On March 14, 1879, a man was born in the city of Ulm, who later turned the scientific world upside down. His work is at the heart of understanding the universe - in particular, gravity. What is the whole genius of Albert Einstein's works and what is their place in the 21st century?
When young Albert Einstein published General Relativity in 1915, hardly anyone could have guessed what impact it would have on science. Relativity has changed our understanding of the universe and provided new ways to study fundamental physics that govern the world around us.
Despite the importance of the principle of relativity, it is not as simple as we would like. And even if it may seem to someone that this theory is too abstract and divorced from reality, in fact, it is directly related to our existence at a fundamental level. It has enabled the exploration and exploration of space, and on Earth it is behind technologies associated with many discoveries: from GPS to nuclear power, from smartphones to particle accelerators - many innovations that we take for granted are rooted in Einstein's theory.
How relativity works
First of all, it is worth noting that General Relativity consists of two separate theories. The first, Special Theory of Relativity, was published in 1905 and was accepted by the scientific community with mixed feelings. What is the reason for this reaction? The fact is that the special theory of relativity turned over much of what - as it seemed to scientists - was known about the world.
Before Einstein published his scientific revelation, it was generally accepted that time always and everywhere flows at the same speed. Regardless of the speed of the object's movement, the nature of seconds, minutes and hours was considered unchanged. However, Einstein believed that time is actually not constant and changes depending on how fast the object is moving.
The great scientist argued that the real constant value - a constant - is the speed of light. Light travels at a constant speed of 299,792,458 meters per second in a vacuum, while time flows differently depending on the speed at which an object is moving through space. For objects moving very quickly, time slows down.
This revelation shook the foundations of physics, but it didn't end there. Just ten years later, the ingenious nonconformist from the Berne patent office added a new detail to the theory - this time it was about gravity.
Gravity as the curvature of space-time
General relativity became a real decoration of Einstein's ideas. She answered the centuries-old question: how exactly does gravity work?
When an apple fell on Isaac Newton's head in the middle of the 17th century, as popular legend has it, the revolutionary theory of gravity was born. Newton determined that gravity exists and postulated its effects, but he could not say for sure what its origins were.
The answer was found nearly three centuries later through Albert Einstein's General Theory of Relativity. He believed that since space and time are "fluid" and changeable, they can be bent by massive objects.
Imagine a bowling ball in the middle of a stretched trampoline. Since it is heavy, it bends the fabric, thus pulling all objects at the edges of the trampoline towards the center. Gravity works in a similar way.Massive objects like the Earth warp the fabric of space and time, attracting matter, as well as time and light.
Evidence of relativity
Like many theories, relativity is not easy to prove conclusively. But all the data collected over more than 100 years indicate the absolute correctness of Einstein in this matter. The clocks installed on skyscrapers measure time a little faster than the clocks installed at their bases, since the clocks are located farther from the center of the Earth, which means that space-time is less curved at this height.
Occasionally, in deep-sky images such as the Hubble Ultra-Deep Field, you can see some objects that appear distorted and magnified against the background of galaxy clusters: this is the phenomenon of gravitational lensing. The mass of such objects distorts space-time, which causes the image to be distorted.
However, perhaps the most significant proof of General Relativity was the event announced in 2016 - more than 100 years after the publication of the work. This proof was gravitational waves - ripples on the fabric of space-time. They were registered by means of LIGO detectors (Laser Interferometer Gravitational-Wave Observatory, laser interferometric gravitational-wave observatory) in Livingston and Hagnford, which have been developed by theoretical physicist Kip Thorne since 1992.
If space and time is a fabric that resembles the surface of a trampoline, then such large-scale and massive events as the merging of black holes will create ripples on it. If Einstein's theory is correct, then we should be able to detect these waves, but until recently this was only a theory with no experimental evidence.
In early 2016, scientists announced that they had used the LIGO detector to detect gravitational waves, pinpointing subatomic expansions and contractions through spacetime.
LIGO resembles an incredibly powerful ruler: it directs a laser beam between two mirrors located four kilometers apart, then a laser beam is launched and the time it takes for the laser to travel that path is measured. Because of the gravitational waves, everything shifts, and if the laser beam stops moving synchronously, then for scientists it is a sign that a gravitational wave crossed its path and caused a subatomic displacement of the mirror. The registration of gravitational waves can be called the most important advantage of Einstein's theory. In addition, relativity has been applied to postulate the Big Bang and the expansion of the universe.
Einstein's legacy and the future of science
Relativity helped us assume that the universe is 95% dark energy and dark matter. The same theory helped develop particle accelerators, in which electrons, protons and other elementary particles are accelerated to speeds close to light.
The theory of relativity has done indescribably much for science and our understanding of the structure of the world. And now that it is possible to register gravitational waves, we can look even deeper into the structure of the Universe, study objects such as black holes and neutron stars, relying on the theory's unprecedentedly accurate predictions.
It's been just over a century since Einstein's relativity fundamentally turned our understanding of the universe upside down. But his greatest legacy is not his revolutionary theories: his work inspired thousands of scientists who eventually followed him in search of the true nature of reality.
Today, Einstein's theory is regularly subjected to various tests, which are passed with dignity. Thanks to the theory of relativity and other works of the once humble employee of the Berne patent office, we have the Standard Model, the inflationary model of the Universe and new hypotheses born in attempts to understand the deepest principles of the structure of things, which would help to describe the universe and reality as such in an exhaustive completeness. …