Conducting scientific experiments is what scientists do most of their working time. It is as a result of experiments that they make discoveries that tell interesting details about the structure of the world around us. Experiments usually take several weeks or months, but some last for many years. For example, this is thedripping pitch experimenton measuring the flow time of bitumen at the University of Queensland (Australia). Pitch is a residue from the distillation of coal tar and appears as a solid substance. The authors of this study wanted to show that even things that appear to be solid can actually be highly viscous liquids. The experiment has been going on for almost a hundred years, and you can watch it live during the winter.
American physicist John Mainstone watches the falling bitumen. Photo source: peoples.ru
Experience with falling pitch
The longest experiment according to the Guinness Book of Records was started in 1927 by Australian physics professor Thomas Parnell. To demonstrate the properties of highly viscous materials, he took residues from the distillation of coal tar. The professor heated them and placed them in a glass funnel – it took three years for the material to take the shape of the vessel.
The girl holds a piece of paper with the dates of the falling drops of pitch. Photo source: The University of Queensland
In 1930, a researcher cut off the bottom of the funnel, allowing the highly viscous liquid to slowly flow into a vessel mounted underneath. Need I say that drops of extremely viscous material took a very long time to form? The first drop of bitumen fell into the vessel eight years after the start of the experiment. Subsequently, drops formed approximately once every ten years. The drop fell for the ninth time in 2014, but the cameras were too weak to capture the moment. To date, no one has yet witnessed this event.
The cameras tried to capture the moment the drop fell, but failed
The longest experiment in history
The experiment has been going on for almost a hundred years. Professor Thomas Parnell and his assistant John Mainstone have already died, so Andrew White is now overseeing the project. The funnel with the viscous material is located under a glass flask so that the process is not affected by external conditions. Several webcams are directed at this cone, which broadcast live daily on the University of Queensland website.
This broadcast does not have many viewers, because 99% of the time nothing happens there. This spectacle can be compared to the British film “Paint Drying”, which shows a wall of drying paint for 10 hours. Only in the case of a drop of bitumen, the effect continues for many years. However, viewers have a small chance to see with their own eyes the moment the viscous mass falls into the vessel. But who needs it?
You can watch a live broadcast of the experiment with dripping pitch on the university website
It is noteworthy that since 1988, the experiment began to last longer than usual. Until this moment, the temperature in the room where the vessel stood was constantly changing, which is why the drops fell at intervals of 8-10 years. Then an air conditioner was installed in the room to maintain the same temperature, so now drops are formed with a frequency of 12-14 years.
To date, the experiment has only shown that coal smog residue has a viscosity approximately 230 billion times greater than by the water.
Rosenhan's experiment:how to get into a madhouse?
The longest experiment with weeds
Another very long experiment is being conducted at the University of Michigan. In 1879, botany professor William James Beall filled twenty whiskey bottles with wet sand and placed seeds from 21 types of weeds. He buried them upside down to prevent water from getting inside – the purpose of the experiment was to test how resilient the weeds are.
The researcher, and then the scientists who took over his work, dug up one bottle every few years. Gradually they increased the time between studying each vessel. The fifteenth bottle was only dug up in 2000, the next one will not be recovered until 2100.
Another experiment in the world lasts more than 100 years, but is not included in the Guinness Book of Records . Photo source: atlasobscura.com
So far, the experiment has helped identify the most resilient weed species. Scientists are already trying to figure out why they can survive for decades.
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The experiments described above are extremely safe. But sometimes scientific experiments lead to terrible consequences – for example, the story of the Universe-25 experiment is especially shocking. It ended with the subjects engaging in cannibalism, so it’s good that the experiment was carried out on mice.