The helix

Listen to a lecture about the helix shape to practise and improve your listening skills.

Instructions

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

Transcript

I'd like to turn now to the object which is the main point of this talk: the helix. This is a fascinating mathematical object which touches many parts of our lives. Movement, the natural world, the manufactured world and our genetic make-up are all connected to the shape of the helix.

A helix is a type of three-dimensional curve that goes around a central cylindrical shape in the form of a spiral, like a corkscrew or a spiral staircase. The helix is a very popular shape in nature because it is very compact. In fact, helices are sometimes referred to as 'nature's space saver'. In architecture too, the helix shape of a spiral staircase is an attractive option in buildings where space is very restricted.

The most renowned type of helix is probably the double helix of DNA, or deoxyribonucleic acid. DNA is made of two helices that curve around each other, a bit like a twisted ladder. DNA contains the genetic information or 'code' that determines the development and functioning of all known living things. The helix shape is a very efficient way to store a long molecule like DNA in the limited space of a cell.

There are different types of helices. Helices can twist clockwise, right-handed, or anti-clockwise, left-handed. An interesting experiment is to hold a clockwise helix, such as a corkscrew, up to a mirror. The clockwise helix appears to become counterclockwise.

We can perceive examples of helices in many areas of our world. Spiral staircases, cables, screws and ropes can be right-handed or left-handed helices. A helix that goes around a cone is called a conical helix. Examples of conical helices are screws or the famous spiral ramp designed by the architect Frank Lloyd Wright in the Guggenheim Museum in New York.

Helices are also prevalent in the natural world. The horns of certain animals, viruses, seashells and the structure of plants, flowers and leaves can all contain helices. The human umbilical cord is in fact a triple helix.

With the discovery that the helix is the shape of the DNA molecule, it is not surprising that the helix is found in so many areas. It's one of the most natural shapes in nature.

Let's turn our attention now to the mathematical description of the helix. You'll need a pen and paper for the next part of the talk as I am going to give you some variables to write down. Take your time to notice the different ...

Discussion

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Average: 4.5 (2 votes)

Submitted by yoyoraw on Sun, 14/06/2020 - 19:49

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Sometimes, although I am not that interested in scientific lessons , but I like to watch few of them every once and a while .

Submitted by Asierge on Fri, 24/04/2020 - 11:53

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I am very interested on this type of scientific information and despite using quite technical language, it is understandable, so thank you for improving our knnowledge and english.

Submitted by hrahmani on Thu, 06/02/2020 - 10:27

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I am interested in scientific lectures, in particular the ones that explain important discoveries or scientific achievements. Especially, the ones like this one that introduces a complicated geometrical shape and its applications without entering the mathematical complexities. So it is clear and understandable. Such lectures are really motivating and show the importance of the scientific research activities and their impacts in the daily life. Therefore, such lectures further demonstrate the importance of the hard work done by researchers in their laboratories.

Submitted by Evgeny N on Mon, 30/12/2019 - 16:34

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Dear teachers of Brirtish Council, Thank you very much indeed for your work which gives all of us opportunity to learn English language! I wish you all Happy New Year!

Hello Evgeny,

Thanks for your good wishes. I hope you have a great 2020 and learn a lot of English!

Best wishes from all of us here at the site.

 

Peter

The LearnEnglish Team

Submitted by om mariam on Tue, 27/08/2019 - 10:13

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I’d been attending science lectures for five years when I was student in faculty of science.I am still keen in the genetic subject, the development in this field is promising for example in medicine :curing difficult cases like cancer and some inherited diseases . furthermore, there are ongoing researches work on the human genome to find out why some people are more vulnerable to get sick with a disease while other has a resistance. Also in agriculture genetic engineering help to provide kinds of crops which has resistance to agricultural pest .

Submitted by nikoslado on Tue, 09/07/2019 - 18:46

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Dear Team, I think,in Task 2/quest.5, we can write either ''alternating'' and ''alternate'',using it as an adjective.Could you check it , please, if I'm right?

Hello nikoslado

Yes, it appears that you are right, i.e. that 'alternate' is also possible in that sentence. In my experience, 'alternating' is much more commonly used, but I will change the exercise so that 'alternate' is also correct.

Thanks for pointing this out to us.

All the best

Kirk

The LearnEnglish Team