Talk:Archimedes/Archive 2

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Contents

New stuff about Archimedes and Calculus

http://www.sciencenews.org/articles/20071006/mathtrek.asp Gwen Gale 09:17, 8 October 2007 (UTC)

Thanks, there are some good pictures in this article. --♦IanMacM♦ (talk to me) 09:28, 8 October 2007 (UTC)

In the opening paragraph there's a sentence that's probably spam, saying "for more information visit..." I can't believe it's in a featured article. Someone should clean that up. I'm viewing the page on Firefox and Archimedes' volume equations are coming up as errors (syntax). Is there a way to fix that?—Preceding unsigned comment added by 137.238.149.150 (talk) 01:28, 29 January 2008 (UTC)

It was fixed, may have just been a problem with the first load. —Preceding unsigned comment added by 137.238.149.150 (talk) 01:46, 29 January 2008 (UTC)

Unclear flash point relevancy

I commented out this text at the end of the penultimate paragraph of "Death ray", because I could discen no sense in it:

"However, the flash point of wood is around 300 degrees Celsius (572 degrees F), and this is hotter than the maximum temperature produced by domestic ovens."

This was reverted with a request to bring it to Talk. Is something preceeding missing that would give the However meaning? Also I still cannot see what the flash point nor domestic ovens has to do with the section. The sentence preceeding the However was "Critics of the MIT experiments have argued that the moisture content of the wood needs to be taken into consideration" so I was expecting something like "However, MIT used dry wood" (so contradicting the need for consideration). Finally I looked through the ref and it only supplies the flash point. -Wikianon 19:52, 19 October 2007 (UTC)

The moisture content of wood affects its flash point, which is the temperature at which it bursts into flames. A piece of wood in a domestic oven on maximum temperature (usually 250 Celsius) would not catch fire. This is the most likely reason why the Mythbusters experiment failed, because it would take too long to get the wood to the flash point using the mirrors described. I'll have another look at the wording of this section, but do not think that it is particularly unclear. --♦IanMacM♦ (talk to me) 08:13, 20 October 2007 (UTC)

I see, and I don't see. The text makes no mention of any oven so a reader such as myself who is unaware of the Mythbusters experiment details will not understand. Even now I cannot make the connection - did MIT repeat the boat in the bay experiment using a boat in an oven? -Wikianon 01:30, 27 October 2007 (UTC)

I have reworded the section and hopefully made it clearer. Wood does not catch fire until it reaches its flash point, and the comparison with an oven is given largely to show how hot wood needs to be before it will catch fire. --♦IanMacM♦ (talk to me) 07:34, 27 October 2007 (UTC)
I didn't like the (reworded) oven reference either. Why is an oven mentioned? We all know that ovens get that hot, I don't think it's necessary to remind us. Tempshill (talk) 18:27, 29 January 2008 (UTC)
Removed: ", and this is hotter than the maximum temperature produced by a domestic oven" Tempshill (talk) 18:39, 29 January 2008 (UTC)

a wonderful biography

I was astounded on the sheer volume of information that was provided in this article! I loved the fact the author added all of the mathematical info! That information is well beyond my ability! Thanks for a great article!Historybuffc13 (talk) 01:26, 29 January 2008 (UTC)

I second that; great job to the chief editors here.--Pericles of AthensTalk 02:55, 29 January 2008 (UTC)
Agreed, an excellent article on a topic of general notability. There should be more of it. -- Mattinbgn\talk 03:13, 29 January 2008 (UTC)
Agreed. Yay for Archimedes, and boo for the "knife making guy" and "marching band of a college" featured articles. Tempshill (talk) 18:26, 29 January 2008 (UTC)

Protection

Did somebody forget to semi-protect this before it went up on the front page? I think the vandalism that just happened is a great example of why front page articles need to be at least semi-protected before they go up.Skywalkert65b (talk) 06:21, 29 January 2008 (UTC)

They usually don't protect them on purpose because more editors and potentially new wikipedia users are going to be editing it. It makes sense, more people would be checking it for vandalism too. It may very temporarily impair a "perfect image" for wikipedia but is it worth it, and is it really that spotless in the first place? --fs 11:01, 29 January 2008 (UTC)
See Wikipedia:Main Page featured article protection for more information. The current guideline is only to semi-protect in extreme cases. Consensus is unclear, some users (like me) support protection, others do not. Puchiko (Talk-email) 22:13, 29 January 2008 (UTC)

Archimedes screw

This cross-section shows how the screw probably looked in ancient times.
This cross-section shows how the screw probably looked in ancient times.

This article defines the 'Archimedes screw' as hand-driven. The article 'Archimedes screw' does not. Also it gives non-hand driven examples. I would like to change it here but I don't have any academic resources to back it up. I no one object I'll do it today. Pukkie (talk) 10:37, 29 January 2008 (UTC)

In ancient times the screw would probably have been hand driven, and screws in developing countries are still operated like this today. However, modern screws are often driven by a motor. You can watch a video of a modern Archimedes screw here --♦IanMacM♦ (talk to me) 22:17, 30 January 2008 (UTC)

Reverts

I reverted the claim that the story about the sphere and cylinder on the tomb of Archimedes is a legend, as it is sourced to Cicero in the article. Also, I restored the quote from Gauss. Like many quotes from mathematicians, this lacks a direct source, but has often been quoted and is worth mentioning. --♦IanMacM♦ (talk to me) 08:11, 30 January 2008 (UTC)

It's not the formal question of whether or not a link was given. Actually, if you care to read any standard source on history of mathematics, you'll find that the tomb story is a legend, and that the tomb was never found. Also, I did a bit of digging and found an attribution for the Gauss quote (it's not that hard; E.T. Bell, notoriously unreliable). My point was that the quote is a distraction: everyone agrees that Archimedes was the greatest scientist of the antiquity, this has never been in doubt. Gauss "endorsement" does not add anything there. On the contrary, it only raises more questions, for example, to state the most obvious, why Eisenstein occupies the third spot. Arcfrk (talk) 20:40, 30 January 2008 (UTC)
Unless Cicero was inventing things, the story about the discovery of the tomb in 75BC is not a legend. [1] Unfortunately, many of the details of the life of Archimedes remain apocryphal by modern standards, but are given in the article so that people can find out what is usually said about his life and works.

I removed the comment about the Gauss quote because it is best to avoid adding HTML comments to Wikipedia articles, and to raise the matter on the talk page instead. If you have a direct source for the Gauss quote, please could you give it here. The Gauss quote has been in the article for a long time, and this is the first complaint. --♦IanMacM♦ (talk to me) 22:05, 30 January 2008 (UTC)

Yes, Cicero might well have made up things, as was frequent with other writers of the period, e.g. Plutarch. To the best of my knowledge, the story that "At his [Archimedes'] request his tomb was carved with a sphere inscribed within a cylinder" has not been corraborated by other sources, and even Cicero speaks of it in a lot less certain terms that what's presently in the article.
There two issues with the Gauss quote: first, and most important, is that it is not approprite, in my opinion. The fact that no "one complained before" is not a good argument for keeping it, or anything else on Wikipedia (e.g. many articles contain factually wrong statements for years), unless you want to permanently "lock" the article in its present state. (For what it's worth, I've read forceful complaints about this article's poor coverage of Archimedes' mathematical contributions. It is by no means perfect.) That sentence also doesn't fit with anything else in the lead, and it's not "what is usually said about his life and works". Second, the reason that I left an html comment in there is to simplify the sourcing task if it will be decided to keep it, the present source is below the lowest standard that can be imagined (a joculary comment in a hear-say format in a book review!) It appears from your comments and actions that you are not interested in improving the quality of the article, concentrating instead on creating hurdles for anyone else who is, or might be. I, on the other hand, only have limited time, and will concentrate on other projects. Arcfrk (talk) 22:59, 30 January 2008 (UTC)

There is an Error on his birth and death information

How did Archimedes become born 75 years after he died? AnaxMcShane (talk) 12:21, 30 January 2008 (UTC)

It's BC. 287 BC is earlier than 212 BC. Just like -4 is more than -10. Puchiko (Talk-email) 14:32, 30 January 2008 (UTC)

I think you have it backwards, but no matter, backwards is correct too. 76.83.127.79 (talk) 18:50, 31 January 2008 (UTC)

BC means before Christ so it is 287 years before Christ so therefore he did not die 75 years before he was born! 69.138.166.53 (talk) 23:35, 1 February 2008 (UTC)

Roman admiration for Archimedes?

Would anyone care to explain (and possibly, source) the following sentence in the lead:

The historians of Ancient Rome showed a strong interest in Archimedes and wrote accounts of his life and works.

I am familiar with Plutarch's account of the siege of Syracuse, during which Archimedes installed terrible fear in Romans with his machines, and after which he was killed by a Roman soldier. Plutarch, however, was Greek. Historians of science wrote that "the works of Archimedes were not widely known in antiquity [except in Alexandria]". Who are these enlightened Romans, then? (Cicero?) There are many other similarly bold statements scattered throughout the article, including the lead. Since I was told that this article operates by the "complaint principle" (any changes not related to previously made complaints are reverted), I am going to complain. Arcfrk (talk) 00:48, 31 January 2008 (UTC)

Introduction of the article

The introduction has been through numerous versions in the past few months, and still seems to be attracting a lot of edits. According to WP:LEAD, the intro should summarise the article without going into too much detail. The current version aims to do this, and has maintained the previous material by making it more succinct and moving some of it elsewhere. --♦IanMacM♦ (talk to me) 12:55, 31 January 2008 (UTC)

The aims are good, but if the introduction is as unstable as you are hinting, trying to lock it in may be premature. Longer articles can afford longer summaries. Often by adding just a few words, a vague and/or misleading claim can be transformed into an accurate statement. Obviously, editorial discretion is needed, but I disagree with some of your picks and think that quality and coherence, not "tradition" (whatever stayed the longest), should inform the decision. Arcfrk (talk) 16:53, 31 January 2008 (UTC)

Archimedes pop culture trivia

While Archimedes was Today's Featured Article (29 Jan 2008), the following nuggets of information were added:

  • Archimedes appears in the Monty Python sketch International Philosophy. This is a spoof game of football between a team of German and Greek philosophers.

Both of these were reverted because they seemed to be trivia. What do other users think? --♦IanMacM♦ (talk to me) 20:12, 31 January 2008 (UTC)

In the section that they were placed, they didn't fit. The Monty Python sketch for example, was placed in the legacy section. That doesn't seem like the correct place to put a comical reference to Archimedes. El Greco(talk) 21:44, 31 January 2008 (UTC)
The IP user is very unwilling to discuss this at all. El Greco(talk) 22:23, 31 January 2008 (UTC)
It is hard to discuss the history of Spam without mentioning the Monty Python sketch, but Archimedes plays only a small part in the sketch mentioned above. Also, apart from being called Archimedes, there is nothing particularly notable about the owl in The Sword and the Stone. So on balance, I think that the revert decisions were correct. --♦IanMacM♦ (talk to me) 08:38, 1 February 2008 (UTC
ah but in greek mythology the owl is a sybol for being wise so they mean that archimedes is very wise that is why they chose the name for the owl69.138.166.53 (talk) 16:41, 24 February 2008 (UTC)

why is there such thing as the three edits only?

why are there the 3 edits only? i mean i need to make more changes but i'mm afraid to be booted from editing the article. 69.138.166.53 (talk) 23:45, 1 February 2008 (UTC)

Three reverts only. A revert is sending the article back to a specific revision. Actually adding information is different from a revert, and there is no penalty, it is improving Wikipedia after all.--LWF (talk) 02:28, 2 February 2008 (UTC)
For more information, see Wikipedia:Three-revert rule. For future reference, the best place to ask questions like this about using Wikipedia is the Wikipedia:Help desk. Since you seem to be new to Wikipedia, it may be helpful to read the Welcome page.  --Lambiam 10:01, 2 February 2008 (UTC)
thanks for helping and u above i am NOT NEW!69.138.166.53 (talk) 16:43, 24 February 2008 (UTC)

The Gauss quote

After being removed by User:Arcfrk, who objected strongly to its inclusion, the Gauss quote (as follows) was put back in the article by another user:

Carl Friedrich Gauss is said to have remarked that Archimedes was one of the three epoch-making mathematicians, with the others being Sir Isaac Newton and Ferdinand Eisenstein.

A couple of points here: I was unable to find a direct source for this quote, although Gauss has often been quoted as saying this. Also, some people might say that it is an example of WP:PEACOCK, although Archimedes needs few endorsements from Gauss or anyone else. If anyone has a direct source for this quote, could they add it to the article. Any other comments are welcome. --♦IanMacM♦ (talk to me) 09:06, 3 February 2008 (UTC)

I removed the quote again as I agree with Arcfrk (the quote doesn't add to the article, the inclusion of Eisenstein distracts, it's dubious whether Gauss actually said this) and the IP editor did not give any reasons for reinstating the quote. -- Jitse Niesen (talk) 14:22, 3 February 2008 (UTC)

Error in the Sphere/Cylinder relationship discussed in the figure

There seems to be a mathematical error at two points in this article. Since I am new to Wikipedia, I thought I'd point it out and leave it to veterans to correct it. The surface area of the sphere and the cylinder are the same, so there is no factor of 2/3 involved in their relationship. The relationship is stated incorrectly in the caption of the figure, and in the section entitled `On the sphere and the cylinder'. The surface area of the sphere is correctly reported as 4πr2. The latter section says the surface area of the circumscribing cylinder is 6πr2, and below the figure it says "The sphere has 2/3 the surface area and volume of the circumscribing cylinder". I think what must be meant is "The sphere has 2/3 the volume, and the same surface area of the circumscribing cylinder" A simple argument is that the circumference of the circumscribing cylinder is 2πr, and its height is simply 2r. So if you unroll it into a rectangle, its area is the product, 4πr2. I hope someone can fix it so we don't have Archimedes giving blatantly absurd formulas. There is no other mathematician I find more impressive, and otherwise I find the article very informative. Bpalais (talk) 02:03, 5 February 2008 (UTC)

There seems to be some confusion here about whether the cylinder is open or closed. Assuming that the cylinder is like a can of baked beans, it will have a lid at the top and the bottom. These will both have an area of πr2, so when they are added to the area of the rolled out tube (4πr2), the total will be 6πr2 (example at [2]). Please could someone else comment on this. --♦IanMacM♦ (talk to me) 09:20, 5 February 2008 (UTC)
That is correct. Does anyone know the ancient report on the (lost) inscription on the tombstone?  --Lambiam 10:02, 5 February 2008 (UTC)
The story about the tomb is sourced to Cicero, and can be found in English and the original Latin at [3]. Unfortunately, the exact wording of the inscription seems to be lost. --♦IanMacM♦ (talk to me) 10:19, 5 February 2008 (UTC)
I am not sure that the previous version in Writings was incorrect, since it relied on the generally accepted definition of the surface area of a cylinder, which includes the area of the two lids (or congruent circular bases as they are formally known). Otherwise, you would be talking about the surface area of a tube rather than a cylinder. The current version in Writings is a bit long winded, and could probably go back to the previous version without too much potential for confusion. --♦IanMacM♦ (talk to me) 11:10, 5 February 2008 (UTC)
At the time of writing, it seemed that the statement that Archimedes' cylinder has an area of 6πr2 was uncontroversial. The formal definition of a cylinder given at [4] is a space figure having two congruent circular bases that are parallel. Without the bases it would be a tube, so there is a risk of stating the obvious by including the information that the bases are included in the surface area. Archimedes' cylinder is a special case of the formula, since its two bases have an area exactly half of that of the connecting tube. --♦IanMacM♦ (talk to me) 16:06, 5 February 2008 (UTC)
Thanks for the clarifications. I see this is correct with that interpretation of cylinder. Perhaps it would be helpful to note `including its bases' as I have seen elsewhere. Another current mathematical interpretation of the word cylinder that is consistent with other Wikipedia entries is a surface generated by parallel lines through some set, e.g., a `circular cylinder', `elliptical', `oblique' `square cylinder', etc. The `formal definition' above that I have never heard would exclude these and include any object however distorted as long as the ends were congruent, circular and parallel. The formulation with the closed circumscribing cylinder has the nice symmetry between the volume and surface area formulas, does give the area of the solid cylinder. The `open' finite cylinder formula has its own beauty too, and the reason I think of it that way is that it was the starting point of lectures by Sir Michael Atiyah several years ago on `area preserving geometry' (symplectic geometry) that became so important in mathematical physics. The amazing property is that not only the area of the open circumscribing cylinder and the sphere are the same, but the same is true for any subset of the sphere and the subset of the cylinder on which it projects! Archimedes knew this, as he gave formulas for the area of portions of the sphere between two parallel planes. This relation fails for the projection on the flat caps of course, and the lasting mathematical importance of the equality of spherical and cylindrical area is completely lost. Thanks again for clarifying the meaning! (Simon Donaldson also recalls Atiyah's talk entitled ”A generalisation of a theorem of Archimedes” in a paper called Geometry in Oxford 1980-1985 ) Bpalais (talk) 17:09, 5 February 2008 (UTC)
After this issue was raised, it seemed like a good idea to see what Archimedes himself had to say about this. This can be done by looking at the complete works of Archimedes in English as translated by T.L. Heath, which can be downloaded in PDF form at [5]. Book One of On the Sphere and the Cylinder begins on page 191, while the key passage can be found on page 233:
“ From what has been proved it follows that every cylinder whose base is the greatest circle in a sphere and whose height is equal to the diameter of the sphere is 3/2 of the sphere, and its surface together with its bases is 3/2 of the surface of the sphere. ”

This shows that Archimedes considered the statement about the congruence between the volume and surface area to be at the heart of the theorem, and he uses the relationship 3/2 (2/3 is another way of expressing it).

A cylinder in geometry is usually considered to be a solid (like a sphere or cone), and several dictionary definitions that I consulted agreed with this. However, the word cylinder is also used to describe a hollow tube, notably when it describes the cylinder of an engine where fuel is burned. The wording on page 233 above includes the phrase its surface together with its bases to remove any ambiguity. --♦IanMacM♦ (talk to me) 20:00, 5 February 2008 (UTC)

That's very helpful. I agree that the `together with its bases' does assist the modern mathematician. It is interesting that Archimedes felt the coincidence of volume and surface area formulas was most interesting, while later mathematicians found the equality of spherical and cylindrical area (without the bases) was the only aspect that had far reaching and significant generalizations. I think the definition preference between solid vs. hollow cylinders was not at issue, just the definition of a cylinder as a space figure having two congruent circular bases that are parallel which can't be correct if it says nothing about what happens in between the bases. Thanks again. Bpalais (talk) 22:13, 5 February 2008 (UTC)

Archytas and the lever

I removed the statement that Archytas was the first person to describe the principle of the lever, mainly due to concerns about its reliability. We know even less about Archytas than we do about Archimedes, and again there is the problem of claims being made in Roman times long after his death. Some scholars argue that Aristotle's Mechanics is actually the work of Archytas, but nobody knows for sure. See also [6] for Marshall Clagett's view on this issue. Other comments welcome here. --♦IanMacM♦ (talk to me) 18:47, 17 February 2008 (UTC)

The lever

The replaced text sounds nonsensical: I am sure that people used the lever well before Archimedes came on the scene! What you probably mean is that he was one of the first to describe the principle of the lever, although recent scholarship seems to indicate that Archytas was the author of Mechanical Principles, and that theory should be mentioned at least. Presumably cave men were acquainted with levers, so Archimedes cannot be said to have invented the lever. Peterlewis (talk) 19:33, 17 February 2008 (UTC)

The principle of the lever was almost certainly known well before Archimedes, even to the builders of Stonehenge. The question of who gave the first mathematical description is harder to answer, and the claim that it was Archytas is at best vague, as Marshall Clagett explains. There could be a compromise form of wording that brings in Archytas, but it should avoid weasel words, in view of the less than strong evidence of direct involvement by Archytas. --♦IanMacM♦ (talk to me) 19:48, 17 February 2008 (UTC)