SCIENTIFIC EDUCATIONAL CENTER science idea

The passage of time, unlike how most people imagine it, is far from a constant value — it is known that an increase in the forces of gravity slows down the passage of time. Because of this, the clocks on the Earth's surface will go a little slower than the same clocks placed in near-Earth orbit, and a person living in a penthouse will age a little faster than a person living on the first floor of the same building. In fairness, it should be noted that the time difference, even at such scales, is almost imperceptible, at least for human perception, but with the help of high-precision measuring equipment it can be measured, and recently a group of physicists managed to measure the gravitational deformation of time at a record small scale, a scale of only one millimeter.

The idea that the passage of time is affected by the influence of the forces of gravity belongs to Albert Einstein and is part of his General Theory of Relativity, formulated in 1915. In our world, space and time are closely interconnected, and large amounts of matter form distortions of the space-time continuum by their gravity. The time dilation effect is especially pronounced when approaching massive stars or, in the most extreme case, supermassive black holes.

Changes in the course of time are usually measured using the most accurate clocks — atomic clocks. Using atomic clocks installed on airplanes and spacecraft, scientists have already measured these effects at distances of thousands of kilometers. But measuring time dilation at a smaller scale level was previously impossible due to the lack of appropriate measuring equipment.

And only recently, researchers from the JILA Institute (Joint Institute for Laboratory Astrophysics) of the University of Colorado, who specialize in creating the most high-precision atomic clocks, managed to create suitable tools and measure the effect of time dilation on a scale of one millimeter.

The basis of this experiment was, of course, specialized atomic clocks, the "heart" of which was a cloud of 100 thousand cooled strontium atoms. The signal for timing is generated by atoms constantly moving from one energy state to another and back, which occurs at a strictly defined frequency unique to each chemical element. By carefully regulating and controlling the parameters, the scientists achieved complete synchronization, all the atoms of the cloud oscillated (made transitions) absolutely simultaneously for 37 seconds, a record for such a period of time.

In this case, strontium atoms were placed in the nodes of a multilayer three-dimensional optical lattice, which can be imagined as a tall stack of pancakes. After completing the forced synchronization procedure, the scientists used high-precision measuring time to detect the difference in the frequencies of vibrations of atoms at the top of the lattice and at its base.

The shift in the frequency of vibrations of atoms between these two regions, which were separated by a distance of one millimeter, was 0.0000000000000000001 percent. This is a very, very small deviation, which, nevertheless, still remains in the sensitivity zone of the most modern measuring equipment used.

The scientists said that their work and experiments not only made it possible to make atomic clocks 50 times more accurate than their previous versions. Now this watch has turned into a kind of tool for "probing" new areas that lie beyond the currently known limits of fundamental physics. For example, the nature of the forces of gravity still cannot be explained from the point of view of quantum mechanics, but the ability to see and measure the effects of gravity on the smallest scale can reveal some of the mysteries and possibly point to the missing link that will become a bridge between classical physics and quantum mechanics.

The article was published in the journal Nature
PHOTO: A 1 mm thick cloud of strontium atoms suspended in a laser lattice has helped physicists more accurately
than ever before to measure the effect of gravity on the passage of time © R. Jacobson/NIST

Source: dailytechinfo.org, sci-dig.ru