Vera Rubin, the American astronomer who confirmed the existence of dark matter, died at the age of 88 years.

Vera Rubin, the American astronomer who confirmed the existence of dark matter,  died at the age of 88 years, on the December 25, 2016.

First, the existence of this material was proposed by astrophysicist Fritz Zwicky in the 30s, but Rubin is one that confirmed his hypothesis. The observations made by scientists in the 70s were met with skepticism, but were confirmed in the decades that followed.

BBC - Universe - Vera Rubin photo: bbc

Reaching for the Stars - Vera Rubin photo: vq.vassar.edu

First, the existence of this material was proposed by astrophysicist Fritz Zwicky in the 30s, but Rubin is one that confirmed his hypothesis. The observations made by scientists in the 70s were met with skepticism, but were confirmed in the decades that followed.

Dark matter is invisible and impossible to detect because it does not absorb or emit light, so even until this day no one knows exactly what it consists of.

Proof of its existence came when astronomers began to weigh galaxies and noticed that they are much heavier than was originally thought. Vera Rubin worked with a new spectrographs to determine the stars from the edge moves faster than was observed since the first calculations use only the visible matter. It is argued that this difference in speed is due to dark matter.

Rubin's discovery was presented in 1980 in an influential paper that supported the idea that dark matter is an essential mystery that astronomers need to solve.


Other articles on the same theme:

• The First Stars in the Universe could provide clues about Dark Matter

• Dark Energy vs. Dark Matter

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

• The universe: Reading the future from the distant past

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

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

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