Theory of relativity for dummies

Albert Einstein

Space and time are United, there is a relationship between mass and energy the special theory of relativity that changed at the beginning of the last century the generally accepted views of the world, still continues to haunt the minds and hearts of the people.

In 1905 albert Einstein published the special theory of relativity, which explains how to interpret motion between different inertial frames of reference – simply put, objects that move with constant velocity relative to each other.

Einstein explained that when two objects are moving with constant velocity, should consider their movement relative to each other, instead of accepting one of them as the absolute reference system.

So, if the two cosmonauts, you and, say, German, fly two spaceships and want to compare your observations, the only thing you need to know is your speed relative to each other.

Special relativity considers only one special case (hence the name), when the movement rectilinearly and uniformly.

If a material body accelerates or turns, the HUNDRED laws no longer apply. Then, by entering the General theory of relativity, which explains the motion of material bodies in General.

Einstein's theory is based on two main principles:

  • 1. The principle of relativity: physical laws are preserved, even for bodies, non-inertial frames of reference, i.e. moving at a constant speed relative to each other.
  • 2. The principle of the speed of light: the speed of light remains constant to all observers regardless of their speed relative to the light source. (Physicists refer to the speed of light by the letter C).
One of the reasons for the success of albert Einstein is that he put the experimental data are higher than the theoretical. When the number of experiments showed results that contradict the generally accepted theory, many physicists have decided that these experiments are incorrect.

Albert Einstein was one of the first who decided to build a new theory based on new experimental data .

In the late 19th century, physicists were in search of the mysterious ether – the medium in which according to the generally accepted assumptions had to spread light waves, like acoustic, for distribution of which requires air, or other medium – solid, liquid or gaseous.

The belief in the existence of the ether led to the belief that the speed of light should vary depending on the speed of the observer relative to the ether.

Albert Einstein abandoned the concept of ether and suggested that all physical laws, including the speed of light remain constant regardless of the speed of the observer – as it was shown by experiments.

Homogeneity of space and vremenu HUNDRED and Einstein postulated the fundamental relationship between space and time. The material universe has three spatial dimensions: up-down, right-left and forward-back. It has added another dimension – the temporal. Together, these four dimensions make up space-time continuum.

If you are moving with great speed, your observations on space and time will differ from the observations of others, moving at a slower speed.

The picture shows a thought experiment that helps to understand this idea.

Imagine that you are on a space ship, hands you a laser, you send rays of light in the ceiling, which is fixed to the mirror. The light reflected is incident on the detector that registers them.

Top – you sent a ray of light in the ceiling, it is reflected vertically fell to the detector. Bottom – Herman for your beam of light moves diagonally to the ceiling, and then diagonally to the detector

Let's say your ship is moving with a constant velocity equal to half the speed of light (0.5 c). According to Einstein's str, for you it doesn't matter, you don't even notice its movement.

However, the German watching you with the rest of the ship, will see a completely different picture. From his point of view, a beam of light will pass through the diagonal to the mirror on the ceiling, reflected from it and the diagonal will fall on the detector.

In other words, the trajectory of the beam of light for you and for Herman will look different and the length will be different. And therefore and the length of time it takes for the laser beam to pass the distance to the mirror and to the detector, and you seem to be different.

This phenomenon is called time dilation: time in the spaceship, moving with great speed, from the point of view of an observer on Earth runs much slower.

This example, as well as many others, demonstrates the inextricable link between space and time. This relationship is clearly evident to the observer only when it comes to large speeds close to the speed of light.

The experiments conducted since the publication by Einstein of his great theory, confirmed that space and time really are perceived differently depending on the speed of the objects.

The unification of mass and energies his famous paper published in 1905, Einstein unified mass and energy in a simple formula, which since then is known to every schoolchild: E=mc^2.

According to the theory of the great physicist, when the velocity of material bodies increases, approaching the speed of light, increases its mass. I.e. the faster an object is moving, the harder it becomes. If you reach the speed of light, mass of a body, as did his energy become infinite.

The heavier the body the harder it is to increase its speed; to accelerate a body with infinite mass requires infinite energy, so material objects can reach the speed of light is impossible.

To Einstein's concept of mass and energy in physics were considered separately. A brilliant scientist proved that the law of conservation of mass, as the law of conservation of energy, are part of a more General law of mass-energy.

Due to the fundamental relationship between these two concepts, matter can be converted to energy and Vice versa – energy into matter.


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