The helix

The helix

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

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

Preparation

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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Hello BobMux,

We still haven't finished the Advanced section, but you can find some advanced-level grammar points in the Grammar reference. Not all of the pages there have an advanced section, but some do -- for example, the Present tense page.

All the best,

Kirk

The LearnEnglish Team

Submitted by Cami on Mon, 05/10/2020 - 12:03

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I never watched talks like this neither scientific lecture online, but I watched them on tv and at school. On tv I saw, not a long time ago, an interesting program about the discover of electricity and the progress that human beings have made during ages using it.

Submitted by indhiradlc on Mon, 28/09/2020 - 23:43

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Scientific lectures are not the first thing that comes to my mind. However, there are specific topics that I have an interest in. I enjoy talks about how the wires of our brain determine our behaviour, as long as the language used is not too technical because I'm not proficient in science.
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Submitted by nicoibanezo on Sat, 29/08/2020 - 00:40

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Of course. I love biology so much, when I was in school, I always hoped anxiously the class biology because I had a great teacher who taught me very good. She always taught me about DNA and cells. And then I was very interest about it that I studied a career related to biology and health. I remember every day I wrote on my board about biology topic as DNA conjugated, cells, viruses, cell theory among other topics. I love a lot biology because you can find a lot of things about nature, your body, your cells, things that happened in the past or will happen in the future. For sure, it’s a very interesting subject which you can find out and know more about what happens inside of you.

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!