REPORT II MAGNETS- HISTORICAL PROPECTIVES

January 21, 2016 (Revised and re-posted on April 23, 2020)

In my first report published earlier (Jan 8, 2016), I reported that the history of the magnetic materials and the field of magnetism date back to ancient times – well before the stone and pre-stone ages, and tried to provide a relationship between magnetism and-bio medicine. In this report, I will elaborate on how these magnetic materials were perceived in old ages and what led them to become most important materials in the modern era.

Interestingly, the magnetic history and the history of science began at the same time. The curiosity in magnetic materials is prompted by the ability of the invisible and remote-control nature of magnet to attract or dispel materials from a distance. To understand more about the invisible magnetic energy or force, we need to have either two pieces of permanent magnets, or one permanent magnet and other pieces of magnetic materials such as Fe, Co, Ni, etc., or even Loadstones – weak magnetic materials.

Loadstones are widely popular and abundantly available rocks in the earth and are rich in magnetite -also known as Fe3O4. These rocks are fascinating because they are still very good magnets, though they were magnetized by huge lightning strikes thousands of years ago.

While it would not be wrong to say that the application of magnets dates back to stone and pre-stone ages, to our knowledge, the initial application of magnet in the form of “Spoon, also named as a south pointer” by humans’ dates back to mid-11th century (1064 AD) in China. A century later, a European re-invented the magnet in the form of a compass. The discovery of the compass eventually helped Mr. Christopher Columbus discover America in the late 15th century (1492 AD). Between the periods of the 5th and 15th century, also known as the medieval age, many compared the magnet to the human soul because of its interesting movement, and also believed that the alignment of the compass along the north and south direction was due to the effect of the positioning of stars around the earth. After the medieval age, however, it was, Gilbert who investigated the phenomenon of magnetism systematically using scientific method in the early 17th century (1600 AD).

The investigation on magnetism and magnetic material continued and an important development in magnetism was made by Swiss Mathematician Daniel Bernoulli in late 18th century (1743 AD) who invented Horse Shoe magnet, that is still widely used in school text books around the globe.

By the 18th century, people already knew that magnets have two poles, one is north and the other south. By now, they also knew that electrons in metals have two charges, negative and positive.

A true relationship between magnets (magnetism) and electrons (electricity), was accidently discovered in the early 19th century (1820 AD) by Hans Christian Oerstan from Denmark. Immediately after that, Andrew-Marie Ampere and Dominic Francois Arago from Paris, demonstrated that a current carrying coil was equivalently a magnet.

It was Michael Faraday who discovered electromagnetic induction in the early 19th century (1821 AD). He used a “still” magnet, a current carrying coil, and discs of mercury to demonstrate the principle of electric motor. Michael Faraday also discovered the interrelationship between magnetics and optics in the late 19th century (1845 AD). In the next report, you will learn more about magnetic materials and magnetism, and their potential applications in health care industry.

 

To download the relevant text, click Ferromagnetic Alloys: Magnetoresistance, Microstructure, Magnetism, and Beyond (Review)

REPORT I – APPLICATION OF MAGNETIC MATERIALS (चुम्बकीय सामाग्री र पृष्ठभुमि, संभावित प्रयोग र चुम्बकीय पदार्थ को भप्बिश्य )

चुम्बकीय पदार्थ हरु को उपयोगिता सम्बन्धि को इतिहास धेरै लामो छ र वेद-वेदान्त को अबधि सम्म फैलिएको छ। तर अहिले आएर चुम्बकीय पदार्थ हरु को उपयोगिता र महत्तो ह्यात्तई बढेर गएको छ, बिशेस गरेर नया उपकरण हरुको बिकाशले यसको उपोगीयोता बढ्दै गएको हो । मेरो पन्ध्र बर्षको अनुसन्धान मा मैले चुम्बकीय पदार्थ हरु को पयोगिता येति धेरै बढेर गएको एस अघि कहिल्लेइ अनुभ गरेको थिएन. हो, कम्प्युटर क्षेत्र मा, चुम्बकीय सेन्सर (जीएमआर सेन्सर को नाममा चिनिञ्छ, जसमा पदार्थ को बिधुतिय अबरोथ शक्ति, थोरै चुम्बकीय फिल्ड लगाउदा पनि अत्यतिक मात्रामा कम हुने असर भएको सेन्सर) को प्रयोग इसबी सन् १९९० भन्दा पनि पहिले देखि हुदैआएको थियो । तर इसबी सन् १९९७ मा पहिलो पटक जीएमआर सेंसर को प्रयोग आइ बि एम (IBM) ले कम्प्युटर मा “रिड हेड” को रुपमा प्रयोग गरेर देखाइ दियो। पछि एसले त इन्टरनेट मा रिभुलेशन नै ल्याइदियो । म तेतातिर अहिले जान चाहन्न । मैले अनुसन्धान गर्दै आएको बिषय अहिले “जीएमआर सेन्सर” र “नानोकर्ण” (एक मीटर लम्बाई भएको पदार्थलाइ, एक करोड पटक सम्म टुक्रा – टुक्रा पर्दा हुन आउने एक अँश लाइ एक नानो मीटर भनिन्छ) र यी दुवै मिलाएमा (अर्थात, जीएमआर सेन्सर र नानो कर्ण मिलाएमा ) कसरि अरु कुनै पनि माध्यम बाट थाहा पाउन नसकिने थुप्रै क्रोनिक रोग हरु, जस्तै, क्यान्सरको प्रारम्भिक अवस्था (रोग लाग्ने बित्तिकै), पता लगाउ सकिन्छ र जसबाट यसको तुरुन्त रोकथाम र उपचार गर्न सकिन्छ ।

तर जीएमआर सेन्सर र नानो कर्ण लाइ उपयोग गरि ब्येबहारमा उतार्न केहि बाधा-अड्चन हरु छन् । उदाहरनकोलागि अस्पतालहरुमा व्यावहारिक रुपमा प्रयोग गर्न, सेंसरको सम्बेदनशीलता र नानोकर्ण को चुम्बकीय मोमेन्ट क्रमश रुमतापक्रम 10 / Oe (ओरेस्तेड) द्वारा र 300 इएमयु / ग्राम भन्दा बढी हुनुपर्छ । र नया प्रबिधि बिकासको लागि अहिले तदारुकता को साथ अनुसन्धान भै रहेको छ र मेरो प्रमुख प्राथमिकता पनि रोग लाग्ने बित्तिकै ( जसलाई अर्ली डिजिज डिटेक्सन प्रबिधि भनिन्छ) कसरि त्यो रोग पत्त्ता लगाउन सकिन्छ र तुरुन्तै उपचार गरी रोग विस्तार हुन् बाट बचाउन सकिन्छ भन्ने अनुसन्धान सङग सम्बन्धित छ । चुम्बकीय नानो कर्णको अर्को उपयोगिता पाउनुहुनेछ चुम्बकीय इमजिङ छेत्रमा । व्यापक अनुसन्धान कै क्रममा छ, यो पनि । चुम्बकीय नानोकर्ण को उपयोगमा येतिमा नै सिमित छैन । एकान्तरण चुम्बकीय फिल्ड प्रयोग गरि चुम्बकीय नानोकर्ण लाइ प्रयोग ल्याई क्यान्सर को सेल मार्न सकिन्छ । त्यसै गरी , औसधिको रुपमा प्रयोग गर्न अझ विस्तार गर्न सकिन्छ ल्याई म्याग्नेटिक नानो कर्ण को उपयोग येतिमा मात्रै सिमित छैन. ऊर्जा उत्पादन गर्न र अन्तरिक्ष अनुसन्धान मा विस्तार गर्न पनि सकिन्छ।

मैले थाहापाएसम्म, सभावित नयाँ प्रविधिहर बिकास गर्नको लागि ईन्जिनियरहरु, भौतिकशास्त्रीहरु, रसायनशास्त्री हरु, जीवशास्त्रीहरु, इत्यादीको बीचमा बलियो, मैत्रीपुर्ण, र दिर्घकालिन सहयोग हुन आवश्यक छ । इच्छुक महानुभाब हरुले तलको लिंक मार्फत अध्यन गर्न सक्नु हुनेछ । अहिलेलाइ , यो छोटो विवरण येही समाप्त गर्न अनुमति चाहन्छु । साथै, निकट भबिष्यमा अझ चुम्बकीय पदार्थ को उपयोग सम्बन्धि रोचक सामग्री लिएर ब्रिस्तित रुपमा हुनेछु । धन्न्यबाद ।