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| SCIENCE TRIBUNE | Thursday,
March 21, 2002, Chandigarh, India |
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NEW PRODUCTS & DISCOVERIES
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Effect of magnetic field on life EVERY part of matter generates a magnetic field because each electron, the building block of matter, is a little permanent magnet. The reason that we are not more often aware of the magnetic properties of matter is that the magnetic fields of different electrons are so small and usually cancel because of their different orientations. A magnet is described to have a combination of North and South poles. The N-pole is the one from which the magnetic field lines emerge from the magnet into the surrounding space. All the attempts so far have failed to isolate N-S poles and even braking the magnets to atoms and electrons has not resulted in the isolated magnetic pole or a magnetic monopole. Thus, the simplest magnetic structure that can exist in nature is the magnetic dipole. Put a bar magnet (may be a human body), an electron (body is made up of electrons) having its N-S poles in a uniform magnetic field. The N-S poles experience equal forces in opposite directions with zero net force. Unless the object (i.e., body) is already lined up with the field there will, however, to a torque tending to make N-S axis parallel to the field. If the field is not uniform, for example, that the filed lines converge, indicating that the field becomes stronger (near North Pole) where the lines are closer together. Torque acts are before but when the N-pole points along the field it will now be in a stronger field. The net result is that the whole object is pulled towards the strongest part of the field. Any type of experiment involving the motion of electron is required to be performed by making the direction of electron motion in the Earth’s magnetic meridian in order to avoid the interference of Earth’s magnetic with that of electron. A magnetic field causes a torque on an electron that tends to line up with the field. This torque, therefore, acts to break up the electron alignment and so to destroy the uniformity of matter that leading to the change in behaviour of the matter. Magnetism and superconductivity (a most ordered form of matter) are this natural enemies. The people do not know magnets with their magnetic fields and their applications as commonly as electric current. Nowadays, the most familiar magnets may well be the small decorative devices used to fasten notes but magnets play a much larger part in our daily lives than that, however. Even, if we restrict ourselves solely to the household environment, we can find magnets or magnetic materials in the motors of our electric appliances: in television sets and VCRs; in doorbells and thermostats; in relayx, circuit breakers, and the electric utility meter; in loudspeakers, stereo headsets, floppy disks, and aquarium pumps. Magnets or magnetic materials are contained in the ink used on checks and on dollars bills; in answering machines, telephones, tape decks, credit cards, audio cassettes, cupboard doors, and portable chess sets. And beyond household applications are thousands of uses of magnets and of magnetic materials in industry and in scientific research. William Gilbert, a British physician in 1600 from his systematic survey pointed that Earth was a huge magnet. Earth’s magnetic field for points near the Earth’s surface can be represented as the field of a magnetic dipole located near the center of the Earth. Dipole axis of Earth makes an angle of 11.5° with the Earth’s rotational axis. Earth’s magnetic dipole moment is 8.0x1022 J/T. Dipole axis intersects the Earth’s surface at two points, called the geomagnetic North Pole (in northwest Greenland) and the geomagnetic South Pole (in Antarctica). There is at present no satisfactory detailed explanation for the origin of the Earth’s magnetic field. Earth’s magnetic field has been studied for its applications in navigation, communications and processing but it is least studied systematically for its effects on the human life on Earth. The quantities of interest related to Earth’s magnetic field have been its magnitude and direction at different locations on the Earth’s surface and in the surrounding space but not its interactions with the biological systems on Earth. In spite of the local variations involved in the magnitude and directions of the Earth’s magnetic field, the best-fit dipole field changes only slowly over such time periods which are after all very short compared to the age of the Earth. This field is weal (=2pT) but also important because of the vast volume it occupies and influences every thing on the Earth. There may be some positive as well as negative aspects being associated with the influence of Earth’s magnetic field on human life which have to be studied in detail. Owing to the apparent mystery of magnetic forces, people of the past, and even today, have looked for effects of the magnetic field on human and other animal life. In many cases people have believed they have found such effects but never in a way that could be replicated. According to the old age scientific knowledge in our culture it is advised and practiced not to sleep with our "Head" pointing towards North (Uttar in Hindi) of Earth. This is termed in local language as "Auttra" means to be childless i.e., consequences of low reproductive capacity. But this position (i.e., Head towards North of Earth) is advised and practiced while putting the "dead" body to rest before cremation. Similarly, it is advised and practiced to avoid movements making loops about any living organism except few cases such as plants for worship etc. There may be many more such beliefs in our cultural heritage related to our day today life activities pointing towards the optimum use of Earth’s magnetic field. Like bearing of magnetic earring’s and magnetic necklace for controlling body weight and body pains. This all is advised to protect us from the bad effects on our health, mind, behaviour and prosperity in our life. But as these effects vary from person to person and can not be replicated or demonstrated so are not accepted on the scientific basis. Similarly, as mariners use a magnetic compass to guide them, migratory birds and nectar-seeking bees could use a magnetic sense. Over the years many investigators have explored this possibility. They have attached magnets and dummy magnets to birds and claimed an altered behaviour for the case of magnets. It is said that pigeons not only detect direction but also can detect a change in magnetic field strength. Bees are thought to use a magnetic map and convey, by dances, directions to prospective foragers. The application of Magnetic Resonance Imaging (MRI) technology for diagnosis of human body indicates its (human body’s) response towards magnetic forces. It is known that a large class of bacteria, some billions of years ago, developed a magnetic guidance system that guided them in their movements. In 1975, however, Richard Blakemore discovered a completely replicable effect of the Earth’s magnetic field on a class of living organisms — the magnetotactic bacteria. The discovery showed a direct and repeatable influence of the Earth’s magnetic field on a living organism. Blakemore and his coworkers also showed that life was not essential to the orientation of bacteria in the magnetic field. Killed bacteria would rotate to follow an imposed magnetic field (field alignment) but, since they were dead, would not migrate in that field. Each bacteria behaves as a small magnetic dipole that would rotate in a magnetic field. The self-field alignment in the Earth’s magnetic field is only possible for a body with a volume of the order of 10-22 -10-21m3 that is the size of a bacteria. For a body of human body size, field alignment in the Earth’s magnetic field can be achieved by oneself, whereas, in case of a dead body the alignment is made by others. Though, no one has found so far a
mechanism of these few above mentioned and many more possible effects
of magnetic field (Earth’s as well as artificial one) on any type of
biological systems bigger than magnetotactic bacteria. If it were a
local magnetic dipole, it would have to be connected to the nervous
system of higher organisms (like in bees, birds and human) rather than
act as a passive torque as in the case of the bacteria. Indeed, no one
has been able to condition a bird, bee or human to be attracted or
repelled by a magnetic field. Consequently, the case for magnetic
sensitivity and the effect of Earth’s magnetic field on the higher
organisms still have to be proved. Nature holds unsuspected secrets,
which she is, however, willing, sparingly, to uncover to diligent and
imaginative search. |
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NEW PRODUCTS & DISCOVERIES AT first glance this may look like an ordinary travel pillow, but with integral speakers on each side, this one plays a relaxing range of sounds, from the ocean lapping against the shore, birdsong, a gentle stream, summer nights, tropical forests.... No matter how stressed out you are, after a few moments with this you will descend into a feeling of total bliss and relaxation... It has integral speakers (two volume settings), six "natural" sounds to choose from: Ocean, Night crickets, Gentle Stream, Spring Rain Mountain Sunrise, Birds chirping and measures 22" x 17 1/4" x 12 7/8" . Requires 3 AA batteries. Sells for about 18 pounds. Indian invents novel generator A scientist in the country has developed a unique "space power generation (SPG)" which he claims produces more power than it consumes and is a possible precursor to the elusive" perpetual machine." Working on the concept of space power generation for more than 15 years, Paramanhamsa Tewari, former director of the Kaiga atomic station, three months ago completed the latest version of his machine with funding from Crompton Greeves Company in Mumbai. He unveiled the machine to the media recently in presence of electrical engineers from the Kaiga atomic power station. During the demonstration, the SPG generated electrical power that was 2.63 times the mechanical input applied at its shaft. According to Tewari the over unity efficiency of the machine "is a result of the specific configuration of rotating magnetic circuits with respect to the conductor where current is generated by electromagnetic induction." Prasada Rao, a senior electrical engineer in the Kaiga project who was present at the demonstration said that availability of high current at low voltage would make SPGs useful in electrolysis to generate hydrogen fuel from seawater. Tewari does not rule out further improvements that could lead to development of free-running SPGs — machines that run perpetually without any external power.
Tewari has been invited by German
scientists to speak at an energy conference in Berlin and display his
unique "space power generator (SPG)." PTI |
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Science & Technology Crossword Clues: Across: 1. A major pollutant. 4. An iron packing piece to clasp together the parts of a joint. 7. A white aromatic solid, poisonous and corrosive. 9. Magnetic field acting at a point for 1 coulomb charge moving at 1 m/sec velocity. 12. ......... Domini, full term for A.D. 13. An establishment of Indian Army defence system (abbr.) 14. A time system that has a uniform rate and has tropical year as its unit. 15. 17th Greek letter. 16. A band that passes around the celestial sphere extending 9 degree on either side of the ecliptic. 19. Inflammable substance lighter than water and insoluble in it. 22. Pertaining to air. 23. The force by virtue of which a moving body tends to maintain its velocity. 25. Strip of wood bound to fracture limb. Down: 1. A long handled small paint brush bound with tin. 2. Vegetables of onion family with long white bulb. 3. Unlimited three dimensional expanse. 5. A bond formed by transfer of electrons from one atom to other. 6. A fluid tissue found in humans and animals. 8. Excavated material. 10. Rate of change of distance. 11. Structure of laths or bars crossing each other. 16. A protein from maize. 17. Unit of resistance. 18. Small social hymenoptreous insects. 20. A common metal used in tools. 21. A storage space under a roof. 22. Language used by the deaf in USA (abbr.) 24. Short name for your personal computer. Solution to last week’s crossword:
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