Question

explain how time is measured in ancient times. also write notes on cesium clock​

Answer 1

In ancient times time was measured according to the sun set and fawn

Answer 2

One of the earliest of all devices to tell time was the sundial. The sundial is looked on as being a form of sun-powered clock. ... There was another more advanced shadow clock or sundial in use by the ancient Egyptians around 1500 BC. This shadow clock or sundial permitted one to measure the passage of hours within a day.

One of the earliest of all devices to tell time was the sundial. The sundial is looked on as being a form of sun-powered clock. ... There was another more advanced shadow clock or sundial in use by the ancient Egyptians around 1500 BC. This shadow clock or sundial permitted one to measure the passage of hours within a day.The caesium standard is a primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133 atoms are used to control the output frequency. The first caesium clock was built by Louis Essen in 1955 at the National Physical Laboratory in the UK.[1] and promoted worldwide by Gernot M. R. Winkler of the USNO.

One of the earliest of all devices to tell time was the sundial. The sundial is looked on as being a form of sun-powered clock. ... There was another more advanced shadow clock or sundial in use by the ancient Egyptians around 1500 BC. This shadow clock or sundial permitted one to measure the passage of hours within a day.The caesium standard is a primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133 atoms are used to control the output frequency. The first caesium clock was built by Louis Essen in 1955 at the National Physical Laboratory in the UK.[1] and promoted worldwide by Gernot M. R. Winkler of the USNO.Time was also measured by Sun rotation