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Wednesday, May 20, 2020

One Big Bang, or were there many?

https://www.theguardian.com/science/2006/may/05/spaceexploration.universe

The universe is at least 986 billion years older than physicists thought and is probably much older still, according to a radical new theory.
The revolutionary study suggests that time did not begin with the big bang 14 billion years ago. This mammoth explosion which created all the matter we see around us, was just the most recent of many.
The standard big bang theory says the universe began with a massive explosion, but the new theory suggests it is a cyclic event that consists of repeating big bangs.
"People have inferred that time began then, but there really wasn't any reason for that inference," said Neil Turok, a theoretical physicist at the University of Cambridge, "What we are proposing is very radical. It's saying there was time before the big bang."

Under his theory, published today in the journal Science with Paul Steinhardt at Princeton University in New Jersey, the universe must be at least a trillion years old with many big bangs happening before our own. With each bang, the theory predicts that matter keeps on expanding and dissipating into infinite space before another horrendous blast of radiation and matter replenishes it. "I think it is much more likely to be far older than a trillion years though," said Prof Turok. "There doesn't have to be a beginning of time. According to our theory, the universe may be infinitely old and infinitely large."
Today most cosmologists believe the universe will carry on expanding until all the stars burn out, leaving nothing but their cold dead remains. But there is an inherent problem with this picture. The Cosmological Constant - a mysterious force first postulated by Albert Einstein that appears to be driving the galaxies apart - is much too small to fit the theory. Einstein later renounced it as his "biggest blunder".
The Cosmological Constant is a mathematical representation of the energy of empty space, also known as "dark energy", which exerts a kind of anti-gravity force pushing galaxies apart at an accelerating rate.
It happens to be a googol (1 followed by 100 zeroes) times smaller than would be expected if the universe was created in a single Big Bang. But its value could be explained if the universe was much, much older than most experts believe.
Mechanisms exist that would allow the Constant to decrease incrementally through time. But these processes would take so long that, according to the standard theory, all matter in the universe would totally dissipate in the meantime.
Turok and Steinhardt's theory is an alternative to another explanation called the "anthropic principle", which argues that the constant can have a range of values in different parts of the universe but that we happen to live in a region conducive to life.
"The anthropic explanations are very controversial and many people do not like them," said Alexander Vilenkin a professor of theoretical physics at Tufts University in Massachusetts. Rather than making precise predictions for features of the universe the anthropic principle gives a vague range of values so it is difficult for physicists to test, he added.
"It's absolutely terrible, it really is giving up," said Prof Turok, "It's saying that we are never going to understand the state of the universe. It just has to be that way for us to exist." His explanation by contrast is built up from first principles.
But if he's right, how long have we got until the next big bang? "We can't predict when it will happen with any precision - all we can say is it won't be within the next 10 billion years." Good job, because if we were around we would instantly disintegrate into massless particles of light.

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There are not One Single Big Bang but Many Bangs

نسف نظرية الانفجار العظيم
يوجد انفجارات عظيمه كثيره واكوان
كثيره كثيره يصعب الفهم ادراكها

There are not One Single Big Bang but Many Bangs and not one Universe but many ones.

Wednesday, November 28, 2018

Niels Bohr (1885 - 1962) Nobel Prize winner At 37 Years Old



Niels Bohr

Niels Henrik David Bohr was born in Copenhagen in 1885 to Christian Bohr, a professor of physiology at the University of Copenhagen and a Nobel Prize winner, and Ellen Adler Bohr, who came from a wealthy Sephardic Jewish family prominent in Danish banking and parliamentary circles. Bohr received his doctorate from Copenhagen University in 1911 and then studied under Ernest Rutherford in the Victoria University in Manchester, England.
In 1911, Bohr visited Cambridge, where he followed the experimental work occurring in the Cavendish Labroartory under Sir J.J. Thomson's guidance and pursued his own theoretical studies. In 1912, he worked in Professor Rutherford's laboratory in Manchester. Based on Rutherford's theories, Bohr published his model of atomic structure in 1913, which is still commonly used and taught today as an educational simplification. The model introduced the theory of electrons traveling in orbits around the atom's nucleus, the chemical properties of the element being largely determined by the number of electrons in the outer orbits. Bohr also introduced the idea that an electron could drop from a higher-energy orbit to a lower one, emitting a photon (light quantum) of discrete energy. This became the basis for quantum theory.
Following in his father's footsteps, in 1916, Bohr became a professor at the University of Copenhagen. In 1920, he became director of the newly constructed "Institute of Theoretical Physics" and was awarded the Nobel Prize in Physics in 1922 "for his services in the investigation of the structure of atoms and of the radiation emanating from them."

After 1930, Bohr's activities in his Institute were focused on research on the constitution of the atomic nuclei and of their transmutations and disintegrations. He also contributed to the clarification of the problems encountered in quantum physics, which is discussed in several essays written between 1933 and 1962.
In 1943, shortly before he was to be arrested by the German police, Bohr escaped to Sweden and then traveled to London. He worked at Los Alamos on the Manhattan Project, where he was allegedly known by the assumed name of Nicholas Baker for security reasons. However, his role in the project was minor, as he was seen as a knowledgeable consultant. After the war, he returned to Copenhagen, advocating for a peaceful use of nuclear energy. In 1955 he organized the first Atoms for Peace Conference in Geneva, Switzerland.

Bohr and his wife Margrethe had six children, one of whom,

Aage Niels Bohr, became a very successful physicist and also won a Nobel Prize.

Bohr died in Copenhagen in 1962.

The element bohrium is named in his honor.

Tuesday, November 20, 2018

Mystery of Intelligence in Universe by Sherif S. Monem

One of the mysteries in the universe. In universe turbulent one with lot of material, gasses, so vast there is intelligence.  We as  an example we have thinking  and intelligence. Not only us but other creations in our late. Even plants adapt to nature in form of intelligence. What is the origin of the intelligence? We take it for grant our ability to think.

Thursday, December 19, 2013

Newton's constant of gravitation

The main aim of this paper is to describe the problems that confront experimentalists who attempt to determine Newton's constant of gravitation, G. I will motivate this work by discussing the role of Newton's constant of gravitation in classical physics and recent ideas as to its role in quantum physics. I will then discuss some key aspects of a precision determination of G. This will include criteria for the selection of the detector of the gravitational torque from the point of view of random uncertainties due to read-out noise, thermal and vibrational noise. Another important factor in precise determinations of G is the control of systematic effects (type B uncertainties) such as those due to uncertainties in absolute calibration of the gravitational torque, density homogeneity of source masses and length metrology. I will illustrate the discussion using the determination of G currently underway at the International Bureau of Weights and Measures in France, and describe other experimental configurations that have been used in the past or are being currently developed.

http://rsta.royalsocietypublishing.org/content/363/1834/2265.full

http://rsta.royalsocietypublishing.org/

Sunday, March 24, 2013

more than one dimension of time

Physics
Special relativity describes spacetime as a manifold whose metric tensor has a negative eigenvalue. This corresponds to the existence of a "time-like" direction. A metric with multiple negative eigenvalues would correspondingly imply several timelike directions, i.e. multiple time dimensions, but there is no consensus regarding the relationship of these extra "times" to time as conventionally understood.

Nonetheless, theories with more than one dimension of time have sometimes been advanced in physics, whether as a serious description of reality or just as a curious possibility. Itzhak Bars's work on "two-time physics",[1] inspired by the SO(10,2) symmetry of the extended supersymmetry structure of M-theory, is the most recent and systematic development of the concept (see also F-theory).

http://en.wikipedia.org/wiki/Multiple_time_dimensions