kava Kava, St. John's Wort, and Valerian root on there, but I'm unsure of where exactly and "herbs" category would fit best. Your thoughts? PetRockStealer ---

Cannabis IS a hallucinogen, this is widely accepted not only in the scientific and medical community, but also amongst users who actually know what they're talking sbout. Hint, this excludes the guy who had a joint back in highschool (but didn't inhale, natch) and braindead all-day tokers. Whilst visual hallucinations are rare and require extremely high doses, 'thought' hallucinations are a central part of the cannabis experience. Cannabis alters the perception of your own thought patterns in much the same way as LSD or mushrooms (except less strongly and well.. different). But it is definitely hallucinogenic in nature. After thought : oh and by the way, try listening to your favourite music stoned and tell me your audio perception isn't altered !

 * With respect to the debate about whether marijuana is or isn't a hallucinogen, my understanding is that it is something of a hybrid, or at least a difficult drug to classify. It certainly has different properties than traditional hallucinogens (such as LSD, mescaline, psilocybin/psilocin) and dissociative hallucinogens (PCP/Ketamine).  The fact that LSD and PCP are both usually just called "hallucinogens" doesn't mean anything except that they can both cause hallucinations.  If you look at their effects further, you realize that's where the similarities end.  Dissociatives have limited medical and veterinary use as anesthetic agents, but traditional hallucinogens do not.  People I have spoken with that have used both PCP and LSD say the drugs are completely different.

 * So yes, marijuana can cause hallucinations at high doses, but so does diphenhydramine (Benadryl). And yes, it does cause altered perception, but so do most drugs of abuse.  Just because the medical profession wants to group marijuana neatly with the other hallucinogens doesn't mean they're correct.  It wasn't until a few decades ago that cocaine was reclassified from a narcotic to a stimulant by the medical community.  I had a medical textbook that was published in the mid 70's that claimed cocaine was a narcotic, alongside codeine and morphine.  Here we have a drug that has been around for over 100 years, and it was only a few decades ago that science/medicine figured that out, so forgive me if I don't just take their word for it.  Science (which I have a great deal of respect for) is about classifying, measuring, and describing things - and changing theories when new information comes to light.  The "tree of life" used to be categorized into plants, animals, and fungi.  Eventually, different types of life were discovered, and they had to totally redesign the tree.  Now we know about bacteria existing at the bottom of the ocean that reduce sulfur instead of oxygen and they had to create a new phylum for them.

 * If you want to classify it as some kind of an "atypical hallucinogen" fine, but classifying it in the same group as PCP without an explanation is inappropriate and deceptive. We don't see marijuana users (medicinal or otherwise) lifting cars, killing people, jumping out of windows because they think they can fly, etc.  Calling it a hallucinogen also does a disservice to people who use it medically, by implying that they are no different than users of hallucinogens.

 * THC activates a different receptor than any other hallucinogen (the same one as anandamide). So, in my opinion, marijuana should be classified either as an atypical hallucinogen or (better yet) in its own group.  --ZZYZX 07:27, 26 October 2005 (UTC)

Page as hub article?
I am thinking the article could become more of a hub article (a bit like Cannabis). Drug (disambiguation) will not serve because it has to refer to drug or demon in ancient Vedic Hinduism and Drûg or Drúedain, a race of Men from Middle-earth in the fiction of J. R. R. Tolkien. I picture the hub article with opening sentences as follows:

 * In most states many drugs are illegal, or they are if produced, supplied or possessed without licence. Medicines are usually licensed drugs. Illegal drug use is called often recreational drug use, but this concept can include also drugs which are perfectly legal in most states (such as tea and coffee) as well as drugs supplied via licensing arrangements for essentilly recreational purposes (eg tobacco and alcohol.

 * Drug may meean or refer to:

I would not include the disambig template, which seems to me inconsistent with a page's use as a hub article. Laurel Bush 10:05, 14 May 2005 (UTC).

Sahel
What is the name of that plant that many people consume in the Sahel? It's named chatt or chott or something similar. -- Error It's khat, sometimes spelled as qat The Way 04:16, 30 September 2005 (UTC)

New Entry: Lactucarium
I just added Lactucarium AKA "Lettuce Opium" to Wikipedia. It is a drug from wild lettuce fluids. It has opium-like properties and contains extremely minute amounts of morphine. I am not sure what category it would be classified into as far as drugs go.

 * Good job. It doesn't contain any morphine, though.  I'm not sure what the active component of it is, or if anyone even knows - but it's not morphine.  Supposedly regular lettuce has some small amount of whatever drug wild lettuce has, but it's much less.  I've read about this on various newsgroups.  Some people say it works, others say it doesn't.  If it really does do anything, it's apparently not worth listing as a controlled substance by the DEA.  If it really does contain a drug, it seems like it would be listed as an opiate.  Someone should research this, though - it may be an (as yet) undiscovered pain drug.  ZZYZX 07:40, 26 October 2005 (UTC)

The future of this page
A lot of the material on this page runs parallel to pharmacology, and there are a number of important deficiencies. I am quite in favour of rewriting the whole thing, but some community opinion needs to preface such a move. JFW | T@lk  22:15, 4 Oct 2004 (UTC)

Drug Chart
Here is my drug chart (in progress). Please provide some feedback :) --Thoric |  T@lk  17:45, 12 Nov 2004 (UTC)
 * Stimulants (blue) are more potent as you go up and to the left
 * Depressants (red) are more potent as you go down and to the right
 * Hallucinogens (green) are more generally potent/unpredictable as you go down.
 * Also, Hallucinogens are more psychedelic to the left, and more dissociative to the right.
 * Keep in mind that areas overlap:
 * The yellow area includes dissociatives with a CNS depressant effect.
 * The cyan area includes psychedelics with a stimulant effect.
 * The pink area represents antipsychotics.
 * The purple area represents mild stimulants which produce cognitive and/or antipsychotic benefits.
 * The white area in the center includes drugs that don't properly fall into any one category.
 * Ibogaine is in the middle between psychedelics and dissociatives as there is disagreement as to which it is.
 * The psychedelic area is the whole left side of the hallucinogen region (not just the cyan portion), and dissociatives are the whole right side of the hallucinogen region (not just the yellow portion).

(See also my drug chart graphic image)

(Very two-dimensional. Drug effects are much more complex and multi-dimensional. There is no single, simple and neutral system of classification. Laurel Bush 13:10, 25 Feb 2005 (UTC))
 * It's hard to make a multi-dimensional table that will fit on a single page. My intent was to produce something that would help the average person understand how different common drugs relate to each other. --Thoric 04:57, 24 Mar 2005 (UTC)

Drugs Expiration Dates
I think this would be worth mentioning in Wikipedia. Apparently, research by department of defence suggest drugs remain in good condation long after expirely date. I wonder what you guys have to say about this article. Quote "ata from the Department of Defense/US Food and Drug Administration (FDA) Shelf Life Extension Program, which tests the stability of drug products past their expiration date, showed 84% of 1122 lots of 96 different drug products stored in military facilities in their unopened original container would be expected to remain stable for an average of 57 months after their original expiration date.[25] Some US Army studies on Valium, for example, show that the drug is very stable and completely safe and effective for up to 8 years after manufacture. Tablets of ciprofloxacin, an expensive antibiotic, were found completely safe and effective when tested 9.5 years after the expiration date." gathima 06:18, 23 Feb 2005 (UTC)

 * It would be good to have information on the shelf-life of certain drugs, but it would be dangerous to assume that all drugs last significantly longer than their expiration date. --Thoric 21:23, 3 May 2005 (UTC)

 * I read about this a few weeks ago. Most drugs will last much longer than the listed expiration date on the prescription bottle.  Most drugs also break down into inactive chemicals, but there are drugs that are dangerous to use after the expiration date.  Tetracyclines, for example, decompose into a toxic chemical.  It's best not to use expired drugs unless you know for sure that that particular medicine doesn't become toxic over time.  ZZYZX 07:56, 26 October 2005 (UTC)

Medication?
At the moment this page is mainly about psychoactive drugs. Can we please agree whether all non-psychoactive drugs should be discussed on medication instead? I voiced same on 4/10/2004 with no response. JFW | T@lk  06:43, 9 May 2005 (UTC)

 * Medication represents a rather narrow definition of drug. Laurel Bush 09:11, 9 May 2005 (UTC).

Yeah, but at the moment there is a large overlap between the two, and I think the reader is more helped if the subjects are disambiguated. For example, all those psychoactive drugs are potentially drugs of abuse and hence need relevant information about incidence of addiction, rehab/detox and similar. On the other hands, simvastatin is only abused by people with a cholesterol phobia :-) JFW | T@lk  09:44, 9 May 2005 (UTC)

 * Sorry, but I think the article is about (or should be about) drug(s) (including medication), and not about perceptions of drug abuse. Laurel Bush 10:58, 9 May 2005 (UTC).

 * Agreed. Plenty of medications are abused, and likewise plenty of drugs are used in moderation.  Drug abuse has its own page already, and also exist pages on addiction and substance abuse.  Any specific abuse information should be there, or on specific separate abuse pages for each drug... i.e. alcohol abuse.  BTW, psychoactive drugs already have their own page, though there seems to be dispute whether it should be an article or a category.  --Thoric 17:02, 9 May 2005 (UTC)

 * So what shall we do: merge and redirect, or limit the scope of this article? JFW | T@lk  18:05, 9 May 2005 (UTC)

 * Truthfully this particular article needs a lot of work. Ideally a broad and complex topic such as this should primarily link people to more specific articles.  This is done to some degree, but it's a bit of a mess at the moment.  Things start to fall apart around the Effiacy section.  The classification section should be in a table, and possible save the big list of drugs for category pages, or at the least list the drugs in a comma separated list under each category rather than one line per drug.  So the answer is yes -- merge medication into this article, redirect medication to drug, and also limit the scope of this article moreso to a definition of what a drug is from Alcohol to Zyprexa, with a list of different categories of groupings and links to articles with specific information.  --Thoric 20:02, 9 May 2005 (UTC)

 * I tend to read medication as meaning licensed (medical) drugs/drug use and I think actually it is a subject quite big enough for its own article, but with some sort of summary within the drug article''
 * yes, medication tends to be prescribed, but they are still drugs --Thoric 22:45, 19 May 2005 (UTC)

 * As respects revision of the drug article I suggest we try to avoid implicit assumptions like:
 * If its possession/use is illegal then its use is abuse.
 * If it is not medication (licensed medicine) then it is without therapeutic use or potential.
 * Addiction/dependence is a symptom of abuse, or of the drug's potential to be abused.
 * These are assumptions. They are not self evident truths.
 * Laurel Bush 15:38, 10 May 2005 (UTC).

Ah, yes. So can we please agree that the drug article is about non-licensed substances, and medication about licenced/medically prescribed pharmaca? At the moment this page overlaps too much with medication and causes confusion. The list at the bottom only mentions drugs that have some psychotropic action.

Laurel Bush, I agree that we should avoid your two last "assumptions". There are plenty of unlicensed substances with therapeutic use or potential (think St. John's Wort), and addiction/dependence may not be a result of abuse at all (think all those people taking benzodiazepines). I do disagree with your first point. The term "abuse" has a medical and a legal meaning. In a country where owning and using cannabis is illegal, a multiple sclerosis patient using cannabis for symptom control is legally abusing the substance, even though his/her doctor may warmly condone this activity. The law has no other term for it, so "abuse" it is. JFW | T@lk  19:29, 19 May 2005 (UTC)
 * Are acetaminophen and the NSAIDs psychotropic? The word drug does not imply psychotropic.  The word drug also does not imply lack of licensing or legitimacy.  The drug article contains many licensed substances.  Were are not all in your country of illegal cannabis.  Several countries allow medical use of cannabis.  Kindly refrain from mislabeling use as abuse based solely on your local laws.  Looking over the medication page, it doesn't appear that there is significant overlap, and as long as both pages cross-reference each other, I don't see any problem.  --Thoric 22:45, 19 May 2005 (UTC)

The basic problem seems to be that the name or title drug has acquired a multiplicity of often competing meanings and connotations. The article can not avoid being in many respects a rather long and complex disambiguation exercise. Laurel Bush 10:46, 28 May 2005 (UTC).

 * There is nothing wrong with this page clarifying the definition and linking off to more appropriate specific pages. Social-political polluting of terminology should have little bearing here.  Example:  Drug store redirects to Pharmacy, not to Drug dealer ;)  --Thoric 16:13, 2 Jun 2005 (UTC)

Abuse and illegal. Perceived abuse is cited often as a reason for prohibition/licensing. Perception of abuse often precedes the illegal status. And if abuse did mean simply illegal then we would not need abuse: we would just need illegal and acceptance of arbitary law. Laurel Bush 10:15, 30 May 2005 (UTC).

Medication drugs
Medication drugs should follow a convention on how to write them(sections for side effects, mechanism of action etc.), it will be easier to follow and most of all, to contribute in those articles. Fadix 17:41, 23 Jun 2005 (UTC)

 * It sounds like a good idea to me. If you didn't notice it already, I think you might want to take a look at this: WikiProject Drugs -- Stereotek 11:13, 25 Jun 2005 (UTC)

 * Yeh, I have seen it, I'll try to contribute, I think I'll just search for a drug that the entry isen't complete, or creat those that have no entries. The drugs entries I've viewed are not as complete as they should, considering that it is an encyclopedia, which has to be more complete. It will be interesting to make of those entries, like the essential pharmacist of doctor guide, and even adding interactions with other drugs and herbals, and including few of thse studies lists of their efficiencies and side effects vs placebo etc. It would be very practical. Fadix 17:27, 25 Jun 2005 (UTC)

Disambig
This page is beyond hope. At the moment the page lacks a philosophy, and it attempts to cover anything from psilocybe (e.g. psychoactive substances with no medical use) to methotrexate. I think it should be a disambiguation page, one linking to medication and one linking to psychoactive drugs. This is not the first time I've complained about this, and I'm very tempted to be bold. JFW | T@lk  16:11, 4 August 2005 (UTC)

 * There are just two kinds of drug? Medication and psychoactive drugs, with no overlap between the two types? The suggestion seems to represent a wish for simplicity and clarity which just do not exist. Laurel Bush 12:07, 5 August 2005 (UTC).

So what should this page be about? At the moment it fails to cover anything properly. And of course the disambig can contain more than two links. JFW | T@lk  01:18, 7 August 2005 (UTC)

 * I feel an urge to be bold, pretty much in the way Ed Poor deleted VFD. JFW | T@lk  17:20, 8 August 2005 (UTC)

Go for it, SqueakBox 17:51, August 8, 2005 (UTC)

 * It seems this has come up before. Medications are still drugs, and psychedelics do have history (old and recent) of medical use.  As it stands, the current page is already a disambiguation page (of sorts), it just needs more of its content to be compacted and/or merged onto other pages.  The classification section could/should be collapsed into a table... same with the regulation section.  I don't think it should be a simple disambiguation page such as drug (disambiguation), but similar to the Psychedelics, dissociatives and deliriants page and how it is expanded in more detail by the individual psychedelic drug, dissociative drug and deliriant pages.  --Thoric 21:20, 8 August 2005 (UTC)

 * Thoric, does that mean you agree in principle to turning this into a proper disambig? JFW | T@lk  00:58, 18 August 2005 (UTC)
 * That depends on what a "proper disambig" is ;) Let us hear your proposal (brief outline is fine) :) --Thoric 12:21, 18 August 2005 (UTC)
 * To me "proper disambig" means "complete with the disambig classification template", which tends to discourage links to the article from within other articles, in favour of links to articles listed in the disambig page. I dont feel "proper disambig" is appropriate for Drug. Laurel Bush 14:50, 18 August 2005 (UTC).

Classification Section Cleaned but still messy
I made some changes to the classification scheme used in the article. It was a major mess, with classifications that were made up by whoever devised it. I created a category for stimulants and added the proper drugs, added the correct (pharmaceutical/chemical) name for vicodin, darvocet, valium, etc. More proper names need added. The categories are still messy and many specific drugs and types are still missing. The Way 04:05, 1 September 2005 (UTC)

 * I continued to revamp the classification scheme and I believe it is much more correct now, though the various categories still need alphabetized. The Way 04:42, 1 September 2005 (UTC)

Dictionary definition
"The dictionary definition of drug states that a drug is "any substance used for the diagnosis, treatment, or prevention of disease, or a component of medication." By this definition, anything used in conjuction with disease is a drug, regardless of whether it is natural, synthetic, legal, or illegal." - Wondering which dictionary this refers to. Laurel Bush 14:09, 6 October 2005 (UTC).

 * The site DICTIONARY.COM, specifically http://dictionary.reference.com/search?q=drug
 * ZZYZX 08:03, 26 October 2005 (UTC)

Flame
Before you undo the move, please read my posting on talk:Drug and flame me there accordingly. JFW | T@lk  03:07, 17 October 2005 (UTC)

 * How about posting a proposal (as requested above) rather than making said, "bold move", which is completely POV in favour of the status quo of drug prohibition. --Thoric 05:53, 18 October 2005 (UTC)

Well, because the replies were highly divergent, generally poorly argued and generally unhelpful in doing something about the sorry state of this article. I am fully aware of your own POV vis a vis prohibition, so I doubt a long discussion on this subject will make much difference now.

You are completely within your rights to:
 * merge this article with recreational drug use, which gives you an opportunity to remove the "pro-prohibition bias"
 * request a move to a more balanced title
 * edit the article extensively

I think we should continue this discussion on talk:drug, where all other replies have been made. JFW | T@lk  04:39, 20 October 2005 (UTC)

Abuse and non-clinical use
"A drug of abuse is any substance that is used for non-clinical purposes to modify a chemical process or processes in the body such as to enhance a performance or ability, or to alter states of mind": Does this mean that any non-clinical use is abuse? Laurel Bush 12:15, 20 October 2005 (UTC).

 * If it's a registered drug, certainly. If its possession/use/sale is illegal, certainly. But I agree that my new version sounds POVish, and I was half expecting you to disagree on its premises :-) JFW | T@lk  21:30, 20 October 2005 (UTC)

So, as used by yourself, the intended meaning of the sentence is A drug of abuse is any substance used non-clinically to modify a chemical process or processes in the body such as to enhance a performance or ability, or to alter states of mind, while it (the substance) is registered as a drug for clinical use or is otherwise illegal in non-clinical use.? Or what? Sorry. You seem to have introduced some qualification to your definition of drug of abuse and the syntax of the original sentence was itself somewhat problematic. And I suggest that your perception of drug abuse is that it is essentially any unlicensed drug use. Laurel Bush 10:50, 22 October 2005 (UTC).

 * Would you agree with this statement (you can take my word for it that I have done the plumbing): I am not a qualified plumber but I have done some plumbing now and again, here and there. It may not be very good. It may not be legal. But it is still plumbing. If however I practise inexpert medicine or pharmacy then I can not call it medicine or pharmacy and I must call it something else, such as drug abuse or drug pushing.? Or would you agree that it makes nonesense of the English language and tends to block the possibility of rational dscussion? Also, would your agree that clinical drug use can amount to drug abuse, or institutionalised drug abuse? Laurel Bush 11:19, 22 October 2005 (UTC).

Ah, that's a nice analogy; let's see where it fails... I think the use of legally restrained (e.g. POM in the UK) substances to achieve any result apart from its registered used and with a prescription would make it abuse. I do agree that medication can be "abused" by professionals if they are used in a way that is not in the patient's best interest (such as administering morphine in a terminal patient if that patient is not in visible distress, because "they have to die some way or another").

Hence my distinction between use and abuse is determined both by legal parameters (the government wants epo to be used by patients with renal failure, not by bicyclists anxious to win the Tour de France) and by ethical ones (is the professional recommending its use/prescribing the substance acting in the interest of the patient). Failure to meet these parameters is making improper use (or abuse) of these substances.

As for the plumbing thing, the practice of plumbing is not restricted by law; it is the responsibility of the person who calls out this "plumber" to check whether he is a member of a professional organisation, insured for poor work and accidents and actually value for money. The governments in most countries have decided that this cannot be expected of patients vis a vis their medical professionals. That is why these titles (and the right to prescribe) are protected by the law. As for being ethical, a hobby plumber who wilfully causes harm will soon discover this is a great way to get in trouble. JFW | T@lk  22:04, 23 October 2005 (UTC)

 * There's also a cultural compponent to the term. What used to be considered drug abuse in "Reefer Madness" days is now considered by many people to be recreational drug use and in some cases, medicinal use.  Various native American cultures have been using hallucinogens in a way that many people would consider abuse, and most college students have used alcohol in a manner that would classify as abuse.  What I'm trying to point out is that it's going to be difficult to come up with a definition for drug abuse that everyone will agree with, since there is such a range of opinions as to what constitutes it.  ZZYZX 08:21, 26 October 2005 (UTC)

Thinking maybe Medicine should be a disambiguation page. Laurel Bush 16:10, 28 October 2005 (UTC).

 * Whether a substance is restricted by law or sanctioned by professional medical practice is entirely irrelevant to the present topic, DSM and other criteria notwithstanding, and should be disregarded. If the editors cannot create a definition of abuse that can stand independent of the franchise of states or guilds, then perhaps the term abuse itself is meaningless, underscoring the moral bankrupcy of most policy carried out in its name.  -SM 13:56, 30 October 2005 (UTC)

-- I dislike the title as it is emotive and biased. Something value neutral such as 'non medical drugs' or 'non clinical drugs' would be more appropriate to an impartial encyclopedia.

Why substance abuse counselors need to understand Pharmacology? 98.167.251.48 (talk) 07:53, 25 March 2013 (UTC)
<

title: Talk:Drug of abuse


text:
Talk:Dilbert

Why doesn't this have Ratbert?
This really should have Ratbert in the characters list, because he is a major character in Dilbert. 56KPK (talk) 11:27, 12 September 2020 (UTC)
 * Agree - added. Ckruschke (talk) 18:06, 15 September 2020 (UTC)ckruschke
 * Not only Ratbert but Catbert. The eminent web-site  dilbert.com maintains a full list of seventeen Fishing Publication (talk) 19:07, 27 February 2023 (UTC)
 * @Fishing Publication, both Ratbert and Catbert are listed in the article. Schazjmd   (talk)  19:14, 27 February 2023 (UTC)

That poll
The Poll That Did in Dilbert Creator Scott Adams Is Even Dumber Than You Can Imagine Doug Weller  talk 19:23, 28 February 2023 (UTC)
 * Really Slate news circular-referencing New York Times namecalling is the best they have against this poll ?  I've heard the argument that It's okay to be white is a dogwhistle or invalid because it apparently originated on 4chan, if this is true, I really am not sure that the man on the Clapham omnibus would be familiar with this esoteric internet lore (and respond to poll questions in accordance) ...   this is like when people on the Right talk about the coroner's report which described George Floyd  if I remember correctly as having traces of fentanyl, methamphetamine and so on at the time of his death --  you can cast aspersions about technical subjects but the principle is the same, the issue is there (police brutality, anti-White hatred) and we should talk openly and honestly about it -- my two cents. If you're looking for support to include this in the article, I don't oppose it, we should also include anything from Rasmussen if they've issued a statement (from what I understand the poll has been widely discussed)  or an opposing perspective Fishing Publication (talk) 13:02, 13 March 2023 (UTC)

Dilbert.com now redirects to Linktree but Wikipedia rejects the domain
Hello, The provided link Dilbert.com which resolved as recently as a few days ago to an archive of Dilbert strips going back into the 90s has started redirecting to a Linktree page with the name Scott Adams. I have included this information in the infobox -- but I can't provide the link, because the domain is forbidden. Can any administrator kindly do this ? Fishing Publication (talk) 17:40, 13 March 2023 (UTC)

 * The url has been unresponsive for at least 2 months now, no redirect, nothing. I've amended the text to reflect this.
 * The domain registration doesn't expire until 22 Jan 2024 which is why I've left the url rather than simply deleting it - in case it is brought back to life in some manner.
 * 220.235.82.123 (talk) 04:42, 27 August 2023 (UTC)

 * According to sources I found (including our article on Scott Adams), Dilbert has been moved to Adams' own Locals site and is no longer available on dilbert.com. ~Anachronist (talk) 05:08, 27 August 2023 (UTC)
 * Yeah, found out that info and came back to update the article but I see that you've done that. Thanks. 220.235.82.123 (talk) 03:53, 29 August 2023 (UTC) (a hang-glider pilot!)

Dilbert.com missing from DNS
Looks like dilbert.com is no longer found as a DNS entry (A, AAAA and CNAME records are blank), though it is still shown by whois as registered domain. 84.198.244.196 (talk) 06:39, 5 July 2023 (UTC)

title: Talk:Dilbert