text:
Wikipedia talk:User preferences help

What is the email function for? Do we get an automatic subscription to wikipedia-L if we enter it? Dreamyshade

It would be nice if this help page or the prefs page reminded us what TZ the server was in, to help us set the offsets. (Of course, it would be best if the server was set to UTC) -- Gareth Owen

 * It might be even nicer if you could choose a time zone, rather than a number of hours of offset. The server would have to use some database of time zones, which is (admittedly) some work for the programmers. But it's all about the users. :-) -- Rootbeer

*I* want my 'display minor edits' function back! There's no reason to see all the minor edits. That's why they're minor. Those who want to keep closer track are welcome to! --MichaelTinkler

 * Wherever it went, it seems to be back now. -- Rootbeer

I'd like to use Wikipedia sans frames. I unchecked the box on User Preferences, and I still get frames. Also, how do you set up the 'My watchlist' feature? -- BenBaker

 * There no longer seems to be an option for frames. As for the watchlist, you simply need to choose "Watch this article for me" on any you want to watch. Of course, you have to periodically look at your watchlist page to see what's happened to your favorite articles. -- Rootbeer

Comments/feature requests moved from article: Enchanter
 * Note: Some of these items may have questions or omissions marked with a triple sharp sign ("###") to indicate that a Wikipedia Guru should step in to elucidate or make a correction in the software.

 *  QuickBar
 * This is the list of links to the various special pages. You may optionally have it appear at the right or left side of each page. There's no option yet to have it appear at the top or bottom of the page. ### Currently, the QuickBar must be enabled to allow you to move (rename) a page or to vote on any article.

 * Hide minor edits. Registered users may choose to mark edits as being minor (meaning fixes too trivial for trusting users to check up on). It applies to Recent Changes and Enhanced Recent Changes, but not to the Watchlist. ### It also affects Related changes, but currently in an undesirable way: if the last edit of a page linking to the current page was minor, than neither that nor the last major change is shown.

 * Auto-number headings. This adds hierarchical outline-style numbering to headers in articles. But why is it called auto-numbering? Is there anything auto about it? Maybe this setting should be called "Numbering headings". ###

You cannot change your username. If for some reason you feel unbearably compelled to change it, create a new username and mark the old one for deletion. (If this is not the best/only way to do this, can someone please provide instructions?) ###

What is the threshold for stub display option for? Stephen C. Carlson

 * You set a value - say 500 - then all links to any article that is less than 500 bytes has a different colored link to it. I have mine set on 1000. --mav

 * Thanks. I tried to explain this on the help page. SCCarlson

I added a section explaining the math markup prefs, but I kind of guessed on some of them (shame on me). If anyone knows better, please change it. -- Merphant 22:53 5 Jun 2003 (UTC)

 * I also added some more explanations for the misc, prefs pane, but there are still a few left unexplained. Merphant 23:19 5 Jun 2003 (UTC)

Do we really need screenshots here? Can't the reader just look at the page themselves? CGS 07:42 6 Jun 2003 (UTC).

 * Sure, but it's nice to have a quick reference. It's more convenient than clicking back and forth. -- Merphant

Let me just say that this page is linked to from way too few places. I'll try and fix it, but let me rant first :-) I have been here for 2 and a half months, and yet, even as I was actively searching for help. I never stumbled on this page. It must be my stupidity, but that is no excuse. A page like this should be easy to find even for dummies like me. -- Cimon Avaro on a pogo stick 19:30 29 Jun 2003 (UTC)

Let me amend that. This place is linked to from nowhere at all. And that means, that I won't even try to help fixing it. EARS FUMING -- Cimon Avaro on a pogo stick 19:37 29 Jun 2003 (UTC)

Eh?

Ahem, let me amend my amendation. I (the dummy that I am) checked to see what linked to this talk page, not what linked to the real preferences help page. I'll just go and silently sit in the corner now. Thanks. -- Cimon Avaro on a pogo stick 19:52 29 Jun 2003 (UTC)

 * (pat, pat) That's okay, it happens to the best of us sometimes. (Well, I'm just saying that to make you feel better. But it could be true, couldn't it? :) --Brion 19:57 29 Jun 2003 (UTC)

Wikipedia:User preferences help

(List of links)

The following pages link to here:

 * Help/User preferences (redirect page)
 * Emailing users
 * User:Stephen Gilbert/Documentation survey
 * Related Changes
 * How to explore Wikipedia
 * Talk:List of reference tables
 * Village pump/June 2003 archive 2
 * How to start a page
 * Recent Changes
 * How to log in
 * Help
 * Village pump archive
 * Searching
 * List of articles in the Wikipedia namespace
 * Utilities
 * Village pump

But the preferences page itself does not, and that is where one would expect to find a link to the help page. Nafnaf

 * Fixed. --Brion 20:26 29 Jun 2003 (UTC)

 * Thanks! Nafnaf

Thanks for this. This was exactly what I was looking for. RickK 21:49 29 Jun 2003 (UTC)

External Links and Internal Links
I am just wondering is there any way to diplay external links differently than internal links. The list of links at Open content look so confusing. I guess there is none thought -- Taku 00:40 Jan 11, 2003 (UTC)

 * They do actually display in slightly different colours, I think. We could, of course, have an icon for them -- many wikis have a little "planet" icon that goes in front of external links. That's a question for the mailing list. -- Tarquin 00:43 Jan 11, 2003 (UTC)

 * Well, I don't think there should be mixed lists of internal and external links like that at all - the list in question should have "ghost" links to unwritten 'pedia articles (on Openlaw and so on), and the external links should be in the "External links" section. Then there's no problem. --Camembert 00:46 Jan 11, 2003 (UTC)

 * With Internet Explorer I get external links in blue, links to articles that do not yet exist in brown and internal links (visited and not visited) in the two colors I have specified in the IE options, so I made sure they are different. I understand that the first two are specified in http://www.wikipedia.org/style/wikistandard.css and not the other two, they are left to the user to choose and are the same as for surfing elsewhere. - Patrick 14:25 Jan 11, 2003 (UTC)

 * I should mention that this is with Standard skin, with Cologne Blue I get external links in green, links to articles that do not yet exist in brown and internal links (visited and not visited) both in blue, all different from the two colors I have specified in the IE options; apparently you can not choose any colors with this skin. - Patrick 17:26 Jan 11, 2003 (UTC)

I agree with Camembert. And what do you mean by a question for mailing list Tarquin?

 * If you meant a fancy icon -- implementing that would be a question for wikipedia-L -- Tarquin

Taku

The colour I get for external links is soothing green. The purple I see when I web my tracks makes me feel vast. The blue I see to another article fills me with trepidation. But the red I see when there is no article, fills me with fire. Hope you're seeing in technicolur soon. Two16 16:31 Jan 11, 2003 (UTC)

Oh, I see. Because I am using a laptop, I can't recognize the slight difference in color at all. -- Taku 18:03 Jan 11, 2003 (UTC)

 * "web my tracks" = make web log? - Patrick 18:28 Jan 11, 2003 (UTC)

When I am reading and editing the encyclopedia I surf down differnt paths leaving my tracks as I read and write, which show up as a beautiful purple when people are bold in other articles that I visit. Not knowing wiki words for the phenomenon I made my own: "web my tracks". I was trying to convey the experiance of colour wikipedia to a plasma screen wikipedian. I explained all the different high lights. The red really does fire me up. Soon I will know enough to strip red from the wikipedia like bits of red from my atlas. Two16

 * Ah, then blue are internal links not yet visited, and it fills you with fear of not yet knowing the precious knowledge behind them. I don't get what stripping bits of red from your atlas means.   - Patrick 23:03 Jan 11, 2003 (UTC)

hey mav maybe the nile blue you see is the nile green i see ;-} I'm using a  Mac with os9 and microsoft and netscape 4.7

The bits of red represent the map colour of the worldaround British Empire. As each new country gained independance, the red was slowly diminished and was offset by the new colours of worldaround British Commonwealth of Nations.

Two16

 * Um, huh? --Brion

I think the paragraph tags in the cologne blue theme are way to tight, surely, a simple touch of the css should fix this.. anyone agree? --spiff

I don't seem to be able to stay logged in all the time. I have checked "Remember password across sessions" but most of the times I go to this site I'm not logged in. Sometimes I am, and I can't see why I sometimes am and sometimes I'm not. I don't have trouble with cookies on any other sites. I thought it had to do with me going to the NL wikipedia now and then but they're different cookies, so that shouldn't matter. Any help is appreciated!

Update - I have found more info about it (and I've learned how to sign my name Ü), it seems this problem IS related to using two wikipedias. I haven't found a solution yet though, if someone can point me in the right direction I'd appreciate it. --poco poco 09:40 19 Jul 2003 (UTC)

Moving this page to meta soon
We need one place to develop MediaWiki documentation so I'm starting a project-neutral MediaWiki User's Guide in meta and think it would be a good idea to cross wiki redirect this page to meta:MediaWiki User's Guide: Setting preferences as soon as I'm done with the conversion. --mav
 * The MediaWiki user's guide is a good idea, but I am very unhappy with the idea of using cross wiki redirects from pages such as this. Help pages are there primarily for new users, and should be as helpful and user friendly as possible.  For new users to find themselves automatically redirected to another would make things confusing for them - why should they expect to end up in another website just because they asked for help?.

 * Granted, not using an inter-wiki redirect will make it harder to keep this page and similar help pages on other wikis updated in line with the best and most accurate version. But our priority should be to make the help pages helpful, not to make life easier for ourselves as contributors. Enchanter 12:58, 31 Aug 2003 (UTC)

 * I'm not happy about this going to meta either. It just adds confusion. You don't want new users feeling they have to read a whole MediaWiki user guide before they even begin. Meta could say something generic about preferences, but language specific help pages should stay on each Wikipedia. Why would you move this help page off en:, but leave the German one, for example, at de:Wikipedia:Handbuch - Einstellungen? Angela 13:07, 31 Aug 2003 (UTC)

You also have to create an extra account for MEtawiki, and that is something that I think is really annoying for most of the users. Meta is only for Really involved Wikipedians. The avarage Wikipedian should not need to go to Meta. He should be able to find everything that he needs for everyday work on Wikipedia in his language (IMHO). Keep Meta as small as possible. E.g. Mailinglist things can go there, I would say. Fantasy 14:11, 31 Aug 2003 (UTC)

But the whole problem is that this material is about the software specifically and that having the same text in several different places is forking the content. MediaWiki is not the sole property of Wikipedia and in fact is its own Wikimedia project. Wikibooks, Wiktionary, Wikiquote and dozens of other websites all use it too. It is therefore best to have the manual in one neutral place and direct all edits to that version. Granted meta needs to be moved to the Wikimedia.org domain, needs a Wikimedia logo, and the user account login problem has to be fixed, but those are technical issues that have technical fixes.

My idea for this page was to leave a short help pages here that has all the bare basics (an executive summary) and then have the larger description (which I recently updated) on meta. Same thing for editing help and most of the others. The reason why this is more important for English at the moment, is that there are already 4 different Wikimedia projects in English and so far none in other languages. When that changes, there will be increasing pressure to centralize their documentation as well. And all links to meta will be clearly marked as such. --mav 20:17, 31 Aug 2003 (UTC)

 * Fair point. I hadn't considered the duplication at Wikibooks et al. It does need to be made clear to newbies visiting the page that meta is a different site though. Angela 20:30, 31 Aug 2003 (UTC)

User name
How do I change my User name without losing continuity of my homepage etc? I am beginning to think that constantly citing myself as "Dr Adam Carr" looks rather formal and pretentious. Could someone who knows how to do this change me to just "Adam Carr"? Thanx. 210.10.32.12 08:36, 28 Sep 2003 (UTC) Oops that should be Dr Adam Carr 08:41, 28 Sep 2003 (UTC) (I am STILL getting logged out when I press "Save Page" and I know I am not alone in this problem).

 * If you want to change your actual user name, a developer needs to do it. Normally Tim does them but he is away until 5 October. If you leave the request here another developer may deal with it but there's no guarantee. You could also try Brion's to-do list on Meta. The alternative is just to change the name you sign with. You can set this in your preferences. This means that when you sign, whatever name you choose will show up, but Dr Adam Carr will still show up in the history of the page etc. Angela 08:43, 28 Sep 2003 (UTC)

 * Angela thankyou, that is a good solution, I didn't realise I could do that.
 * Could you direct the bugs committee or whoever to the "getting logged out when pressing 'Save Page'" problem? Others have told me they have the same problem. Adam 08:55, 28 Sep 2003 (UTC)

 * The bugs committee may be found at Sourceforge. Bug reports has instructions. Angela 08:58, 28 Sep 2003 (UTC)

 * Do you check the box "Remember my password across sessions" when you log in? If not, you should. It solved my problem with that feature. BL 17:00, 28 Sep 2003 (UTC)

This page is out of sync with the user prefs page:

Prefs:
 * Auto-number headings
 * Edit pages on double click (JavaScript)
 * Enable section editing via [edit] links
 * Remember password across sessions.
 * Edit box has full width.
 * Add pages you edit to your watchlist
 * Add pages you edit to your watchlist

Help:
 * Auto-number headings
 * Remember password across sessions.
 * Edit box has full width.
 * Edit pages on double click.
 * Watch new and modified articles.
 * Watch new and modified articles.

Of course I could just fix the page...but there are images to fix too, and I haven't done that yet...

title: Wikipedia talk:User preferences help


text:
Lists of United States Supreme Court cases

This page serves as an index of lists of United States Supreme Court cases. The United States Supreme Court is the highest federal court of the United States.

By chief justice
Court historians and other legal scholars consider each chief justice who presides over the Supreme Court of the United States to be the head of an era of the Court. These lists are sorted chronologically by chief justice and include most major cases decided by the court.

 * Jay, Rutledge, and Ellsworth Courts (October 19, 1789 – December 15, 1800)
 * Marshall Court (February 4, 1801 – July 6, 1835)
 * Taney Court (March 28, 1836 – October 12, 1864)
 * Chase Court (December 15, 1864 – May 7, 1873)
 * Waite Court (March 4, 1874 – March 23, 1888)
 * Fuller Court (October 8, 1888 – July 4, 1910)
 * White Court (December 19, 1910 – May 19, 1921)
 * Taft Court (July 11, 1921 – February 3, 1930)
 * Hughes Court (February 24, 1930 – June 30, 1941)
 * Stone Court (July 3, 1941 – April 22, 1946)
 * Vinson Court (June 24, 1946 – September 8, 1953)
 * Warren Court (October 5, 1953 – June 23, 1969)
 * Burger Court (June 23, 1969 – September 26, 1986)
 * Rehnquist Court (September 26, 1986 – September 3, 2005)
 * Roberts Court (September 29, 2005 – present)

By volume
Decisions of the Supreme Court of the United States are officially published in the United States Reports.

 * Lists of United States Supreme Court cases by volume

By term
These lists contain detailed tables about each term since 1999, including which justices filed the court's opinion, dissenting and concurring opinions in each case, and information about justices joining opinions. The tables conclude with term statistics and concordance data.

 * 1999 term opinions
 * 2000 term opinions
 * 2001 term opinions
 * 2002 term opinions
 * 2003 term opinions
 * 2004 term opinions
 * 2005 term opinions
 * 2006 term opinions
 * 2007 term opinions
 * 2008 term opinions
 * 2009 term opinions
 * 2010 term opinions
 * 2011 term opinions
 * 2012 term opinions
 * 2013 term opinions
 * 2014 term opinions
 * 2015 term opinions
 * 2016 term opinions
 * 2017 term opinions
 * 2018 term opinions
 * 2019 term opinions
 * 2020 term opinions
 * 2021 term opinions
 * 2022 term opinions
 * 2023 term opinions

By subject matter

 * Arbitration
 * Capital punishment
 * Copyright
 * First Amendment
 * Immigration
 * Jehovah's Witnesses
 * Legal standing
 * LGBTQ rights
 * Mental health
 * Native American tribes
 * Patents
 * Taxation and revenue
 * Trademarks

Other lists

 * List of pending United States Supreme Court cases
 * List of landmark court decisions in the United States (most frequently from the Supreme Court)

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


text:
Henry Cavendish

Henry Cavendish (10 October 1731 – 24 February 1810) was an English natural philosopher and scientist who was an important experimental and theoretical chemist and physicist. He is noted for his discovery of hydrogen, which he termed "inflammable air". He described the density of inflammable air, which formed water on combustion, in a 1766 paper, On Factitious Airs. Antoine Lavoisier later reproduced Cavendish's experiment and gave the element its name.

A shy man, Cavendish was distinguished for great accuracy and precision in his researches into the composition of atmospheric air, the properties of different gases, the synthesis of water, the law governing electrical attraction and repulsion, a mechanical theory of heat, and calculations of the density (and hence the mass) of the Earth. His experiment to measure the density of the Earth (which, in turn, allows the gravitational constant to be calculated) has come to be known as the Cavendish experiment.

Early life
Henry Cavendish was born on 10 October 1731 in Nice, where his family was living at the time. His mother was Lady Anne de Grey, fourth daughter of Henry Grey, 1st Duke of Kent, and his father was Lord Charles Cavendish, the third son of William Cavendish, 2nd Duke of Devonshire. The family traced its lineage across eight centuries to Norman times, and was closely connected to many aristocratic families of Great Britain. Henry's mother died in 1733, three months after the birth of her second son, Frederick, and shortly before Henry's second birthday, leaving Lord Charles Cavendish to bring up his two sons. Henry Cavendish was styled as "The Honourable Henry Cavendish".

From the age of 11 Henry attended Newcome's School, a private school near London. At the age of 18 (on 24 November 1748) he entered the University of Cambridge in St Peter's College, now known as Peterhouse, but left three years later on 23 February 1751 without taking a degree (at the time, a common practice). He then lived with his father in London, where he soon had his own laboratory.

Lord Charles Cavendish spent his life firstly in politics and then increasingly in science, especially in the Royal Society of London. In 1758, he took Henry to meetings of the Royal Society and also to dinners of the Royal Society Club. In 1760, Henry Cavendish was elected to both these groups, and he was assiduous in his attendance after that. He took virtually no part in politics, but followed his father into science, through his researches and his participation in scientific organisations. He was active in the Council of the Royal Society of London (to which he was elected in 1765).

His interest and expertise in the use of scientific instruments led him to head a committee to review the Royal Society's meteorological instruments and to help assess the instruments of the Royal Greenwich Observatory. His first paper, Factitious Airs, appeared in 1766. Other committees on which he served included the committee of papers, which chose the papers for publication in the Philosophical Transactions of the Royal Society, and the committees for the transit of Venus (1769), for the gravitational attraction of mountains (1774), and for the scientific instructions for Constantine Phipps's expedition (1773) in search of the North Pole and the Northwest Passage. In 1773, Henry joined his father as an elected trustee of the British Museum, to which he devoted a good deal of time and effort. Soon after the Royal Institution of Great Britain was established, Cavendish became a manager (1800) and took an active interest, especially in the laboratory, where he observed and helped in Humphry Davy's chemical experiments.

Chemistry research
About the time of his father's death, Cavendish began to work closely with Charles Blagden, an association that helped Blagden enter fully into London's scientific society. In return, Blagden helped to keep the world at a distance from Cavendish. Cavendish published no books and few papers, but he achieved much. Several areas of research, including mechanics, optics, and magnetism, feature extensively in his manuscripts, but they scarcely feature in his published work. Cavendish is considered to be one of the so-called pneumatic chemists of the eighteenth and nineteenth centuries, along with, for example, Joseph Priestley, Joseph Black, and Daniel Rutherford. Cavendish found that a definite, peculiar, and highly inflammable gas, which he referred to as "Inflammable Air", was produced by the action of certain acids on certain metals. This gas was hydrogen, which Cavendish correctly guessed was proportioned two to one in water.

Although others, such as Robert Boyle, had prepared hydrogen gas earlier, Cavendish is usually given the credit for recognising its elemental nature. In 1777, Cavendish discovered that air exhaled by mammals is converted to "fixed air" (carbon dioxide), not "phlogisticated air" as predicted by Joseph Priestley. Also, by dissolving alkalis in acids, Cavendish produced carbon dioxide, which he collected, along with other gases, in bottles inverted over water or mercury. He then measured their solubility in water and their specific gravity, and noted their combustibility. He concluded in his 1778 paper "General Considerations on Acids" that respirable air constitutes acidity. Cavendish was awarded the Royal Society's Copley Medal for this paper. Gas chemistry was of increasing importance in the latter half of the 18th century, and became crucial for Frenchman Antoine-Laurent Lavoisier's reform of chemistry, generally known as the chemical revolution.

In 1783, Cavendish published a paper on eudiometry (the measurement of the goodness of gases for breathing). He described a new eudiometer of his invention, with which he achieved the best results to date, using what in other hands had been the inexact method of measuring gases by weighing them. Then, after a repetition of a 1781 experiment performed by Priestley, Cavendish published a paper on the production of pure water by burning hydrogen in "dephlogisticated air" (air in the process of combustion, now known to be oxygen). Cavendish concluded that rather than being synthesised, the burning of hydrogen caused water to be condensed from the air. Some physicists interpreted hydrogen as pure phlogiston. Cavendish reported his findings to Priestley no later than March 1783, but did not publish them until the following year. The Scottish inventor James Watt published a paper on the composition of water in 1783; controversy about who made the discovery first ensued.

In 1785, Cavendish investigated the composition of common (i.e. atmospheric) air, obtaining impressively accurate results. He conducted experiments in which hydrogen and ordinary air were combined in known ratios and then exploded with a spark of electricity. Furthermore, he also described an experiment in which he was able to remove, in modern terminology, both the oxygen and nitrogen gases from a sample of atmospheric air until only a small bubble of unreacted gas was left in the original sample. Using his observations, Cavendish observed that, when he had determined the amounts of phlogisticated air (nitrogen) and dephlogisticated air (oxygen), there remained a volume of gas amounting to 1/120 of the original volume of nitrogen. By careful measurements he was led to conclude that "common air consists of one part of dephlogisticated air [oxygen], mixed with four of phlogisticated [nitrogen]".

In the 1890s (around 100 years later) two British physicists, William Ramsay and Lord Rayleigh, realised that their newly discovered inert gas, argon, was responsible for Cavendish's problematic residue; he had not made an error. What he had done was perform rigorous quantitative experiments, using standardised instruments and methods, aimed at reproducible results; taken the mean of the result of several experiments; and identified and allowed for sources of error. The balance that he used, made by a craftsman named Harrison, was the first of the precision balances of the 18th century, and as accurate as Lavoisier's (which has been estimated to measure one part in 400,000). Cavendish worked with his instrument makers, generally improving existing instruments rather than inventing wholly new ones.

Cavendish, as indicated above, used the language of the old phlogiston theory in chemistry. In 1787, he became one of the earliest outside France to convert to the new antiphlogistic theory of Lavoisier, though he remained sceptical about the nomenclature of the new theory. He also objected to Lavoisier's identification of heat as having a material or elementary basis. Working within the framework of Newtonian mechanism, Cavendish had tackled the problem of the nature of heat in the 1760s, explaining heat as the result of the motion of matter.

In 1783, he published a paper on the temperature at which mercury freezes and in that paper made use of the idea of latent heat, although he did not use the term because he believed that it implied acceptance of a material theory of heat. He made his objections explicit in his 1784 paper on air. He went on to develop a general theory of heat, and the manuscript of that theory has been persuasively dated to the late 1780s. His theory was at once mathematical and mechanical: it contained the principle of the conservation of heat (later understood as an instance of conservation of energy) and even included the concept (although not the label) of the mechanical equivalent of heat.

Density of the Earth
Following his father's death, Henry bought another house in town and also a house in Clapham Common (built by Thomas Cubitt), at that time to the south-west of London. The London house contained the bulk of his library, while he kept most of his instruments at Clapham Common, where he carried out most of his experiments. The most famous of those experiments, published in 1798, was to determine the density of the Earth and became known as the Cavendish experiment. The apparatus Cavendish used for weighing the Earth was a modification of the torsion balance built by geologist John Michell, who died before he could begin the experiment. The apparatus was sent in crates to Cavendish, who completed the experiment in 1797–1798 and published the results.

The experimental apparatus consisted of a torsion balance with a pair of 2-inch 1.61-pound lead spheres suspended from the arm of a torsion balance and two much larger stationary lead balls (350 pounds). Cavendish intended to measure the force of gravitational attraction between the two. He noticed that Michell's apparatus would be sensitive to temperature differences and induced air currents, so he made modifications by isolating the apparatus in a separate room with external controls and telescopes for making observations.

Using this equipment, Cavendish calculated the attraction between the balls from the period of oscillation of the torsion balance, and then he used this value to calculate the density of the Earth. Cavendish found that the Earth's average density is 5.48 times greater than that of water. John Henry Poynting later noted that the data should have led to a value of 5.448, and indeed that is the average value of the twenty-nine determinations Cavendish included in his paper. The error in the published number was due to a simple arithmetical mistake on his part. What was extraordinary about Cavendish's experiment was its elimination of every source of error and every factor that could disturb the experiment, and its precision in measuring an astonishingly small attraction, a mere 1/50,000,000 of the weight of the lead balls. The result that Cavendish obtained for the density of the Earth is within 1 per cent of the currently accepted figure.

Cavendish's work led others to accurate values for the gravitational constant (G) and Earth's mass. Based on his results, one can calculate a value for G of 6.754 × 10−11N-m2/kg2, which compares favourably with the modern value of 6.67428 × 10−11N-m2/kg2.

Books often describe Cavendish's work as a measurement of either G or the Earth's mass. Since these are related to the Earth's density by a trivial web of algebraic relations, none of these sources are wrong, but they do not match the exact word choice of Cavendish, and this mistake has been pointed out by several authors. Cavendish's stated goal was to measure the Earth's density.

The first time that the constant got this name was in 1873, almost 100 years after the Cavendish experiment. Cavendish's results also give the Earth's mass.

Electrical research
Cavendish's electrical and chemical experiments, like those on heat, had begun while he lived with his father in a laboratory in their London house. Lord Charles Cavendish died in 1783, leaving almost all of his very substantial estate to Henry. Like his theory of heat, Cavendish's comprehensive theory of electricity was mathematical in form and was based on precise quantitative experiments. Working with his colleague, Timothy Lane, he created an artificial torpedo fish that could dispense electric shocks to show that the source of shock from these fish was electricity. He published an early version of his theory of electricity in 1771, based on an expansive electrical fluid that exerted pressure. He demonstrated that if the intensity of electric force were inversely proportional to distance, then the electric fluid more than that needed for electrical neutrality would lie on the outer surface of an electrified sphere; then he confirmed this experimentally. Cavendish continued to work on electricity after this initial paper, but he published no more on the subject.

Cavendish wrote papers on electrical topics for the Royal Society but the bulk of his electrical experiments did not become known until they were collected and published by James Clerk Maxwell a century later, in 1879, long after other scientists had been credited with the same results. Cavendish's electrical papers from the Philosophical Transactions of the Royal Society of London have been reprinted, together with most of his electrical manuscripts, in The Scientific Papers of the Honourable Henry Cavendish, F.R.S. (1921). According to the 1911 edition of Encyclopædia Britannica, among Cavendish's discoveries were the concept of electric potential (which he called the "degree of electrification"), an early unit of capacitance (that of a sphere one inch in diameter), the formula for the capacitance of a plate capacitor, the concept of the dielectric constant of a material, the relationship between electric potential and current (now called Ohm's law) (1781), laws for the division of current in parallel circuits (now attributed to Charles Wheatstone), and the inverse square law of variation of electric force with distance, now called Coulomb's law.

Death
Cavendish died at Clapham on 24 February 1810 (as one of the wealthiest men in Britain) and was buried, along with many of his ancestors, in the church that is now Derby Cathedral. The road he used to live on in Derby has been named after him, as has a road near his house in Clapham, of which the north part is part of the South Circular Road. The University of Cambridge's Cavendish Laboratory was endowed by one of Cavendish's later relatives, William Cavendish, 7th Duke of Devonshire (Chancellor of the University from 1861 to 1891).

Personality and legacy
Cavendish inherited two fortunes that were so large that Jean Baptiste Biot called him "the richest of all the savants and the most knowledgeable of the rich". At his death, Cavendish was the largest depositor in the Bank of England. He was a shy man who was uncomfortable in society and avoided it when he could. He could speak to only one person at a time, and only if the person were known to him and male. He conversed little, always dressed in an old-fashioned suit, and developed no known deep personal attachments outside his family. Cavendish was taciturn and solitary and regarded by many as eccentric. He communicated with his female servants only by notes. By one account, Cavendish had a back staircase added to his house to avoid encountering his housekeeper, because he was especially shy of women. The contemporary accounts of his personality have led some modern commentators, such as Oliver Sacks, to speculate that he was autistic.

His only social outlet was the Royal Society Club, whose members dined together before weekly meetings. Cavendish seldom missed these meetings, and was profoundly respected by his contemporaries. However, his shyness made conversation difficult; guests were advised to wander close to him and then speak as if "into vacancy. If their remarks were scientifically worthy, they might receive a mumbled reply". Cavendish was more likely not to reply at all. Cavendish's religious views were also considered eccentric for his time. He was considered to be agnostic. As his biographer, George Wilson, comments, "As to Cavendish's religion, he was nothing at all."

The arrangement of his residence reserved only a fraction of space for personal comfort as his library was detached, the upper rooms and lawn were for astronomical observation and his drawing room was a laboratory with a forge in an adjoining room. He also enjoyed collecting fine furniture, exemplified by his purchase of a set of "ten inlaid satinwood chairs with matching cabriole legged sofa".

Because of his asocial and secretive behaviour, Cavendish often avoided publishing his work, and much of his findings were not told even to his fellow scientists. In the late nineteenth century, long after his death, James Clerk Maxwell looked through Cavendish's papers and found observations and results for which others had been given credit. Examples of what was included in Cavendish's discoveries or anticipations were Richter's law of reciprocal proportions, Ohm's law, Dalton's law of partial pressures, principles of electrical conductivity (including Coulomb's law), and Charles's Law of gases. A manuscript "Heat", tentatively dated between 1783 and 1790, describes a "mechanical theory of heat". Hitherto unknown, the manuscript was analysed in the early 21st century. Historian of science Russell McCormmach proposed that "Heat" is the only 18th-century work prefiguring thermodynamics. Theoretical physicist Dietrich Belitz concluded that in this work Cavendish "got the nature of heat essentially right".

As Cavendish performed his famous density of the Earth experiment in an outbuilding in the garden of his Clapham Common estate, his neighbours would point out the building and tell their children that it was where the world was weighed. In honour of Henry Cavendish's achievements and due to an endowment granted by Henry's relative William Cavendish, 7th Duke of Devonshire, the University of Cambridge's physics laboratory was named the Cavendish Laboratory by Maxwell, the first Cavendish Professor of Physics and an admirer of Cavendish's work.

Selected writings

 * – edited by James Clerk Maxwell and revised by Joseph Larmor
 * – edited by James Clerk Maxwell and revised by Joseph Larmor

title: Henry Cavendish


text:
Talk:Cinema of China

Wiki Education Foundation-supported course assignment
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Haitaoyu.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 17:43, 16 January 2022 (UTC)

Tightening/trimming from the artistic/entertainment perspective?
Over a period of time, I have done some revising on cinema that is significant from a political-historical perspective. I believe it has significantly improved the article.

We could use some work on the artistic or entertainment aspects of cinema: trimming unsourced, refining the presentation, and so forth.

Is there anyone out there who would feel confident in doing so? JArthur1984 (talk) 12:52, 1 April 2024 (UTC)

title: Talk:Cinema of China


text:
Mustafa II

Mustafa II (مصطفى ثانى Muṣṭafā-yi s ānī; 6 February 1664 – 29 December 1703) was the sultan of the Ottoman Empire from 1695 to 1703.

Early life
He was born at Edirne Palace on 6 February 1664. He was the son of Sultan Mehmed IV (1648–87) and Gülnuş Sultan, originally named Evmania, who was of Greek descent.

Much of Mustafa's childhood was passed in Edirne, the city of his birth. While he was in Mora Yenişehiri with his father in 1669, he began his religious education under Vani Mehmed Efendi, undergoing the bed-i besmele ceremony. The writing teacher was the famous calligrapher Hâfiz Osman. In 1675, he and his brother Ahmed were circumcised and his sisters Hatice Sultan and Fatma Sultan were married. The celebration lasted 20 days.

Great Turkish War
During his reign the Great Turkish War, which had started in 1683, was still going on. After the failure of the second Siege of Vienna (1683) the Holy League had captured large parts of the Empire's territory in Europe. The Habsburg armies came as far as Niš, modern-day Serbia, before being pushed back across the Danube by 1690. Sultan Mustafa II was determined to recapture the lost territories in Hungary and therefore he personally commanded his armies. He set out from Niš with a large Ottoman Army to campaign against the Holy League.

Capture of Chios
First, the Ottoman Navy recaptured the island of Chios after defeating the Venetian Fleet twice, in the Battle of the Oinousses Islands (1695) and in the Battle of Chios (1695), in February 1695. In June 1695, Mustafa II left Edirne for his first military campaign against the Habsburg Empire. By September 1695 the town of Lipova was captured. On 18 September 1695 the Venetian Navy was again defeated in the naval victory of Zeytinburnu. A few days later the Habsburg army was defeated in the Battle of Lugos. Afterwards the Ottoman Army returned to the capital. Meanwhile, the Ottoman fortress in Azov was successfully defended against the besieging Russian forces.

As Mustafa attempted to realize his thoughts quickly, the island of Chios, which had previously fallen into the hands of the Venetians, was taken back at that time, the Crimean Tatars Shahbaz Giray entered the territory of Poland and proceeded to Lemberg (Lviv), and returned with many captives and booty. There were reports that the Venetians were influenced by the Ottoman forces on the Herzegovina front in Peloponnese. Especially the recovery of Chios was considered auspicious and was celebrated with great festivities in Edirne. Meanwhile, the tips of the people were distributed to the locals.

Habsburg wars
In April 1696 Mustafa II left Edirne for his second military campaign against the Habsburg Empire. In August 1696 the Russians besieged Azov for the second time and captured the fortress. In August 1696 the Ottoman troops defeated the Habsburg army in the Battle of Ulaş and in the Battle of Cenei. After these victories the Ottoman troops captured Timișoara and Koca Cafer Pasha was appointed as the protector of Belgrade. Afterwards the army returned to the Ottoman capital.

In June 1697 Mustafa II left the capital on his third military campaign against the Habsburg Empire. However, the Ottoman Army suffered a defeat in the Battle of Zenta and Grand Vizier Elmas Mehmed Pasha died in the battle. Afterwards the Ottomans signed a treaty with the Holy League.

The most traumatic event of his reign was the loss of Hungary by the Treaty of Karlowitz in 1699.

Yet even if Ottoman power seemed to wane on one side of the empire, this did not mean that Ottoman efforts at expansion ceased. In 1700, for example, the Grand Vizier Amcazade Hüseyin boasted to a recalcitrant tribe residing in swamps near Baghdad that they ought to abide by the sultan's rule, since his grasp extended even to their marshy redoubts. The Grand Vizier added that, after all, Mustafa II was "the Lord of Water and Mud."

At the end of his reign, Mustafa II sought to restore power to the Sultanate, which had been an increasingly symbolic position since the middle of the 17th century, when Mehmed IV had signed over his executive powers to the Grand Vizier. Mustafa II's strategy was to create an alternative base of power for himself by making the position of timars, the Ottoman cavalrymen, hereditary and thus loyal to him. The timars, however, were at this point increasingly an obsolete part of the Ottoman military machine.

Deposition
The stratagem failed, the disaffected troops bound to a Georgian campaign mutinied in the capital (called the "Edirne event" by historians), and Mustafa was deposed on 22 August 1703.

Character
Defined as having a red beard, a short neck, he was of medium height and majestic. Mustafa II has a miniature made by Levni. After 1699, like his father, he was interested in hunting and entertainment, engaged in literature and wrote poems with the pseudonym. A curiosity of this sultan, who had lines in the style of Celi, Nesih and Sulus was archery. Silahdar Findiklili Mehmed Agha, who was assigned to write the history of his period. He described Mustafa's reign in his book Nusretname.

Family
With the rise of Mustafa II, the title of "Haseki Sultan" was definitively abolished, to be permanently replaced by the less prestigious and not exclusive "Kadın" (imperial consort). Mustafa II also created a new class of concubines, the "Ikbal": inferior in rank to the Kadın in the hierarchy of the harem, they were initially called with the normal title of "Hatun" (woman), later modified in that, superior, of "Hanim" (lady).

Several of his concubines and consorts were married after his deposition by order of the new sultan, his brother Ahmed III.

Consorts
Mustafa II had at least ten consorts:
 * Alicenab Kadın (died 20 April 1699, Edirne Palace, Edirne, buried in Darülhadis Mosque). BaşKadin (first imperial consort) until her death.
 * Afife Kadın (c. 1682 – Constantinople, after 1718). BaşKadin after Alicenab's death. Also called Hafife, Hafiten, Hafize, Hafise or Hafsa in the European chronicles, she was Mustafa's most loved consort, sentiment reciprocated, even if they were never legally married. She had a daughter in 1696 and later became the mother of five of Mustafa's eight sons.
 * Saliha Kadın (died 21 September 1739, Tırnakçı Palace, Istanbul, buried in Turhan Sultan Mausoleum, New Mosque). She was Valide Sultan of Mahmud I.
 * Şehsuvar Kadın (died 27 April 1756, Topkapı Palace, Istanbul, buried in Nuruosmaniye Mosque). She was Valide Sultan of Osman III.
 * Bahtiyar Kadın. One of his first concubines, she was probably the mother of one of Mustafa's oldest daughters.
 * Ivaz Kadın. Mentioned as a Kadin in a document dated 1696/1697, she was probably the mother of one of Mustafa's oldest daughters.
 * Hatice Kadin. Before becoming a consort, she was a high-ranking harem lady-in-waiting.
 * Hüsnüşah Kadın. She died on 1 January 1700.
 * Fatma Şahin Hatun, then Hanim. Baş Ikbal (firts ikbal). After Mustafa's deposition she was removed from the harem and married by order of Ahmed III.
 * Hanife Hatun, then Hanim. After Mustafa's deposition she was removed from the harem and married by order of Ahmed III. From her new husband she had a son named Ibrahim and a daughter.

Sons
Mustafa II had at least eight sons, including five who died as infants with Afife Kadın:
 * Mahmud I (2 August 1696 – 13 December 1754) – with Saliha Kadin. 24th Sultan of the Ottoman Empire.
 * Şehzade Mehmed (27 November 1698 – 3 June 1703, Edirne Palace, Edirne, buried in Turhan Sultan's türbe, New Mosque) – with Afife Kadın. He was the favorite son of Mustafa II, who suffered his death immensely.
 * Osman III (2 January 1699 – 30 October 1757) – with Şehsuvar Kadin. 25th Sultan of the Ottoman Empire.
 * Şehzade Hasan (28 March 1699 – 25 May 1733). He became heir to the throne in 1730 and spent most of his life locked up in the Kafes, where he finally died.
 * Şehzade Hüseyn (16 May 1699 – 19 September 1700, Edirne Palace, Edirne, buried in New Mosque) – with Afife Kadın.
 * Şehzade Selim (16 May 1700 – 8 June 1702, Edirne Palace, Edirne, buried in Turhan Sultan's turbe New Mosque) – with Afife Kadın.
 * Şehzade Ahmed (3 March 1702 – 7 September 1703, Edirne Palace, Edirne, buried in Darülhadis Mosque) – with Afife Kadın.
 * Şehzade Suleyman (25 December 1703 – 25 December 1703, Edirne Palace, Edirne, buried in Turhan Sultan's turbe New Mosque) – with Afife Kadın. Stillbirth. Four days after, Mustafa II died, too.

Daughters
Mustafa II had at least twelve daughters, of which one, among the three eldest, with Afife Kadin:
 * Ayşe Sultan (30 April 1696 – 26 September 1752, Istanbul, buried in New Mosque). Nicknamed "the eldest" to distinguish her from her cousin Ayşe Sultan "the younger", daughter of Ahmed III. She married three times, but had no children.
 * Emine Sultan (1 September 1696 –1739, Istanbul, buried in New Mosque). She married four times, but had no children.
 * Safiye Sultan (13 October 1696 – 15 May 1778, Istanbul, buried in New Mosque) - maybe with Afife Kadin. She married four times and had three sons and a daughter.
 * Hatice Sultan (15 March 1698 – before 1703, Edirne Palace, Edirne, buried in Darülhadis Mosque).
 * Rukiye Sultan (13 November 1698 – 28 March 1699, Edirne Palace, Edirne, buried in Darülhadis Mosque).
 * Rukiye Ismihan Sultan (after April 1699 – 24 December 1703, Istanbul, buried in New Mosque). Her father promised her in wife to Maktülzade Ali Paşah, but the baby girl died before being able to celebrate the wedding.
 * Fatma Sultan (8 October 1699 – 20 May 1700, Istanbul, buried in New Mosque).
 * Ümmügülsüm Sultan (10 June 1700 – 2 May 1701, Edirne Palace, Edirne, buried in Darülhadis Mosque).
 * Emetullah Sultan (22 June 1701 – 19 April 1727, Istanbul, buried in New Mosque) – with Şehsuvar Kadın. Also called Ümmetullah Sultan or Heybetullah Sultan. She married once and had a daughter.
 * Zeynep Sultan (10 June 1703 – 18 December 1705, Istanbul, buried in New Mosque).
 * Atike Sultan (? – ?). She died in infancy.
 * Esma Sultan (? – ?). She died in infancy.

Death
After the new sultan's return to Istanbul, Mustafa and his princes were brought to Istanbul in the Topkapı Palace they were locked up in the Kafes. Mustafa's cage life lasted four months. He died of either sadness or an unknown cause on 29 December 1703. He was buried next to his grandmother, Turhan Hatice Sultan, in the New Mosque, Eminönü, Istanbul, Turkey.

title: Mustafa II


text:
Museum of Pop Culture

The Museum of Pop Culture or MoPOP is a nonprofit museum in Seattle, Washington, United States, dedicated to contemporary popular culture. It was founded by Microsoft co-founder Paul Allen in 2000 as the Experience Music Project. Since then MoPOP has organized dozens of exhibits, 17 of which have toured across the U.S. and internationally.

The museumformerly known as Experience Music Project and Science Fiction Museum and Hall of Fame (EMP|SFM) and later EMP Museum until November 2016—has initiated many public programs including "Sound Off!", an annual 21-and-under battle-of-the-bands that supports the all-ages scene; and "Pop Conference", an annual gathering of academics, critics, musicians, and music buffs.

MoPOP, in collaboration with the Seattle International Film Festival (SIFF), presents the Science Fiction and Fantasy Short Film Festival which takes place every winter. Since 2007, the MoPop celebrates recording artists with the Founders Award for their noteworthy contributions.

Exhibits and activities
MoPOP is home to numerous exhibits and interactive activity stations as well as sound sculpture and various educational resources:
 * A 140000 sqft building, designed by Frank O. Gehry, housing several galleries and the Sky Church, which features a Barco C7 black package LED screen, one of the largest indoor LED screens in the world.
 * Exhibits covering pop culture, from the art of fantasy, horror cinema, and video games to science fiction literature and costumes from screen and stage.
 * Interactive activities are included in galleries like Sound Lab and On Stage where visitors can explore hands-on the tools of rock and roll through instruments, and perform music before a virtual audience.
 * IF VI WAS IX, a guitar sculpture consisting of more than 500 musical instruments and 30 computers conceived by British exhibit designer Neal Potter and developed by sound sculptor Trimpin.
 * The world's largest collection of artifacts, hand-written lyrics, personal instruments, and original photographs celebrating the music and history of Seattle musician Jimi Hendrix and the band Nirvana.
 * Educational resources including MoPOP's Curriculum Connections in-museum workshops and outreach programs; STAR (Student Training in Artistic Reach); Creativity Camps for Kids; Teen Artist Workshops; Write Out of This World, an annual sci-fi and fantasy short story contest for 3rd to 12th graders; and the Hip-Hop Artist Residency.
 * Public programs such as MoPOP's Science Fiction + Fantasy Short Film Festival, Pop Conference, the Youth Advisory Board (YAB), and Sound Off!, the Pacific Northwest's premier battle-of-the-bands.

MoPOP was also the location of the first NIME workshop's concert and demo program. This subsequently became the annual International Conference on New Interfaces for Musical Expression, a venue for research on music technology.

Science Fiction Museum
The Science Fiction Museum and Hall of Fame was founded by Paul Allen and his sister Jody Patton, and opened to the public on June 18, 2004. It incorporated the Science Fiction and Fantasy Hall of Fame which had been established in 1996. The museum was divided into several galleries with themes such as "Homeworld", "Fantastic Voyages", "Brave New Worlds", and "Them!", each displaying related memorabilia (movie props, first editions, costumes, and models) in large display cases, posters, and interactive displays. It was said about the museum that "From robots to jet packs to space suits and ray guns, it's all here."

Members of the museum's advisory board included Steven Spielberg, Ray Bradbury, James Cameron, and George Lucas. Among its collection of artifacts were Captain Kirk's command chair from Star Trek, the B9 robot from Lost in Space, the Death Star model from Star Wars, the T-800 Terminator and the dome from the film Silent Running. Although the Science Fiction Museum as a permanent collection was de-installed in March 2011, a new exhibit named Icons of Science Fiction opened as a replacement in June 2012. At this time the new Hall of Fame display was unveiled and the class of 2012 inducted.

Science Fiction and Fantasy Hall of Fame
The Science Fiction and Fantasy Hall of Fame was founded in 1996 by the Kansas City Science Fiction and Fantasy Society and the Center for the Study of Science Fiction (CSSF) at the University of Kansas (KU). The chairmen were Keith Stokes (1996–2001) and Robin Wayne Bailey (2002–2004). Only writers and editors were eligible for recognition and four were inducted annually, two deceased and two living. Each class of four was announced at Kansas City's annual science fiction convention, ConQuesT, and inducted at the Campbell Conference hosted by CSSF.

The Hall of Fame stopped inducting fantasy writers after 2004, when it became part of the Science Fiction Museum affiliated with the Museum of Pop Culture, under the name "Science Fiction Hall of Fame". Having inducted 36 writers in nine years, the organization began to recognize non-literary media in 2005. It retained the quota of four new members and thus reduced the annual number of writers. The 2005 and 2006 press releases placed new members in "Literature", "Art", "Film, Television and Media", and "Open" categories, one for each category. In 2007 and 2008, the fourth inductee was placed in one of the three substantial categories.

MoPOP de-installed the Science Fiction Museum in March 2011. When the "Icons of Science Fiction" exhibition opened in June 2012, a new Hall of Fame display was unveiled and the class of 2012 was inducted.

Nominations are submitted by the public, but the selections are made by "award-winning science fiction authors, artists, editors, publishers, and film professionals."

MoPOP restored the original name online during June 2013 and announced five new members, one daily, beginning June 17, 2013. The first four were cited largely or wholly for science fiction works, however the final one was J.R.R. Tolkien, who was "hailed as the father of modern fantasy literature".

Science Fiction and Fantasy Hall of Fame inductions

 * 1996: Jack Williamson; A. E. van Vogt; John W. Campbell, Jr.; Hugo Gernsback
 * 1997: Andre Norton; Arthur C. Clarke; H. G. Wells; Isaac Asimov
 * 1998: Hal Clement; Frederik Pohl; C. L. Moore; Robert A. Heinlein
 * 1999: Ray Bradbury; Robert Silverberg; Jules Verne; Abraham Merritt
 * 2000: Poul Anderson; Gordon R. Dickson; Theodore Sturgeon; Eric Frank Russell
 * 2001: Jack Vance; Ursula K. Le Guin; Alfred Bester; Fritz Leiber
 * 2002: Samuel R. Delany; Michael Moorcock; James Blish; Donald A. Wollheim
 * 2003: Wilson Tucker; Kate Wilhelm; Damon Knight; Edgar Rice Burroughs
 * 2004: Brian Aldiss; Harry Harrison; Mary Wollstonecraft Shelley; E. E. "Doc" Smith
 * 2005: Steven Spielberg; Philip K. Dick; Chesley Bonestell; Ray Harryhausen
 * 2006: George Lucas; Frank Herbert; Frank Kelly Freas; Anne McCaffrey
 * 2007: Ed Emshwiller; Gene Roddenberry; Ridley Scott; Gene Wolfe
 * 2008: Ian Ballantine and Betty Ballantine; William Gibson; Richard M. Powers; Rod Serling
 * 2009: Edward L. Ferman; Michael Whelan; Frank R. Paul; Connie Willis
 * 2010: Octavia E. Butler; Richard Matheson; Douglas Trumbull; Roger Zelazny
 * 2011: Vincent Di Fate; Gardner Dozois; Harlan Ellison; Jean Giraud
 * 2012: Joe Haldeman; James Tiptree, Jr.; James Cameron; Virgil Finlay
 * 2013: H. R. Giger; Judith Merril; Joanna Russ; David Bowie; J. R. R. Tolkien
 * 2014: Frank Frazetta; Hayao Miyazaki; Leigh Brackett; Olaf Stapledon; Stanley Kubrick
 * 2015: James E. Gunn; Georges Méliès; John Schoenherr; Kurt Vonnegut; Jack Gaughan
 * 2016: Terry Pratchett; Douglas Adams; Star Trek; Blade Runner
 * 2017: J. K. Rowling; Stan Lee; The Legend of Zelda; Buffy the Vampire Slayer
 * 2018: Neil Gaiman; Vonda N. McIntyre; Doctor Who; Magic: The Gathering
 * 2019: Ted Chiang; D. C. Fontana; Star Wars; Watchmen
 * 2021: Nichelle Nichols; Sigourney Weaver; Godzilla; A Trip to the Moon
 * 2023: John Carpenter; N.K. Jemisin; Dune; The Rocky Horror Picture Show

20th anniversary
In 2016, the Hall of Fame's 20th anniversary year, the scope was changed again to include not only creators, but creations (from such genres as Cinema, Television and Games), with two examples. A total of 20 additional inductees in both categories were also announced:
 * Creators: Margaret Atwood; Keith David; Guillermo del Toro; Terry Gilliam; Jim Henson; Jack Kirby; Madeleine L'Engle; C. S. Lewis; H. P. Lovecraft; Leonard Nimoy; George Orwell; Rumiko Takahashi; John Williams
 * Works: 2001: A Space Odyssey; Dungeons & Dragons; The Matrix; Myst; The Princess Bride; Wonder Woman; The X-Files

The class of 2023 brought the number of members to 109, which includes the 20 additional inductees added in 2016.

In November of 2016, the museum changed its name from the Experience Music Project Museum to the Museum of Pop Culture, or MoPOP for short.

Architecture
MoPOP is located on the campus of Seattle Center, adjacent to the Space Needle and the Seattle Center Monorail, which runs through the building. The structure itself was designed by Frank Gehry and resembles many of his firm's other works in its sheet-metal construction, such as Guggenheim Museum Bilbao, Walt Disney Concert Hall, and Gehry Tower. Much of the building material is exposed in the building's interior. The building contains 140000 sqft, with a 35000 sqft footprint. The name of the museum's central Sky Church pays homage to Jimi Hendrix. A concert venue capable of holding up to 800 guests, the last structural steel beam to be put in place bears the signatures of all construction workers who were on site on the day it was erected. Hoffman Construction Company of Portland, Oregon, was the general contractor, while Magnusson Klemencic Associates of Seattle were the structural engineers for the project.

Even before groundbreaking, the Seattle Weekly said the design could refer to "the often quoted comparison to a smashed electric guitar." Gehry himself had in fact made the comparison: "We started collecting pictures of Stratocasters, bringing in guitar bodies, drawing on those shapes in developing our ideas." The architecture was greeted by Seattle residents with a mixture of acclaim for Gehry and derision for this particular edifice. British-born, Seattle-based writer Jonathan Raban remarked that "Frank Gehry has created some wonderful buildings, like the Guggenheim Museum in Bilbao, but his Seattle effort, the Experience Music Project, is not one of them." New York Times architecture critic Herbert Muschamp described it as "something that crawled out of the sea, rolled over, and died." Forbes magazine called it one of the world's 10 ugliest buildings. Others describe it as a "blob" or call it "The Hemorrhoids". Despite some critical reviews of the structure, the building has been called "a fitting backdrop for the world's largest collection of Jimi Hendrix memorabilia." The building's exterior, which features a fusion of textures and colors including gold, silver, deep red, blue and a "shimmering purple haze," has been declared "an apt representation of the American rock experience."

Finances
The museum has had mixed financial success. In an effort to raise more funds, museum organizers used Allen's extensive art collection to create a 2006 exhibit at the museum entitled DoubleTake: From Monet to Lichtenstein. The exhibit included Roy Lichtenstein's The Kiss (1962), Pierre-Auguste Renoir's The Reader (1877), Vincent van Gogh's Orchard with Peach Trees in Blossom (1888), Pablo Picasso's Four Bathers (1921) and several works of art from Claude Monet including one of the Water Lilies paintings (1919) and The Mula Palace (1908). Since then the museum has organized numerous exhibitions focused more specifically on popular culture, such as Sound and Vision: Artists Tell Their Stories, which opened February 28, 2007. This brought together both music and science fiction in a single exhibit, and drew on the museum's extensive collection of oral history recordings. The museum's recent exhibitions have ranged from horror cinema, video games, and black leather jackets to fantasy film and literature.

Founders Award
Since 2007, the Museum of Pop Culture's Founders Award has celebrated artists whose "noteworthy contributions continue to nurture the next generation of risk-takers". The annual benefit gala is key in funding the museum's educational programs, community engagement, and exhibitions. In 2020, due to the COVID-19 pandemic, the gala had to be cancelled and for the first time ever, the event was made free to the public, streaming online on December 1, 2020, as MoPOP honored Seattle's own Alice in Chains. The benefit streaming raised more than $600,000 for MoPOP in its first night. A compilation featuring highlights from the tribute was made available for streaming on Amazon Music.

 * Recipients
 * 2007: Ann & Nancy Wilson
 * 2008: Robbie Robertson
 * 2009: Steve Cropper
 * 2010: Billy Cox
 * 2011: Buddy Guy
 * 2012: Carlos Santana
 * 2013: Crosby, Stills & Nash
 * 2014: Jackson Browne
 * 2015: Jimmy Page
 * 2016: Joe Walsh
 * 2017: The Doors
 * 2018: John Fogerty
 * 2019: Brandi Carlile
 * 2020: Alice in Chains
 * 2022: Quincy Jones

title: Museum of Pop Culture


text:
Silly Symphony

Silly Symphony (also known as Silly Symphonies) is an American animated series of 75 musical short films produced by Walt Disney Productions from 1929 to 1939. As the series name implies, the Silly Symphonies were originally intended as whimsical accompaniments to pieces of music. As such, the films usually did not feature continuing characters, unlike the Mickey Mouse shorts produced by Disney at the same time (exceptions to this include Three Little Pigs, The Tortoise and the Hare, and Three Orphan Kittens, which all had sequels). The series is notable for its innovation with Technicolor and the multiplane motion picture camera, as well as its introduction of the character Donald Duck making his first appearance in the Silly Symphony cartoon The Wise Little Hen in 1934. Seven shorts won the Academy Award for Best Animated Short Film.

The series also spawned a Silly Symphony newspaper comic strip distributed by King Features Syndicate, as well as a Dell comic book series and several children's books.

The Silly Symphonies returned to theaters with its re-issues and re-releases, and eventually tied with Joseph Barbera and William Hanna's Tom and Jerry's record for most Oscar wins for a cartoon series in the Academy Award for Best Animated Short Film category.

Production
While Walt Disney and Carl Stalling, a theatre organist from Kansas City, were in New York to add sound to the Mickey Mouse shorts The Gallopin' Gaucho, The Barn Dance and Plane Crazy, Stalling suggested the idea of making a series of musical animated shorts that combined the latest sound technology with storytelling. At first Walt did not seem interested, but when they returned to New York in February to record the sound for a fifth Mickey Mouse cartoon, The Opry House, they also recorded the soundtrack for The Skeleton Dance, the type of short that Stalling had suggested and the first Silly Symphony cartoon.

Within the animation industry, the series is known for its use by Walt Disney as a platform for experimenting with processes, techniques, characters, and stories in order to further the art of animation. It also provided a venue to try out techniques and technologies, such as Technicolor, special effects animation, and dramatic storytelling in animation, that would be crucial to Disney's plans to eventually begin making feature-length animated films.

Shortly after the switch to United Artists, the series became even more popular. Walt Disney had seen some of Dr. Herbert Kalmus' tests for a new three-strip, full-color Technicolor process, which would replace the previous two-tone Technicolor process. Disney signed a contract with Technicolor which gave the Disney studio exclusive rights to the new three-strip process through the end of 1935, and had a 60% complete Symphony, Flowers and Trees, scrapped and redone in full color. Flowers and Trees was the first animated film to use the three-strip Technicolor process, and was a phenomenal success. Within a year, the now-in-Technicolor Silly Symphonies series had popularity and success that matched (and later surpassed) that of the Mickey Mouse cartoons. The contract Disney had with Technicolor would also later be extended another five years as well.

The success of Silly Symphonies would be tremendously boosted after Three Little Pigs was released in 1933 and became a box office sensation; the film was featured in movie theaters for several months and also featured the hit song that became the anthem of the Great Depression, "Who's Afraid of the Big Bad Wolf". Several Silly Symphonies entries, including Three Little Pigs (1933), The Grasshopper and the Ants (1934), The Tortoise and the Hare (1935), The Country Cousin (1936), The Old Mill (1937), Wynken, Blynken, and Nod (1938), and The Ugly Duckling (1939, with an earlier black-and-white version from 1931), are among the most notable films produced by Walt Disney.

Due to problems related to Disney's scheduled productions of cartoons, a deal was made with Harman and Ising to produce three Silly Symphonies: Merbabies, Pipe Dreams, and The Little Bantamweight. Only one of these cartoons, Merbabies, ended up being bought by Disney, the remaining two Harman-Ising Silly Symphonies were then sold to MGM who released them as Happy Harmonies cartoons. Disney ceased production of Silly Symphonies in 1939.

Distribution
The series was first distributed by Pat Powers from 1929 to 1930 and released by Celebrity Productions (1929–1930) indirectly through Columbia Pictures. The original basis of the cartoons was musical novelty, and the musical scores of the first cartoons were composed by Carl Stalling.

Columbia Pictures
After viewing "The Skeleton Dance", the manager at Columbia Pictures quickly became interested in distributing the series, and gained the perfect opportunity to acquire Silly Symphonies after Disney broke with Celebrity Productions head Pat Powers after Powers signed Disney's colleague Ub Iwerks to a studio contract. Columbia Pictures (1930–1932) agreed to pick up the direct distribution of the Mickey Mouse series on the condition that they would have exclusive rights to distribute the Silly Symphonies series; at first, Silly Symphonies could not even come close to the popularity Mickey Mouse had. The original title cards to the shorts released by Celebrity Productions and Columbia Pictures were all redrawn after Walt Disney stopped distributing his cartoons through them. Meanwhile, more competition spread for Disney after Max Fleischer's flapper cartoon character Betty Boop began to gain more and more popularity after starring in the cartoon Minnie the Moocher. By August 1932, Betty Boop became so popular that the Talkartoon series was renamed as Betty Boop cartoons.

United Artists
In 1932, after falling out with Columbia Pictures, Disney began distributing his products through United Artists. UA refused to distribute the Silly Symphonies unless Disney associated Mickey Mouse with them somehow, resulting in the "Mickey Mouse presents a Silly Symphony" title cards and posters that introduced and promoted the series during its five-year run for UA. United Artists also agreed to double the budget for each cartoon from $7,500 to $15,000.

RKO Radio Pictures
In 1937, Disney signed a distribution deal with RKO Radio Pictures to distribute the Silly Symphony cartoons, along with the Mickey Mouse series. RKO would continue to distribute until the end of the series in 1939.

Home media
Several Symphonies have been released in home media, most of the time as bonus shorts that relate to something within various Disney films. For instance, the original Dumbo VHS included Father Noah's Ark, The Practical Pig and Three Orphan Kittens as bonus shorts to make up for the film's short length. In the UK, several Silly Symphonies were released in compilations under Disney Videos' "Storybook Favourites" brand. The three "Storybook Favourites Shorts" volumes released included among others, The Three Little Pigs, The Tortoise and the Hare and the remake of The Ugly Duckling.

On December 4, 2001, Disney released "Silly Symphonies" as part of its DVD series "Walt Disney Treasures". On December 19, 2006, "More Silly Symphonies" was released, completing the collection and allowing the cartoons to be completely available to the public.

Some Disney Blu-ray discs include Silly Symphonies as high definition special features. Snow White and the Seven Dwarfs includes six, Beauty and the Beast and Dumbo both contain two and Pixar's A Bug's Life contains one.

The Silly Symphony shorts originally aired on Turner Classic Movies' period program block "Treasures from the Disney Vault".

Some Silly Symphony shorts are viewable on Disney+.

List of films
The Silly Symphonies are listed here in production order.

Reception
Disney's experiments were widely praised within the film industry, and the Silly Symphonies won the Academy Award for Best Animated Short Film seven times, maintaining a six-year-hold on the category after it was first introduced. This record was matched only by MGM's Tom and Jerry series during the 1940s and 1950s.

Legacy
The Symphonies changed the course of Disney Studio history when Walt's plans to direct his first feature cartoon became problematic after his warm-up to the task The Golden Touch was widely seen (even by Disney himself) as stiff and slowly paced. This motivated him to embrace his role as being the producer and providing creative oversight (especially of the story) for Snow White while tasking David Hand to handle the actual directing.

Silly Symphonies brought along many imitators, including Warner Bros. cartoon series Looney Tunes and Merrie Melodies, MGM's Happy Harmonies, and later, Universal's Swing Symphony.

Years later after the Silly Symphonies ended, Disney occasionally produced a handful of one-shot cartoons, playing the same style as the Silly Symphony series. Unlike the Silly Symphonies canon, most of these "Specials" have a narration, usually by Disney legend Sterling Holloway.

In the 1934 MGM film Hollywood Party, Mickey Mouse appears with Jimmy Durante, where they introduce The Hot Choc-late Soldiers.

The 1999–2000 television series Mickey Mouse Works used the Silly Symphonies title for some of its new cartoons, but unlike the original cartoons, these did feature continuing characters.

As of 2021, three of the Silly Symphony shorts (Three Little Pigs, The Old Mill, and Flowers and Trees), have been selected for preservation in the United States National Film Registry by the Library of Congress, for being "culturally, historically, or aesthetically significant".

Comic adaptations
A Sunday Silly Symphony comic strip ran in newspapers from January 10, 1932, to July 12, 1942. The strip featured adaptations of some of the Silly Symphony cartoons, including Birds of a Feather, The Robber Kitten, Elmer Elephant, Farmyard Symphony and Little Hiawatha. This strip began with a two-year sequence about Bucky Bug, a character based on the bugs in Bugs in Love.

There was also an occasional Silly Symphonies comic book, with nine issues published by Dell Comics from September 1952 to February 1959. The first issue of this anthology comic featured adaptations of some Silly Symphony cartoons, including The Grasshopper and the Ants, Three Little Pigs, The Goddess of Spring and Mother Pluto, but it also included non-Symphony cartoons like Mickey Mouse's Brave Little Tailor. By the third issue, there was almost no Symphony-related material in the book; the stories and activities were mostly based on other Disney shorts and feature films.

title: Silly Symphony


text:
Talk:Go professional

Keep or merge?
This article is silly. We should just integrate it into the Go (board game) entry (which already has half this content anyway) and delete it. --k.lee

 * Rather, it should be renamed to a more standard English entry such as professional Go play, with info from the overly large Go article incorporated. The Go article needs to be broken up. --The Cunctator

 * We should move it into the Go article if the subject page is unlikely to become much larger than it is currently.

 * However, I can see it expanded to contain a list of the major prizes, with current prize holders and brief bios of the major players. If this is done well, it would become large enough to justify its existence as a separate article.

 * In order to plan ahead, my vote would be to keep the subject page as it is. I also agree that the big Go article should be broken up. David 17:57 Oct 11, 2002 (UTC)

 * Just my 2c, I think it's a page that's needed (not only because I've linked to it externally). Sensei's Library, for example, has a lot of information and discussion about pros. It's part of the... culture of Internet go. And Hikaru no Go, which is how a lot of people recently have been introduced to go, is all about the pro scene (only a slight exaggeration). I don't too much mind the idea of changing the name to professional Go play as suggested by The Cunctator, but I feel personally that the core concept here is more about the professional Go scene than about the actual play of the game (after all, only the pros can really understand that). BenBildstein 10:12, 6 July 2007 (UTC)

 * I say the page should be kept, but updated and expanded with information about how the pro status is attained in different organisations. There is little or less information about that available in English. — Preceding unsigned comment added by 109.240.231.17 (talk) 08:25, 15 October 2011 (UTC)

External links modified
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Go is not declining?
The last paragraph of the introduction states that go is on a decline. I think this should be deleted because if anything, the new AI has boosted the interest in Go. Samwri (talk) 22:43, 11 July 2020 (UTC)

 * You're correct. The source offered no support to this claim, so I've removed it. Mattpartridge24 (talk) 19:52, 10 March 2022 (UTC)

title: Talk:Go professional


text:
Polyacrylamide gel electrophoresis

Polyacrylamide gel electrophoresis (PAGE) is a technique widely used in biochemistry, forensic chemistry, genetics, molecular biology and biotechnology to separate biological macromolecules, usually proteins or nucleic acids, according to their electrophoretic mobility. Electrophoretic mobility is a function of the length, conformation, and charge of the molecule. Polyacrylamide gel electrophoresis is a powerful tool used to analyze RNA samples. When polyacrylamide gel is denatured after electrophoresis, it provides information on the sample composition of the RNA species.

Hydration of acrylonitrile results in formation of acrylamide molecules (C3H5NO) by nitrile hydratase. Acrylamide monomer is in a powder state before addition of water. Acrylamide is toxic to the human nervous system, therefore all safety measures must be followed when working with it. Acrylamide is soluble in water and upon addition of free-radical initiators it polymerizes resulting in formation of polyacrylamide. It is useful to make polyacrylamide gel via acrylamide hydration because pore size can be regulated. Increased concentrations of acrylamide result in decreased pore size after polymerization. Polyacrylamide gel with small pores helps to examine smaller molecules better since the small molecules can enter the pores and travel through the gel while large molecules get trapped at the pore openings.

As with all forms of gel electrophoresis, molecules may be run in their native state, preserving the molecules' higher-order structure. This method is called native-PAGE. Alternatively, a chemical denaturant may be added to remove this structure and turn the molecule into an unstructured molecule whose mobility depends only on its length (because the protein-SDS complexes all have a similar mass-to-charge ratio). This procedure is called SDS-PAGE. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) is a method of separating molecules based on the difference of their molecular weight. At the pH at which gel electrophoresis is carried out the SDS molecules are negatively charged and bind to proteins in a set ratio, approximately one molecule of SDS for every 2 amino acids. In this way, the detergent provides all proteins with a uniform charge-to-mass ratio. By binding to the proteins the detergent destroys their secondary, tertiary and/or quaternary structure denaturing them and turning them into negatively charged linear polypeptide chains. When subjected to an electric field in PAGE, the negatively charged polypeptide chains travel toward the anode with different mobility. Their mobility, or the distance traveled by molecules, is inversely proportional to the logarithm of their molecular weight. By comparing the relative ratio of the distance traveled by each protein to the length of the gel (Rf) one can make conclusions about the relative molecular weight of the proteins, where the length of the gel is determined by the distance traveled by a small molecule like a tracking dye.

For nucleic acids, urea is the most commonly used denaturant. For proteins, sodium dodecyl sulfate (SDS) is an anionic detergent applied to protein samples to coat proteins in order to impart two negative charges (from every SDS molecule) to every two amino acids of the denatured protein. 2-Mercaptoethanol may also be used to disrupt the disulfide bonds found between the protein complexes, which helps further denature the protein. In most proteins, the binding of SDS to the polypeptide chains impart an even distribution of charge per unit mass, thereby resulting in a fractionation by approximate size during electrophoresis. Proteins that have a greater hydrophobic content – for instance, many membrane proteins, and those that interact with surfactants in their native environment – are intrinsically harder to treat accurately using this method, due to the greater variability in the ratio of bound SDS. Procedurally, using both Native and SDS-PAGE together can be used to purify and to separate the various subunits of the protein. Native-PAGE keeps the oligomeric form intact and will show a band on the gel that is representative of the level of activity. SDS-PAGE will denature and separate the oligomeric form into its monomers, showing bands that are representative of their molecular weights. These bands can be used to identify and assess the purity of the protein.

Sample preparation
Samples may be any material containing proteins or nucleic acids. These may be biologically derived, for example from prokaryotic or eukaryotic cells, tissues, viruses, environmental samples, or purified proteins. In the case of solid tissues or cells, these are often first broken down mechanically using a blender (for larger sample volumes), using a homogenizer (smaller volumes), by sonicator or by using cycling of high pressure, and a combination of biochemical and mechanical techniques – including various types of filtration and centrifugation – may be used to separate different cell compartments and organelles prior to electrophoresis. Synthetic biomolecules such as oligonucleotides may also be used as analytes.

The sample to analyze is optionally mixed with a chemical denaturant if so desired, usually SDS for proteins or urea for nucleic acids. SDS is an anionic detergent that denatures secondary and non–disulfide–linked tertiary structures, and additionally applies a negative charge to each protein in proportion to its mass. Urea breaks the hydrogen bonds between the base pairs of the nucleic acid, causing the constituent strands to separate. Heating the samples to at least 60 °C further promotes denaturation.

In addition to SDS, proteins may optionally be briefly heated to near boiling in the presence of a reducing agent, such as dithiothreitol (DTT) or 2-mercaptoethanol (beta-mercaptoethanol/BME), which further denatures the proteins by reducing disulfide linkages, thus overcoming some forms of tertiary protein folding, and breaking up quaternary protein structure (oligomeric subunits). This is known as reducing SDS-PAGE.

A tracking dye may be added to the solution. This typically has a higher electrophoretic mobility than the analytes to allow the experimenter to track the progress of the solution through the gel during the electrophoretic run.

Preparing acrylamide gels
The gels typically consist of acrylamide, bisacrylamide, the optional denaturant (SDS or urea), and a buffer with an adjusted pH. The solution may be degassed under a vacuum to prevent the formation of air bubbles during polymerization. Alternatively, butanol may be added to the resolving gel (for proteins) after it is poured, as butanol removes bubbles and makes the surface smooth. A source of free radicals and a stabilizer, such as ammonium persulfate and TEMED are added to initiate polymerization. The polymerization reaction creates a gel because of the added bisacrylamide, which can form cross-links between two acrylamide molecules. The ratio of bisacrylamide to acrylamide can be varied for special purposes, but is generally about 1 part in 35. The acrylamide concentration of the gel can also be varied, generally in the range from 5% to 25%. Lower percentage gels are better for resolving very high molecular weight molecules, while much higher percentages of acrylamide are needed to resolve smaller proteins. The average pore diameter of polyacrylamide gels is determined by the total concentration of acrylamides (% T with T = Total concentration of acrylamide and bisacrylamide) and the concentration of the cross-linker bisacrylamide (%C with C = bisacrylamide concentration). The pore size is reduced reciprocally to the %T. Concerning %C, a concentration of 5% produces the smallest pores, since the influence of bisacrylamide on the pore size has a parabola-shape with a vertex at 5%.

Gels are usually polymerized between two glass plates in a gel caster, with a comb inserted at the top to create the sample wells. After the gel is polymerized the comb can be removed and the gel is ready for electrophoresis.

Electrophoresis
Various buffer systems are used in PAGE depending on the nature of the sample and the experimental objective. The buffers used at the anode and cathode may be the same or different.

An electric field is applied across the gel, causing the negatively charged proteins or nucleic acids to migrate across the gel away from the negative electrode (which is the cathode being that this is an electrolytic rather than galvanic cell) and towards the positive electrode (the anode). Depending on their size, each biomolecule moves differently through the gel matrix: small molecules more easily fit through the pores in the gel, while larger ones have more difficulty. The gel is run usually for a few hours, though this depends on the voltage applied across the gel; migration occurs more quickly at higher voltages, but these results are typically less accurate than at those at lower voltages. After the set amount of time, the biomolecules have migrated different distances based on their size. Smaller biomolecules travel farther down the gel, while larger ones remain closer to the point of origin. Biomolecules may therefore be separated roughly according to size, which depends mainly on molecular weight under denaturing conditions, but also depends on higher-order conformation under native conditions. The gel mobility is defined as the rate of migration traveled with a voltage gradient of 1V/cm and has units of cm2/sec/V. For analytical purposes, the relative mobility of biomolecules, Rf, the ratio of the distance the molecule traveled on the gel to the total travel distance of a tracking dye is plotted versus the molecular weight of the molecule (or sometimes the log of MW, or rather the Mr, molecular radius). Such typically linear plots represent the standard markers or calibration curves that are widely used for the quantitative estimation of a variety of biomolecular sizes.

Certain glycoproteins, however, behave anomalously on SDS gels. Additionally, the analysis of larger proteins ranging from 250,000 to 600,000 Da is also reported to be problematic due to the fact that such polypeptides move improperly in the normally used gel systems.

Further processing

Following electrophoresis, the gel may be stained (for proteins, most commonly with Coomassie brilliant blue R-250 or autoradiography; for nucleic acids, ethidium bromide; or for either, silver stain), allowing visualization of the separated proteins, or processed further (e.g. Western blot). After staining, different species biomolecules appear as distinct bands within the gel. It is common to run molecular weight size markers of known molecular weight in a separate lane in the gel to calibrate the gel and determine the approximate molecular mass of unknown biomolecules by comparing the distance traveled relative to the marker.

For proteins, SDS-PAGE is usually the first choice as an assay of purity due to its reliability and ease. The presence of SDS and the denaturing step make proteins separate, approximately based on size, but aberrant migration of some proteins may occur. Different proteins may also stain differently, which interferes with quantification by staining. PAGE may also be used as a preparative technique for the purification of proteins. For example, preparative native PAGE is a method for separating native metalloproteins in complex biological matrices.

Chemical ingredients and their roles
Polyacrylamide gel (PAG) had been known as a potential embedding medium for sectioning tissues as early as 1964, and two independent groups employed PAG in electrophoresis in 1959. It possesses several electrophoretically desirable features that make it a versatile medium. It is a synthetic, thermo-stable, transparent, strong, chemically relatively inert gel, and can be prepared with a wide range of average pore sizes. The pore size of a gel and the reproducibility in gel pore size are determined by three factors, the total amount of acrylamide present (%T) (T = Total concentration of acrylamide and bisacrylamide monomer), the amount of cross-linker (%C) (C = bisacrylamide concentration), and the time of polymerization of acrylamide (cf. QPNC-PAGE). Pore size decreases with increasing %T; with cross-linking, 5%C gives the smallest pore size. Any increase or decrease in %C from 5% increases the pore size, as pore size with respect to %C is a parabolic function with vertex as 5%C. This appears to be because of non-homogeneous bundling of polymer strands within the gel. This gel material can also withstand high voltage gradients, is amenable to various staining and destaining procedures, and can be digested to extract separated fractions or dried for autoradiography and permanent recording.

Components
Polyacrylamide gels are composed of a stacking gel and separating gel. Stacking gels have a higher porosity relative to the separating gel, and allow for proteins to migrate in a concentrated area. Additionally, stacking gels usually have a pH of 6.8, since the neutral glycine molecules allow for faster protein mobility. Separating gels have a pH of 8.8, where the anionic glycine slows down the mobility of proteins. Separating gels allow for the separation of proteins and have a relatively lower porosity. Here, the proteins are separated based on size (in SDS-PAGE) and size/ charge (Native PAGE).

Chemical buffer stabilizes the pH value to the desired value within the gel itself and in the electrophoresis buffer. The choice of buffer also affects the electrophoretic mobility of the buffer counterions and thereby the resolution of the gel. The buffer should also be unreactive and not modify or react with most proteins. Different buffers may be used as cathode and anode buffers, respectively, depending on the application. Multiple pH values may be used within a single gel, for example in DISC electrophoresis. Common buffers in PAGE include Tris, Bis-Tris, or imidazole.

Counterion balance the intrinsic charge of the buffer ion and also affect the electric field strength during electrophoresis. Highly charged and mobile ions are often avoided in SDS-PAGE cathode buffers, but may be included in the gel itself, where it migrates ahead of the protein. In applications such as DISC SDS-PAGE the pH values within the gel may vary to change the average charge of the counterions during the run to improve resolution. Popular counterions are glycine and tricine. Glycine has been used as the source of trailing ion or slow ion because its pKa is 9.69 and mobility of glycinate are such that the effective mobility can be set at a value below that of the slowest known proteins of net negative charge in the pH range. The minimum pH of this range is approximately 8.0.

Acrylamide (C3H5NO; mW: 71.08) when dissolved in water, slow, spontaneous autopolymerization of acrylamide takes place, joining molecules together by head on tail fashion to form long single-chain polymers. The presence of a free radical-generating system greatly accelerates polymerization. This kind of reaction is known as vinyl addition polymerisation. A solution of these polymer chains becomes viscous but does not form a gel, because the chains simply slide over one another. Gel formation requires linking various chains together. Acrylamide is carcinogenic, a neurotoxin, and a reproductive toxin. It is also essential to store acrylamide in a cool dark and dry place to reduce autopolymerisation and hydrolysis.

Bisacrylamide (N,N′-Methylenebisacrylamide) (C7H10N2O2; mW: 154.17) is the most frequently used cross linking agent for polyacrylamide gels. Chemically it can be thought of as two acrylamide molecules coupled head to head at their non-reactive ends. Bisacrylamide can crosslink two polyacrylamide chains to one another, thereby resulting in a gel.

Sodium dodecyl sulfate (SDS) (C12H25NaO4S; mW: 288.38) (only used in denaturing protein gels) is a strong detergent agent used to denature native proteins to individual polypeptides. This denaturation, which is referred to as reconstructive denaturation, is not accomplished by the total linearization of the protein, but instead, through a conformational change to a combination of random coil and α helix secondary structures. When a protein mixture is heated to 100 °C in presence of SDS, the detergent wraps around the polypeptide backbone. It binds to polypeptides in a constant weight ratio of 1.4 g SDS/g of polypeptide. In this process, the intrinsic charges of polypeptides become negligible when compared to the negative charges contributed by SDS. Thus polypeptides after treatment become rod-like structures possessing a uniform charge density, that is same net negative charge per unit weight. The electrophoretic mobilities of these proteins is a linear function of the logarithms of their molecular weights. Without SDS, different proteins with similar molecular weights would migrate differently due to differences in mass-charge ratio, as each protein has an isoelectric point and molecular weight particular to its primary structure. This is known as native PAGE. Adding SDS solves this problem, as it binds to and unfolds the protein, giving a near uniform negative charge along the length of the polypeptide.

Urea (CO(NH2)2; mW: 60.06) is a chaotropic agent that increases the entropy of the system by interfering with intramolecular interactions mediated by non-covalent forces such as hydrogen bonds and van der Waals forces. Macromolecular structure is dependent on the net effect of these forces, therefore it follows that an increase in chaotropic solutes denatures macromolecules,

Ammonium persulfate (APS) (N2H8S2O8; mW: 228.2) is a source of free radicals and is often used as an initiator for gel formation. An alternative source of free radicals is riboflavin, which generated free radicals in a photochemical reaction.

TEMED (N, N, N′, N′-tetramethylethylenediamine) (C6H16N2; mW: 116.21) stabilizes free radicals and improves polymerization. The rate of polymerisation and the properties of the resulting gel depend on the concentrations of free radicals. Increasing the amount of free radicals results in a decrease in the average polymer chain length, an increase in gel turbidity and a decrease in gel elasticity. Decreasing the amount shows the reverse effect. The lowest catalytic concentrations that allow polymerisation in a reasonable period of time should be used. APS and TEMED are typically used at approximately equimolar concentrations in the range of 1 to 10 mM.

Chemicals for processing and visualization
The following chemicals and procedures are used for processing of the gel and the protein samples visualized in it.

Tracking dye; as proteins and nucleic acids are mostly colorless, their progress through the gel during electrophoresis cannot be easily followed. Anionic dyes of a known electrophoretic mobility are therefore usually included in the PAGE sample buffer. A very common tracking dye is Bromophenol blue (BPB, 3',3",5',5" tetrabromophenolsulfonphthalein). This dye is coloured at alkali and neutral pH and is a small negatively charged molecule that moves towards the anode. Being a highly mobile molecule it moves ahead of most proteins. As it reaches the anodic end of the electrophoresis medium electrophoresis is stopped. It can weakly bind to some proteins and impart a blue colour. Other common tracking dyes are xylene cyanol, which has lower mobility, and Orange G, which has a higher mobility.

Loading aids; most PAGE systems are loaded from the top into wells within the gel. To ensure that the sample sinks to the bottom of the gel, sample buffer is supplemented with additives that increase the density of the sample. These additives should be non-ionic and non-reactive towards proteins to avoid interfering with electrophoresis. Common additives are glycerol and sucrose.

Coomassie brilliant blue R-250 (CBB)(C45H44N3NaO7S2; mW: 825.97) is the most popular protein stain. It is an anionic dye, which non-specifically binds to proteins. The structure of CBB is predominantly non-polar, and it is usually used in methanolic solution acidified with acetic acid. Proteins in the gel are fixed by acetic acid and simultaneously stained. The excess dye incorporated into the gel can be removed by destaining with the same solution without the dye. The proteins are detected as blue bands on a clear background. As SDS is also anionic, it may interfere with staining process. Therefore, large volume of staining solution is recommended, at least ten times the volume of the gel.

Ethidium bromide (EtBr) is a popular nucleic acid stain. EtBr allows one to easily visualize DNA or RNA on a gel as EtBr fluoresces an orange color under UV light. Ethidium bromide binds nucleic acid chains through the process of Intercalation. While Ethidium bromide is a popular stain it is important to exercise caution when using EtBr as it is a known carcinogen. Because of this fact, many researchers opt to use stains such as SYBR Green and SYBR Safe which are safer alternatives to EtBr. EtBr is used by simply adding it to the gel mixture. Once the gel has run, the gel may be viewed through the use of a photo-documentation system.

Silver staining is used when more sensitive method for detection is needed, as classical Coomassie Brilliant Blue staining can usually detect a 50 ng protein band, Silver staining increases the sensitivity typically 10-100 fold more. This is based on the chemistry of photographic development. The proteins are fixed to the gel with a dilute methanol solution, then incubated with an acidic silver nitrate solution. Silver ions are reduced to their metallic form by formaldehyde at alkaline pH. An acidic solution, such as acetic acid stops development. Silver staining was introduced by Kerenyi and Gallyas as a sensitive procedure to detect trace amounts of proteins in gels. The technique has been extended to the study of other biological macromolecules that have been separated in a variety of supports. Many variables can influence the colour intensity and every protein has its own staining characteristics; clean glassware, pure reagents and water of highest purity are the key points to successful staining. Silver staining was developed in the 14th century for colouring the surface of glass. It has been used extensively for this purpose since the 16th century. The colour produced by the early silver stains ranged between light yellow and an orange-red. Camillo Golgi perfected the silver staining for the study of the nervous system. Golgi's method stains a limited number of cells at random in their entirety.

Autoradiography, also used for protein band detection post gel electrophoresis, uses radioactive isotopes to label proteins, which are then detected by using X-ray film.

Western blotting is a process by which proteins separated in the acrylamide gel are electrophoretically transferred to a stable, manipulable membrane such as a nitrocellulose, nylon, or PVDF membrane. It is then possible to apply immunochemical techniques to visualise the transferred proteins, as well as accurately identify relative increases or decreases of the protein of interest.

title: Polyacrylamide gel electrophoresis