Editing Pitch drop experiment (section)

==University of Queensland experiment==
[[Image:Pitch drop experiment with John Mainstone.jpg|thumb|left|The [[University of Queensland]] pitch drop experiment, featuring its custodian, John Mainstone (taken in 1990, two years after the seventh drop and 10&nbsp;years before the eighth drop fell).]]
The best-known version<ref name=" BBC1" /> of the [[experiment]] was started in 1927 by [[Thomas Parnell (scientist)|Thomas Parnell]] of the [[University of Queensland]] in [[Brisbane]], Australia, to demonstrate to students that some substances which appear solid are highly viscous fluids.<ref name="NS_Queensland">{{cite journal |title=Feedback |journal=New Scientist |date=15 November 1984 |page=38|issn=0028-6664 |url=https://books.google.com/books?id=siZ1j_5wdqwC&pg=PA38 |access-date=5 May 2023 }}</ref> Parnell poured a heated sample of the pitch into a sealed [[funnel]] and allowed it to settle for three years.<ref name="EurJPhys_Queensland">{{cite journal |first1=R |last1=Edgeworth |first2=B J |last2=Dalton |first3=T |last3=Parnell |title=The pitch drop experiment |year=1984 |journal=European Journal of Physics |volume=5 |issue=4 |pages=198–200 |doi=10.1088/0143-0807/5/4/003 |bibcode=1984EJPh....5..198E |s2cid=250769509 |url=https://iopscience.iop.org/article/10.1088/0143-0807/5/4/003 |url-access=subscription }}</ref> In 1930, the seal at the neck of the funnel was cut, allowing the pitch to start flowing. A glass dome covers the funnel and it is placed on display outside a lecture theatre.<ref name="life">{{Cite news|author=Dalton|first=Trent|date=6 April 2013|title=Pitch fever|newspaper=The Australian|url=http://www.theaustralian.com.au/news/features/pitch-fever/story-e6frg8h6-1226613215795|url-status=dead|access-date=9 July 2013|archive-url=https://web.archive.org/web/20130406075404/http://www.theaustralian.com.au/news/features/pitch-fever/story-e6frg8h6-1226613215795|archive-date=6 April 2013}}</ref> Each droplet forms and falls over a period of about a [[decade]].

Between 1961 and 2013, the experiment was supervised by John Mainstone {{small|{{bracket|[[:de:John Mainstone|de]]}}}}.

The seventh drop fell at approximately 4:45&nbsp;p.m. on 3 July 1988, while the experiment was on display at Brisbane's [[World Expo 88]]. However, apparently no one witnessed the drop fall itself;<ref>[https://www.newspapers.com/clip/113380954/ Just a drip – but what great timing], ''[[Sydney Morning Herald]]'', 16 July 1988, page 3.</ref> Mainstone had stepped out to get a drink at the moment it occurred.<ref name=" BBC1" />

The eighth drop fell on 28 November 2000, allowing experimenters to calculate the pitch as having a [[viscosity]] of approximately 230&nbsp;[[1,000,000,000|billion]] times that of [[water]].<ref name="pitchdrop">{{cite web|last1=Edgeworth|first1=R.|last2=Dalton|first2=B.J.|last3=Parnell|first3=T.|title=The Pitch Drop Experiment|url=http://www.physics.uq.edu.au/physics_museum/pitchdrop.shtml|url-status=dead|archive-url=https://web.archive.org/web/20130328064508/http://www.physics.uq.edu.au/physics_museum/pitchdrop.shtml|archive-date=28 March 2013|access-date=15 October 2007|publisher=The University of Queensland Australia}}</ref>

This experiment is recorded in [[Guinness World Records]] as the "world's longest continuously running laboratory experiment",<ref name="smp.uq.edu.au">{{cite web|title=The Pitch Drop Experiment|url=http://smp.uq.edu.au/content/pitch-drop-experiment|url-status=live|archive-url=https://web.archive.org/web/20200615174548/https://smp.uq.edu.au/pitch-drop-experiment|archive-date=15 June 2020|access-date=17 August 2016|website=The University of Queensland Australia: School of Mathematics and Physics|date=6 January 2016}}</ref> and it is expected there is enough pitch in the funnel to allow it to continue for at least another hundred years. This experiment is predated by two other (still-active) scientific devices, the [[Oxford Electric Bell]] (1840) and the [[Beverly Clock]] (1864), but each of these has experienced brief interruptions since 1937.

The experiment was not originally carried out under any special controlled atmospheric conditions, meaning the viscosity could vary throughout the year with fluctuations in [[temperature]].  Sometime after the seventh drop fell (1988), air conditioning was added to the location where the experiment takes place. The lower average temperature has lengthened each drop's stretch before it separates from the rest of the pitch in the funnel, and correspondingly the typical interval between drops has increased from eight years to 12–13 years.

In October 2005, Mainstone and Parnell were awarded the [[Ig Nobel Prize]] in physics, a parody of the [[Nobel Prize]], for the pitch drop experiment.<ref name="VPsJL">[http://improbable.com/ig/winners/#ig2005 The 2005 Ig Nobel prize winners]. Improbable Research. Retrieved 6 July 2013.</ref> Mainstone subsequently commented:

{{blockquote|I am sure that Thomas Parnell would have been flattered to know that Mark Henderson considers him worthy to become a recipient of an Ig&nbsp;Nobel prize. Professor Parnell's award citation would of course have to applaud the new record he had thereby established for the longest lead-time between the performance of a seminal scientific experiment and the conferral of such an award, be it a Nobel or an Ig&nbsp;Nobel prize.<ref name="Mainstone-Ig">{{cite web |url=http://smp.uq.edu.au/content/comment-professor-mainstone |title=A Comment from Professor Mainstone |last=Mainstone |first=John |publisher=[[University of Queensland]] |access-date=5 November 2012 |url-status=dead |archive-url=https://web.archive.org/web/20121115170011/http://smp.uq.edu.au/content/comment-professor-mainstone |archive-date=15 November 2012}}</ref>}}

The experiment is monitored by a [[webcam]]<ref name="thetenthwatch.com">{{Cite web|url=http://www.thetenthwatch.com/|title=The Tenth Watch for the ninth Pitch Drop}}</ref> but technical problems prevented the November 2000 drop from being recorded.<ref name="smp.uq.edu.au" /> The pitch drop experiment is on public display on Level&nbsp;2 of Parnell building in the [[School of Mathematics and Physics]] at the [[St Lucia, Queensland|St Lucia]] campus of the [[University of Queensland]]. Hundreds of thousands of Internet users check the live stream each year.<ref name="life" />

John Mainstone died on 13 August 2013, aged 78, following a [[stroke]].<ref name="xkAbQ">{{cite web|last=Helsel|first=Phil|date=27 August 2013|title=Professor in charge of famous 'Pitch Drop' experiment for 50 years dies waiting to see it in action|url=http://www.nypost.com/p/news/international/professor_never_charge_event_famous_AKmMGqJi1lfJ0J3xbxW8fJ|url-status=live|archive-url=https://web.archive.org/web/20200615174812/https://nypost.com/2013/08/27/professor-in-charge-of-famous-pitch-drop-experiment-for-50-years-dies-waiting-to-see-it-in-action/|archive-date=15 June 2020|access-date=27 August 2013|work=New York Post}}</ref> Custodianship then passed to Andrew White.<ref name="calligeros">{{Cite web|last=Calligeros|first=Marissa|date=27 August 2013|title=Pitch drop has new custodian after physicist's death|url=https://www.brisbanetimes.com.au/national/queensland/pitch-drop-has-new-custodian-after-physicists-death-20130827-2sne4.html|url-status=live|archive-url=https://web.archive.org/web/20200615174951/https://www.brisbanetimes.com.au/national/queensland/pitch-drop-has-new-custodian-after-physicists-death-20130827-2sne4.html|archive-date=15 June 2020|access-date=15 June 2020|website=Brisbane Times|language=en}}</ref>

The ninth drop touched the eighth drop on 12 April 2014;<ref name="www.uq.edu.au_news">{{cite web|date=17 April 2014|title=Pitch drop touches down – oh so gently|url=http://www.uq.edu.au/news/article/2014/04/pitch-drop-touches-down-%E2%80%93-oh-so-gently|url-status=live|archive-url=https://web.archive.org/web/20200615175106/http://www.uq.edu.au/news/article/2014/04/pitch-drop-touches-down-%E2%80%93-oh-so-gently|archive-date=15 June 2020|access-date=19 April 2014|publisher=The University of Queensland Australia}}</ref><ref name="usRFt">{{cite news|author=Cantor|first=Matt|date=18 April 2014|title=Big News in World's Longest Experiment, Drop of pitch falls after 13 years of waiting|work=Newser|publisher=[[Newser.com]]|url=http://www.newser.com/story/185539/big-news-in-worlds-longest-experiment.html|url-status=dead|access-date=18 April 2014|archive-url=https://web.archive.org/web/20140418191701/http://www.newser.com/story/185539/big-news-in-worlds-longest-experiment.html|archive-date=18 April 2014}}</ref><ref name="theconversation.com">{{cite web|date=10 November 2014|title=Explainer: the pitch drop experiment|url=https://theconversation.com/explainer-the-pitch-drop-experiment-33734|url-status=live|archive-url=https://web.archive.org/web/20141213123150/https://theconversation.com/explainer-the-pitch-drop-experiment-33734|archive-date=13 December 2014|publisher=[[The Conversation (website)|The Conversation]]}}</ref> however, it was still attached to the funnel. On 24 April, Professor White decided to replace the beaker holding the previous eight drops before the ninth drop fused to them (which would have permanently affected the ability of further drops to form). While the bell jar was being lifted, the wooden base wobbled and the ninth drop snapped away from the funnel.<ref name="ninthdrop">{{cite news|last1=White|first1=Andrew|last2=Baglot|first2=Julie|date=24 April 2014|title=Pitch Drop Experiment enters an exciting new era|publisher=The University of Queensland Australia|url=http://www.uq.edu.au/news/article/2014/04/pitch-drop-experiment-enters-exciting-new-era|url-status=live|access-date=25 April 2014|archive-url=https://web.archive.org/web/20200615175538/http://www.uq.edu.au/news/article/2014/04/pitch-drop-experiment-enters-exciting-new-era|archive-date=15 June 2020}}</ref>

===Timeline===
Timeline for the University of Queensland experiment:

{| class="wikitable"
! rowspan="2" | Date
! rowspan="2" | Event
!colspan="3"| Duration
|-
!Years
!Months
!Bar chart
|-
| align="right" |1927||Hot pitch poured|| colspan="3" |
|-
| align="right" |October 1930||Stem cut|| colspan="3" |
|-
| align="right" |December 1938||1st drop fell||8.1|| {{bartable|98}}
|-
| align="right" |February 1947||2nd drop fell||8.2||  {{bartable|99}}
|-
| align="right" |April 1954||3rd drop fell||7.2||  {{bartable|86}}
|-
| align="right" |May 1962||4th drop fell||8.1||  {{bartable|97}}
|-
| align="right" |August 1970||5th drop fell||8.3||  {{bartable|99}}
|-
| align="right" |April 1979||6th drop fell||8.7||  {{bartable|104}}
|-
| align="right" |July 1988||7th drop fell||9.2||  {{bartable|111}}
|-
| align="right" |November 2000||8th drop fell{{efn-ua|After the 7th drop, air conditioning was installed, lowering the average temperature.}} ||12.3||  {{bartable|148}}
|-
| align="right" |April 2014||9th drop fell{{efn-ua|12 April 2014: 9th drop touched 8th drop; 24 April 2014: 9th drop separated from funnel during beaker change.}}||13.4||  {{bartable|161}}
|}
{{notelist-ua}}