Physics of time: Flash, superpowers and relativistic time dilation





Many are familiar with the hero of DC Comics Flash, which is faster than a bullet and is considered the fastest hero of the comic book universe.



In addition, Barry Allen is also a scientist, so why not assess his abilities on the part of science and see how real they are and whether they contradict physics. It turns out that the scientific world has long recognized the possibility of slowing down time and even conducting experiments with it.



And today I will try to tell about it, and Richard Muller’s book “Now. Physics of time.



Relative theory of relativity



If, for example, I say: "This train arrives at 7 o'clock", then I have

I mean something like this: “Pointing my little arrow

hours at 7 and the arrival of the train will be simultaneous events. "

Albert Einstein


It was with these words that Albert Einstein began to introduce the concepts of space and time into physics, without which he could not create the theory of relativity.



In his article, published on June 30, 1905, Einstein begins to explain the concept of time on the fingers using simple examples. Perhaps it looks absurd, but it was impossible to do otherwise — he needed to break the shackles of reason that limited the thinking of his fellow physicists.



So what is the time - this did not explain Newton and did not explain Einstein, but he was able to explain his relativity and make it clear that everything is not as simple as previously thought.

Try to remember your perception of time in childhood, when it was not yet absolute for you. Do you remember how it stretches in the queue, and how quickly it flies for interesting activities.



What did Einstein say about it:
"When you sit with a beautiful girl for two hours, they seem like a minute to you, but if you sit on a hot stove for at least a minute, it will seem like two hours has passed."


So, using simple examples with small clock hands and a hot frying pan, the genius of the 20th century will lay down the theory of relativity in his article “On the electrodynamics of moving bodies”, and after 10 years developed it, explaining the principles of gravity and its nature.



But where is the relativity? To do this, we will stop for a minute and answer one question: “What is my driving speed now?”.



"Zero" answer you and you will be right if you are sitting or standing, but at the same time the correct answer will be "1679 km / h" if we imagine that you are in the mouth of the Amazon, because this is the rotation speed of the earth near the equator .



But remember about the speed of rotation of the Earth around the Sun, and 30 km / s also turns out to be the right answer.



This is all relativity - it all depends on your learning platform, or as it is called physics, the "reference system".



Your reference system (CO) can be anything - the chair, floor, earth, or the plane in which you fly, and maybe our galaxy or the universe.

Everything is relative and this is the essence.



Everything is so relative that even the time flow rate will depend on the chosen reference system. And this means that there is no absolute concept of time and two ticks of hours can mean completely different amounts of time.



You may have read and studied other books on the theory of relativity and encountered confusing notions of “dissenting observers” moving at different speeds, and therefore they have different perceptions of time, and therefore they do not agree with each other, but this is not important. Observers do not agree among themselves only in the degree of error regarding the speed of movement of the aircraft, but they know that the speed is relative and its indicator will depend on the chosen reference system.



The main highlight of the general theory of relativity - all observers agree with each other.



“The Constancy of Memory” Salvador Dali, 1931



Such different reference systems



Using the theory of relativity, Einstein proved that time will vary depending on the chosen reference system, and this or that action will take a different amount of time.



At relatively low speeds (up to 1 500 000 km / h), this difference will be insignificant, but the closer to the speed of light, the greater will be the difference in time.



Take an example: you are on a spacecraft moving at a speed of 97% of the speed of light. We take two for the reference points - the spacecraft and the Earth, and recall the observers who agree with each other.



So, being on the ship, the interval between your two birthdays will be one year, but on the earth - three months. The observer on the ship will say this, and the observer on Earth will agree with him. But what is the reference system to take as the base, in which of them we are. The correct answer is: all at once.



Yes, you are in all at once reference systems - Earth, aircraft, outer space and many others. These systems are needed for one thing - to determine the movement of bodies in relation to them. So, if your speed on Earth will be zero, then this reference system will be called your own.



For example, in relation to the Sun’s own reference system, we are moving at a speed of 29 km / s, while on Earth making revolutions around the star. Perhaps you are familiar with another explanation of the relativistic time dilation: “clocks in motion, it seems to us, are slower than yours,” but this is not quite the correct explanation.



It does not seem to us that moving clocks go slower, they actually go slower, but only if we measure the course of their time in our frame of reference. At the same time, they will go faster in their own frame of reference than in ours, and this is not a paradox or a contradiction. Or a contradiction, but no more than the speed of a person in an aircraft, which is simultaneously equal to 0 km / h and 900 km / h. While all observers will agree with these answers.



The relativity of time is easily measurable in experimental physics. Experimental scientists working with radioactive elementary particles (pions, muons and hyperons) face it all the time.



Radioactive particles have a half-life and it differs for different elements.



For example, uranium has a half-life of 4.5 billion years, and a radioactive carbon isotope has 5700 years. So tritium, which is used in some luminous hands of the clock in a mixture with phosphorus, has a half-life of 13 years, which is why, after 13 years, the hands begin to glow half weaker than before.



Peonies, which are studied in experimental physical laboratories, have a slightly smaller half-life - 26 billionths of a second, or 26 nanoseconds in another. Although it seems a very small amount of time, but only for a person.



When studying fast-moving pions, their speed was 0.999998 from the speed of light, they conducted an experiment - they were pushed against protons. It turned out that their half-life was 637 times longer than that of pions in a state of rest.



Before these experiments, the relativity of time was an abstract theory, but after - it turned into reality.



Is it possible that moving at a higher speed, time for us will move slower? Yes, and this was confirmed in 1971 by Joseph Hafele and Richard Keating with the help of a passenger jet and four sets of cesium atomic clocks. Their experiment proved the practical operation of the theory of relativity and the effect of time dilation.



Every day spent on an airplane that moves at a speed of 900 km / h will be 29 nanoseconds longer than a day spent on Earth.



It may not seem like such a lot of time, but the higher the speed, the greater the difference. So for GPS satellites, the time delay is 7200 nanoseconds per day, and this will already give an error in positioning of 2.2 kilometers per day. And every day this error will grow by 2.2 kilometers.



Thanks to Einstein's theory of relativity, calculations were made, and this error is taken into account when calculating the location. When flying on airplanes, you will live longer with respect to the Earth’s frame of reference, but you will not feel this effect on yourself - your time will slow down, but at the same time the heartbeat and brain activity will also slow down. Here it is - an amazing property of relativism. Everything will be slower, because the very speed of time changes.



So it turns out that Flash can slow down time, but only in relation to its own reference system in relation to the earthly one. It turns out that the abilities of Barry Allen, he Flash, do not contradict the laws of physics, and therefore can be quite real.



On this today, everything, even more about the mystery of time, you can find out by reading the source.



Watch out for lightning, respect physics and read clever books!




A source:

By: Richard Muller

Now. Time physics

Publisher: Mann, Ivanov and Ferber



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