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Power from the sky New fingerprint technique Paintings can be “heard” as well
as seen Prof Yash
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THIS UNIVERSE
The basic reason why they attract each other is that they have opposite charges. No, their masses are not the same, but even if they were they would still attract each other.
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Power from the sky
The energy consumption is the index of industrial growth of a nation. More and more energy is needed to sustain this growth. The energy we need is just a few miles above our head, which is renewable. It is the wind energy at high altitudes (15,000 feet or above), which can be harnessed by flying electric generators (FEGs). This energy is clean, non global warming and potentially more economical than other forms of energy. There are temperate zone winds, all over the world, possessing tremendous energy, which can be captured for electricity generation. These high energy winds are at attitudes of 15000 feet or above and not just a few hundred feet where these are tapped by rotor on towers of conventional windmills. An Australian Professor Bryan Roberts working at Sky Wind Power Corporation has already demonstrated that the FEG’s technology is practical at low altitudes. Now, Roberts has the plan to demonstrate this technology at altitudes of 15,000 feet or above. The devices based on this technology are termed as “Flying Windmills” or “Gyromills”. The FEG looks a bit like a cross between a balsawood helicopter and kite (Fig. 1). It is tethered to the ground by cable.
It uses its rotors to climb up into the sky and flies in the sky. The cable connecting FEG to the ground first draws energy from the ground and uses that energy to power the machine as a helicopter. Once the machine gets to its altitude, FEG is switched on to the generator mode. The rotors generate electricity when they rotate about a horizontal axis due to high wind velocities. The electrical energy is transferred to a transformer at a ground station and then, it is transmitted to the electricity power grid. There is another tethered device, called Magenn Power Air Rotor System (MARS), which also converts high altitude winds into electrical energy (Fig.2). It is a closed structure device, like a balloon, which is filled with helium gas. The helium gas sustains the Air Rotor, which ascends it to an attitude for best winds. The rotation of rotor causes the Magnus effect, providing additional lift, stabilisation and keeping it to pull up overhead than drifting downwind on its tether. According to wind power math formula, the wind power is proportional to the cube of the wind velocity. At altitude of 30,000 feet, the wind velocity is found to be two to three times that at 100 feet above the ground. Thus, the wind power potential at high altitude is eight to 27 times as compared to that of traditional windmills. The wind capacity factor also plays significant role in efficiency of FEGs. The capacity factor is the percentage of energy actually captured relative to what would be captured if the turbines were operating at full capacity all the time. The wind capacity factor at high altitudes is found higher as compared to at the ground level. The highest capacity factor is found to be 95% in Gough Island in the Atlantic Ocean between Africa and South America. In India, Patiala is found to have a capacity factor of 72% at altitude of 35,000 feet. The writer is Assoc. Professor (Physics) Deptt. of Chem. & Physics, CCSHAU, Hisar.
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Catching criminals could become quicker thanks to a new fingerprint technique developed by British scientists. Researchers at the University of Sheffield in England have developed a technique to compress fingerprints lifted from a crime scene so they can be transmitted to a fingerprint bureau in a fraction of the normal four to 20 minutes. “Now we can transmit a lift within 30-60 seconds,” Prof Nigel Alinson told a news conference at the British Association Festival of Science. The system, which will be used by all 43 U K police forces, was approved by the National Fingerprint Board earlier this year. Instead of visiting several crime scenes and waiting until the end of the day to get the prints to a bureau, crime scene examiners can use a laptop with a wireless card and a small scanner to send them via mobile phone networks. In an area of England where the system was tested it takes, on average, four days to get an identity. The system could reduce that to less than two hours, according to Alinson. “The current record time for an examiner attending a scene to a suspect’s identity being obtained is 20 minutes,” he said. Alinson and his colleagues are also working on developing technology to identify footwear impressions and shoe patterns taken from crime scenes. Although footwear evidence is not as unique as DNA or fingerprints, Alinson said there is more chance of picking up footprints from the scene than fingerprints. Since January, new police powers in England allow footwear impressions to be taken from crime scenes and stored and searched in a database. “There is no practical technology to do this at the moment — it is done manually,” said Alinson. The software he and his team are working on will compare features of the shoe with a reference library of up to 12,000 different models.
— Reuters |
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Paintings can be “heard” as well
as seen
Artists such as Wassily Kandinsky appeal to more than just the visual sense because their work can also be heard — at least by some people, a British neuroscientist says. Synaesthetes are individuals in whom one sense triggers another. Their senses are connected, so as well as seeing a painting such as “Composition VIII, 1923” by the Russian painter, the work also triggers sounds. “What Kandinsky wanted to do was for it to appeal to hearing as well,” Dr Jamie Ward, a neuroscientist at University College London (UCL), told a British science conference. Whether or not Kandinsky was a synaesthete is not known but Ward said the artist certainly knew about the sensory phenomenon. Synaesthetes make up only about one to two per cent of the population but Ward believes everyone links music and art unconsciously. To test the theory, in a series of experiments he asked synaesthetes to draw and describe their vision of music played by the New London Orchestra. Other people without synaesthesia, who acted as a control group, did the same and a professional artist created animations of the images related to the music. “We played them musical notes and got them to draw and describe what they see,” Ward said. When more than 200 people were shown 100 images and asked to choose the animations that best suited the music they consistently selected the images from the synaesthetes. “It’s almost as if everybody can appreciate these synaesthetic images even if they don’t have synaesthesia,” he added. People are born with synaesthesia, which runs in families. Ward and other scientists believe that by studying the phenomenon they can learn more about how the senses and thoughts are linked in the brain. “Kandinsky wanted to make visual art more like music — more abstract. He also hoped that his paintings would be heard by his audiences,” Ward added. — Reuters  |
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THIS UNIVERSE
What is the physical difference between an electron and a proton that they attract each other, as their charges are equal but opposite and their masses are also same. The basic reason why they attract each other is that they have opposite charges. No, their masses are not the same, but even if they were they would still attract each other. The electric force is usually called the Coulomb force. It is attractive between like charges and repulsive between unlike charges and varies inversely as the square of the distance between them. You perhaps know that a hydrogen atom consists of a proton and an electron. If there were no other considerations the electron would go on spiraling towards the proton till they merge. This does not happen. In ordinary language we say that the orbit of the electron around the proton is stabilised because of quantum considerations. A few months back you said that photons have no mass, but how is that possible? The momentum equation is p = mass times velocity; therefore photons would have no momentum! For a person who has just started learning Newtonian laws of motion your curiosity and concern is quite valid. When I saw your question I first thought of asking you to wait till you have learnt the theory of special relativity and a bit of quantum mechanics. But that might be a wait of at least a couple of years. Till that time this question would have kept bothering you. Therefore, I decided to gamble on something which you must have heard of and connect the argument with that. You must have read of the famous equation of Einstein: E = Mc2. Here c is the velocity of light, M the mass of an entity and E its energy. This is the equation behind production of energy in nuclear reactors, in atomic bombs or in the production of energy at the centre of the sun. What this equation says is that all forms of energy have inertia designated here by M. In other words the inertia of energy M given by the equation: M = E / c2 For a photon E = hv . Here h is the Planck constant and v is the frequency of the photon. You know that frequency of light is connected with its wavelength and if you do not know about the Planck constant at this time, it does not matter. Remembering that M represents the inertia, like mass in the mechanics you are learning, we can write that the “mass” of a photon as mp = hv/c2, and the momentum of the photon as product of mass and velocity: mp x c = hv/c. Remember always that we are talking of the inertial mass and not the rest mass of the photon, which is, of course, zero. I wonder if you are a little
happy now.
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