We do not value him, very often we neglect him, sometimes we kill him. It is constantly lacking, it flies so fast that you want to stop it, and sometimes it even heals wounds. Time is a physical quantity, it is constantly changing, and it is not a figure of speech: its course accelerates, slows down, stops and continues. And also a minute is not always 60 seconds, time has a beginning and an end, but first things first.
Time started about 13.8 billion years ago. At least theoretical physicists, including Albert Einstein, believed that time began at the moment of the Big Bang. Stephen Hawking in his lectures on the origin of time said that before the Big Bang, all matter in the universe was compressed, and its density tended to infinity. This incredibly dense point is called a singularity, before which there was nothing at all.
However, in 2018, a scientific article "Through the Big Bang" was published, in which a team of authors argued that there was time before the Big Bang. If you explain a clever theory with a lot of formulas and equations on your fingers, then imagine that the universe is your sock, and rewinding time is the process of turning it inside out. So, the Big Bang is the moment when the sock is in a state of a lump, a singularity. If you turn it in one direction, you get the front side: our time flow and the modern universe, and if you turn it inside out, you get the universe that was before the Big Bang.
By the way, the Big Bang and the launch of all processes of the formation of the universe are separated by the so-called Planck time - a quantum of time, the smallest value. It is equal to the time it takes for a wave or particle that has no mass, moving at the speed of light, to overcome the Planck length (approximately 1.6x10−35 meters). Planck time determines the scale at which modern physical theories stop working, and general relativity loses its meaning altogether. And all because of 5.39x10-44 seconds.
In classical physics, time is considered absolute. All processes in the world, regardless of their complexity, have no effect on the course of time. Newton argued that all motions can accelerate or decelerate, while the course of absolute time cannot change. On the one hand, everything is so. But the theory of relativity states that the passage of time depends on the speed of movement. In other words, in an hour on the subway you will grow old less than sitting in a chair at home.
Another amusing fact confirming that time is plastic was confirmed by practical physicists. The source of gravity acts on this fundamental quantity: deep underground, the passage of time passes more slowly than at the top of a mountain. Einstein spoke about this effect of gravitational deceleration in 1907, but his theory was confirmed only with the advent of ultra-precise equipment. You will never feel it, but the person living on the 17th floor is aging faster than their downstairs neighbors. And this is not a joke: corrections for the time curvature are always introduced into the work of near-earth equipment.
The most accurate atomic clock today is at the University of Colorado. They define one second as 9 192 631 770 periods of electromagnetic radiation arising from the transition between two hyperfine levels of the ground state of the cesium-133 atom. The clock is so accurate that it is only one second behind in five billion years. And they are able to record the effect of gravitational deceleration when the height changes by several tens of centimeters.
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Atomic clock at the University of Colorado, USA.
Another change in the current time is associated with gravity. As it rotates, the Moon acts on the Earth, slowing it down. In the distant past, the rotation of our planet was so fast that the day lasted no more than 2-3 hours, and the Moon managed to fly around the Earth in just five hours. The deceleration process continues to this day: 0.002 seconds are added to the day in a hundred years. Theoretically, there will come a moment when time on our planet will stop, but our descendants will not catch it, since the expanding Sun will swallow the Earth much faster.
By the way, if you think that there are always exactly 60 seconds in a minute, then we hasten to disappoint you. There is a so-called leap second, it is also called "jumping" and "leap" seconds. It is periodically added either at the end of June 30 or December 31 to Coordinated Universal Time (UTC) to match it with the mean solar time (UT1). This is done so that UTC time does not differ from UT1 by more than ± 0.9 seconds. It is considered that on such days after 23:59:59 time is 23:59:60. Due to the increase in the length of the day due to the weakening influence of the Moon's gravity on the Earth, in the future additional seconds will have to be entered more and more often, in each next century it will be necessary to enter about 64 seconds more than in the previous one. So, in the 22nd century, it will be necessary to enter already two seconds a year,and after 2000 years, do the same about once a month. In 200,000,000 years, a day will last 25 hours.
And finally, one more interesting fact. Everyone knows the statement that it is impossible to catch up with the future, it will always be one step ahead of you, it’s like jumping over your head - unrealistic. But you will have to come to terms with the fact that at this moment, second of the current moment in time, you are in the past. This is due to the fact that our brain processes events with a delay. Neuroscientist David Eagleman found that it takes 80 milliseconds for our brains to linger in sync with reality. And in extreme situations and under stress, the time for our brain slows down: it captures many times more information than in a calm state. This is a kind of slow motion mode, like your smartphone camera, in which video is recorded at twice the frame rate.
Sasha Epstein
