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Today in History – 3 March

By
Syskool
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0
today in history 3 march

today in history 3 march

78

Shaliwahan Shaka Hindu Calendar started.

1575

A battle was fought at Turkra or Turkra Qasba (in the Balasore district) in which the Afghans were routed.

1700

Chhatrapati Rajaram Maharaj died of small pox at Raigarh or Sinhagarh fort.

1707

Shehejade Muazzam declared himself as the successor of Aurangzeb and renamed himself Bahadurshah First.

Also Read: DECLINE AND FALL OF MUGHAL EMPIRE

1839

Jamshedji Nasarvanji Tata, famous industrialist and father of modern technology, was born at Navsari near Surat, Gujarat. He started cotton mills in Bombay and Nagpur and founded the Tata Iron and Steel Company, which is one of the largest integrated steel mills in the world.

1847

Alexander Graham Bell, great pioneer, inventor and professor, was born at Edinburgh, Scotland.

1859

A length of 119 miles of line was laid in the North from Allahabad to Kanpur.

1885

Congress passes Indian Appropriations Act (Indians wards of fed govt).

1924

Mustafa Kamal Attaturk abolished the caliphate and established a nationalist government and thus Khilafat Movement ended without achieving its aim.

Also Read: Non-cooperation and Khilafat Movement

1931

Gandhi and Viceroy Irwin sign Delhi Pact giving Indians right to make salt if civil disobedience stops.

1939

Gandhiji commences “”fast unto death”” at Rajkot to protest state’s autocratic rule at Bombay and to secure ruler’s adherence of promise given towards reform administration, and ends it on March 7 on Viceroy’s intervention.

1943

Gandhi breaks his hunger strike after 21 days.

1967

India signed the International Space Treaty in Moscow.

1983

Seventh Non-Aligned Summit started at New Delhi.

Also Read: Today in History – 2 March

The North East of India

By
Syskool
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9
north-east india

The North East of India is made up of seven separate states and is the most tribal region of India. Northeast India is the eastern-most region of India connected to East India via a narrow corridor squeezed between Nepal and Bangladesh.

The North East of India comprises the contiguous Seven Sister States—Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura—and the Himalayan state of Sikkim.

These states cover about 7 percent of India’s total area. The northeastern states, having 3.8% of India’s total population, are allotted 25 out of a total of 543 seats in the Lok Sabha This is 4.6% of the total number of seats.

All the seven states are members of the North East Council, organized on 1st August 1972 and within the Jurisdiction of Guwahati High Court.

Sikkim joined the Indian union through a referendum in 1975 and was recognized as a part of North-East states in the 1990s. Northeast India’s population size is roughly equal to the state of Odisha.

The states are officially recognized in the North Eastern Council (NEC), constituted in 1971 as the acting agency for the development of the eight states. The North Eastern Development Finance Corporation Ltd was incorporated on 9 August 1995 and the Ministry of Development of North Eastern Region was set up in September 2001.

Read Also: Renewable Energy (RE): Promoting ‘Make in India’

North East India is known for its unique culture, handicrafts, martial arts, and scenic beauty. Problems include insurgency, unemployment, and lack of infrastructure. Since the beginning of the economic liberalization in the 1990s, studies have shown that this region is lagging behind the others in terms of development.

A place renowned for its magical beauty and bewildering diversity, North East India is the home of more than 166 separate tribes speaking a wide range of languages. Some groups have migrated over the centuries from places as far as South East Asia; they retain their cultural traditions and values but are beginning to adapt to contemporary lifestyles. Its jungles are dense, its rivers powerful and rain and thunderstorms sweep across the hills, valleys, and plains during the annual monsoons.

Must Read: Water Resources of India

Each state is a traveler’s paradise, with picturesque hills and green meadows which shelters thousands of species of flora and fauna. In addition, the states provide scope for angling, boating, rafting, trekking, and hiking. Besides, there are a number of wildlife sanctuaries and national parks where rare animals, birds, and plants which will surely provide the fascinating insight to the visitors.

Don’t Miss:

Global warming

By
Syskool
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4
Global warming
Global warming

Global warming is the unequivocal and continuing rise in the average temperature of Earth’s climate system. Since 1971, 90% of the warming has occurred in the oceans. “Global warming” is also used to refer to increases in average temperature of the air and sea at Earth’s surface.

The IPCC stated that the largest driver of global warming is carbon dioxide (CO2) emissions from fossil fuel combustion, cement production, and land-use changes such as deforestation.

Warming is expected to be strongest in the Arctic, with the continuing retreat of glaciers, permafrost, and sea ice. Other likely effects of the warming include more frequent extreme weather events including heat waves, droughts and heavy rainfall; ocean acidification; and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the loss of habitat from inundation.

Read Also: Ozone Depletion

Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes.

The United Nations Framework Convention on Climate Change (UNFCCC), whose ultimate objective is to prevent dangerous anthropogenic (human-induced) climate change. Parties to the UNFCCC have adopted a range of policies designed to reduce greenhouse gas emissions and to assist in adaptation to global warming. Parties to the UNFCCC have agreed that deep cuts in emissions are required, and that future global warming should be limited to below 2.0 °C (3.6 °F) relative to the pre-industrial level. Reports published in 2011 by the United Nations Environment Programme and the International Energy Agency suggest that efforts as of the early 21st century to reduce emissions may be inadequate to meet the UNFCCC’s 2 °C target.

Depletion of the ozone layer by chemical refrigerants has also resulted in a strong cooling effect in the stratosphere. If the sun were responsible for observed warming, warming of both the troposphere and the stratosphere would be expected. The main negative feedback is the energy which the Earth’s surface radiates into space as infrared radiation.

Climate change could result in global, large-scale changes in natural and social systems. Two examples are ocean acidification caused by increased atmospheric concentrations of carbon dioxide, and the long-term melting of ice sheets, which contributes to sea level rise.

Must Read: The Greenhouse Effect

Global Warming Impacts

Rising Seas, Changes in rainfall patterns, The increased likelihood of extreme events, Melting of the ice caps, Widespread vanishing of animal populations, Spread of disease, Bleaching of Coral Reefs due to warming seas and acidification due to the carbonic acid formation, Loss of Plankton due to warming seas.

Also, Read:

Stanford Develops Plastic from Agricultural Waste

Agro-Forestry

Examine the ill effect of green revolution in India.

Quantum Accelerometers and Gravimeters: Precision Inertial and Gravitational Sensing

By
Kumar Prafull
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0
quantum accelerometers and gravimeters

Table of Contents

  1. Introduction
  2. Classical vs Quantum Inertial Sensors
  3. Principles of Atom Interferometry
  4. Matter-Wave Interference and Phase Accumulation
  5. Raman Transitions and Beam Splitters for Atoms
  6. Atom Interferometer Architectures
  7. Quantum Accelerometers: Operating Principle
  8. Quantum Gravimeters: Operating Principle
  9. Differential Measurements and Gradiometry
  10. Sensitivity and the Standard Quantum Limit
  11. Applications in Navigation and Geodesy
  12. Fundamental Physics Tests
  13. Environmental Effects and Noise Suppression
  14. Portable and Miniaturized Quantum Sensors
  15. Cold Atom Sources and Vacuum Systems
  16. Advances in Laser and Frequency Control
  17. Quantum Enhancements: Squeezing and Entanglement
  18. Integration with Classical Systems
  19. Challenges and Future Outlook
  20. Conclusion

1. Introduction

Quantum accelerometers and gravimeters exploit the wave nature of atoms to perform ultra-sensitive measurements of acceleration and gravity. These devices use atom interferometry to achieve precision beyond classical limits and are poised to transform navigation, geophysics, and fundamental physics.

2. Classical vs Quantum Inertial Sensors

Classical accelerometers and gravimeters rely on mechanical displacement or optical interferometry. Quantum sensors use coherent atomic wave packets whose phase evolution encodes inertial forces or gravitational acceleration.

3. Principles of Atom Interferometry

In atom interferometry, atoms in superposition travel along separate paths and recombine. The resulting phase difference encodes information about external forces:


\[
\Delta \phi = ec{k}{ ext{eff}} \cdot ec{a} T^2
\]

where \( ec{k}{ ext{eff}} \) is the effective wave vector, is acceleration, and is the interrogation time.

4. Matter-Wave Interference and Phase Accumulation

Atoms act as de Broglie waves. When split and recombined, interference fringes arise whose phase shift corresponds to motion or gravitational field variations.

5. Raman Transitions and Beam Splitters for Atoms

Laser pulses act as beam splitters and mirrors for atoms:

  • First pulse: creates superposition
  • Second: reflects wave packets
  • Third: recombines and creates interference
    Stimulated Raman transitions transfer momentum to atoms and enable path separation.

6. Atom Interferometer Architectures

Common configurations:

  • Mach–Zehnder-type for inertial sensing
  • Fountain geometry for extended interrogation time
  • Dual-species setups for differential measurements

7. Quantum Accelerometers: Operating Principle

Measures linear acceleration by tracking phase shifts in free-falling atomic wave packets. Sensitive to changes in motion and suitable for:

  • Inertial navigation
  • Seismology
  • Vehicle and submarine guidance

8. Quantum Gravimeters: Operating Principle

Measures local gravitational acceleration \( g \) via vertical phase shifts:
\[
\Delta \phi_g = k_{ ext{eff}} g T^2
\]
Used for:

  • Geophysical surveys
  • Subsurface structure detection
  • Volcanology and hydrology

9. Differential Measurements and Gradiometry

Using two atom clouds at different heights or locations allows measurement of gravity gradients. Quantum gradiometers map variations in the gravitational field with high spatial resolution.

10. Sensitivity and the Standard Quantum Limit

Sensitivity improves with:

  • Longer interrogation time \( T \)
  • Larger effective wave vector \( k_{ ext{eff}} \)
  • More atoms \( N \)
    SQL sets the fundamental noise floor:
    \[
    \Delta g \propto rac{1}{\sqrt{N T^2}}
    \]

11. Applications in Navigation and Geodesy

Quantum inertial sensors provide:

  • GPS-independent navigation
  • High-resolution topography
  • Monitoring of geophysical changes like water tables or tectonic shifts

12. Fundamental Physics Tests

  • Tests of Einstein’s equivalence principle (dual-species drop)
  • Searches for fifth forces and dark energy
  • Measurements of \( G \), the gravitational constant

13. Environmental Effects and Noise Suppression

Noise sources include:

  • Magnetic fields
  • Vibrations and tilt
  • Laser phase noise
    Mitigation strategies:
  • Active vibration isolation
  • Common-mode rejection
  • Shielding and servo control

14. Portable and Miniaturized Quantum Sensors

Progress in:

  • Compact laser systems
  • Microfabricated atom chips
  • Fiber-based optical systems
    is enabling field-deployable quantum gravimeters and accelerometers.

15. Cold Atom Sources and Vacuum Systems

Laser cooling and magneto-optical traps (MOTs) prepare ultracold atoms. Ultra-high vacuum environments are required for long interrogation times and reduced decoherence.

16. Advances in Laser and Frequency Control

High phase stability and narrow linewidth lasers are essential. Frequency stabilization techniques include:

  • Optical cavities
  • Frequency combs
  • Locking to atomic transitions

17. Quantum Enhancements: Squeezing and Entanglement

  • Spin squeezing can surpass SQL
  • Entangled atom ensembles improve phase sensitivity
  • Potential for Heisenberg-limited performance

18. Integration with Classical Systems

Hybrid systems combine classical MEMS and quantum sensors for robustness and calibration. Enables continuous operation and redundancy.

19. Challenges and Future Outlook

  • Reducing size, weight, and power (SWaP)
  • Enhancing long-term stability
  • Scaling up to mobile and aerospace platforms
  • Toward commercial deployment in surveying, oil exploration, and defense

20. Conclusion

Quantum accelerometers and gravimeters mark a new era in precision sensing. By leveraging the coherence and interference of atomic wavefunctions, they enable transformative applications in science, industry, and navigation with accuracy unmatched by classical technologies.

.

History of Civil Servies in India

By
Syskool
-
0
civil services history

The civil service was the ‘steel-frame’ of British administration. Lord Clive was the first to pay attention to the Civil Services. He prohibited the employees of the company from undertaking any private trade. Cornwallis adopted the policy of Europeanization of the civil services which was a bane for the Indians as they could not be appointed to higher posts. The highest post that an Indian could aspire to was that of Munsif, Sadar Amin or Deputy Collector.

The credit for introducing the first step towards the training of the company’s civil servants to improve their efficiency goes to Lord Wellesley, who founded the Fort William College at Calcutta in 1800.

Till 1853, all appointments of the civil services were made by the director of the East India Company. The Charter act of 1853 declared that all recruits were to be selected through a competitive examination.

In the days of Cornwallis, the Indians were completely excluded from the civil services which was a deliberate policy.

Reasons for introduction of Civil Services in India

Failure of the attempts of Clive and Warren Hasting to put an end to the corruption among officials.

Introduction of civil services by Cornwallis and his reforms to purified and improve administration.

Establishment of the college of Fort William at Kolkata by Wellesley to train the young civil servants, and its replacement by East India College at Haileybury in England.

Discontinuation of the practice of appointing civil servants by the court of directors and starting the practice of selecting civil servants through a competitive exam with the passes passing of the Charter Act of 1853.

A special feature of Indian civil service was the exclusion of Indians from it. Reason for this–

  1. The belief that an administration based on British model could be firmly established only by the English personnel.
  2. Lack of trust in the ability and integrity of Indians.
  3. A deliberate policy – because the task of establishing in establishing and consolidating British rule in India could not be left to Indians.
  4. The desire of the influential class of British society to preserve the lucrative post in civil service for their sons.

However, Indians were recruited in large numbers to fill subordinate post as they were cheaper and much more readily available then Englishman.

Sir Charles Aitcheson Commission, 1886

Lord dufferin appointed this commission in 1886 to consider the demand for simultaneous examination and the loading of maximum age. It recommended –

Dropping the term ‘covenanted’ and ‘un-covenanted’ and divided the source into three classes – Imperial Indian Civil Services, The Provincial and The Subordinate
Services. The first was to be recruited in England and the latter was in India exclusively from Indian.

It suggested that the age limit to be 19 and 23 as the minimum and maximum respectively.

It rejected the idea of simultaneous examination and advised the abolition of statutory civil services.

The Montague Chelmsford Report 1918

Report’s recommendations with regard to civil services are as follows –

The holding of simultaneous examination in India and England.

One-third of the superior post in Indian Civil Services were to be recruited in India and this percentage to be increased annually by 1.5% full stop

There should be no racial discrimination in the matter of appointments.

Lee Commission, 1923

Another Royal Commission on Superior civil services exam in India was appointed in June 1923 with Lord Lee as its chairman. Its recommendations were:

The Secretary of State should continue to recruit the Indian Civil Service, the irrigation branch of some of the Service of Engineers and the Indian Forest Services.

On the basis of the Government of India Act 1990, it recommended the establishment of a public service commission.

20% of the officers should be recruited by promotion from provincial civil services and of the remaining 80%, half should be Indian and half should be British.

Read More:Civil Services of India

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