On the occasion of the winter solstice, which began today, Dr. Nadia Goldovski - the person in charge of time and frequency measurements at the National Physics Laboratory at the Ministry of Economy and Industry, explains in an interview to the science website how the time is determined in her laboratory using atomic clocks
The time of the State of Israel is determined at the National Physics Laboratory in the Ministry of Economy with the help of a special system that compares 86,400 times a day the results of time measurement in Israel with the results of time measurement of other national laboratories in the world. Explains Dr. Nadia Goldovski - the person in charge of time and frequency measurements at the National Physics Laboratory at the Ministry of Economy and Industry in an interview with the science website
The National Physics Laboratory is actually the country's clock and the national time standard. Israel time is determined according to the Time Law from 1992. The laboratory determines and measures the time and frequency used for security and civilian purposes such as: television broadcasts, telephone calls, computers, navigation devices and military systems such as: "Iron Dome", the "Arrow" system and "Magic Wand" ".
at the national laboratory There are four cesium-type atomic clocks, equipment for international comparisons, equipment for performing measurements and calibrations for industrial and military customers such as: Rafael, Elbit, the Aerospace Industry, Air Force, Electricity Company.
In 2019, in accordance with the national standard for time and frequency, new generation atomic clocks were introduced as well as an innovative international comparison system. As a result of the renewal of the equipment, the accuracy of the national standard rose to the 1X10 level-14.
In an interview with the scientist website, Dr. Golodovsky explained that according to the 1992 Time Determination Law, the Israeli national time must be determined according to precise cesium-based atomic clocks and they must be synchronized to world time based on clock measurements in similar laboratories around the world. "We keep the exact time and make comparative measurements with the clocks around the world and also with satellites in all these measurements."
How do atomic clocks work?
"The accuracy of our clocks is ten to the power of minus 14. There are also cesium clocks with an accuracy of ten to the power of 16 that is built in a cooling chamber for a temperature of almost absolute zero. We are aware that due to the lower level of accuracy we have a deviation compared to the world clock. However, since we measure the frequency in all atomic clocks against the world clock, the accuracy increases to ten to the power of minus 15.
We actually measure the times reported to us by all the navigation satellites in space, be it GPS, the European Galileo satellites or the Russian GLONASS. Every navigation satellite has an atomic clock and sometimes even two or three. However, they are less accurate than the clocks found in 85 laboratories like ours around the world. We check the clocks on the satellite, make comparisons between them and our clocks and send the data to an international center located in Paris. We check our accuracy on the satellite systems and they receive the corrections to maintain the world time we all see on our phones and computers. that you receive both on the phone and on computers and everywhere.
Time measurement is important for navigation, satellites, airplanes, military uses, geodesy, geology, communication and more. Therefore, those laboratories located in the developed countries, including Israel, calibrate the satellites and transmit the data through the center in Paris to the satellite operators. This is how a huge global network was created for her to determine the time.
Our system analyzes data from up to eight satellites at the same time, with each satellite being observed by us for approximately 13 minutes.
What are the plans next?
The technology, methods and equipment are advanced and there are already clocks in the world with an accuracy of ten to the power of minus 18.
We have four clocks in the lab with an accuracy of ten to the power of minus 14. I hope they will also buy atomic clocks based on hydrogen lasers that are 10 times more accurate than the cesium clocks, meaning an accuracy of ten to the power of minus 15.
More of the topic in Hayadan:
