Note4Students

From UPSC perspective, the following things are important :

Prelims level: Optical Atomic Clock and Classical Atomic Clock; Difference between them.

Why in the News?

Atomic clocks power GPS systems, guiding us in navigation, emergencies, and military operations.
- Scientists are developing optical atomic clocks to enhance timekeeping accuracy for Navies.

What are Atomic Clocks?

Atomic clocks are accurate timekeeping devices that use the vibrations of atoms as a precise measure of time.
They rely on the natural oscillations of atoms, usually Caesium or Rubidium atoms, which are extremely stable and predictable.
This stability allows atomic clocks to keep time with extraordinary accuracy, often losing or gaining less than a second over millions of years.
- However they are big, need a lot of power, and are expensive, so they’re mostly used in big research places.

Use of Stable Atoms: Atomic clocks use stable atoms like Cs-133 to keep time really accurate.
Atom Energy Levels: Atoms have energy levels like steps on a ladder, and they move between these levels when they’re excited.
Creating Resonance: Cesium atomic clocks make caesium atoms vibrate by using microwave radiation at a certain frequency.
Defining Time: One second is how long it takes for caesium atoms to vibrate a certain number of times, which sets the standard for time.
Accuracy Control: Atomic clocks keep themselves accurate by constantly adjusting to make sure they’re vibrating at the right rate.

New portable optical atomic clocks for ships are more accurate and durable, making them suitable for use at sea.
These clocks are the best at sea, which is a big deal for keeping time on ships.

Use of Laser: Optical atomic clocks are even more accurate because they use lasers instead of microwaves.
Operating Frequency: They work at higher frequencies, which means they can measure smaller time intervals more precisely.
Narrow Linewidths: Optical atomic clocks are really stable because they have a narrow range of frequencies, which helps them stay accurate.

Initial Testing: Scientists tested the new clocks and found they were really stable and accurate, which is a big deal for keeping time.
Comparative Performance: These new clocks worked better than old ones, showing they could change how we keep time.
Sea Trials: Tests at sea showed the clocks worked well even on a moving ship, proving they could be used for navigation and other important tasks.

Three rubidium atomic clocks and six hydrogen maser clocks onboard the Indian Regional Navigation Satellite System (IRNSS) had failed.
The failed satellite, IRNSS-1A, is still being used for messaging activities, and the data from other operational satellites will be used to maintain the system’s functionality.

[2018] Why is Indian Regional Navigational Satellite System (IRNSS) needed? How does it help in navigation?

[2018] With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements:

IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits.
IRNSS covers entire India and about 5500 sq. km beyond its borders.
India will have its own satellite navigation system with full global coverage by the middle of 2019.

Which of the statements given above is/are correct?

(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) None