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 Ehsan on Tue, 19/07/2022 - 09:06


Yes, I have read about important experiments. for example the experiment that Graham Bell did for telephone invention.

Submitted by jmajo on Wed, 30/03/2022 - 13:27


Yes, I do remember reading about an experiment in which in the year 1964 a 17 years old American student spent 11 days awake without the help of chemical drugs, the goal for the experiment was to determine how long could a person keep being awake without a single moment of sleep and study the reactions of the brain and the rest of his body. The conclusion of the study was that the brain have the ability of rest by sectors maintaining activity in some parts and resting others at the same time until the complete exhaustion.

Thanks for the lesson.
Great site!

Submitted by vuhoap on Sat, 18/12/2021 - 13:38


Actually, I don't remember about any famous experiments. However, I was just looking for information and knew about a strange experiment that is called Project MKUltra. It was a series of experiments on human subjects by the CIA. The project developed drugs and procedures to be used in torture in order to weaken the individual to confess through mind control.

Submitted by Suraj paliwal on Mon, 11/10/2021 - 13:29


Yes, I know a experiment it's about Newtown gravity experiment. When an apple falling from a tree there is a gravity.

Submitted by Abrarhussain on Mon, 23/08/2021 - 00:11

Yes I know other famous experiments, one is about earth gravity famous experiment of Newton through an apple. The other famous experiment is about the Invention of the telephone by Graham Bell.

Submitted by GiulianaAndy on Fri, 16/07/2021 - 23:29

Hello, I have a question, I'm sorry if it is not related with the topic, it is about these two sentences: 1) We can either make an omelette or pancake 2) She can play either the guitar or the dumb at the concert. As you can see, there's a different position for the word "either" in these sentences. In the first one "either" is located between the modal verb "can" and the verb "make" and in the second one "either" is located after the verb "play". Can I use those two structures if I want to a do sentence with a modal verb or auxiliary verb and a common verb or is there any difference between those structures? Thank you

Hello GiulianaAndy,

In these examples the position of either makes no difference. The action (play/make) remains the same and the instrument/dish is the option.


It's possible to use either to show a choice between actions. In this case either must come before the verb:

She can either play the guitar or sing a song.



The LearnEnglish Team

Submitted by GiulianaAndy on Thu, 15/07/2021 - 00:03

Yes, I do. I actually know one famous experiment, well a psychological experiment, it was execute in 1961. The general setup of this experiment was that the subject who has been assured payment would be told by an authority figure called the experimenter to give an electric shock punishment to a student when a wrong answer is given. The subject is aware that each wrong answer would have a progressively increased voltage. What the subject doesn't know is that there is no electrical shock, the student is an actor, and the administrator is following a script. It was found that despite the voltage getting to fatal levels with some simple prodding from the administrator around 2-3 of the subject continued pressing that bottom even when the student would scream and beg for mercy. It demonstrates that the majority of these subjects have the "accomplishment" to become party to monstrous acts with the imperative of obeying authority annulling a personal sense of ethic.

Submitted by lean on Sun, 09/05/2021 - 18:24

Thank you for the detailed answer :-)))

Submitted by lean on Sun, 09/05/2021 - 10:25

I'm sorry, but for some unknown reason my comments are being erased. Am I asking off topic ? I am just interested, why in the first sentence of the preparation task isn't used "was" before "given" ? ("Pitch is the name given to a black substance ..." vs "Pitch is the name was given to a black substance..." Will it be incorrect If I use "was" ?