by Curious Kids is a series for children of all ages. If you have a question you want to answer from an expert, send it to curiouskidsus@theconversation.com.
Why does time change when it travels close to the speed of light? – Timothy, 11 years, Shoreview, Minnesota
Imagine you are in a car that drives through the country that is watching the landscape. A tree in the distance gets closer to your car, passes you directly and then moves behind you again in the distance.
Of course, you know that the tree does not actually get up and leaves or away from them. They are in the car that moves to the tree. The tree only moves in comparison or relative to them – that’s what we call physicists relativity theory. If you had a friend standing on the tree, you would see that you will move to him at the same speed as you see how to move on them.
In his book “Dialogue about the two main systems of the main world” from 1632, the astronomer Galileo Galilei first described the principle of relativity – the idea that the universe should behave in the same time, even if two people experience an event differently because one respects the other.
If you are in a car and throw a ball into the air, the physical laws that work on it should be the same as the power of gravity as the one that is observed on an observer that is observed from the roadside from the roadside. While she moves the ball up and down again, someone on the roadside moves to you and by you as well as from you as well as down and down.
Special theory of relativity and speed of light
Albert Einstein suggested the idea much later, which is now called a special theory of relativity in order to explain some confusing observations that had no intuitive explanation at that time. Einstein used the work of many physicists and astronomers at the end of the 19th century to put together his theory in 1905, starting with two important ingredients: the principle of relativity and the strange observation that the speed of light is the same for every observer and nothing can move faster. Anyone who measures the speed of light will achieve the same result, no matter where they are or how quickly they move.
Let’s say you are in the car at 60 miles per hour and drive on the tree on the tree. If you throw a ball on you at a speed you perceive as a 60 miles per hour, you could logically think that you would watch your friend and tree with 60 miles per hour and the ball will go to you to you with 120 miles per hour. This is very close to the right value, but actually something wrong.
This discrepancy between what you could expect by adding the two numbers and the real answer grows when one or both of them move closer to the speed of light. If you were traveling in a rocket at 75% of the speed of light and your friend throws the ball at the same speed, you would not apply the ball to you at 150% of the speed of light. This is because nothing can move faster than light – the ball still seems to move on it at less than the speed of light. Although all of this may seem very strange, there are many experimental evidence to underpin these observations.
Time dilation and the twin paradox
Speed is not the only factor that changes in relation to what makes observation. Another consequence of the theory of relativity is the concept of dilution of time, in which humans measure different time sales, depending on how quickly they move in relation to each other.
Every person usually experiences time in relation to themselves. But the person who moves faster experiences less time for them than the person who moves more slowly. Only when you connect and compare your watches do you realize that one clock says that less time has passed while the other says more.
This leads to one of the strangest results of the theory of relativity of the double paradox, which says that one of two twins on a high-speed rocket takes a trip to space to find that their twin has aged faster than her. It is important to note that the time behaves “normal” as it is perceived by every twin (just like you now have time), even if your measurements do not agree.
You may ask yourself: If every twin sees yourself as a stationary and the other than moving to you, do you not measure the others that you age faster? The answer is no because they cannot be both older, which is compared to the other twin.
The twin on the spaceship is not only at a certain speed, in which the reference frame remains the same, but also accelerates on earth compared to the twin. In contrast to speeds that are relative to the observer, accelerations are absolute. When you step on a scale, the weight you measure is your acceleration due to gravity. This measurement remains the same regardless of the speed with which the earth moves through the solar system, or the solar system moves through the universe through the galaxy or the galaxy.
Neither Twin does not experience any strangeness with their watches when you approach the speed of light – both experience the time as normal as you or me. Only when you meet and compare your observations will you see a difference – one that is perfectly defined by the mathematics of relativity theory.
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This article will be released from the conversation, a non -profit, independent news organization that brings you facts and trustworthy analyzes to help you understand our complex world. It was written by: Michael Lam, Rochester Institute of Technology
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Michael Lam does not work for a company or an organization that benefits from this article and have not published any relevant affiliations about their academic appointment.
