Have you ever wondered if it is possible to travel at light speed? Perhaps, with the necessary technology to help us achieve this speed, we could one day fly to the edge of the universe and see what is beyond it?
A bit of theory
The speed of light in a vacuum is a constant that we know quite accurately: for example, light moves at a speed of 299,792,458 meters per second. This is the speed of propagation of all electromagnetic fields in a vacuum, including radio waves, infrared, ultraviolet, X-ray and gamma radiation.
According to Einstein's Special Theory of Relativity, nothing can travel faster than light. Under normal conditions, light really moves instantaneously for us. For example, we don't have time to see how photons are reflected from objects and absorbed by surfaces in the room when the light is turned off - this happens so quickly.
The speed of light in empty space (vacuum) does not depend on the relative speed between its source and the observer. Some believe that this statement is contrary to common sense, however, this is precisely what has been demonstrated experimentally. The most famous such experiment was carried out by physicists Albert Michelson and Edward Morley in the late 19th century. They found that the speed of light is the same in all directions, regardless of the fact that the Earth itself moves through space.
Albert Michelson.
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Man and speed
People definitely love speed. Since the wheel was invented, and speed was no longer determined by the strength of our legs, we wanted to move faster and faster. The faster a person moves, the more delightful he becomes (although, it is worth noting that for some people high speeds are a frightening thing). Today, humanity has managed to develop incredibly fast aircraft, ultra-fast fighters, super-fast high-speed trains, and so on. However, the universe has something up its sleeve faster than anything we've achieved - light.
So, perhaps some of you one evening after a hard day, sitting with a bottle of beer or a mug of tea, wondered what it would be like to move at the speed of light.
What happens if we move at the speed of light
A person moving at the speed of light will experience time dilation. For him, time will pass more slowly compared to a person who stands still. In addition, their field of vision will change greatly. For a person moving at the speed of light, the universe will appear in the form of a tunnel in front of the apparatus on which he travels. Consider this exciting idea.
Until the 20th century, the world was convinced of the correctness of Isaac Newton's views on objects and gravity. However, in the 1900s, none other than Albert Einstein took over and changed the world forever.
Albert Einstein lecturing in Vienna in 1921.
The theory of relativity, proposed by him, clarified many issues related to mass and energy. The equation of equivalence of mass and energy proved that mass and energy are interchangeable, that is, one can be transformed into another - and vice versa. He also suggested that there is no single standard frame of reference. Everything is relative even time. Then the understanding came to him that the speed of light is constant and does not depend on the observer. Thus, if a person moves at 50% of the speed of light in the same direction as the light, then the light beam will look to him the same as for a person standing still.
As for the equivalence of mass and energy, in a nutshell, this means that if an object moves 10% of the speed of light, its mass will increase by 0.5% of its original mass. At the same time, if an object moves at 90% of the speed of light, its mass will double.
Can we travel at the speed of light
No, we cannot move at light speed. The point is that when moving at the speed of light, the mass of an object will increase exponentially. Imagine the following: the speed of light is almost 300 thousand kilometers per second, and when an object moves at that speed, its mass becomes infinite. Therefore, to move this object, it will take infinite energy (remember the equivalence of mass and energy), which is extremely impractical.
Roughly speaking, it is for this reason that no object can move at the speed of light (except for light itself) or faster.
As for the movement almost at the speed of light, say at 90% of it, then we will have interesting observations.
Moving (almost) at the speed of light
First of all, a person moving at such a speed will experience time dilation. Time will pass more slowly for him than for someone standing still. For example, if a person moves at 90% of the speed of light, then when 10 minutes pass for him, 20 minutes pass for a person standing still.
A diagram showing the curvature of time as it approaches the speed of light.
It is worth mentioning the major changes in the field of vision. For a person moving - wherever - at 90% of the speed of light, as mentioned above, the universe will look as if he is looking at it through a window in front of his spacecraft. The stars he approaches will appear blue, and those that remain behind will appear red. This is because light waves from stars in front of it will clump together, making the object appear blue, and light waves from stars left behind will stretch and turn red, causing the extreme Doppler effect.
After overcoming a certain mark, a person would plunge into darkness, since the wavelengths that fall into his eyes would be outside the visible spectrum.
Of course, even with all the impracticalities and obstacles associated with traveling at the speed of light (or near), this would definitely be another adventure.
Vladimir Guillen