Inside a glass bell jar at the University of Queensland in Brisbane, a dark mass of pitch has been shifting almost unnoticed through a funnel since its sealed stem was sliced in 1930. Thomas Parnell initiated the experiment in 1927, and nine drops have been documented since then. No individual has witnessed the moment one of the Queensland drops fell freely from the funnel. <\/p>\n
Parnell, UQ\u2019s inaugural professor of physics, aimed to illustrate that a substance sturdy enough to break under a hammer at room temperature could also flow. He warmed a sample of pitch, poured it into a glass funnel with a sealed stem, and let it settle for three years. In 1930, he unsealed the stem and allowed gravity to commence its function. <\/p>\n
Parnell passed away in 1948. By that time, the first two drops had reached the beaker, but he had not observed either one fall. <\/p>\n
## What is actually in the jar<\/p>\n
The setup is modest. A glass funnel is clamped above a beaker, with the entire arrangement enclosed within a bell jar. The black pitch hangs from the funnel in a lengthy tendril that appears solid when observed over minutes or hours. <\/p>\n
A 1984 analysis published in the European Journal of Physics estimated the pitch\u2019s viscosity to be around 2.3 \u00d7 10^8 pascal-seconds, or roughly 230 billion times that of water at 20\u00b0C. This estimation carried considerable uncertainty because the funnel could not be assessed accurately without jeopardizing the experiment. <\/p>\n
Pitch functions as an extremely viscous fluid over extended periods, even though it feels solid and can break when struck abruptly. A drop gradually forms, elongates, and ultimately disconnects from the material above. Temperature is significant as well. Initial drops appeared approximately seven to nine years apart, whereas subsequent drops took longer following adjustments in the building\u2019s temperature conditions. <\/p>\n
## The chronicle of missed appointments<\/p>\n
The recorded dates span across generations. The first drop fell in December 1938, eight years after the stem was unsealed. The following drops were logged in 1947, 1954, 1962, 1970, 1979, 1988, 2000, and 2014. <\/p>\n
John Mainstone became the experiment\u2019s second custodian in 1961 and cared for it for 52 years. In 1988, he briefly left for five minutes while the experiment was on display at Brisbane\u2019s World Expo. In 2000, a 20-minute power interruption hindered the monitoring camera from recording the pivotal moment of the eighth drop\u2019s detachment. <\/p>\n
Mainstone and Parnell jointly received the 2005 Ig Nobel Prize in physics, with Parnell being awarded the honor posthumously. Mainstone continued to oversee the experiment until his passing in August 2013. <\/p>\n
## The one that fell in Dublin<\/p>\n
An alternate pitch-drop demonstration was set up at Trinity College Dublin in October 1944 by an unknown individual. On 11 July 2013, physicists Shane Bergin and Stefan Hutzler successfully captured a drop detaching and falling on video. Trinity claims it was the first successful documentation of such an occurrence. <\/p>\n
The footage displays a gradual separation followed by a sudden drop into the container below. Mainstone viewed and repeatedly analyzed the Dublin recording prior to his death about six weeks later. <\/p>\n
Queensland\u2019s ninth drop acted differently. In April 2014, it made contact with the eighth drop instead of breaking away. Researchers deduced the date of contact from variations in its descent rate since the intersection was obscured from the cameras. <\/p>\n
On 24 April, custodian Andrew White sought to replace the beaker. The apparatus briefly lifted when the deteriorated seal beneath the bell jar resisted, and the resulting movement detached the ninth drop\u2019s stem from the funnel. It is counted as the ninth drop, although it was not an ordinary, freely falling event captured by a webcam. <\/p>\n
## Why the falls are so easily missed<\/p>\n
A drop forms over about a decade, while its ultimate separation can occur in mere moments. For any given observer, the probability of looking at the funnel at exactly the right moment is minimal. The eighth drop also demonstrated that continuous monitoring equipment can fail at precisely the wrong time. <\/p>\n
The ninth drop presented a different challenge. Since it contacted the older pitch below instead of falling freely, there was no abrupt motion for an observer to detect. Even multiple cameras were unable to reveal a specific instant of contact without later analysis. <\/p>\n
Human focus is attuned to changes occurring over seconds and minutes. The Queensland experiment operates on a timeline of years and decades. <\/p>\n
## What the experiment is really for<\/p>\n
Guinness World Records recognizes the setup as the longest-running laboratory experiment. It began as a demonstration for a lecture, but it has also yielded a published viscosity estimation and a chronicle of the pitch\u2019s uneven flow. <\/p>\n
Its scientific contributions are limited rather than nonexistent. The 1984 paper utilized<\/p>\n","protected":false},"excerpt":{"rendered":"
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