Class 10 Exam > Class 10 Questions > Earlier the SI unit of time, second, was desc...
Start Learning for Free
Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one?
Most Upvoted Answer
Earlier the SI unit of time, second, was described on the basis of rot...
In earlier days, one second is defined on the basis of Earth's movement. It takes 24 hours for Earth to rotate about its own axis and 365 days to revolve around the sun. Earlier theories are based on this fact and they defined one second as 1/86400 th part of one full Earth day, 1/3600 th part of an hour and 1/60 th part of a minute. But international definitions of fundamental quantities must be very much precise as they are the reference for many other units. As time elapsed, there is an advancement in technologies and scientists then proved that the earlier definitions were not accurate because they found out that the Earth speed is not always constant and it is decreasing very slowly. Also, the speed of rotation of Earth varies slightly from place to place. So, they said defining second on basis on rotation of Earth is not precise as we couldn't compare the second of today to the second of yesterday. And even defining it on revolution of Earth too was not correct because it doesn't take exactly 365 days to revolve around the sun. So, scientists tried give a definition for second which is very much precise and must be constant throughout on Earth. Finally, in 1950's scientists gave the currently used definition of time as "9,192,631,770 periods of the radiation corresponding to the transition between the two hyper-fine levels of the ground state of the cesium 133 atom”. This gave birth to the so called "atomic clock" which is very much precise and scientists predict that this won't lose even a second for 300 million years. Atomic clocks play an important role in calibrating computers and GPS systems, among other things, and to get faster processors and better positioning systems, we’ll need even better systems of time-keeping. In 2016, German researchers proposed an even better atomic clock, one based on the element strontium, and which uses optical light, rather than microwave emissions for calibration.
There is a very good article written on this topic. Check it out here.
https://www.discovermagazine.com/the-sciences/why-1-second-is-1-second
Attention Class 10 Students!
To make sure you are not studying endlessly, EduRev has designed Class 10 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 10.
|
Explore Courses for Class 10 exam
|
|
Similar Class 10 Doubts
Top Courses for Class 10View all
Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one?
Question Description
Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? for Class 10 2024 is part of Class 10 preparation. The Question and answers have been prepared according to the Class 10 exam syllabus. Information about Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? covers all topics & solutions for Class 10 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one?.
Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? for Class 10 2024 is part of Class 10 preparation. The Question and answers have been prepared according to the Class 10 exam syllabus. Information about Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? covers all topics & solutions for Class 10 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one?.
Solutions for Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? in English & in Hindi are available as part of our courses for Class 10.
Download more important topics, notes, lectures and mock test series for Class 10 Exam by signing up for free.
Here you can find the meaning of Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? defined & explained in the simplest way possible. Besides giving the explanation of
Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one?, a detailed solution for Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? has been provided alongside types of Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? theory, EduRev gives you an
ample number of questions to practice Earlier the SI unit of time, second, was described on the basis of rotation. But afterwards it was described on the basis of revolution saying that the time before was not accurate because it varies. And again the definition of the SI unit of time that is second was not found accurate by the scientists. What was the variation? Why did the change the definition and moved to a new one? tests, examples and also practice Class 10 tests.
|
|
Explore Courses for Class 10 exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup