Tagged: Horizon Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 9:01 am on March 6, 2020 Permalink | Reply
    Tags: , , , Horizon, , Speleology-the study of caves   

    From Horizon The EU Research and Innovation Magazine: “Cave rock studies provide window into ancient civilisations” 

    1

    From Horizon The EU Research and Innovation Magazine

    05 March 2020
    Caleb Davies

    There is a certain romance to speleology, the study of caves, if you can see past the cold and the damp and the dark. Caves are ancient and often beautiful places. And they can be useful. Rock formations in caves, it turns out, hold within them chemical secrets that provide a window on both ancient civilisations and the climate of the future.

    1
    Speleothems, such as stalactites and stalagmites, may hold the secrets of why ancient civilisations collapsed. Image credit – Sebastian Breitenbach.

    Many people think of speleothems, or cave rocks, as being dull and brown. But they come in a wide palette of colours. ‘I was recently with a friend in an abandoned mine where there were some rocks that had a bluish, greenish sheen because they had a lot of copper in them,’ said Dr Sebastian Breitenbach. ‘It’s really rare to see that.’

    Think of a speleothem and you’re probably imagining stalactites and stalagmites. (To remember which is which, try thinking of stalactites having to hold on tight; they’re the ones that hang from the ceiling.) These rocks are formed as water drips into a cave and the dissolved carbonate it contains gradually precipitates out. You also get flowstones formed from underground streams and thin-walled tubes of rock known as ‘soda straws’.

    These rocks grow achingly slowly: a few tenths of a millimetre per year in the fastest cases. This means stalactites can be tens of thousands of years old. And because cave rock is laid down gradually by individual drops of water, it stores a record of their chemical composition.

    It turns out that some of these chemical signatures vary depending on the climate at the time. Take for instance the ratio of two isotopes of oxygen, oxygen-16 and oxygen-18. Rainwater contains a specific ratio of the two and so by grinding down samples from speleothems and analysing the isotope ratio at different points along the length of the rock, geochemists can get a hint of how rainy it was, or where the rain originated from when the rock formed. There are plenty of other proxies besides oxygen too.

    Ancient

    This record of ancient climate entombed in stone turns out to be useful in giving us a handle on what life was like for ancient civilisations. It can also tell us about periods such as the mysterious Bronze Age collapse.

    This was the 50-year period in which several major civilisations in the Mediterranean, including the Egyptian empire, the Mycenaeans and the Hittites, all collapsed about 3,000 years ago. Some reckon this might have been to do with a megadrought that hit the region. But this is a controversial idea and there are plenty of other theories. Some ancient texts pin the blame on invading hordes known as the ‘sea peoples’.

    ‘Turkey has been home to many important ancient human cultures, from some of the world’s earliest farming societies in the Palaeolithic to more modern societies like the Hittites, classical Greeks, Roman, Byzantine and Ottoman empires,’ said Dr Ezgi Unal-Imer at the Middle East Technical University in Ankara, Turkey. ‘We are sure that they must have been heavily influenced by (changing) environmental conditions.’

    That’s why she began the Speleotolia project, with the goal of collecting high resolution paleoclimate data from Turkey. She has been collecting samples from caves over the past few years including 10 stalagmites from western Turkey.

    Five of these cover the Holocene period and she has one sample that provides a continuous line of growth going back 1,825 years. ‘This covers almost the entire common era – it’s a really good sample,’ she said.

    She’s currently about halfway through drilling 420 samples, which will help her reconstruct the past climate conditions. Dr Unal-Imer is excited about what they’ll uncover. We just don’t know what we will find, she says.

    Rain

    One thing her project won’t do, however, is quantify how much rain fell in any given year in the past.

    At the moment, most speleothem data can only signal short-term climate trends, says Dr Breitenbach who is based at Northumbria University in Newcastle, UK. In other words, it can tell us a certain period was much rainier than the one before – but not how many millimetres of rain fell. Why so?

    Well, let’s take the ratio of oxygen isotopes in a rock again. In truth, though this is influenced by rainfall it is also nudged up and down by other factors like temperature, and the topography and humidity of the particular cave.

    2
    Organo-metallic molecules in cave rock may be able to tell scientists about historical temperatures. Image credit – Adam Hartland.

    The QUEST project that Breitenbach led is trying to change that uncertainty, using two strategies. The first involves detailed work on one of the Waitomo caves in New Zealand. The plan is to measure many proxies in parallel and see how they all vary over time. Variations in one proxy might be caused by several factors and it’s impossible to know how much each contributed. But look at the variations in 10 or 15 proxies in tandem and there should be only one hypothesis for how the rainfall has changed quantitatively, say, that fits all the facts. ‘Then it’s like an Agatha Christie crime novel,’ said Dr Breitenbach. ‘All the facts that we learned from the proxies must fit in the interpretation.’

    One minus to this strategy, however, is that it requires a detailed understanding of the cave where the speleothem samples were taken. This means the researchers would have to summon their inner detective afresh with nearly every rock sample.

    The second strategy is to discover new proxies that really are only impacted by one variable and so can provide quantitative data directly. Dr Adam Hartland at the University of Waikato in Hamilton, New Zealand has been leading this part of the work.

    Calibrate

    He’s discovered some molecules known as organo-metallic complexes for which it’s possible to quantify how they change in cave rocks in response to temperature in great detail. The trick will be to calibrate this proxy, so that we can say a measurement of a certain amount of the complex signifies a certain temperature. ‘We know how to do that – but we haven’t quite done it yet,’ said Dr Breitenbach.

    What does all this have to do with the future though? Well, harvesting information about the past is crucial for answering questions about what will happen to rainfall and temperature in the face of the climate emergency. Take the El Niño–Southern Oscillation (ENSO), a weather pattern that affects ocean temperatures and shifts rain around in the southern hemisphere with catastrophic effects on fishing and farming.

    At the moment, we have a poor grasp of how ENSO was affected by climate change in the past. But with speleothems, we can go back in time and look at a period that was particularly warm. ‘We can see how often there were El Niños, how strong were they, and where were their strongest impacts? Then we can use the past as a key to the future,’ said Dr Breitenbach.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

     
  • richardmitnick 11:06 am on February 28, 2020 Permalink | Reply
    Tags: "How astronomers are piecing together the mysterious origins of superluminous supernovae", , , , , , Horizon,   

    From Horizon: “How astronomers are piecing together the mysterious origins of superluminous supernovae” 

    1

    From Horizon The EU Research and Innovation Magazine

    26 February 2020
    Jonathan O’Callaghan

    1
    Superluminous supernovae, though rare, tend to be found in star-forming regions of our universe. Image credit – ESO/L. Calçad/ Wikimedia, licenced under CC BY 3.0

    When a massive star reaches the end of its life, it can explode as a supernova. But there’s a unique type of supernova that’s much brighter that we’re just starting to understand – and which may prove useful in measuring the universe.

    Known as superluminous supernovae, these events are typically 10 to 100 times brighter than a regular supernova but much more rare. We’ve spotted about 100 so far, but many aspects of these events remain elusive.

    Why are they so much brighter than regular supernovae, for example, and what stars cause them? Astronomers are hoping to answer these and more questions in the coming years, with various studies underway to understand these events like never before.

    Formation

    Dr Ragnhild Lunnan from Stockholm University, Sweden, is one of the co-investigators on the SUPERS project, which is attempting to work out what stars lead to the formation of superluminous supernovae. With dozens found already, the team are building the largest collection of these events in an effort to learn more about them.

    ‘By following the evolution of these supernovae into a very late phase, you can decode their (structure),’ she said. ‘This tells you things about the star that exploded, and possibly how it exploded.’

    To find these explosions, Dr Lunnan and her team are making use of a camera called the Zwicky Transient Facility (ZTF), part of the Palomar Observatory in California, US, to survey the sky.

    Zwicky Transient Facility (ZTF) instrument installed on the 1.2m diameter Samuel Oschin Telescope at Palomar Observatory in California. Courtesy Caltech Optical Observatories

    Caltech Palomar Samuel Oschin 48 inch Telescope, located in San Diego County, California, United States, altitude 1,712 m (5,617 ft)

    Only one supernova is expected per galaxy per century, with only one in 1,000 or even one in 10,000 of those being superluminous. But by looking at many galaxies simultaneously with the ZTF, it’s possible to spot these events.

    Superluminous supernovae are found more often in star-forming galaxies than older galaxies, which means they are likely explosions of young stars, notes Dr Lunnan.

    ‘Additionally, you very often find them in galaxies that are kind of chemically primitive, called low-metallicity, and we think this is also a clue,’ she said. ‘We think they’re associated with very massive and metal-poor stars. But beyond that, we really don’t know.’

    In 2018, Dr Lunnan and her team discovered a superluminous supernova with a giant shell of material around it [Nature Astronomy], which it must have ejected in the final years of its short life. ‘That discovery (of the shell) is another clue that the stars must be very massive,’ said Dr Lunnan.

    Going supernova

    The exact process that causes a superluminous supernova is another question. Typically, stars can go supernova either by independently collapsing, or sharing material with a small dense star known as a white dwarf before an explosion takes place, known as a Type 1a supernova. But what happens in a superluminous event?

    Dr Avishay Gal-Yam from the Weizmann Institute of Science in Israel, project coordinator on the Fireworks project, has been trying to answer this question. The project has been using observations of the night sky from cameras like the ZTF that have a rapid cadence, meaning they show an event shortly after it occurred, to study cosmic explosions.

    Previously we would only see supernovae about two weeks after they happened, but ZTF’s constant observations of the sky allows us to see them within about one or two days. And that’s particularly useful for superluminous supernovae. A regular supernova can brighten and fade over a period of weeks, but a superluminous supernovae can last several times longer, while also reaching its peak brightness slower.

    ‘They are relatively slowly evolving,’ he said. ‘The time for the explosion to reach its peak could be a couple of months, sometimes even longer. So studies of these objects are not focused on rapid observations, but rather a continuous follow-up campaign which takes months and sometimes years.’

    So far Dr Gal-Yam and his team have published several studies [Annual Review of Astronomy and Astrophysics], examining some of the theories for how these events happen. One idea is that a regular supernova leaves behind a rapidly spinning and highly magnetised neutron star, called a magnetar, which acts as a giant magnet and pumps energy into the supernova explosion.

    But Dr Gal-Yam’s more favoured theory is the same advocated by Dr Lunnan – that collapsing massive stars are the cause. ‘What can generate so much energy that can power such a luminous emissions, both in terms of the amount of energy and the very long amount of time the emission continues to happen?’ he said. ‘The most intriguing (theory) is an explosion from a very massive star 100 times more massive than the sun.’

    Distance

    While many questions about superluminous supernovae remain unanswered, they are already proving useful as distance markers in the universe. Called ‘standard candles’, bright events like supernovae can tell us how far away a particular galaxy is as we know how bright they should be.

    Standard Candles to measure age and distance of the universe from supernovae. NASA

    ‘The idea here is a standard candle, an object of known luminosity,’ said Dr Mark Sullivan, project coordinator on the SPCND project that looked at how explosive events like this might be useful for cosmological studies. ‘If you can find it in the sky and measure how bright it appears to be to us on Earth, you can tell how far away it is.’

    The brightness of superluminous supernovae makes them particularly useful. Using the Dark Energy Survey (DES), a survey of the night sky using the Cerro Tololo Inter-American Observatory in Chile, Dr Sullivan and his team found more than 20 superluminous supernovae in galaxies up to eight billion light-years from Earth, giving us a new cosmic distance ladder. ‘We got a new data set of these objects in the distant universe,’ said Sullivan.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

    With a growing sample size of these events, astronomers will now be hoping to answer once and for all what causes them. Upcoming telescopes like the Vera C. Rubin Observatory in Chile could prove vital, performing new sweeping surveys of the night sky, and finding more of these objects than ever before.

    Fritz Zwicky discovered Dark Matter in the 1930s, when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, did most of the work on Dark Matter.

    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.

    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.

    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    The Vera C. Rubin Observatory currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    LSST Data Journey, Illustration by Sandbox Studio, Chicago with Ana Kova

    ‘We really are in this era where we’re finding so many objects – even things that are rare,’ said Dr Lunnan. ‘It’s a lot of fun.’

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

     
  • richardmitnick 12:36 pm on September 8, 2017 Permalink | Reply
    Tags: , , , , Horizon, , X-ray flares   

    From Horizon: “Robin Hood black holes steal from nebulae to make new stars” 

    1

    Horizon

    05 September 2017
    Ethan Bilby

    1
    Discarded gas from black holes spreads across galaxies and can even influence the formation of stars. Image credit – Flickr/ NASA Goddard Space Flight Center

    It’s easy to picture a black hole as a kind of all-powerful cosmic drain, a sinkhole of super-strong gravity that snags and swallows passing nebulae or stars. While it is true we can’t observe matter once it crosses a black hole’s event horizon, scientists are zeroing in on what happens in the margins, where molecular clouds release vast amounts of energy as it circles the plughole.

    EU scientists are honing in on just what happens to gas discarded by a black hole’s ferocious velocity, and how this can influence star formation in galaxies like ours, and even interstellar space.

    Astronomer Dr Bjorn Emonts, from the National Radio Astronomy Observatory in the US, has been using some of the world’s biggest radio telescopes to look into what happens to such jets of gases as part of the EU-funded BLACK HOLES AND JWST project.

    ‘We wanted to see how black holes can affect the evolution of galaxies as a whole,’ he said.

    Using advanced radio telescopes in the Atacama Desert of northern Chile, located 5 000 metres above sea-level, Dr Emonts can detect the characteristic spectral signatures of gas molecules as they are driven outward by the black hole.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    ‘If you have a rotating black hole with an accretion disk (particles orbiting the black hole), it can actually act like a kind of dynamo. It can trigger magnetic fields on either side of the accretion disk and these magnetic fields can trap charged particles,’ he said.

    ‘What you get is two jets … that can really propagate out very far away from the black hole – they can cross the entire galaxy and even influence the surroundings.’

    Almost every galaxy is likely to have a rotating supermassive black hole at its centre. Dr Emonts found that the Dragonfly Galaxy, an ancient system from the early universe made up of merging galaxies, had tornado-like jets of particles coming off its black hole which could, in fact, kick-start its star formation.

    2
    https://www.quora.com/What-would-theoreticly-happen-if-the-Dragonfly-44-Galaxy-collided-with-our-Galaxy

    ‘We actually saw the amount of gas being displaced is the same rate as which stars are being formed,’ Dr Emonts said.

    By scanning radio waves to detect carbon monoxide in another star system, the Spiderweb Galaxy, he was also able to show that molecular gas could exist and form stars outside of galaxies, and that jets of particles could even help the process by triggering cooling.

    Dr Emonts hopes these findings will lay the groundwork for using the next generation of space telescope, the James Webb telescope, which can see molecular gas near black holes in unprecedented detail. This will lead to an even deeper understanding of the important role that black holes play in the evolution of galaxies.

    X-ray collisions

    Another way to detect energy given off from black hole accretion disks is through the X-ray spectrum. Dr Gabriele Ponti, who led the EU-funded HIGH-Z & MULTI-λ project at Max Planck Institute in Germany, said: ‘Most of the emissions from material that is falling into the black holes is in X-rays.’

    His goal was to look for evidence that X-ray flares are caused when clouds of gas cross over supermassive black holes in the centre of galaxies.

    For the first time ever he was able to observe an X-ray flare while gas clouds were being sucked into the black hole at the centre of our galaxy, called Sagittarius A*.

    SGR A* NASA’s Chandra X-Ray Observatory

    Nevertheless, it’s still too soon to say for sure if that may be the only reason for increased X-rays.

    ‘The X-rays are very bright. If you take a nuclear reaction, you have only a small fraction of energy from matter that is released – black hole accretion is many times more efficient,’ Dr Ponti said.

    Better observations of emissions from black hole accretion disks can also lead to increased understanding of the size of black holes, as well as how exactly they help seed star formation.

    ‘We observed a sample of nearby supermassive black holes and we measured their variability, and we saw that it’s extremely well correlated with the black hole mass,’ Dr Ponti said.

    That correlation can be used to determine distance, because they can correlate the intensity of emissions with the object’s mass and distance.

    Star formation

    ‘If the earth was size of the galaxy, a (super massive) black hole would only be as big as your finger nail. Yet that object can influence the physics of something the size of the earth,’ Dr Ponti said.

    To better understand the particle wind that comes off supermassive black holes, Dr Ponti looked at stellar mass black holes, millions of times smaller than those in galactic cores, and more manageable.

    The surprising thing they observed was that they only saw the winds occasionally, depending on the orientation of the accretion disk to earth. That meant that such winds were flowing off on the same plane as the disk.

    ‘When the accretion disk is face on, our line of sight is not crossing through the wind and so we don’t observe it through absorption,’ Dr Ponti said.

    Such particle winds, carrying gas that can form stars, are probably a feature of most black holes, and some studies have speculated they may even cast off more material than some black holes absorb. This adds to the growing evidence that black holes aren’t just an intergalactic destructive force, but rather a key player in the formation of galaxies.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 11:39 am on August 25, 2017 Permalink | Reply
    Tags: Dr Singh Ahluwalia, , Horizon, , , Next-gen nanoscopes can take super-res images of the atomic world, Photonic circuits could offer researchers a cost-effective way to delve deeper into the nano world,   

    From Horizon: “Next-gen nanoscopes can take super-res images of the atomic world – Dr Singh Ahluwalia” 

    1

    Horizon

    23 August 2017
    Lou Del Bello

    1
    Compact photonic chips will be able to be used with any standard optical microscope. Image credit – Geir Antonsen

    With some nanoscopes costing €1 million it’s not cheap examining the world at an atomic level, but according to Dr Balpreet Singh Ahluwalia, from the Arctic University of Norway, photonic circuits could offer researchers a cost-effective way to delve deeper into the nano world.

    Nanoscopy is still a relatively young research field, but the technology you developed is already revolutionising it. Can you tell us a bit more about your invention?

    ‘For the past 150 years people believed that microscopes cannot see images below 200 nanometres. They thought that was an established fact – all the new knowledge in the field has been acquired.

    ‘In 2007, when I started working on my idea, nanoscopy was still in its infancy so the timing was right to try new things. Today, I successfully introduced a cheap and more effective alternative to the conventional nanoscopes currently available, which can cost between €500 000 and €1 million.’

    How exactly does your alternative nanoscope work?

    ‘Currently, advanced microscopes are complex and costly. They are used to shape and deliver the specialised laser illumination patterns required to achieve high-resolution images.

    ‘In this type of microscope, the sample is placed on top of a simple glass slide or cover slip. I proposed an inverse solution, where the sample is placed on top of a complex photonic chip and images are acquired using a standard optical microscope. The photonic chip is used both to hold the sample, like a glass cover slide, and to deliver the required illumination pattern to achieve the super-resolution images.

    ‘This alleviates the need for sophisticated laser illumination and consequently any standard optical microscope can be used with our photonic chip. Integrated photonic chips can also be used to generate any exotic set of illumination patterns, which is very difficult to achieve with conventional solutions.

    ‘Our long-term goal is to retrofit the highest possible number of standard optical microscopes with the novel photonic chip and convert them into high-resolution optical nanoscopes.’

    Your chip is smaller and more manageable than any other nanoscope, but how is it also cheaper?

    ‘These photonic chips can be mass produced by semi-conductor foundries (factories) and are similar to silicon chips that are inside our mobile phones. Therefore, their cost is significantly lower, within the tens of euros.

    ‘We hope that this advantage will increase the penetration of optical nanoscopy to the developing world. In research environments where resources are limited, most labs are equipped with low-quality optical microscopes because the upfront costs of nanoscopes are prohibitive.’

    You said that your photonic chip is not only a cheaper alternative to laser nanoscopes, but also more effective. What applications could it lead to?

    ‘Besides being more compact, stable and affordable, our chip-based nanoscope also captures images over extremely large fields of view. It can acquire super-resolved images from a field of view 100 times larger than what can be presently achieved using commercial optical nanoscopy systems.

    ‘This could prove a game-changer in fields such as pathology, where you have to analyse samples with a surface of several square millimetres. An average optical microscope will scan an area of 50 microns at a time, so it would take days to scan an entire pathology sample (such as tissue, blood or urine).

    ‘Our local research team, in collaboration with the medical department, is currently working on the liver, trying to understand how filtration within the cells works. Until now, this could not be done because the specialised cells have small holes, or nanoholes, which are around 50-200 nanometres wide. You can’t see that with a normal microscope.’

    Your research was part of an EU-funded project called NANOSCOPY – do you have a business plan to scale-up your innovation?

    ‘I was lucky to have the right financial support from the EU’s European Research Council (ERC) that chose to invest in my high-risk, high-return research project.

    ‘We are now in touch with potential manufacturers, and our business case is strong. Imagine a coffee machine – the customer only needs to replace the coffee, which is much cheaper than buying a brand new machine every time you fancy an espresso.

    ‘So it’s the same principle, the initial barrier to the technology is very low, compared to what exists at the moment. Until now you had to have EUR 500 000 to buy a nanoscope, but now you just need to add a chip to your inexpensive microscope and adapt the laser input.’

    Does your scientific approach come from your background or a particular experience in your life?

    ‘My personal journey has left me with the very strong belief that the place where you work or study is not important, the people are important. I studied different subjects in various labs all over the world, and the teams I met along the way provided a unique mix of perspectives on any scientific dilemma.

    ‘I grew up in a small town in India called Varanasi, also called Kashi, it is the oldest city of India – it’s very ancient with a very distinctive culture. My mother always told me that scientists travel a lot and have an adventurous life which gives them opportunities to also help people. During my university studies I was sure that I wanted to be a researcher, but I did not have the possibility to study in the US like most Indian students who want to further their education abroad, because after the 9/11 terror attacks the frontiers were closed for a while. So I chose to study in Singapore first and did my PhD at Nanyang Technological University (Singapore), after that I relocated to Norway and had lived and worked for a one year in the UK and USA. Presently, I work in Norway where I fell in love with Europe.

    ‘While my somehow unconventional career path led me to see a problem through a creative lens, much of my success has been made possible by the very diverse group that we have (here in Norway). Our group includes people from almost all the continents, from Asia to Africa and the Americas. We have researchers with a chemistry background, pure biology, from bio-optics, physics and engineering. So we have a multidisciplinary group as well as a multi-ethnic group and I think it’s very important because we need people with diverse expertise to curate various sides of the project.’

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 10:00 am on June 12, 2017 Permalink | Reply
    Tags: , EU-funded XCYCLE project, Green wave strategy, Horizon, Micro-Doppler, Small-scale Doppler effect to help cyclists stay safe   

    From Horizon: “Small-scale Doppler effect to help cyclists stay safe” 

    1

    Horizon

    12 June 2017
    Ethan Bilby

    1
    Researchers are looking into smart radar and on-bike avoidance tech to prevent accidents with cyclists. Credit: CC0 Public Domain

    An extremely sensitive radar that can detect when different parts of people’s bodies are moving at different speeds could help drivers avoid collisions with vulnerable road users such as cyclists.

    Bicycles haven’t changed much in function since Karl Drais took the first ride 200 years ago in Germany, but while cyclists once only contended with horse-drawn buggies, modern city traffic leaves them more vulnerable than ever.

    That’s why researchers are looking at how to make cars smarter to help drivers avoid vulnerable road users like cyclists and pedestrians.

    ‘The city has to be for pedestrians,’ said Andres Aparicio, senior manager for ADAS and connected and automated vehicles at the Spanish engineering group IDIADA. ‘Step by step the car needs to go out of the city.’

    Until that happens, he is working with large automotive manufacturers like Audi, BMW, Daimler, Toyota, Volvo, Bosch, and Continental to develop prototype vehicles with automated systems that can help drivers avoid collisions.

    Aparicio runs an EU-funded research project called PROSPECT which has developed a sophisticated radar and car-mounted camera system that can provide advance detection of cyclists and pedestrians at intersections – from up to 80 metres away. And it’s not just a blip on a screen.

    ‘These are long-range high-resolution radar systems that are able to detect a shape or an object … it can detect the shape of the legs of a pedestrian or the square shape of a car,’ he said.

    The PROSPECT researchers are also using camera motion recognition and micro-Doppler effects from radar. The Doppler effect, the change in frequency of sound, light, or other waves from an object as it approaches a target, can be used to measure its speed. Micro-Doppler has an even tighter focus, and detects varying speeds of various parts of one object.

    Predicting intent

    ‘Different parts of the body moving at a different speeds, that helps predict pedestrian intent. If you are about to start walking or running, we can predict it,’ said Aparicio.

    Such judgements are made without a second thought by human drivers, but are harder for a machine. By using micro-Doppler, the system is better able to pick up subtle movement cues we take for granted.

    ‘The cars are sensing not only cyclists that may be crossing, but also parked cars and walkers on the side of the road as well,’ said Aparicio.

    It’s important that the system is not too sensitive though, or else the car would be overreacting to the stimuli for a busy urban environment.

    It is therefore designed to provide drivers with a warning from metres away, but the collision avoidance only kicks in at the last second, choosing the best option, to steer around or to brake, to stop a crash.

    Even though fully automated cars are on the way, the city is still the most complicated scenario and the hardest for vehicles to perform in, Aparicio explained.

    ‘Full automation will first come in comfortable situations like highways, where cars are all going the same speed and things are more predictable.’

    Fatalities

    In the meantime, systems like these may be the last line of defence to protect vulnerable pedestrians and cyclists. While motorist deaths are on the decline in Europe, fatalities from two-wheeled vehicles, bicycles and motorcycles, remain stubbornly high.

    Cyclists account for a stable or growing share of people injured in traffic accidents, with a rate 7-9 times higher than car travel, according to researchers.

    Professor Luca Pietrantoni from the University of Bologna in Italy runs the EU-funded XCYCLE project, which has analysed hundreds of accidents between cyclists and cars to try and look for ways to cut down the numbers.

    A common problem with cyclists is the crossing of junctions on red signals, so to cut back on this the team has tested a new system of timed green lights known as a green wave.

    They are programmed so that if cyclists ride at a speed of 20 kilometres per hour, they will hit green lights all the way through their journey. The system is designed to coincide with cyclists flowing into city in the mornings and out in the afternoons.

    ‘The system increases the comfort and safety of cyclists,’ Prof. Pietrantoni said.

    ‘This green wave strategy will be launched this summer in the bike-friendly city of Groningen in the Netherlands for user behavioural evaluation purposes,’ said Prof. Pietrantoni.

    Researchers on the project are also developing new systems for motorised vehicles, such as audio and visual warnings for lorry drivers that can help prevent one of the most common accidents – hitting cyclists when lorries turn across bike lanes.

    ‘For example, a bicycle bell that rings as an auditory reminder to truck drivers to avoid a collision,’ said Prof. Pietrantoni.

    Kitting out bikes, especially electric bikes, with better avoidance systems could also help.

    ‘Most of the on-bike systems available in the market give information to the cyclist about the route, but it’s relatively uncommon to find a safety-related on-bike system,’ said Prof. Pietrantoni.

    The team was specifically interested in trying to understand the risk of a crash at an intersection. In a controlled area in Italy they tested a safety system installed on the handle bar of a bicycle which provided visual and auditory warnings to the cyclist, preventing an unsafe encounter between them and any nearby vehicles.

    The team found that cyclists will adapt their behaviour if they have access to such additional avoidance tools.

    ‘Some cyclists are quite reluctant to have expensive technology on their bike, but other types of consumers who are using electric bikes are more willing to accept this type of safety-related tech,’ said Prof. Pietrantoni.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: