Evolution of Timekeeping Devices | 07 Aug 2024

Source: TH

Why in News?

Recently, researchers have made significant developments in nuclear clocks by developing a laser for thorium-229 nuclei stimulation and linking it with an optical clock.

• The world has evolved from keeping time with the Sun and the moon to atoms and their nuclei.

How Timekeeping Devices Evolved Over History?

• Historical Timekeeping Devices:
  • Sundials: Ancient devices that indicated time by casting shadows from sunlight.
  • Water Clocks: Measured time through the gradual filling of a vessel with water.
  • Hourglasses: Used sand instead of water to measure time.
• Development of Mechanical Clocks:
  • Early Mechanical Clocks: Improved water clocks included additional tanks, gears, and pulleys.
  • Astrarium (Medieval Astronomical Clock): A sophisticated instrument to track celestial movements.
  • Pendulum Clock: Spring-driven clocks replaced weights with coiled springs.
• Modern Clocks:
  • Electric Clocks: Emerged in the 19th century, using batteries or electric motors instead of springs or weights.
  • Quartz Clocks: Use a quartz crystal that oscillates when electrically charged. These clocks are affordable and widespread, leading to the popularity of quartz watches and wall clocks.
• Atomic Clocks:
  • Operation: Use lasers and atoms of the same isotope to measure time. The frequency of radiation emitted when atoms transition between energy states defines the time.
    • India is setting up atomic clocks nationwide to make sure that the time on digital devices matches Indian Standard Time (IST), as part of the One-Nation, One-Time initiative.
  • Caesium Atomic Clocks: Utilize caesium-133 atoms and are highly accurate, maintaining the IST.
    • IST is a cesium atomic clock used at the National Physical Laboratory (NPL), New Delhi.
    • Council Of Scientific And Industrial Research–National Physical Laboratory (CSIR–NPL) maintains the IST.
  • Next-Generation Optical Clocks: Use atoms like strontium or ytterbium to achieve even greater precision of time.
• Future Developments in Timekeeping:
  • Nuclear Clocks: Focus on the nuclei of atoms for even higher precision. The emission frequency of these nuclear clocks is around 2,020 terahertz, indicating ultra-high precision.

How Clocks Evolved Over History In India?

• The development of clocks in Indian history reflects a rich blend of indigenous ingenuity and external influences.
• Ancient India utilised various timekeeping methods, such as water clocks (known as ghatika yantra) and sundials, which were used in temples and for daily activities.
  • Ancient Indians tracked time using the stars and planetary positions (Nakshatras) to accurately record significant events.
  • Timekeeping linked to planetary positions led to the development of astrology and exploring the influence of planets on human life.
  • Despite the advanced system, daily time was often measured in hours or pahars, and simple clock towers were sufficient for general public use.
• With the arrival of Islamic rulers, more advanced water clocks and astronomical instruments were introduced, blending with local traditions.
• The colonial period saw the introduction of mechanical clocks and pocket watches.