In November 1915, Albert Einstein He was experiencing one of the most prominent moments in his career as a scientist, when he presented his famous book Theory of relativity before Prussian Academy of Sciences, in Berlin. Four years later, on May 29, 1919, twentieth-century science reached its climax with confirmation of this theory.
but, Your initial articlesHe incorporated the first ideas of relativity into the world of science, dating back to 1905 and published when the physicist was only 26 years old. If you can get a copy of these texts in your hands now, you will be surprised by the following Ease of reading. The text is simple and the equations do not exceed the complexity that can be presented by some mathematical algebra problems.
This is because Einstein had A very visual way of thinkingThis is done by presenting small mental problems and solving them in his mind, thus expressing ideas more clearly. An example of this developmental process is the famous twin paradox.
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Einstein has evolved in his entirety Two theories: general relativity, related to the gravitational field and reference systems, and special relativity, related more to the physics of motion as a function of spacetime. As a whole, their work completely changed the view of the universe and many phenomena and concepts such as time, space, and gravity.
Thus, although it may be difficult to understand and a bit intimidating to confront, it can be simplified into a series of key points that bring together its findings and make them accessible to anyone who wants them. We present to you, therefore, The five basic points To finally understand the theory of relativity.
The speed of light is absolute
One of the key points of the theory of relativity states that light propagates Always at 300,000 km/s Regardless of the reference system from which we observe. What does this mean exactly? Einstein explains this with one of his mental games in a very simple way.
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Put a person on a train moving at 100 km/h. At the same time, another person is traveling on another train in the same direction, but this one is traveling at 90 km/h. Thus, for the observer of the second train, the first is moving at only 10 km/h, and not at 100 km/h, which he would notice if his train suddenly stopped. That is, the speed at which you see the first train Depends on whether your reference system Stopped or moving. Well, with light that's not true.
Einstein said that no matter where you look from, whether you are moving or not, you will always see light moving at the same speed: 300,000 km/s. Applying to your own game, we will assume that the person on the first and second trains will see the light moving at the same speed. Thus the theory of relativity is established Light as a constantAny quantity is always fixed.
Time is relative
Another major consequence of this theory is that time, unlike the speed of light, It's not absolute It will depend on the movement of observers. That is, two events that appear simultaneous from one person's point of view may not be simultaneous from another person's point of view. And the most curious thing about all this is that They would both be right.
To understand this, Einstein recalls the mental example of trains. This time, it involves the first person standing next to the tracks when the train passes. Then, while the middle car was in front of him, lightning struck the first and last car. Since he is at an intermediate distance from both events, his light reaches the eye at the same time and he can confirm without error that the two rays hit At the same time.
Now, for someone else sitting in the same center car, inside the train, things would be completely different, but just as true. In their view, the rays would also travel the same distance, but because of the relative motion of the train, the light from the beam in the tail would reach the observer later. So this person will say, also without error, that lightning struck in different times.
This idea is Very unintuitiveBecause it is a seemingly contradictory inference, but it is not. Another very useful example of this relative appreciation of the passage of time is the twin paradox, which is somewhat more complex, but just as strange.
Time and space are not independent
Among other concepts, the theory of relativity highlights its importance Redefining the concepts of space and timebecause they are not independent terms, but are combined into one term known as Free time. It is as if both concepts were inseparable companions: what happens to one will affect the other.
Einstein in one of his lessons
This statement was, for Einstein, a clear consequence of the relativity of time: if an event, such as lightning striking a train, occurs at a different time depending on the location each person is in, then both concepts must be together. in this way, They cannot be treated independently Until the end.
In the words of the physicist himself: “I am with Minkowski that from now on, space and time are destined to fade separately into the shadows, and only the union of the two can be achieved.” Part of reality“.
Mass equals energy
Do you know the famous equation? E = MC2? Well, this is probably the most common result of the theory of relativity. Moreover, it was a scientific milestone, because with this simple and elegant equation Einstein was able to combine two amazing conclusions.
First of all, he says that Energy and mass are related And they can become, practically, equivalent. As an illustration, the physicist asks you to imagine an object emitting two pulses of light in opposite directions. Since each pulse carries a certain amount of energy, the body's own energy decreases as it gives it up to those pulses. Well, Einstein determined through algebraic formulas that for this to hold together, the object must also lose mass. This means that energy and mass will be directly related.
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On the other hand, and more profoundly, in this equation lies the key that explains another result of great importance: Why is it impossible for a moving object to reach the speed of light?. According to the equation, if this happened, the mass of the body would have to be infinite, which, according to the above, would require infinite energy, which is impossible. Therefore, it is stipulated that only massless objects, or rather waves with zero mass, will be able to reach speeds similar to the speed of light.
Gravity is just a distortion
If this entire theory is indeed based on unintuitive and almost surreal concepts, then Einstein's concept and definition of gravity as the concluding point of the theory of relativity seems taken from one of Kafka's stories. It is that, and it states that Spacetime is not flatBut it is distorted by the things in it.
A representative graph of gravity as the curvature of spacetime
So, imagine a large piece of fabric suspended in the air and stretched horizontally. If we throw a small ball at it, it will sink a little. Now, if we put a much larger ball a little further away, the fabric will bend much more, so that the smaller ball will move towards it due to the tilt of the fabric caused by the second ball. Well, that's what happens in the universe according to Einstein. We or the things we deal with would be those little balls that barely bend the fabric, while the Earth, for example, would be that big ball, which… It distorts the fabric significantly And it attracts us to Him.
Thus, Einstein ended the theory of relativity by saying that gravity is not a force, but rather a result of the curvature of the plane of space-time and left it on the table One of the most important results physics throughout the twentieth century, perhaps marking the science of the twenty-first century with them.
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Alexander Donovan writes for News Collective, covering news, politics, business, technology, sport, entertainment, and lifestyle. He focuses on clear, reliable reporting and useful information, helping readers stay informed about current events, emerging trends, and stories that matter.