Hedy Lamarr: Frequency hopping star

This was originally posted as a page and the text of the audio, from CS4FN magazine, has been added here.


Hedy Lamarr was both an inventor and a movie star. Working with George Antheil her longtime piano playing friend they had an idea to help with the war. Their idea was to protect radio signals from being jammed by hopping frequencies and patented their encryption invention as a ‘secret communication system’.

Unfortunately, the system was not adopted straight away as it was too tricky to implement. However, it was later! But. Hedy and George let their patent lapse, so they did not get the credit they truly deserved.

Read more about Hedy’s frequency hopping invention on the  cs4fn website. You can also listen to an audio version of the article, called The movie star, the player piano and the torpedo written by Peter McOwan, edited by Paul Curzon and read by Jo Brodie. Click the player below or download the audio file (.m4a).

The text of the audio is below.

The movie star, the player piano and the torpedo
by Peter W. McOwan Queen Mary University of London

Hedy Lamarr was a movie star. Back in the 1940’s, in Hollywood’s Golden Age, she was considered one of the screen’s most beautiful women and appeared in several blockbusters. But Hedy was more than just good looks and acting skills. Even though many people remembered Hedy for her pithy quote “Any girl can be glamorous. All she has to do is stand still and look stupid”, at the outbreak of World War 2 she and composer George Antheil invented an encryption technique for a torpedo radio guidance system!

Their creative idea for an encryption system was based on the mechanism behind the ‘player piano’ – an automatic piano where the tune is controlled by a roll of paper with punched holes. The idea was to use what is now known as ‘frequency hopping’ to overcome the possibility of the control signal being jammed by the enemy. Normal radio communication involves the sender picking a radio frequency and then sending all communication at that frequency. Anyone who tunes in to that frequency can then listen in, but also jam it by sending their own more powerful signal at the same frequency. That’s why non-digital radio stations constantly tell you their frequency “96.2 FM” or whatever. Frequency hopping involves jumping from frequency to frequency throughout the broadcast. Then, only if sender and receiver share the secret of exactly when the jumps will be made, and to what frequencies, can the receiver pick up the broadcast or jam it. That is essentially what the piano roll could do. It stored the secret.

Though the navy didn’t actually use the method during World War II, they did use the principles during the Cuban missile crisis in the 1960’s. The idea behind the method is also used in today’s GPS, Wi-Fi, Bluetooth and mobile phone technologies, underpinning so much of the technology of today. In 2014 she was inducted into the US national inventor’s hall of fame.



History and Science: Find out about World War II and the importance of radio. What form of communication is used now in conflicts? How has science changed war?

This work was supported by the Institute of Coding, which is supported by the Office for Students (OfS).

Teaching London Computing – Newsletter #8 – November 2020

This is the full text of the 8th newsletter which I (Jo B) send to all London-based teachers on our Teaching London Computing subscription list. Teachers outside London usually get a shorter version with anything geographically irrelevant (ie things happening in London) removed, however during lockdown this is less clear. I also send an occasional version to our international subscribers. Details in the text below on how you can sign up if you’re reading this for the first time and would like to get the emailed version in future.

Dear colleagues

Welcome to November 2020’s Newsletter 8 (previous newsletters live here), which is full of online events and courses (mostly free) and some additional resources on the Teaching London Computing website.

We are currently working on the next issue of CS4FN  magazine, which should be arriving in the Spring 2021,changes to working practices during coronavirus had made it impossible to publish an issue this year although all of our previous issues are free to download as PDFs.

As always please feel free to share this newsletter by forwarding it to colleagues in case they’d like to sign up too – new readers can sign up using the orange form on this page. You are receiving this email because you’ve previously signed up to the ‘TLC mailing list’ to hear about new courses and resources etc but if you no longer want to hear from us please let me know (j.brodie@qmul.ac.uk) and I’ll remove you.

TechPathways London – announcment
QMUL are very excited to announce that we are working with London Connected Learning Centre again on the TechPathways London programme. Funded by the Mayor of London we are supporting educators who teach young people from the age of 11 to 25 about computing. To find out more about the programme look here. We won an award the last time we worked on this programme… so it must be good. TechPathways London also has a newsletter, scroll to the end of their website and subscribe.

Best wishes Jo
Follow us on Twitter @cas_london_crc or @cs4fn.


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1. Teaching programming – for IT professionals who teach in schools or work
2. Other CPD courses for teachers
3. The Skills Toolkit
4. Vignettes of how computing and tech are used in the real world (good and bad!)
5. Alan Turing Institute events
6. “Anyone can code? Power, inclusion and the coding fetish”
7. New book – with chapters from Paul Curzon and Jane Waite
8. Home Learning – most resources don’t need a printer
9. Lockdown Lectures – Teaching London Computing’s YouTube channel
10. UK National Data Strategy consultation

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Logo for TechPathways London, Queen Mary University of London and Instiute of Coding

1. Teaching programming – for IT professionals who teach in schools or work
FREE: This course is aimed at IT professionals, adapted from our teachers’ course. Please pass this on to friends and colleagues in industry. It’s suitable for IT people who are helping to run code clubs etc for schools, or for those who are just training new colleagues.

This is a long course, over four sessions on Wednesdays, 6-7.30pm from 25 Nov to 16 December.
[More info on our blog post][Eventbrite tickets][PDF flyer]

2. Other CPD courses for teachers
AQA – Computing CPD courses [GCSE] [A-level]
NCCE Computing courses
– see also How teachers train in Computing with our free online courses blogpost from Raspberry Pi (whose courses are part-supported by NCCE)
OCR – Computer Science and ICT courses
STEM – CPD in Computing (bursaries are available)

3. The Skills Toolkit – general IT / programming courses collated and linked from a Government portal
The Gov’t has created a new Skills Toolkit page to highlight free online digital courses including programming (but also a wide range including maths, business, finance, digital marketing, graphic design). Course providers include Microsoft and Google. All are free and most are self-paced. There are 19 courses on Computing (including cybersecurity, computer networks, artificial intelligence (AI) and cloud computing) and 10 on programming (including HTML, CSS, Python, C, C++).

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4. Vignettes of how computing and tech are used in the real world (good and bad!)
We hope that these pages will help spark some interesting discussion and debate in classrooms.

Computing and Society highlights problems such as biases in algorithms and other technology, ethical concerns about data use and privacy problems that arise from not having considered how tech might be used.

In more cheering news a school hired a 10 year old Nigerian computer whiz to help them teach children to code, we’ve added that to our new page about Positive Stories in Computing.

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5. Alan Turing Institute – free events
The Alan Turing Institute runs free public events (as well as conferences for a technical audience).

6. Anyone Can Code? Power, Inclusion, and the Coding Fetish – FREE EVENT
Dr Kate Miltner, Centre for Research in Digital Education, Edinburgh
1-2pm, Wednesday 11 November 2020 [tickets]
Drawing on a case study from an American coding school, this seminar will interrogate common coding-related claims.

“Over the course of the past decade, learning to code has been positioned as a silver-bullet solution to a variety of structural social concerns, including social mobility for the economically marginalized and the underrepresentation of women and BAME individuals within the tech industry. In response to this discourse, a growing industry of coding ‘academies’ has developed across the globe, insisting that “anyone can code” and get a well-paid tech job with a few months’ intensive instruction. Drawing on a case study from an American coding school, this seminar will interrogate common coding-related claims and illustrate how subtle gatekeeping mechanisms at play within these schools end up subverting the well-intentioned goals they set out to achieve.”

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7. New book – with chapters from Paul Curzon and Jane Waite
Shuchi Grover’s new book ‘Computer Science in K-12: an A-Z handbook of teaching computing’ features contributions from Paul and Jane. Paul’s chapter, co-written with Shuchi, is called “Guided Exploration Through Unplugged Activities” and Jane’s chapter, co-written with Shuchi, is called “Worked Examples and Other Scaffolding Strategies” and you can find out more about the book and see/hear Paul and Jane give a tiny YouTube introduction to their chapters on our blog post.

8. Home Learning – most resources don’t need a printer
During lockdown earlier this year we went through our resources and picked out ones that can be done without a printer and adapted others so that they can be done on-screen. All our ‘Computing At Home’ resources are free, and divided into primary and secondary age groups https://teachinglondoncomputing.org/computingathome/

9. Lockdown Lectures – Teaching London Computing’s YouTube channel
We recorded Paul Curzon’s free Lockdown Lectures over the summer and will be adding the edited versions to our YouTube channel here – the first one “The Chocolate Turing Machine” is already there, along with previously added videos.

10. UK National Data Strategy consultation
Relevant documents: https://www.gov.uk/government/publications/uk-national-data-strategy
Closes 11:45pm 2 December 2020
Your class might be interested in the information and commentary about data and how it’s used, but also about how Government consultations work.