Source- This post on Evolution of clock has been created based on the article “How time has been kept throughout history: from sundials to atomic clocks” published in “The Hindu” on 5 August 2024.
Why in News?
The world has evolved from measuring time using the Sun and the Moon to using atoms and their nuclei.
About clock
1. Clocks measure time by tracking something that repeats at a fixed frequency.
2. Modern clocks have a power source, resonator (like a quartz crystal), and counter.
Evolution of clock
1. Sundials (Ancient Times): It used the position of the Sun to cast shadows, indicating time by the shadow’s length and position.
2. Water Clocks (Ancient Civilizations): It utilized the steady flow of water to measure time, with water levels indicating elapsed periods.
3. Hourglasses (Ancient Times): It employed sand flowing through a narrow passage to measure specific intervals.
4. Mechanical Clocks (13th Century): It featured the verge escapement mechanism, allowing gear movement at fixed intervals, driven by weights and pulleys.
5. Spring-Driven Clocks (15th-18th Centuries): It was introduced coiled springs for power, with fusee mechanisms ensuring consistent force, leading to pocket watches.
6. Pendulum Clocks (1656): It was invented by Christiaan Huygens and this used a pendulum’s regular swings to improve accuracy.
7. Marine Chronometers (1761): It was developed by John Harrison. These were crucial for determining longitude at sea, resistant to ship motion and environmental changes.
8. Electric Clocks (19th Century): It was powered by batteries or electric motors, enhancing accuracy and reliability over mechanical predecessors.
9. Quartz Clocks (20th Century): It utilized quartz crystals oscillating at fixed frequencies due to the piezoelectric effect, leading to widespread use in watches and wall-clocks.
10. Atomic Clocks (1940s-Present): It employed atoms (e.g., caesium-133) as resonators, with lasers exciting atoms to emit radiation at precise frequencies, achieving unprecedented accuracy.
11. Optical Clocks (Next-Generation): It use atoms like strontium or ytterbium, with radiation in the optical range, offering stability and precision over billions of years.
12. Nuclear Clocks (Future Development): It is potential next-next-generation devices, using atomic nuclei as resonators for ultra-high precision, with thorium-229 nuclei being a primary candidate.
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