A lecture about an experiment

A lecture about an experiment

Listen to the lecture about a science experiment to practise and improve your listening skills.

Do the preparation task first. Then listen to the audio and do the exercises.


In today's lecture we're going to be talking about experiments, and I thought it might be interesting for you all to learn about the world's oldest continuously running laboratory experiment that is still going today. In fact, it holds the Guinness World Record for being the longest-running experiment. This experiment began in 1927 and has been going ever since.

It's called the 'pitch drop' experiment and it was created by Professor Thomas Parnell at the University of Queensland, Australia. Parnell was the university's first physics professor, and he wanted to show in this experiment that everyday materials, such as pitch, can have quite surprising properties.

You see, when pitch is at room temperature, it feels solid. You can easily break it with a hammer. However, it isn't in fact solid. At room temperature, pitch is many billions of times more viscous than water, but it's actually fluid.

In 1927, Professor Parnell took a sample of pitch. He heated it and poured it into a glass funnel. He allowed the pitch to cool and settle – for three years. He then turned the funnel upside down and cut the top off it.

Since then, the pitch has slowly dropped out of the funnel. How slowly? Well, the first drop took eight years to fall. It took another forty years for another five drops to fall. Today it's been almost 90 years since the experiment started. Only nine drops have fallen from the funnel. The last drop fell in April 2014 and the next one is expected to fall in the 2020s.

The experiment has a tragic story associated with it. Professor Parnell died without seeing a pitch drop. His replacement, Professor John Mainstone, became responsible for the pitch drop experiment from 1961. He held the job for 52 years, and missed seeing the drop fall three times – by a day in 1977, by just five minutes in 1988 and finally in 2000, when the webcam that was recording the experiment suffered a power outage for 20 minutes, during which time the pitch dropped.

The pitch drop experiment is something we can all participate in now. There's a live web stream that allows anyone to watch the glass funnel and wait for the fateful moment. A similar experiment to the Queensland pitch drop was set up in Dublin, and the video of the moment the pitch actually dropped went viral on the internet. It's interesting to see how a very slow event can spread news so quickly.

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Submitted by swaminathan on Thu, 23/01/2020 - 06:48

this really an ausome thing which i have never met with this type of a think which is interesting biggggg!!!!!!! fan now on words 4 ur course

Submitted by nikisyazwani on Mon, 30/09/2019 - 07:07

I have completed A Lecture About Experiment. The level I chose was Upper Intermediate B2.
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Submitted by Magedelabd on Tue, 24/09/2019 - 18:18

Sorry I really do not know.
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Submitted by kamicounciler on Fri, 20/09/2019 - 20:40

i think i have read about big car industry companies (like tessla & wolex) testing their auto-driving cars in roads.they have lunched the test a few years ago and those cars have passed long distances through highways in america without any problem.

Submitted by Htet on Fri, 30/08/2019 - 04:41

interesting and a good-to-know-story! Thanks!

Submitted by starfish2019 on Mon, 26/08/2019 - 16:38

Do you know of any other famous experiments? What are they? Current famous experiments are the Elon Musk's Neurolink to integrate an eletronic chip into our brain to boost its creative thinking, data processing and many other capabilities of the brain. It sounds to me like a Johnny Memonic The Keanu Reeves Old Sci-Fi Movie, but I hope this will work harmlessly with our Bio Organ Structured Brain. Another one so far is the Uber's Driverless Cars experiment and that is now nearly a success without any casualties. Another exiciting news is the Japanese's Flying Car Experiment and it is now successful. But will take some time to bring for our everday use with low cost.

Submitted by Adam83 on Sat, 24/08/2019 - 17:06

Hi, Could you please explain, why the sentence "He never saw the pitch drop" about Professor John Mainstone is true? Thank you in advance. Regards, Adam
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Submitted by Peter M. on Wed, 28/08/2019 - 08:20

In reply to by Adam83


Hi Adam,

The text does not say directly that John Mainstone did not see the pitch drop, but that is certainly the implication. We are told that he missed seeing it three times and if he had seen it we would expect this to be mentioned (He finally saw it in...). Furthermore, the question asks 'Which of the following sentences is not true...?'). The singular verb ('is') tells us that we are looking for one sentence, not two, and the third sentence is clearly not true. By a process of elimination, therefore, we can see that the first sentence must be true.



The LearnEnglish Team

Submitted by Adam83 on Fri, 06/09/2019 - 22:30

In reply to by Peter M.

Thank you Peter. This site is awesome. Regards, Adam

Submitted by Ola Jamal on Sun, 07/07/2019 - 17:53

Hi, In today's lecture we're going to be talking about experiments. In today's lecture we're going to talk about experiments. Is there any different in meaning between these two sentences?