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Did you know the world’s longest-running lab experiment started in 1927... and it’s still going today? 🤯

In this video, we dive into the mind-bending physics of the famous Pitch Drop Experiment at the University of Queensland. How can a substance that feels like solid rock and shatters under a hammer actually be a liquid? We explore the bizarre science of high viscosity, the history of Thomas Parnell's incredible setup, and the tragic yet hilarious story of the scientist who watched it for 50 years—but missed every single drop!

💧 When do you think the next drop will fall? Let us know in the comments below!

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Learning
Transcript
00:00For almost a century, researchers have been running a single, continuous experiment to prove something that sounds entirely impossible —
00:09that a substance you can shatter with a hammer is actually one of the slowest-moving liquids on Earth.
00:15The setup began in 1927 at the University of Queensland.
00:20Physicist Thomas Parnell realized his students were trapped in a rigid way of thinking, assuming that solid and liquid were
00:27permanent, obvious categories.
00:28He wanted a demonstration that would break those assumptions.
00:32Parnell heated a batch of pitch — a derivative of tar and asphalt — and poured it into a sealed
00:37glass funnel.
00:38He let it sit for three years to allow the material to cool and settle completely, before finally cutting the
00:45stem to let gravity begin its work.
00:47To appreciate the weight, you have to understand pitch at room temperature.
00:51To the touch, it feels like a heavy, brittle rock. Strike it hard enough, and it fractures into sharp, jagged
00:57pieces.
00:57What began as a classroom demonstration became a generational test of patience.
01:03It suggests that whether we call a substance a solid or a liquid depends less on its immediate texture,
01:10and more on the timescale we use to observe it.
01:13The engine driving this experiment is a property called viscosity.
01:17Simply put, viscosity is a measure of how strongly a fluid resists flowing.
01:22This diagram shows the scale in action.
01:25Water flows quickly and easily, while honey provides much more resistance, moving in a thick, sluggish stream.
01:32Pitch sits at the absolute bottom of this scale.
01:35Its resistance to flow is so immense that gravity needs over a decade to pull a single, heavy drop away
01:41from the tip of the glass funnel.
01:42For decades, the drops fell on a reliable schedule of about once every eight or nine years.
01:48But eventually, the intervals between those drops began stretching out to twelve years and beyond.
01:53The delay was caused by a change in the environment.
01:55In the 1980s, the university installed air conditioning in the building.
02:01Cooling the room by just a few degrees thickened the pitch and slowed the flow even further.
02:07Because of its extreme viscosity, the pitch is sensitive to the slightest thermal shifts.
02:12A minor upgrade for human comfort was enough to disrupt the physics of a century-long study.
02:18Observing an experiment this slow requires a dedicated human element.
02:23Physicist John Mainstone took on the role, becoming the funnel's custodian for over half a century.
02:29Despite fifty years of continuous oversight, Mainstone never personally saw a single drop detach.
02:36One drop silently separated and fell over a weekend while the laboratory was empty.
02:41Years later, during a public exhibition of the experiment, Mainstone stepped away for a moment to grab a drink.
02:47By the time he returned, the drop had already hit the bottom of the beaker.
02:51In 2000, researchers tried solving the problem with a live webcam trained on the eighth drop.
02:57However, a local thunderstorm triggered a power failure, resulting in a dark screen and another missed data point.
03:05Mainstone's career highlights the friction between human planning and physical reality.
03:10We can maintain a single experiment for a century,
03:13but the actual event of the drop remains completely elusive.
03:18Mainstone passed away in 2013, just eight months before the ninth drop finally fell.
03:24He and Parnell were eventually awarded a shared Ig Nobel Prize,
03:28a parodic award for research that first makes people laugh and then makes them think.
03:34Custodianship passed to Professor Andrew White, who faced a practical challenge.
03:38He had to swap out the glass beaker below the funnel to ensure the pile of old drops didn't fuse
03:44with the newly forming tenth drop.
03:46A major milestone is approaching.
03:48The year 2027 marks exactly 100 years since Thomas Parnell first heated his pitch and filled that funnel.
03:56The apparatus has evolved from a lab curiosity into a global digital phenomenon.
04:01Thousands of people now watch a continuous livestream of the funnel, hoping to be the ones to witness the tenth
04:08drop.
04:08The pitch drop remains a monument to the value of scientific patients, proving that a simple vision can transcend individual
04:16careers.
04:17If you have the patience to wait a decade for a single drop of data, hit the like button, subscribe,
04:23and tell us in the comments what you think the next century will reveal.
04:27.
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