sip SUMMER 2013 5/7/13 08:38 Page 23

SPEED National Science and Engineering Week Seminar on Thursday 21st March HOW TO MEASURE SPEED

Dr Michael de Podesta MBE National Physical Laboratory Viewing the world through over 18 orders of magnitude! The ‘clock’ is stopped by the the lens of precision Shown as dots are the speed of first runner breaking a beam of measurement brings our (a) sprinters, (b) bullets, (c) infrared light shone across the scientific vision into sharp focus. neutrinos, (d) bridges, (e) finish line. This records the It allows us to see clearly the continents and (f) sound. We winning time but does not beautiful patterns in nature, and will look in turn at how each of detect who has won! This is to compare them with our these speeds is measured. determined by a ‘photo-finish’ expectations – and so refine our system of beautiful ingenuity. A The timing of a sprint race is model of reality. Measurement is camera captures a picture of the easy to understand. A starter a simple idea but one which is finishing line – just the finishing fires a gun and the ‘bang’ is central to our scientific world line –1000 times each second. supposed to start the race fairly. view. The images of the finishing line However, sound travels through are then stitched together to So let us look at precision air at approximately 340 metres Michael de Podesta considering the make an image that looks like a measurement of speed. We per second so that a runner on possibilities of the NPL-Cranfield distorted photograph, but is in acoustic resonator – the most describe speeds as ‘fast’ or the far side of a 10 metre fact a technical record revealing accurate thermometer in the world. ‘slow’, but these assignations are running track would hear the the time at which each athlete anthropocentric. By ‘fast’ we gun approximately 0.030 crossed the line. mean some measurable change seconds later than the runner on has happened in a ‘heartbeat’ or a ‘blink of the eye’. And by ‘slow’ Measurement is the . . . difficulty in accepting that we mean something which comparison of an unknown shows only a small change in a quantity with a standard continents move . . . ‘long’ time, perhaps one ‘year’, amount of that quantity. So one orbit of the Sun, or a when we weigh 250 grams of the near side of the track. Such Bullets are faster than ‘lifetime’ (hopefully) one flour to make a cake, we are a gap – 30 milliseconds – is the athletes but they are still timed hundred orbits of the Sun. comparing the mass of flour difference between winning and photographically. Cameras not- with the mass of the But we see phenomena losing in many races. For this so-different from those international prototype of the taking place with a vast range of reason, the starting ‘pistol’ is commonly used to capture kilogram. When an engineer speeds. Things which appear now electronic, and it triggers a movies at 30 pictures per measures the temperature of instantaneous to humans are sound which is played from a second can be ‘super-charged’ steam to be 337°C, they are just ‘very fast’, and we find that loudspeaker directly behind to capture movies at up to one comparing the temperature of tiny differences in ultra-fast each runner. This ‘pistol’ also million frames a second. But the steam with the speeds can be of profound starts ‘the clock’. each image needs lots of light to temperature of the triple point significance. Similarly processes allow the passage of the bullet of water. This simple idea, which are slow enough can when applied with ingenuity appear to be stationary. But and thoroughness, transforms precision measurement can our vision of the world. reveal even the slowest of motions – and the results can again be of the most profound significance. The figure shows the range of speeds which are significant for human beings – a range of . . . tiny differences can be of profound significance . . .

Science in Parliament Vol 70 No 3 Summer 2013 21 sip SUMMER 2013 5/7/13 08:38 Page 24

. . . brings our scientific vision into sharp focus . . .

to be recorded. It is at this point However, only 0.000 000 000 – where the apparently 000 016% of the neutrinos instantaneous pulse of a camera were detected (16111). flash appears as a slowly Nonetheless, instead of taking brightening and fading light that 2.436801 milliseconds to reach we truly leave the realm of the detector – they took just speed that is appreciable to 2.436741 milliseconds. humans. In the end this discrepancy was resolved by the discovery of a loose cable which delayed a signal by seventy nanoseconds in a way which no one had considered possible. But the lesson of this experiment is that precision experiments test our expectations of the world. It is A colour-coded photograph of two concrete components on a bridge only because of precision showing that the slab on the left (purple) has moved approximately 7 mm And so to the timing of with respect to the slab on the right. neutrinos, possibly the oddest measurement that anyone particles humans have dared to check our expectations will realise that bridges move all be quickly detected. This is discovered. They have a lower that nothing can travel faster the time. And temperature simpler and cheaper than mass than even the electrons than light. And if they had been changes cause bridges to installing and monitoring arrays which whizz around every atom right, the textbooks would have change shape too. Both of strain gauges and allows the in the universe. Neutrinos had to be re-written, and our vibrations and environmental detection of movement in interact so weakly with ordinary conception of the entire changes cause bridges and unexpected places. universe would have changed. other civil engineering matter that they routinely travel We appreciate that bridges So, although that didn’t happen, constructions to change over through the Earth without move, but the idea that that is the power of precision time – something which is of anyone noticing. As a student I continents can move is more measurement – to make, or obvious interest to engineers wrote an essay on the breath- challenging. And the story of break, our most strongly-felt concerned with the safety of taking experiment in which how we came to understand convictions about the world. such structures. neutrinos were first detected! that not only can they move, but Now we can time neutrinos So let us now consider Once again photography that they are still moving now is routinely. Recently it appeared something at the opposite end comes to our aid. Photographs no less astounding. From early as though neutrinos were of Figure 1 – something we taken from precisely the same suspicions based on the shapes travelling faster than 299 792 generally consider to stationary: location days, months or years of the facing coast of Africa and 458 metres per second – the Bridges. However, if you have apart can detect the slow America; through research speed at which light travels ever stood on a motorway motion of structures – a few showing matching rock and through a vacuum. bridge while a lorry passes you millimetres a year of motion can fossil types; to our modern The experiment in which this theories of plate tectonics. This appeared to happen is complex. gives us a real insight into how Protons (ionised hydrogen science advances. atoms) were accelerated in The fundamental difficulty in Switzerland and fired into a accepting that continents move target which emitted neutrinos. is because their motion is so The beam of protons was slow compared with a human vaguely pointed towards the lifetime – and the moving parts Gran Sasso laboratory in Italy, are so large compared with some 730.53461 kilometres human perceptions. There is no away, a distance known with an way we could become directly uncertainty of 20 cm. Over three aware of this motion. Or so it years approximately seemed. 100,000,000,000,000,000,000 neutrinos were emitted in well- Radio telescopes listen to timed bunches. This is a periodic signals from rotating stars called pulsars. A beam of number so large that it makes The path taken by neutrinos fired from CERN towards the Gran Sasso the UK national debt look small! Laboratory in Italy. radio waves from such a star

22 Science in Parliament Vol 70 No 3 Summer 2013 sip SUMMER 2013 5/7/13 08:38 Page 25

described earlier, sound travels sound in a gas can enable a . . . sound travels through a gas at through a gas at quite a measurement of its temperature. comfortable rate. Fast enough For the last 6 years, my a comfortable rate . . . that we are not conscious of the colleagues and I at NPL have delay as someone speaks, but sweeps past the Earth every as the continents on which they been working to make such a slow enough that we can hear second, and these signals are sit are moving. measurement. Our ‘echoes’ in large rooms. What is analysed by radio telescopes measurements – the most around the Earth. When the The movement is slow – often not appreciated is that the accurate ever – will enable a signals from widely separated typically 20 mm per year or one speed of sound in a gas is new definition of the units of radio telescopes are compared, tenth the speed at which hair directly proportional to the temperature (the kelvin and the a small adjustment must be grows – but it is real and can be average speed with which the degree Celsius) in the near made for the delay as the beam monitored week by week. molecules of the gas are future. This will link the unit of sweeps from one telescope to moving. And because the temperature to measurements My own measurement the other. Analysis of this delay temperature of a substance is of molecular speed and energy shows that the time difference is speciality is the speed of sound. related to the speed of motion – and provide a foundation for changing because the position In contrast to the extremely slow of its molecules, a precise future improvements in of radio telescopes is changing and the extremely fast events measurement of the speed of temperature measurement.

SPEED FAST HORSES, ROBOTS AND NEUROTECHNOLOGIES: Discovering how to go fast on legs

Understanding how animals fraction of this cost will have its is used to stabilise the body, or move is one of the grand roots in mobility; movement is how we manage our noisy challenges of modern science. It central to maintaining both good muscles. Stability may be largely has broad impact on society: it circulation and mental health handled by the mechanics of affects our ability to explain the (Halliwell, 2005; Mental Health the body; sensory input may still biological world, to treat human Found. London). We hope to lay be incorporated, but on longer and animal disease, and to aid the foundation for medical time-scales; or, rapid locomotion those recovering from injury. The advances that improve our may be constrained by motor more we know about how ability to treat those facing a lack noise. biological systems control their of mobility, increasingly We are working to uncover Dr Andrew Spence movement, and how different important as our population Lecturer in Biomechanics, Structure the mechanisms by which organs contribute to locomotion, ages, and thus have a huge & Motion Laboratory, animals (including humans!) Royal Veterinary College the better we will be able to treat impact on the quality of life of achieve their extraordinary feats those with neurological disorders many millions of people. of dexterity, in the face of these or musculoskeletal injury, and to Locomotion is the signature constraints. To do so, we employ inspire new technologies, such as behaviour of animals. In the face advantageous techniques and legged robots. of an unpredictable technologies from diverse fields: Movement is critical to health environment, noisy signals from robotics, computer science, and quality of life. The total NHS sense organs and noisy forces mathematics, zoology, spending on musculoskeletal from muscles, animals are able evolutionary and cellular and and neurological disease in to move with speed, dexterity molecular biology. If we can 2007 was £7.4bn (Featherstone, and robustness. Yet for one of discover the mechanisms that 2010; www.policyexchange.co.uk). the most important types of enable legged animals to go Circulatory problems and mental movement, fast terrestrial fast, robustly and economically, it health together cost the UK locomotion on legs, we do not will have a dramatic impact on £17.2bn, and a significant know how sensory information medicine, technology, and our

Science in Parliament Vol 70 No 3 Summer 2013 23 sip SUMMER 2013 5/7/13 08:38 Page 26

understanding of the world understanding of the control of the key to overcoming the we hypothesise the animal is around us. fast locomotion, and how problem of understanding the using, and therefore control the animals must overlay feedback coupled, complex phenomenon behaviour of the “animal.” We A COMPLEX, DYNAMIC on their tuned mechanics. of fast legged locomotion. can bolt on different legs, or add PROBLEM mass to different parts of the But this presents a major It is an extraordinary time to robot, to understand their effects When a horse gallops at 20 obstacle to our understanding of work in the neuromechanics of on locomotion. Furthermore, we metres per second its hooves how the nervous and movement, because several can then perturb the robot to may be on the ground for as musculoskeletal systems work new fields of science are the point of falling, and in doing little as 90 milliseconds (Fig 1). together to produce locomotion. converging to make possible so without using animals, we are This is not enough time for For us to interpret accurately more rapid progress. First, we contributing to the three R’s of signals to come from sense what the role of each of these are beginning to formulate animal welfare: replace, reduce, organs on the horse’s leg up into subsystems is, we need to quantitative, predictive refine. Where our robots are the spinal cord (or brain!), for examine independently and mathematical models of how decent models of moving the nervous system to perform a manipulate each subsystem, in animals move, that integrate animals, they can completely corrective computation, and for an intact, freely behaving from molecular processes in the replace the need for animal signals to be sent back out to animal, in an ethical way. brain and spinal cord, through experiments. muscles, to develop forces that Understanding how each muscles and the skeleton, all the compensate. This means that subsystem works in the context way out to the forces that limbs Third, slow motion video fast moving animals face a big of all of them is important not exert on the outside world. We cameras have become cheap, challenge: can they use this just because history teaches us are in the early stages, but the and open source libraries for feedback in the next step? Can automatic tracking and analysis they use it to change what other . . . seeking to build prosthetic limbs . . . of video using computer vision legs do? Or are they forced to software have matured. This ignore it altogether? means we can gather and that linking across subsystems is fact that we have mathematical analyse large data sets of more Exciting hints to how they a reliable way of gaining insight models that make testable and better quality motion than remain stable have come from into the whole system, but predictions, despite the ever before. These technologies basic biology. In a famous because disease and injury complexity of the problem, allow us to explore and model experiment, Jindrich and frequently affect only one of means that we have a solid the extraordinary feats of animals colleages (Journal of these subsystems, or organs foundation to work from. that escape the naked eye. Experimental Biology, 2000) within a subsystem, at a time. Second, legged robots have perturbed fast running matured to become fantastic cockroaches by placing a small AN INTEGRATIVE, physical models of moving cannon on their backs, and firing MULTIDISCLINARY, animals that can bring it as they ran quickly. They SYSTEMS APPROACH unprecedented insight into the discovered that the cockroaches So called “systems” mechanisms underlying recover not through reflexes, but approaches, where scientists locomotion (Fig 2). Two of the through mechanical tuning of think about how phenomena major limitations in animal their bodies, legs, and overall occur in a broader context, as locomotion research are that locomotion. Just like a car opposed to drilling down to 1) the experimenter cannot having a tuned suspension to smaller and smaller constituent control the behaviour of, or Figure 2 absorb the impact of potholes, parts, are not just proving critical systematically the body evolution can tune the to our understanding of cells conformation of, the animal, and A BRIGHT FUTURE mechanics of fast moving and molecules. They are 2) it can be unethical to perturb legged animals to handle accelerating our understanding A fourth and final technology freely running animals to the perturbations with the animal’s of how whole organisms, is driving a revolution in point at which they are likely to “chassis,” or body! This has including humans, move and neuroscience, and we are fall over, even though this is the major implications for our behave. And they may provide working to bring about another most important point for helping one in the neuromechanics of with, eg, understanding how animal locomotion. It is called humans fall over. optogenetics, and in many ways Robots can overcome these it is the stuff of science fiction. limitations. Using legged robots With optogenetics, specific that we know move in a similar sets of neurons can be switched manner to animals (like the on or off very quickly using light. RHex robot seen in Fig 2, a six By using genetic tools, we can legged, dynamic running specify which sets of neurons cockroach inspired robot), we express these light switches. can programme them to use One of them, Channelrhodopsin, Figure 1 exactly the type of controller that allows us to make neurons fire

24 Science in Parliament Vol 70 No 3 Summer 2013 sip SUMMER 2013 5/7/13 08:38 Page 27

when we shine blue light on Furthermore, we can do it in our we can really tease apart how autoimmune disorders such as them. Another, Halorhodopsin, close mammalian cousin: the different systems (neural, multifocal motor neuropathy) allows us to silence neurons mouse. It is revolutionising mechanical) contribute to nerves. More and more, we are with yellow light. neuroscience because it allows locomotion. seeking to build prosthetic limbs that interface directly with the To understand the us to study the function of parts CONCLUSION patient’s body. Thus, the more neuromechanical basis of of the nervous system in a we understand our bodies and locomotion, we need to turn on causal manner. Optogenetics Over 100 types of peripheral the signals that the nervous and off specific parts of the and movement are a perfect neuropathy have been system uses to control them, nervous system on the combination because identified, and many of these the more we can help people millisecond time scale. The optogenetics can work quickly illnesses predominantly or with neurological problems or extraordinary, revolutionary and reversibly. By combining exclusively affect the sensory injury. An exciting aim indeed. capabilities of optogenetics optogenetics with a (viruses and bacteria, including mean that, for the first time in neuromechanical approach to shingles, cytomegalovirus, and human history, we have the locomotion, we can see an the Epstein-Barr virus) or motor technology to do this. exciting future ahead in which (spasticity, essential tremor,

SPEED SPEED – OF COMPUTERS

The majority of people alive today cannot remember life without computers. They know that computers dominate our lives, affect most of our everyday actions, and allow us to connect to the world via the internet and live digitally-dominated existences. They also know that, within their living memory, computer speed and storage have always increased, device size has always decreased, and nothing has ever looked like stopping the relentless advance of computer technology. Current petaflop machines (capable of performing over 1015 floating point calculations per second) allow us to make calculations of hitherto undreamed-of speed and accuracy, and the technological advantages of being able to perform such calculations are legion. Professor Alistair Fitt Pro Vice-Chancellor (Research & Knowledge Exchange), Oxford For more than 40 years the predictions singularity” where computers become so Brookes University, and Council of increasing computer power supplied by powerful that they develop a kind of member, Institute of Mathematics and its Applications the famous “Moore’s law” have served us consciousness has engendered serious well, but is there a limit to the march of academic debate, and cannot be ruled computing progress, and what are the out. If this were to happen, would it prove current important challenges? The huge to be a blessing or a curse for energy consumption of modern humankind? computers is one real issue, which will assume increasing importance as the COMPUTERS ALWAYS GET FASTER industry approaches exascale (1018 Flops) We can all argue about the identity of “the first capability. As increases in basic CPU clock computer”. The Chinese abacus of 200BC, the speed falter, ever more complicated 1822 Babbage difference engine, the enigma- technology is needed to ensure that cracking Bletchley Park COLOSSUS of 1943 and Moore’s law still holds, and this will the 1944 Los Alamos ENIAC machine that require huge future investment in calculated the details of the Hiroshima atomic bomb all have their claims to being “the first research and skills. Ultimately, theoretical proper computer”. One thing that we all agree on physics (and in particular quantum is that computers always get faster. theory) places limits on what may be achieved. How do we measure how fast computers calculate? Computing speed is usually measured Finally, and possibly most intriguingly, in Flops (Floating Point OPerations per Second), will computers ever “wake up”? The and historical increases in speed have been possibility of a so-called “technological awesome. The NASA Gemini guidance computer

Science in Parliament Vol 70 No 3 Summer 2013 25 sip SUMMER 2013 5/7/13 08:38 Page 28

of 1963 ran at a peak speed of 2006. This leads to worryingly 7,000 Flops (7 KFlops), the first . . . mobile phone recently won a large carbon emissions: for megaflop (106 Flops) machine grandmaster chess tournament . . . example, the world’s data was the CDC 6600 in 1965, the centres currently emit more tons

CRAY2 of 1985 was the first of CO2 per annum than major gigaflop (109 Flops) computer not in vitro or in vivo, but financial consequences, which countries such as Argentina and and the 1996 INTEL ASCI RED instead “in silico”. Bioinformatics could lead directly to a global the Netherlands. If an exascale boasted a peak speed of over a (including gene sequencing), recession. What are the most machine is to become a reality, tera (1012) Flops. The November social science data analysis and important barriers to continual this will require major advances speed increases? Many believe 2012 speed champion is the the processing of digital classics in energy efficiency. Oak Ridge CRAY XK7, with a assets all require the huge that the main things that we The often-misquoted Moore’s peak speed of over 27 petaflops, computational power that is should be worrying about can law (an observation in a 1965 giving an awesome now at our fingertips. Our be summarised fairly simply as paper by George Moore, Intel’s 27,113,000,000,000,000 sums everyday devices are now so energy challenges, infrastructure co-founder) says that the per second. Figure 1 shows the powerful that an HTC mobile & skills, and natural limits. phone recently won a number of components in increase in computer power First, modern computers use integrated circuits doubles over the years: the “N=1” line grandmaster chess tournament. a great deal of energy. Put very approximately every two years. gives the speed of the world’s These are all wonderful roughly, CPUs expend energy Though Moore’s law has proved most powerful computer at that achievements, but they beg an doing two activities: floating point time, the top line gives the sum obvious question, namely operations and moving data uncannily accurate for over 40 of the power of the top 500 whether or not this relentless around. Though each of these in years, there is a great deal of computers, and the third line technological advance can itself uses only minute amounts evidence to show that this is traces the evolution of the continue, and if so, for how of energy, a petaflop machine unlikely to continue for much speed of the world’s 500th- long. does each of them in such vast longer. As a result, some of our fastest computer. The figure also quantities that its energy biggest challenges concern the WILL COMPUTER SPEED provision of the necessary compares supercomputing ALWAYS INCREASE? requirements are ferocious. The speed with our current familiar 2011 USA McKinsey/Uptime infrastructure and skills as devices: for example, it takes an Many economists have report on data centres estimated Moore’s law fails. Moore’s law average of only 6-8 years for the debated what might happen if that the electricity consumption has held for many years world’s most powerful machine computer speed were to stop of an average data centre is essentially because of increases to become relegated to 500th increasing, and the general equivalent to that of 25,000 in underlying CPU clock speed, place, and my current laptop consensus seems to be that a households, and the worldwide and that has now clearly would have been the world’s halting of the speeding-up data centre consumption stopped. As a result, Moore’s law most powerful machine in late process could have negative doubled between 2000 and can only be achieved now via 1993. What can we do with all this computing power? Many important calculations that were completely beyond us just a few years ago can now be carried out. Highly sophisticated climate change models can help to predict what we need to do to conserve our planet. The calculations carried out by the Large Hadron Collider to confirm the existence of the Higgs boson require the interpretation of mind-boggling amounts of data, and the power of current CFD (Computational Fluid Dynamics) calculations mean that F1 racing teams now rely more on simulation than wind tunnel testing to inform car design. The current capabilities of computational biology and medicine mean that important experiments can be carried out (Courtesy of Jack Dongerra, Tennessee)

26 Science in Parliament Vol 70 No 3 Summer 2013 sip SUMMER 2013 5/7/13 08:38 Page 29

multicore processors, and electron leakage from wires an intimate and sentient, strategic plan forward is hyperthreading and the use of will have to be dealt with. The superhumanly intelligent entity. becoming ever more massively parallel architecture. challenges are truly enormous. One result of this could be that complicated and the stakes Unfortunately much of industry biological science finds ways to could not be higher. uses legacy systems that have “TECHNOLOGICAL improve on the natural human been developed over many SINGULARITY” – THE KRAKEN WAKES intellect. Some aspects of years. The UK software business Technological Singularity theory (worth over £3bn per annum) Finally, it is worth debating are rather scary. Some of its faces the huge challenge that whether computers will ever exponents refer to the “post- almost all software will need to become “conscious”. As humans human” era. It has been noted SPEED change to reflect the new we set great store by the fact that that there is no reason why a National Science and architectures. Research and skills we are conscious, living beings – conscious, superhumanly Engineering Week Seminar are crucial to these changes, and but what are the essential intelligent computer should be on Thursday 21st March worldwide investment is urgently differences between our brains friendly to humankind. Serious required. and a computer? Could it be that scientists across the world We also heard from Lord believe that it is only a matter of Drayson (a previous Minister . . . worldwide investment is time before the singularity occurs. for Science) about his urgently required . . . development of superfast CONCLUSIONS electric cars. This included a Inevitably, there are natural we are no more than extremely film of him accelerating from For many years Moore’s law limits to what can be achieved. sophisticated robots? Many have 0-100mph in just over 3 and increased miniaturisation Nothing can grow exponentially debated this exotic question seconds! have combined to guarantee forever, and we are already without coming to a conclusion. that computer speed and The final talk was from facing barriers imposed by basic Nevertheless, eminent computer scientists regularly discuss so- capacity increase. However, the Professor Steve Jones (UCL), physics. Transistors will soon called “Technological Singularity” days of the improvement via the well known geneticist have to be produced on a theory, which countenances the hardware are drawing to a close. and writer. He gave an quantum scale and be just a possibility that, at some time in We still need investment in amusing account about the few atoms large; circuit etching the near future, superhumanly supercomputer hardware and rates of migration of snails is limited by the 50nm intelligent computers that are in data centres, but even more we (and hence their genes), and wavelength of UV light, and some sense “awake” will need investment in research, then segued into human hitherto unforeseen quantum develop. Further, large computer infrastructure & skills, and populations, and in particular complications such as the networks and their associated software development. The the surname “Jones”. Heisenberg uncertainty principle users may combine to become future is still rosy, but the

AN OASIS IN THE DESERT – The growth of a Science Base in Qatar

The UK Science & Innovation Network has recently appointed an officer to cover the Middle East Gulf region. Based at the British Embassy in Doha, Dominic McAllister covers UK S&I links with Qatar, Saudi Arabia, United Arab Emirates, Kuwait, Oman and Bahrain. He writes about his early experiences of Qatar. You can follow him on twitter @UKScienceQatar.

Coming to a new posting in expectations, but returning after from gas and oil reserves are Dominic McAllister the Middle East after three years 15 years has been an education. principally responsible. Doha is UK Science & Innovation Network in Seoul has been a big shift for The rate of modernisation in literally emerging from the (Gulf) my family. We aren’t new to the Doha was the first revelation. A desert (in many places the region – my daughters are forward looking royal family, a pavements are still sand). The proud of the fact they were born relatively cohesive society, and a traditional souk has been rebuilt, in Riyadh. We had some steady investment of income but is now air-conditioned. The

Science in Parliament Vol 70 No 3 Summer 2013 27