Written by Toby Yu
Edited by Yinwa Yung
Despite the common presupposition of time being a constant no matter where you are, as when you are at home, time appears to pass at the same rate as if you were at school. Therefore, it can be assumed that time is the same no matter where you are in the universe, right? This in fact is not the case.
In 1915, Albert Einstein published his discovery of time actually being relative to space, which when woven together, creates the spacetime continuum. Massive objects with a substantial gravitational force, like the Earth, have the ability to warp the fabric of space-time itself. Meaning that the stronger the force of gravity is, the slower that time passes. Hence, while an event can take place at one time for one person, it may appear to take place at a different time for another. This effect is known as time dilation (Redd & Bartels, 2021).
A visual depiction of how the Earth warps a 2D plane of space (NASA’s Gravity, 2011).
Recently, a team of physicists –– lead by Jun Ye, at the research institute JILA –– developed an atomic clock comprised of approximately 100,000 ultracold strontium atoms. The atoms were then placed at slightly different heights through the arrangement of a lattice formation. Over the distance of a millimetre, this clock managed to record a change in a hundredth of a quadrillionth (a quadrillion being 1015) percent in frequency, congruent to general relativity’s predictions (Conover, 2021).
The clock was also found to be the most precise measurement of frequency that has ever been recorded, being able to measure up to 0.76 millionths (106) of a trillionth (1012) of a percent.
The effects of general relativity have been observed by physicists at a greater precision than ever before with the help of incredibly precise atomic clocks, proving that the spacetime curvature can be measured down to the millimetre. According to these clocks, clocks tick slower the closer they are to the Earth.
Theoretical physicists all around the world, including those from the University of New South Wales and the University of Wisconsin, are astonished with the recent discovery using this technology, with the initial thought that it would be nearly impossible to reach this point of scientific development in the near future.
The development of the precision of timekeeping has widened the path for future discoveries and research on further proofs regarding Einstein’s theory of general relativity in detail, with advancing our knowledge of how space and time interact with each other.
References
Conover, E. (2021, October 18). An atomic clock measured how general relativity warps time across a millimeter. https://www.sciencenews.org/article/atomic-clock-general-relativity-time-warp-millimeter-physics
NASA's Gravity Probe B Confirms Einstein Theories. (2011, May 9). https://spacenews.com/nasas-gravity-probe-b-confirms-einstein-theories/
Redd, N. T., & Bartels, M. (2021, June 5). Einstein's theory of general relativity. https://www.space.com/17661-theory-general-relativity.html
Comments