Erik Verlinde's New Theory Of Gravity Tries To Explain Dark Matter

Collage of six cluster collisions with dark matter maps. The clusters were observed in a study of how dark matter in clusters of galaxies behaves when the clusters collide Photo: wikipedia.org

Although gravity is the most familiar force of the universe, it is a thorny problem for theoretical physicists as it has long defied its inclusion in quantum mechanics. Another problem is dark matter only interacts with gravity and also defies the standard model of particle physics.

Professor Erik Verlinde, a researcher from the Delta Institute for Theoretical Physics in Amsterdam, believes that gravity is not an actual force of the universe but an effect due to the increasing entropy of the universe. In his latest paper, which is available on arXiv but is yet to be peer-reviewed, the scientist claimed that this “emergent” (and not real) force of gravity has a dark component that behaves like dark matter.

Mysterious Universe: Super Force Mysterious Universe

Photo: quantumdiaries.org

"We have evidence that this new view of gravity actually agrees with the observations," said Verlinde in a statement. "At large scales, it seems, gravity just doesn't behave the way Einstein's theory predicts."

Erik Verlinde, Theoretical Physicist at Amsterdam

Quite the bold statement from the researcher, especially since it has been shown that Einstein’s general relativity agrees quite well with large-scale observations. In the paper, Verlinde admits that the idea of this dark gravitational component needs to answer several questions before it is able to be as successful at explaining the early universe and large scale cosmology as the current theory of gravity.

The theory of entropic gravity was first proposed by Verlinde in a paper in 2010 and published in the Journal of High Energy Physics in 2011. The proposed idea was welcomed by some as a novel approach to the problem of gravity in quantum mechanics.

Verlinde's new theory of gravity passes first test Phys.org

Others were more skeptical and devised ways to see if gravity could really be an emergent phenomenon. In 2011, Archil Kobakhidze of the University of Melbourne looked at how gravity affects fundamental particles. His findings strongly support the idea that gravity is a real force.

Entropic gravity is appealing because it is able to reproduce the laws of Newtonian gravitation and Einstein field equations from the first thermodynamics and quantum mechanical principles, but the theory itself doesn’t make predictions so it can’t be falsified.

Einstein’s general relativity is constantly being tested, and discoveries like gravitational waves have only strengthened its role as the best theory of gravity we currently possess.


Other articles on the same theme:

• Dark Energy vs. Dark Matter

• The universe: Reading the future from the distant past

• Astronomers issued a shocking theory about the universe: 'The Universe is Flat!'

• Young galaxies "born" at least 50 stars annually

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The above post is reprinted from materials provided by IFL Science . Note: Materials may be edited for content and length.

Astronomers issued a shocking theory about the universe: 'The Universe is Flat!'

The local geometry of the universe is determined by whether the density parameter Ω is greater than, less than, or equal to 1.

From top to bottom: a spherical universe with Ω > 1, a hyperbolic universe with Ω < 1, and a flat universe with Ω = 1. Note that these depictions of two-dimensional surfaces are merely easily visualizable analogs to the 3-dimensional structure of (local) space. photo: wikipedia.org

The universe is flat, has said recently, but there are many subtleties behind this assertion. How can we tell the Universe form? It means that a 3D object to be flat? May be other interesting things to say?

Hubble Eyes Hanny's Voorwerp - Universe Today

For starters, we must define the notion of "flat". Screen that look is flat and the earth is curved, for example, but we can calculate mathematically how this? A plausible answer refers to the parallel lines, for as you draw two parallel on a sheet of paper and will continue, they will be forever parallel, it is the more common definition of parallel lines. 

43K Galaxies: Most Complete 3D Map of the Universe Ever

However, this exercise must be repeated in relation to the Earth's surface, each heading towards the north, and the shape of the curve of the Earth makes them meet at a time. Earth curbaţiei opposite that of a saddle, the surface of which parallel lines move away from each other. So you can measure "flat" structure using only parallels.

Slices through the Sloan Digital Sky Survey 3-dimensional map of the distribution of galaxies with the Earth at the center, an example of an experimental attempt to catalog the observable universe. photo: wikipedia.org

However, determining the shape of the universe is a matter of cosmology, and he has a plurality of deformation, there are masses of energy and there is a close correlation between time and space. Have you ever wondered what the difference between a sphere and a cylinder? Use your schools which have drawn two parallel lines and manufactured a cylinder. Meanwhile observed parallel lines: they remain, indeed, parallel to the cylinder is flat.


This happens because there is a clear distinction between geometry and topography, and as he studied the geometry of the universe is very careful, not topography. But if the universe is indeed flat, this is met in a very distant place, which can not be observed by astronomers, because they never observed galaxies and the CMB identical intersecting.

The universe is flat, has said recently, but there are many subtleties behind this assertion. How can we tell the Universe form? It means that a 3D object to be flat? May be other interesting things to say?

For starters, we must define the notion of "flat". Screen that look is flat and the earth is curved, for example, but we can calculate mathematically how this? A plausible answer refers to the parallel lines, for as you draw two parallel on a sheet of paper and will continue, they will be forever parallel, it is the more common definition of parallel lines. However, this exercise must be repeated in relation to the Earth's surface, each heading towards the north, and the shape of the curve of the Earth makes them meet at a time. Earth curbaţiei opposite that of a saddle, the surface of which parallel lines move away from each other. So you can measure "flat" structure using only parallels.

Mapping the Universe, containing the circular map of the universe

However, determining the shape of the universe is a matter of cosmology, and he has a plurality of deformation, there are masses of energy and there is a close correlation between time and space. Have you ever wondered what the difference between a sphere and a cylinder? Use your schools which have drawn two parallel lines and manufactured a cylinder. Meanwhile observed parallel lines: they remain, indeed, parallel to the cylinder is flat.

Mapping the Universe: Space, Time, and Discoveries

This happens because there is a clear distinction between geometry and topography, and as he studied the geometry of the universe is very careful, not topography. But if the universe is indeed flat, this is met in a very distant place, which can not be observed by astronomers, because they never observed galaxies and the CMB identical intersecting

Other articles on the same theme:

• It was created the most complex map of the Milky Way . It shows that our galaxy is much more extensive than previously thought

• The universe: Reading the future from the distant past

• 10 fascinating planets outside the Solar System

• Young galaxies "born" at least 50 stars annually

Story source:

The above post is reprinted from materials provided by Space . Note: Materials may be edited for content and length.

Physicists have made an unexpected discovery related to the second law of thermodynamics, one of the most important principles of physics

Photo ; insspirito/Pixabay  

Thermodynamic laws are some of the most important principles of modern physics that define how the three amounts fundamental physics - temperature, energy and entropy (the amount of thermal condition of physical systems, which increases during an irreversible transformation of their own, but in the case of reversible transformations remains constant) - behave in certain circumstances.

Now physicists have discovered an ambiguity in one of these laws could create scenarios where entropy could diminish with time. Thanks to modern physics, almost every phenomenon in the universe can be explained using the theory of relativity and quantum mechanics using. But in addition, there are four laws of thermodynamics, which explains how heat (or heat) is converted to or from different types of energy.

But the second law of thermodynamics is of particular importance, since this energy transition from a system usable by one unusable. As usable energy in a closed or isolated system decreases and unusable energy increases entropy, in turn, increases.

As said by researchers, the second law of thermodynamics is probably much deeper than first law (which states that energy can not be created or destroyed), because the limitations of the universe. But what would happen if there was the possibility of creating a system that would decrease the entropy?

Researchers at the US Department of Energy's Argonne National Laboratory said they found ambiguity in the second law of thermodynamics, entropy which is moving towards another direction at a microscopic scale. They investigated a concept that is based on this law, called the theory H which, in its most simple, discloses that if you open a door between two rooms, one heated and the other not, it will produce a balance of heat . But as the researchers claimed, it is imposbil explain how each molecule moves in this scenario, so physicists analyzed as a group, not individually. But to identify the conduct of each molecule, according Theory H Laboratory Argonne decided to treat this study at a quantum scale. They did so using quantum information theory, which is based on a variety of natural materials applied abstract mathematical systems to be condensed discovered a new quantum theory H. "This makes manageable Theory H wording consistent with things that can be observed by physicists," says one of the team who started this study, Ivan Sadovskyy.

The researchers believe it is likely that the circumstances in which entropy decreases to be analyzed using this new vision Theory H.



Source: Science Alert