Scientists have succeeded in observing Einstein’s general theory of relativity on a very small scale that has never been tried before, proving that their ticks are much smaller when two clocks are separated by only a fraction of a millimeter.
According to June Yeh of Boulder University in Colorado, this is the most accurate watch ever developed. And it paves the way for new discoveries in quantum mechanics controlling the subatomic world.
The researcher and his colleagues published their results in the prestigious journal Nature on Wednesday, describing technological advances that allowed them to create an object that was 50 times more accurate than their previous watch, which already broke an accurate record in 2010.
Einstein’s general theory of relativity states that the gravitational field of a very large object distorts space-time, dating to 1915. According to this theory, time slows down when a mass reaches significance.
Thanks to the invention of atomic clocks, which have not been validated for a long time, it measures time by detecting the atoms going to a higher energy state when subjected to a certain frequency.
In 1976, an experiment sent the clock into space, which was shown to be one second faster every 73 years than its equivalent on Earth.
Since then, clocks have become more accurate and therefore better at detecting the effects of relativity.
A decade ago, Jun Yeh’s team broke the record by noticing a time difference when they moved their clock 33 centimeters.
June Yeh’s breakthrough was working with “optical lattice” clocks, using lasers to trap atoms in specific directions. This technique prevents them from falling due to gravity or movement, which can lead to loss of accuracy.
Inside the new clock there are 100,000 strontium atoms, fixed in several layers, measuring a total height of one millimeter.
The clock is so accurate that when this stock is halved, scientists are able to detect time differences between the upper and lower half.
At this level of sensitivity, watches act as probes.
“Time and place are connected,” Jun Yeh told AFP. “And with such precise timing, you can see how space changes in real time – the earth is a living, dynamic body.”
For example, such clocks make it possible to separate solid rock from lava beneath the surface in volcanic areas and thereby help predict eruptions.
Or study how global warming is melting glaciers and raising sea levels.
But what’s most exciting about Jun Yeni is the role these clocks can play in physics.
Today’s clock can detect a time difference of more than 200 micrometers – but reducing that number to 20 can explore the quantum world and help fill in some theoretical gaps.
If relativity beautifully describes how large objects, such as planets or galaxies, behave, it is the opposite of quantum mechanics dealing with very small ones.
The intersection of two fields makes it possible to take a further step towards a “theory of everything” capable of explaining all the physical phenomena of the cosmos.