There is a major problem in physics.

A number called the cosmological constant transcends the microscopic world of quantum mechanics and the macroscopic world of Einstein's theory of general relativity. But no theory can agree on its value.

In fact, there is such a huge discrepancy between the observed value of this constant and what the theory predicts to be considered the worst prediction in the history of physics. Solving the discrepancy may be the most important goal of theoretical physics this century.

Lucas Lombrizer, Assistant Professor of Theoretical Physics at the University of Geneva in Switzerland, introduced a new way of estimating Albert Einstein's gravity equations to find a value for a cosmological constant that closely matches its observed value. He published his method online in the October 1

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## How Einstein's Biggest Mistake Became Dark Energy

The story of the cosmological constant begins more than a century ago when Einstein presented a set of equations , now known as Einstein field equations, which became the framework of his __ theory of general relativity __. The equations explain how matter and energy distort the fabric of space and time to create the force of gravity. At that time, Einstein and astronomers agreed that the universe was fixed in size and that the total space between the galaxies was not changing. However, when Einstein applied general relativity to the universe as a whole, his theory predicted an unstable universe that would either expand or collapse. To force the universe to be static, Einstein adheres to the cosmological constant.

Nearly a decade later, another physicist, __ Edwin Hubble __ discovered that our universe is not static but expanding. The light from distant galaxies indicated that they were all moving away from each other. This revelation convinces Einstein to abandon the cosmological constant from his field equations, since it is no longer necessary to explain the expanding universe. According to physics, Einstein later admits that its introduction into the cosmological constant is __ perhaps his biggest mistake __.

In 1998, observations of distant supernatures show that the universe is not just expanding, but expanding is accelerating. The galaxies were accelerating from one another, as if some unknown force were overcoming gravity and moving these galaxies apart. Physicists have called this mysterious phenomenon __ dark energy __ because its true nature remains a mystery.

In the twist of irony, physicists reintroduce the cosmological constant in Einstein's field equations to take into account dark energy. In the current __ standard model of cosmology __ known as ΛCDM (Lambda CDM), the cosmological constant is interchangeable with dark energy. Astronomers have even estimated its value based on observations of distant supernovae and oscillations in the cosmic microwave background __ __. Although the value is absurdly small (in the order of 10 ^ -52 per square meter), it is significant enough above the scale of the universe to explain the accelerated expansion of space.

"The cosmological constant [or dark energy] currently represents about 70% of the energy content in our universe, which is what we can deduce from the observed accelerated expansion that our universe is currently undergoing. Yet this constant is not understood." "The attempts to explain it have failed and there seems to be something fundamental that we lack in understanding the cosmos. Solving this puzzle is one of the major research areas in modern physics. In principle, solving the problem is expected. may lead us to a more fundamental understanding of physics. "

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## The worst theoretical prediction in the history of Physics

The Cosmological The constant is considered to be what physicists call "vacuum energy". The theory of the quantum field states that even in a completely empty vacuum of space, virtual particles pop in and out of existence and generate energy – a seemingly absurd idea, but one that has been observed experimentally. The problem arises when physicists try to calculate his contribution to the cosmological constant. Their result is different from the observations of the astounding factor 10 ^ 121 (this is 10, followed by 120 zeros), __ the greatest discrepancy between theory and experiment in all physics __.

Such a discrepancy has caused some physicists to doubt Einstein's original gravity equations; some even offer alternative models of gravity. Further evidence of gravitational waves from the Laser Interferometer Gravity Wave Observatory (__ LIGO __) only reinforced general relativity and rejected many of these alternative theories. So instead of rethinking gravity, Lombrizer took a different approach to solving this space puzzle.

"The mechanism I propose does not change Einstein's field equations," said Lombrizer. Instead, "it adds an additional equation to the top of Einstein's field equations." Einstein field equations describes the magnitude of the gravitational force between objects. It is considered one of the fundamental constants of physics, forever unchanged since the beginning of the universe. Lombrizer made the dramatic assumption that this constant could change.

In the Lombier modification of general relativity, the gravitational constant remains the same in our observable universe, but may vary beyond it. It offers a multifaceted scenario where there may be patches of invisible universe that have different values for the basic constants.

This change in gravity gave Lombritzer an additional equation that relates the cosmological constant to the average sum of matter in space-time. After considering the predictive mass of all galaxies, stars, and dark matter in the universe, he could solve this new equation to obtain a new value for the cosmological constant — one that strongly agrees with observations.

Using a new parameter, ΩΛ (omega lambda), which expresses the fraction of the universe made of dark matter, he finds that the universe is made up of about 74% dark energy. This figure coincides exactly with the value of 68.5%, calculated from the observations – a huge improvement over the huge discrepancy detected by quantum field theory.

Although the Lombrizer framework can solve the problem of permanent cosmology, there is currently no way to test it. But in the future, if experiments from other theories confirm his equations, this could mean a major leap into our understanding of dark energy and provide a tool to solve other cosmic mysteries.

* Originally published by ** Live Science **. *

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