Zeeman Pieter's Life and Contribution to The World of Science (1865-1943)

By

Zeeman Pieter is a Dutch physicist who shared the Nobel Prize for Physics with Hendrik Lorentz in 1902 for the discovery of the Zeeman effect.


Zeeman Pieter

Childhood and youth

He was born on May 25, 1865, in Zonnemaire, a small town on the island of Schouwen-Duiveland, in the Netherlands.

 Pieter was the son of Rev Catharines Forandinus Zeeman, a minister of the Dutch Reformed Church, and his wife, Willemina Worst. He became interested in physics at an early age.   When Zeeman was a student at the high school in Zierikzee, the aurora borealis happened to be visible in the Netherlands in 1883. Later in this article, I will give a brief description of the aurora and Zeeman effect. 

He prepared a description and drawing of the phenomenon and submitted it to Nature, and they published it with the editor's praise.

After finishing high school in 1883, Zeeman went to Delft for supplementary education in classical languages, then a requirement for admission to the university.  While in Delft, he first met Heike Kamerlingh Onnes, who became his thesis adviser.

Significant achievements:

  • Birth year 1865
  • Described the aurora borealis and published it in Nature in1883
  • Finished high school in 1883.

Education and early career:


In 1890, before completing his thesis, he became Lorentz's assistant. That was an open door for him to participate in the research of the Kerr effect. In 1893, he submitted his thesis on the Kerr effect. It was about the reflection of polarized light on a magnetized surface. After obtaining his doctorate, he went to Friedrich Kohlrausch's institute in Strasbourg and spent six months there. 

After returning from Strasbourg in 1895, he worked as a Privatdozent (an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds formal qualifications that denote an ability and permission to teach a designated subject at the highest level. If granted the title Privatdozent by a university, the recipient must fulfill the criteria set by the university, which usually require excellence in research, teaching, and further education) in mathematics and physics in Leiden. The same year, he married Johanna Elisabeth Lebret. They had three daughters and a son.

In 1896, before moving from Leiden to Amsterdam, he measured the splitting of spectral lines by a strong magnetic field, a discovery now known as the Zeeman effect, for which he won the 1902 Nobel Prize in Physics. This research involved an investigation of the influence of magnetic fields on a light source. He discovered that a spectral line splits into several components in the presence of a magnetic field. It confirmed Lorentz's prediction about the polarization of light emitted in a magnetic field. The Zeeman effect thus became a tool for elucidating the structure of the atom.


Significant events:

  • In 1893, he submitted his thesis on the Kerr effect.
  • He worked as a Privatdozent (1895)
  • Discovery of Zeeman effect (1896).

Professor in Amsterdam:


 In 1896, Zeeman joined the position of lecturer in Amsterdam. In 1900, he became a professor of physics at Amsterdam University. Five years later, in 1908, he succeeded Van der Waals as professor and director of the Physics Institute in Amsterdam.

In 1918, he published Some experiments on gravitation: The ratio of mass to weight for crystals and radioactive substances, experimentally confirming the equivalence principle regarding gravitational and inertial mass.

A new laboratory built in Amsterdam in 1923 was renamed the Zeeman Laboratory in 1940. This new facility allowed Zeeman to pursue a refined investigation of the Zeeman effect. For the remainder of his career, he remained interested in researching magneto-optic effects.

 Furthermore, he investigated the propagation of light in moving media. Later in his career, he became interested in mass spectrometry [5].


Important official positions

  • Zeeman joined the position of lecturer in Amsterdam (1896)
  • In 1900, he became a professor of Physics
  • Professor and director of the Physics Institute in Amsterdam (1908).
  • In 1935,  retired as a professor 

 

In 1898, Zeeman was elected to membership of the Royal Netherlands Academy of Arts and Sciences[3] in Amsterdam, and he served as its secretary from 1912 to 1920. He won the Henry Draper Medal in 1921, as well as several other awards and honorary degrees. Zeeman was also elected as a Foreign member of the Royal Society (ForMemRS) in 1921. He retired as a professor in 1935. The crater Zeeman on the Moon is named in his honor [4].

 

Zeeman received the following awards for his contributions.

  •  In 1898, Zeeman was elected to membership of the Royal Netherlands Academy of Arts and Sciences[3] in Amsterdam, and he served as its secretary from 1912 to 1920. 
  • · Nobel Prize for Physics (1902),
  • · Matteucci Medal (1912)
  • · Elected a Foreign Member of the Royal Society (ForMemRS) in 1921[1][2]
  • · Henry Draper Medal from the National Academy of Sciences (1921)
  • · Rumford Medal (1922)
  • · Franklin Medal (1925).

 Zeeman died on 9 October 1943 in Amsterdam.


Auroras


An aurora, commonly known as the Northern Lights (aurora borealis) or Southern Lights (aurora australis), is a natural light display in Earth's sky. 

  • Auroras are due to the disturbances in the magnetosphere caused by the solar wind. It is predominantly seen in high-latitude regions (around the Arctic and Antarctic). 
  • Auroras display dynamic patterns of brilliant lights that appear as curtains, rays, spirals, or dynamic flickers covering the entire sky. [6]
  • The enhancement of the speed of the solar wind from coronal holes and coronal mass ejections causes disturbances in the magnetosphere.
  • These disturbances result in changes in the trajectories of charged particles in the magnetospheric plasma. 
  • Charged particles are mainly electrons and protons in the upper atmosphere (thermosphere/exosphere). 
  • The resulting ionization and excitation of atmospheric constituents emit light of different colors and complexity.

Most auroras occur in a band known as the auroral zone, which is typically 3° to 6° wide in latitude and between 10° and 20° longitudes. [7] It is visible at night against a dark sky.



 Causes

  • The cause of aurora involves the interaction of the solar wind with Earth's magnetosphere.
  • Acceleration of auroral charged particles invariably accompanies a magnetospheric disturbance that causes an aurora. 

Red aurora

Particle acceleration provides a complex intermediate process for transferring energy from the solar wind indirectly into the atmosphere.

However, the prime source of auroral particles is the solar wind feeding the magnetosphere, the reservoir containing the radiation zones and temporarily magnetically trapped particles confined by the geomagnetic field, coupled with particle acceleration processes. [8]

 


Auroral particles

 

  • The immediate cause of the ionization and excitation of atmospheric constituents leads to auroral emissions. [9] 

Electrons are mainly responsible for diffuse and pulsating auroras. Pulsations originate at or close to the equatorial crossing point of auroral zone magnetic field lines. [10] 

Green and blue aurora

Atmosphere

  •  Auroras result from emissions of photons in Earth's upper atmosphere, above 80 km, from ionized nitrogen atoms regaining an electron and oxygen atoms and nitrogen-based molecules returning from an excited state to a ground state. [11]
  • They are ionized or excited by the collision of particles precipitated into the atmosphere. Both incoming electrons and protons may be involved. 
The release of excitation energy within the atmosphere is by emitting photons or colliding with another atom or molecule.

 


Images of auroras from across the world, including those with rarer red and blue lights [17]


It is the same principle of laser emission.

 

Oxygen emissions

  •  The color may be green or orange-red, depending on the energy absorbed.

 Nitrogen emissions

 Blue and purple if the molecule regains an electron after ionization. 

  • The red color emits if returning to the ground state from an excited state.

Oxygen is unusual in terms of its return to ground state: it can take 0.7 seconds to emit the 557.7 nm green light and up to two minutes for the red 630.0 nm emission. Collisional quenching prevents emission due to the collision with other atoms or molecules by absorbing the excitation energy. Because the highest parts of the atmosphere contain a higher percentage of oxygen and lower particle densities, such collisions are rare enough to allow time for oxygen to emit red light. Collisions become more frequent when progressing down to the atmosphere due to increasing density, so red emissions do not have time to happen, and even prevention of green light emissions.

That is why there is a color differential with altitude, at high altitudes, oxygen red dominates, then oxygen green and nitrogen blue/purple/red. 

  • Green is the most common color. Then comes pink, a mixture of light green and red, followed by pure red, then yellow (a mixture of red and green), and finally, pure blue.

Zeeman effect:

 

  • The splitting of a spectral line in the presence of a static magnetic field into several components is the Zeeman effect.
The Dutch physicist Pieter Zeeman discovered it in 1896 and received a Nobel prize.

Do you know what the stark effect is?

  • It is also the splitting of spectral lines in the presence of an electric field.

Now let me ask you one question.

Do you think that we can measure magnetic field strength between the Sun and stars by

applying this Zeeman effect?

Yes, we can.

  • The distance between Zeeman sublevels is a function of magnetic field strength.

 Demonstrations

  •  You can demonstrate this Zeeman effect by placing a sodium vapor source in a powerful electromagnet and viewing a sodium vapor lamp through the magnet opening (see diagram).
  •  When the magnet is off, the sodium vapor source will block the lamp light. When the magnet is on, the lamp light will be visible through the vapor.

 

 Zeeman effect demonstration (Source: Wikipedia)



Creation of sodium vapor

You can create sodium vapor by sealing sodium metal in an evacuated glass tube and heating it while the tube is in the magnet. [14]

Alternatively, place salt (sodium chloride) on a ceramic stick in the flame of a Bunsen burner as the sodium vapor source.

When we energize the magnetic field, the lamp image will get brighter. [15] However, the magnetic field also affects the flame, making the observation depend upon more than just the Zeeman effect. [14]

 

  • We know when a magnetic field is applied, due to the Zeeman effect, the spectral line of sodium gets split into several components.

So, what happens if we strengthen the magnetic field?

  • The shift in the spectral lines increases.

 

Applications

 

Astrophysics

 

George Ellery Hale noticed the Zeeman effect in the solar spectra, indicating the existence of strong magnetic fields in sunspots.

Such fields may be high, on the order of 0.1 tesla or higher. 

Today, the Zeeman effect applies to produce magnetograms, a pictorial representation of the spatial variations in the strength of the solar magnetic field. It shows the variation of the magnetic field on the Sun.

 


Zeeman effect on a sunspot spectral line (Source: Wikipedia


Laser cooling

 

The Zeeman effect is utilized in many laser cooling applications, such as a magneto-optical trap and the Zeeman slower.

 I have discussed the properties of laser in my other article in detail. Please have a look (https://retnacpn.blogspot.com/2023/09/laser-fundamentals-history-laser-stands.html). The laser is highly directional, coherent, intense, and monochromatic. It has high focussing property. Hence, wide use in industries.

It has applications in the cooling process also. Laser cooling includes several techniques. Laser cutting and drilling apply the directed energy of lasers. So, laser cooling is counterintuitive.

  • Laser cooling relies on the change in momentum when an object absorbs and emits a photon (a particle of light).
Imagine a laser light illuminates a warm cloud of atoms from all directions, resulting in the tunning of the frequency of atoms below an atomic resonance. This process cools the atoms. 

  • This common type of laser cooling relies on the Doppler effect, where individual atoms preferentially absorb laser light from the direction opposite to the atom's motion and emit it in a random direction.
  •  After repeated emission and absorption of light, the net effect on the cloud of atoms is that they will expand more slowly. 
  • The slower expansion reflects a decrease in the velocity distribution of the atoms. 
  • That corresponds to a lower temperature and the cooling of atoms.

According to the principles of Doppler cooling, an atom modeled as a two-level atom can be cooled using a laser.

  • When the atom moves in a specific direction and encounters a counter-propagating laser beam resonant with its transition, it will absorb a photon.
  • The absorption of this photon brings the atom to its excited state.
  • This state is unstable, and the atom decays back to its ground state via spontaneous emission.
  • The atom re-emits the photon in different directions.
  • Many absorption and emission processes to one atom result in a reduction in absorption. 
  • The emission process does not lead to any change in the speed of the atom because the emission direction is random. 
  • That is, slowing down of the atom by the laser beam.
  •  Because of the decrease in momentum of the atom by a few recoil momenta, it is no longer in resonance with the pump beam because, in its frame, the frequency of the laser has shifted. 
The Zeeman slower [16] uses the fact that a magnetic field can change the resonance frequency of an atom using the Zeeman effect to tackle this problem.

Their thermodynamic temperature is proportional to the variance in their velocity. More homogeneous velocities between particles correspond to a lower temperature.

  •  Laser cooling techniques combine atomic spectroscopy with the aforementioned mechanical effect of light to compress the velocity distribution of an ensemble of particles, thereby cooling the particles.

The 1997 Nobel Prize in Physics was awarded to Claude Cohen-Tannoudji, Steven Chu, and William Daniel Phillips "for the development of methods to cool and trap atoms with laser light".[17]

Before going to the next application,  I will give you a brief description of the Doppler effect and MOT.

 Doppler effect:

  •  It is the change in the frequency of a wave about an observer who is moving relative to the source of the wave. [12][13][14] 
The physicist Christian Doppler described the phenomenon in 1842.

  • An example of a Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer.
 When we compare the received frequency during the approach and recession, it is clear that the frequency is higher at the time of the approach and lower during the recession. [15]

Change of wavelength caused by motion of the source. (Wikipedia)



Magneto-Optical Tracking (MOT)

  • MOT is an apparatus that uses laser cooling. In atomic, molecular, and optical physics, a magneto-optical trap that uses laser cooling. 
  • It can produce samples of cold, neutral atoms.

The intersection of a weak, quadrupolar, spatially-varying magnetic field and six circularly polarized, red-detuned, optical molasses beams form the MOT. 

  • As atoms travel away from the field zero at the center of the trap (halfway between the coils), the spatially varying Zeeman shift brings an atomic transition into resonance, giving rise to a scattering force that pushes the atoms back toward the center. 
This way, a MOT traps atoms. 

  • This force arises from photon scattering atoms receiving momentum in the direction opposite their motion. 
  • It also slows the atoms (i.e., cools them) over repeated absorption and spontaneous emission cycles.
 In this way, a MOT can trap and cool atoms with initial velocities of hundreds of meters per second down to tens of centimeters per second. [17]

 

Zeeman slower

 

  • A Zeeman slower is a scientific instrument commonly used in atomic physics to slow and cool a beam of hot atoms to speeds of several meters per second and temperatures below a kelvin. 
  • The technique is to attach the Zeeman slower to where the hot atoms exit the oven and are used to slow them to less than ten m/s (slowing) with a small velocity (cooling).

 Other applications are: 

Spintronics

In spintronics, Zeeman-energy mediated to couple the spin and orbital motions. It is for controlling electron spins in quantum dots through electric dipole spin resonance. [18]

Metrology

Old high-precision frequency standards may require periodic fine-tuning due to exposure to magnetic fields. It is possible by measuring the Zeeman effect on specific hyperfine structure transition levels of the source element. 

Biology

A theory about the magnetic sense of birds assumes that a protein in the retina changes due to the Zeeman effect. [19]

Nuclear spectroscopy

The nuclear Zeeman effect is significant in such applications as nuclear magnetic resonance spectroscopy, magnetic resonance imaging (MRI), and Mössbauer spectroscopy.

 

References:

1.  "Fellows of the Royal Society". London: Royal Society. Archived from the original on 2015-03-16.

2. ^ Jump up to a b c Rayleigh (1944). "Pieter Zeeman. 1865-1943". Obituary Notices of Fellows of the Royal Society. 4 (13): 591–595. doi:10.1098/rsbm.1944.0010. S2CID 125808317.

3 "Pieter Zeeman (1865 - 1943)". Royal Netherlands Academy of Arts and Sciences. Retrieved 17 July 2015.

4 ^ "Henry Draper Medal". National Academy of Sciences. Retrieved 19 February 2011.


5     Lui, A., 2019. Imaging global auroras in space. Light: Science & Applications, 8(1).

6      Feldstein, Y. I. (2011). "A Quarter Century with the Auroral Oval". EOS. 67 (40): 761. Bibcode:1986EOSTr..67..761F. doi:10.1029/EO067i040p00761-02.

7     Burch, J L (1987). Akasofu S-I and Y Kamide (ed.). The solar wind and the Earth. D. Reidel. p. 103. ISBN 978-90-277-2471-7.

8     ^ McIlwain, C E (1960). "Direct Measurement of Particles Producing Visible Auroras". Journal of Geophysical Research. 65 (9): 2727. Bibcode:1960JGR....65.2727M. doi:10.1029/JZ065i009p02727.

9     ^ Bryant, D. A.; Collin, H. L.; Courtier, G. M.; Johnstone, A. D. (1967). "Evidence for Velocity Dispersion in Auroral Electrons". Nature. 215 (5096): 45. Bibcode:1967Natur.215...45B. doi:10.1038/215045a0. S2CID 4173665.

10 ^ "Ultraviolet Waves". Archived from the original on 27 January 2011.

11  Buys Ballot (1845). "Akustische Versuche auf der Niederländischen Eisenbahn, nebst gelegentlichen Bemerkungen zur Theorie des Hrn. Prof. Doppler (in German)". Annalen der Physik und Chemie. 142 (11): 321–351. Bibcode:1845AnP...142..321B. doi:10.1002/andp.18451421102.

12 ^ Fizeau: "Acoustique et optique". Lecture, Société Philomathique de Paris, 29 December 1848. According to Becker(pg. 109), this was never published, but recounted by M. Moigno(1850): "Répertoire d'optique moderne" (in French), vol 3. pp 1165–1203 and later in full by Fizeau, "Des effets du mouvement sur le ton des vibrations sonores et sur la longeur d'onde des rayons de lumière"; [Paris, 1870]. Annales de Chimie et de Physique, 19, 211–221.

13 ^ Scott Russell, John (1848). "On certain effects produced on sound by the rapid motion of the observer". Report of the Eighteenth Meeting of the British Association for the Advancement of Science. 18 (7): 37–38. Retrieved 2008-07-08.

14   Petrescu, Florian Ion T (2015). "Improving Medical Imaging and Blood Flow Measurement by Using a New Doppler Effect Relationship". American Journal of Engineering and Applied Sciences. 8 (4): 582–588. doi:10.3844/ajeassp.2015.582.588 – via Proquest.

15   Bill Phillips' Nobel lecture

16   Nobel Prize in Physics press release, 1997

17   Wikipedia

18    Tokura, W. G. van der Wiel, T. Obata, and S. Tarucha, Coherent single electron spin control in a slanting Zeeman field, Phys. Rev. Lett. 96, 047202 (2006)

19   ^ Thalau, Peter; Ritz, Thorsten; Burda, Hynek; Wegner, Regina E.; Wiltschko, Roswitha (18 April 2006). "The magnetic compass mechanisms of birds and rodents are based on different physical principles". Journal of the Royal Society Interface. 3 (9): 583–587. doi:10.1098/rsif.2006.0130. PMC 1664646. PMID 16849254.

 

 




Comments

Post a Comment

Popular posts from this blog

My Mother's Home Town: Maranadu Village.

By
Image
  Introduction: Welcome to the beautiful village, where nature's beauty blends seamlessly. Maranadu is a small village in Kollam district, Kerala, India. Its location is 21 km east of the district headquarters, Kollam, 6 km west of Kottarakkara, and 73 km north of the State capital, Thiruvananthapuram. Beautiful greenery  This idyllic village is adorned with lush greenery, making it a visual treat for all who visit. As you stroll through the place, you will encounter enchanting sights along. On one side of the road lies a wetland teeming with vibrant flora and fauna.  Wetlands: Around fifty years ago, all the wetlands were paddy fields. During sowing and planting, it was green everywhere, tilting the soft leaves of the rice plant in a gentle breeze like a green blanket. Around harvesting, we could see golden fields with ripened bunches of paddy. When I was young, I used to behold that beauty. Now, paddy fields turned out as banana fields.   The hill on the other side The role of a
Read more

Treasure Island Kuruva: A Biodiversity Paradise Destination Alongside The Kabini River.

By
Image
Location Nestled amidst the serene landscapes of the Kabini River in  Kerala , India lies a hidden gem known as Kuruva Island.  Nine hundred and fifty acres of protected river delta comprise three densely wooded islands and a few submergible satellite islands. This enchanting place is renowned for its remarkable biodiversity, including rare orchid species, lush ferns, and a haven for birds. This secluded island is home to numerous bird species, making it a haven for avid bird watchers and nature enthusiasts. Kuruva is an uninhabited island that boasts picturesque nature walks, tranquil resting places, and crystal-clear waters that invite visitors to take a refreshing dip. In this article, we will immerse ourselves in the captivating beauty of Kuruva Island while also exploring the unique experience of bamboo rafting, an eco-friendly way to traverse this natural wonder.  Unique Features are... No human habitation on the island, so you will still find it in its pristine and untouched f
Read more

Joy and Benefits of Cooking and Eating on Leaves.

By
Image
  Introduction: In this article, I discuss only the benefits of cooking and eating on leaves. I discussed the method of cooking on leaves in another article. Hence, for details on cooking dessert on leaves, please read my article on hubpages. ( https://hubpages.com/food/happiness-and-benefits-of-cooking-in-leaves-from-our-backyard-an-emotional-link ). Banana Plant Banana leaves: In tropical and sub-tropical areas, they use banana leaves for cooking, wrapping, and food serving. In Tamil Nadu, for packing food, they use dried leaves. Banana leaves have natural antimicrobial properties that kill harmful bacteria. Banana leaves and palm leaves were the primary writing surfaces in South and Southeast Asia.  Banana belongs to the Monocotyledons class, the Zingiberales order, and the Musaceae family. The plant has a herbaceous growth habit with leaves overlapping basal sheaths.  The family includes three genera. The largest and most economically important genus is Musa. It is famous for the
Read more

Prepare Then Nellika Using Jaggery and Honey at Home

By
Image
  Then nellikka is stored in a glass bottle We know that gooseberry (Nellika) is a powerhouse of vitamin C. Its health benefits are well known. My grandma told me that nellika was capable of keeping me young. I know nobody wants to get older anyway. I do not like to. Raw nellikka Being a Physics teacher, it is good to mention the  time dilation  in the theory of relativity. In many science fiction films, you might have seen such scenes. The time dilation resulted in a younger look.  It is for comparing two frames. One of them is stationary, and the other is moving. It states that a clock in a moving frame will appear to go slower than the clock in a stationary frame. Twin paradox: The story is about two twin brothers (same age). One of the twins travels in a rocket with very high velocity for a long time and returns to Earth. In such a case, he will find himself younger than his twin brother, who stayed back on Earth.    Let me tell you the significance of gooseberry in our d
Read more

Science of Holography

By
Image
  Introduction: The term holography comes from the Greek meaning whole writing. It is a technique of recording objects and regenerating images in three dimensions. It is a two-step process:  An object illuminated by coherent light is made to produce interference fringes in photosensitive material. Reillumination of the developed interference pattern by light of the same wavelength produces a three-dimensional image of the original object. Dennis Gabor of the Imperial College of Science and Technology developed this technique in 1948. He was awarded the Nobel Prize in Physics in 1976 for his three-dimensional lensless method of photography (holography). [2] Dove hologram used on some credit cards [7] Basic principle: The basic principle of holography is recording the phase and amplitude of the light scattered from different parts of the object.  The phase recording helps to record the depth of the material.  It is a unique way of recording the interference pattern produced by light wave
Read more

Laser Fundamentals

By
Image
History: Laser stands for Light Amplification by Stimulated Emission of Radiation. Albert Einstein (1916) theoretically proved the process of stimulated emission (that is, when more atoms occupy a higher energy state than a lower one, it is possible to force them to return to an unexcited state by stimulating them with the same energy as would be emitted naturally). German Physicist Rudolf Walther Ladenburg observed the stimulated emission in 1928. In 1951, Charles H.Townes from Columbia University demonstrated a working device that focused excited ammonia molecules in a resonant microwave cavity, where they emitted a pure microwave frequency. Townes named the device a MASER for Microwave Amplification by Stimulated Emission of Radiation.  On May 16, 1960, Theodore H. Maiman (Hughes Research Laboratories) fired bright pulses from a photographer’s flash lamp to excite chromium atoms in a crystal of synthetic ruby and produced red pulses from a Ruby rod about the size of a fingertip.  In
Read more

Is Munroe Island a Sinking Beauty?

By
Image
  Is the island sinking?   I feel a little pain when somebody mentions it. It is a place close to my hometown, Kunnathoor. I wish that would not happen. It  is high time to act. Protect that gem to live long for our kids and grandkids. Research reports said only some buildings and rail tracks were subsiding. What happens to Munroe Island when the sea level rises due to climate change?   An inland group of islands located at the confluence of Ashtamudi Lake and Kallada River is known as Munroe Island. The location is in Kollam district, Kerala, India. Features: There are eight small islets. The total area is about 13.4 sq. kilometers.[1]  We can reach there by road, train, and inland navigation is available. As per the census in 2011, the island has a population only of 9599. Males: 4636 and 4963 females. Local people said the island was sinking. So, people referred to it as a sinking island. The Munroe Island is only 25 kilometers away from Kollam by road.  
Read more

Optical Fiber

By
Image
Optical fiber An optical fiber is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers are used widely in fiber-optic communications. They permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss and are immune to electromagnetic interference. [7] They can carry light into or images out of confined spaces, as in the case of a fiberscope. [8] Specially designed fibers have a variety of other applications, such as fiber optic sensors and fiber lasers. [9] Drawing is a process for making glass optical fibers. For plastic fibers, we can choose either drawing or extrusion . [10][11] Optical fibers typically include a core surrounded by a transparent cladding material with a lower index of refraction. The core keeps the light in the core by total internal reflection, which causes the fiber to act as a wave
Read more

Attukal Pongala: A Celebration of Harmony and Inclusivity

By
Image
  We have a 10-day festival celebrated at the Attukal Bhagavathy Temple in Thiruvananthapuram in the Indian state of Kerala. From the first day onwards, most ladies will be fasting. They prefer to eat vegetarian food during this period.  On the ninth day, there is a gathering of millions of women in the temple surroundings. This gathering is for preparing Pongala.  Pongala preparation and offering it to Attukalamma is dependent on devotion.  They prepare a divine food made of rice, jaggery, ghee, coconut, banana, cardamom, and raisins in earthen pots and offer it to the Attukal Amma (Goddess of the Temple). After the ritual called 'Aduppuvettu' at the temple, the Pongala preparation begins. It is the lighting of the pongala hearth (called Pandarayaduppu) placed inside the temple by the chief priest. This is the earliest Pongala festival in Kerala [1]. Attukal Temple Rituals After the Aduppuvettu of the Attukal Bhagavathy Temple, women light the ritual fires to prepare the s
Read more

Dhanushkodi: The Abandoned Town in Tamil Nadu

By
Image
Dhanushkodi is a town at the south-eastern tip of Pamban Island in Tamil Nadu, India. [1]  It is south-east of Pamban and is about 24 kilometers (15 mi) west of Talaimannar in Sri Lanka.  The 1964 Rameswaram cyclone was a disaster. After that, the place remains uninhabited. Although devoid of inhabitants, Dhanushkodi remains a tourist attraction due to its historical and mythological relevance. [2]   Arichal Munai Geography   Dhanushkodi is on the tip of Pamban Island, separated from the mainland by the Palk Strait.   Transport The National Highway completed the 9.5-km-long road – 5 km from Mukuntharayar Chathiram to Dhanushkodi and 4.5 km from Dhanushkodi to Arichamunai. [3]  Until 2016, Dhanushkodi was reachable on foot along the seashore or in jeeps. [4] In 2016, they built a road from the village of Mukundarayar Chathiram. [5][6] A meter gauge railway line connected Mandapam in mainland India to Dhanushkodi. [7]  Boat mail express ran from Chennai Egmore to Dhanushkod
Read more