Early computers were either designed to do one thing or, if they were programmable, they would be loaded-up with the program, it would run, and then a new program would be run. But a modern computer gives the appearance of doing multiple things at once. This lecture shows that in reality it is a supreme juggling act and, like a plate-spinning act, should be accompanied by The Sabre Dance amazement and applause. A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: https://www.gresham.ac.uk/watch-now/operating-systems Gresham College has offered free public lectures for over 400 years, thanks to the generosity of our supporters. There are currently over 2,500 lectures free to access. We believe that everyone should have the opportunity to learn from some of the greatest minds. To support Gresham's mission, please consider making a donation: https://gresham.ac.uk/support/ Website: https://gresham.ac.uk Twitter: https://twitter.com/greshamcollege Facebook: https://facebook.com/greshamcollege Instagram: https://instagram.com/greshamcollege

Integral transforms are the most rarefied of analyses – only used by a subset of engineers and computer scientists; laboured over by many an undergraduate, usually with the accompanying moans; yet every computer, every electronic circuit is an incomprehensible jumble of wires without knowledge of integral transforms. The most common, the Fourier transform, is estimated to be the algorithm that is most computed in the world but what of Laplace and z-transforms? This lecture will explain without using daunting mathematics. A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: https://www.gresham.ac.uk/lectures-and-events/integral-transforms Gresham College has offered free public lectures for over 400 years, thanks to the generosity of our supporters. There are currently over 2,500 lectures free to access. We believe that everyone should have the opportunity to learn from some of the greatest minds. To support Gresham's mission, please consider making a donation: https://gresham.ac.uk/support/ Website: https://gresham.ac.uk Twitter: https://twitter.com/greshamcollege Facebook: https://facebook.com/greshamcollege Instagram: https://instagram.com/greshamcollege

The most commonly used computer in the world is surely the one in your hand. Mobile or cellular telephony is nowadays hardly about telephony at all, but about communication in its broadest sense. Companies and governments have fallen and risen due to the use of mobile phones and in many countries without a phone you cannot transact with society. The smartphone is therefore a, if not the, pivotal innovation of this century. A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: https://www.gresham.ac.uk/lectures-and-events/cell-phones Gresham College has offered free public lectures for over 400 years, thanks to the generosity of our supporters. There are currently over 2,500 lectures free to access. We believe that everyone should have the opportunity to learn from some of the greatest minds. To support Gresham's mission, please consider making a donation: https://gresham.ac.uk/support/ Website: https://gresham.ac.uk Twitter: https://twitter.com/greshamcollege Facebook: https://facebook.com/greshamcollege Instagram: https://instagram.com/greshamcollege

When was the last time you opened a file and noticed a computer glitch? “Never” is the usual answer. Yet the underlying hardware makes continual errors: disks make errors, the internet loses packets of data, wifi signals get corrupted and so on. This lecture is about the secrets of the mysterious invulnerability that is Error Control Coding: a way of storing or transmitting information such that it knows it has been corrupted and can correct itself. A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: https://www.gresham.ac.uk/lectures-and-events/error-control Gresham College has offered free public lectures for over 400 years, thanks to the generosity of our supporters. There are currently over 2,500 lectures free to access. We believe that everyone should have the opportunity to learn from some of the greatest minds. To support Gresham's mission, please consider making a donation: https://gresham.ac.uk/support/ Website: https://gresham.ac.uk Twitter: https://twitter.com/greshamcollege Facebook: https://facebook.com/greshamcollege Instagram: https://instagram.com/greshamcollege

When you tune into Netflix you might not be aware that the box in your living room starts a complex set of negotiations with servers on moving 563 Gbytes of information into your residence. That is equivalent to having 15,000 copies of the Encyclopaedia Britannica dumped into your home! So, why is watching a Netflix film not the equivalent of the Amazon-delivery from hell? Compression, which this lecture will show is economically and entropically a hot topic. A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: https://www.gresham.ac.uk/lectures-and-events/compression Gresham College has offered free public lectures for over 400 years, thanks to the generosity of our supporters. There are currently over 2,500 lectures free to access. We believe that everyone should have the opportunity to learn from some of the greatest minds. To support Gresham's mission, please consider making a donation: https://gresham.ac.uk/support/ Website: https://gresham.ac.uk Twitter: https://twitter.com/greshamcollege Facebook: https://facebook.com/greshamcollege Instagram: https://instagram.com/greshamcollege

In 1977 or thereabouts a collection of scientists huddled around a secret radio receiver in the US desert. This was the start of GPS, Glonass, Gallileo and the whole navigation industry. A GPS chipset now costs, in bulk, a few dollars so your watch, your phone, your computer all have GPS receivers and everyone knows where they are all the time. But how does this technology work? And are there situations when it does not work? A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: https://www.gresham.ac.uk/lectures-and-events/gps Gresham College has offered free public lectures for over 400 years, thanks to the generosity of our supporters. There are currently over 2,500 lectures free to access. We believe that everyone should have the opportunity to learn from some of the greatest minds. To support Gresham's mission, please consider making a donation: https://gresham.ac.uk/support/ Website: https://gresham.ac.uk Twitter: https://twitter.com/greshamcollege Facebook: https://facebook.com/greshamcollege Instagram: https://instagram.com/greshamcollege

It is now easier to breach the security of people’s personal and business lives than perhaps at any time in recent human history. Technology has brought unimaginable speed, scale and reach to hackers. This lecture looks at the consequences of technology on privacy and security, and considers what options there are for the future, including new technologies and regulations such as blockchain and the right to privacy. A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: http://www.gresham.ac.uk/lectures-and-events/computer-security Gresham College has been giving free public lectures since 1597. This tradition continues today with all of our five or so public lectures a week being made available for free download from our website. There are currently over 2,000 lectures free to access or download from the website. Website: https://gresham.ac.uk Twitter: https://twitter.com/greshamcollege Facebook: https://facebook.com/greshamcollege Instagram: https://instagram.com/greshamcollege

Networks were seen as a rather arcane and dull area in computer science. Then along came the internet, and everything changed for ever. The internet is actually an amalgam of a number of disparate technologies that evolved at just the right time, indeed several of the key technologies were far from optimal. In this lecture we will look at a bit of internet history, show how it works now and look towards the future. A lecture by Richard Harvey The transcript and downloadable versions of the lecture are available from the Gresham College website: http://www.gresham.ac.uk/lectures-and-events/networks-beyond Gresham College has offered free public lectures for over 400 years, thanks to the generosity of our supporters. There are currently over 2,500 lectures free to access. We believe that everyone should have the opportunity to learn from some of the greatest minds. To support Gresham's mission, please consider making a donation: https://gresham.ac.uk/support/