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Science, Maths & Technology

OpenLearn Live: 4th March 2016

Updated Friday 4th March 2016

Supercomputing never went away - it just got more and more super; and 100 years of Dada. Then more free learning across the day.

OpenLearn Live is the place where free learning makes sense. This page will be updated across the day.

Yesterday, we marked the Bottom Line's first decade, celebrated World Book Day and explored social media

See the complete collection of OpenLearn Live

Today's posts

Tax avoidance

Tax avoidance is back in the news today, with Facebook suddenly realising it could find a few more quid to send to HMRC. We'd like to think the multinational social network had its mind changed by last night's Bottom Line, which had a focus on the question of businesses that make millions but contribute a smaller proportion to the exchequer than some other companies.

Read at BBC News: Facebook to pay more tax

Discover more about The Bottom Line: Tax avoidance

Read the OU's Peter Bloom on Understanding tax avoidance

100 years of Dada: A short reading list

February marked the 100th anniversary of the dadaist art movement. Here's a quick dip into some of the best pieces on the web marking that century.

First, BBC Arts produced a multimedia celebration, including this extract of The Shock Of The New:

Intelligent Travel - as you might expect - is as interested as the where as the what. Robert Reed travels to Zurich:

In Zurich, the Odeon quickly became a magnet for disaffected avant-garde intellectuals, including the central figures of the Dada movement—Tzara, a writer, sculptor Jean Arpand his artist-dancer girlfriend, Sophie TaeuberHugo Ball and his girlfriend, fellow poet and performer Emmy Hennings, and visual artist Marcel Janco.

The café seems subdued the morning I am there. A trio of gray-haired locals lean forward in their lounge chairs engaged in eager chitchat, helping to drown out an already barely audible Elvis song playing in the background. Nearby, a 20-something guy in a pink button-up pecks away on his laptop keyboard. A sign behind the bar reads “NO WIFI. TALK TO EACH OTHER.”

I’m midway through my muesli, thumbing through a German-language paper I can’t read, when I hear a Bruce Hornsby song come on. I pause to make a quick note in my journal.

“Is this Dada?”

It’s a question worth asking.

No, Robert. That's just the way it is.

The heart of the movement, the Cabaret Voltaire in Zurich, is under threat even in this year of celebration. Art Review explains why it faces an uncertain future:

Struggling to gain its financial independence, the historic cabaret is looking for a benefactor to acquire the whole building (currently owned by the insurance company Swiss Life) as an 'artwork' for CFH 13 million (approx. £9.2m), to ensure its preservation. The future patron will therefore be expected to preserve the space and not transform it into a real estate opportunity, the same way 'you wouldn't buy a Van Gogh to cut it into pieces and make a carpet out of it, because you know it's an artwork' explains director Adrian Notz.

Over at Hyperallegenic, taking a fresh perspective on the work of those linked to Dada, Barry Schwabsky uncovers the racial imagination of Dada:

But what are we to make of this “European exertion to become Negroes,” as the Belgian poet Paul van Ostaijen called it? Tzara said, “Dada is a state of mind. That is why it transforms itself according to races and events” — and racial transformation was evidently one of its salient desires. Quite simply, “We want a new skin color,” Huelsenbeck declared. That the poets and artists who felt this desire knew absolutely nothing about what they thought they wanted to become is clear enough; it was entirely a matter of stereotypes. Unlike the often-remarked “negrophilia” of the Parisian 1920s and ‘30s, to which it undoubtedly contributed — the cult of Josephine Baker, etc. — Dada’s racial masquerade took place without relation to any actual black people. It’s understandable that in the midst of, and then in the wake of the First World War, a certain number of Europeans felt a profound revulsion against their own European, that is, white identity. This doesn’t mean — to state the obvious — that they actually had the inner resources to do so, since their sense of non-European people and cultures came primarily from their own fantasy rather than a dialogue of equals; instead, they mostly reproduced harmful racial stereotypes brought to them courtesy of European colonialism.

See more on art history from OpenLearn

Superweek: Supercomputers

This week, we've been starting up each day with a look at some things that are, in some way, super. If you've missed any, here's what we've focused on so far:

We're rounding off the week with an exploration of supercomputers.

NERSC Franklin Cray XT4s - supercomputer cluster Creative commons image Icon Lawrence Berkeley Nat'l Lab - Roy Kaltschmidt, photographer under Creative Commons BY-NC-ND 4.0 license

If you're of an age between where you can't quite remember life before Ceefax, and where you're too young to remember Ceefax, you'll probably remember hearing a lot about supercomputers. Especially on programmes like Tomorrow's World, whose presentation style did everything it could to disguise just how exciting these developments might be:

You hear less about supercomputing these days in the general media, mainly because it's something that's become quite commonplace. In addition, although we might think we know what a supercomputer is, it's perhaps a little difficult to know where the boundary between a supercomputer and a not-supercomputer lies.

Obviously, a supercomputer has to be powerful, and capable of performing (human)mind-boggling numbers of calculations in tiny portions of time - and this performance is measured in FLOPS, or floating point operations per second. That, of course, raises its own question of 'what is a floating point?' - and IBM helpfully explains it is:

a method of encoding real numbers within the limits of finite precision available on computers

In other words, it's how a computer can take a really, really huge number - the number of grains of sand on the beach, or people in the world, or pounds earned by Google in a minute - and work with it.

To give you a rough idea, the A8 chip in an iPhone 6 can perform some functions at between 1 and 4 GFLOPS - that's a gigaflop, or one billion of these calculations every second. The most powerful supercomputer in the world, China's National Super Computer Center Tianhe-2 (MilkyWay-2) can perform just under 55,000 TFLOPs. Teraflops. A teraflop is a trillion calculations every second. Yes,  there's a computer capable of doing 55 quadrilion calculations every second. If human minds were actually capable of visualising what that sort of number looks like, we probably wouldn't have spent so much time inventing computers to calculate for us.

The birth of supercomputing dates back to the 1950s, and a man called Seymour Cray. Cray was quick to conceive of the likely benefits of building computers which hitched together a number of processors and used the power of new technology to perform powerful functions. The very first of these machines, the CDC 6600, was built in 1963 and was capable of 9 GFLOPS.

For a long time, his Cray corporation was pretty much the only manufacturer of true supercomputers, but by the 20th Century's end construction of powerful machines had become more widespread, and there are hundreds of thousands in operation around the world now. A list is maintained of the top 500 most powerful computers, and this shows that a lot of that computing power is concentrated in China and the United States.

The UK's most powerful machine is only at 41 in the global list, but it's still capable of more than a not-too-sluggish 1,500 TFLOPs. It's called ARCHER, and lives at the University of Edinburgh, where it works on science projects:

And the future? There's a prediction that computers can keep getting faster and faster to the point where - probably sometime around the end of the next decade - there's going to be a machine capable of performing ZettaFLOPs (1021 calculations per second). That should be enough power to accurately map an entire fortnight's worth of a weather system. All that power, all those calculations - at that level of accuracy, it's going to be a lot more use than just telling us if we need to take a brolly.

See more on computing from OpenLearn

Discover how to study computing with The Open University





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