New Model of Universe

New mathematical model links space-time theories

New mathematical model links space-time theories
The attached image shows a ‘black string’ black hole phenomenon with perturbation. Credit: University of Southampton
Researchers at the University of Southampton have taken a significant step in a project to unravel the secrets of the structure of our Universe.

Professor Kostas Skenderis, Chair in at the University, comments: “One of the main recent advances in is the holographic principle. According to this idea, our Universe may be thought of as a hologram and we would like to understand how to formulate the for such a holographic Universe.”

A new paper released by Professor Skenderis and Dr Marco Caldarelli from the University of Southampton, Dr Joan Camps from the University of Cambridge and Dr Blaise Goutéraux from the Nordic Institute for Theoretical Physics, Sweden published in the Rapid Communication section of Physical Review D, makes connections between negatively curved space-time and flat space-time.

Space-time is usually understood to describe space existing in three dimensions, with time playing the role of a fourth dimension and all four coming together to form a continuum, or a state in which the four elements can’t be distinguished from each other.

Flat space-time and negative space-time describe an environment in which the Universe is non-compact, with space extending infinitely, forever in time, in any direction. The , such as the ones produced by a star, are best described by flat-space time. Negatively curved space-time describes a Universe filled with negative . The mathematics of holography is best understood for negatively curved space-times.

Professor Skenderis has developed a mathematic model which finds striking similarities between flat space-time and negatively curved space-time, with the latter however formulated in a negative number of dimensions, beyond our realm of physical perception.

He comments: “According to holography, at a fundamental level the universe has one less dimension than we perceive in everyday life and is governed by laws similar to electromagnetism. The idea is similar to that of ordinary holograms where a three-dimensional image is encoded in a two-dimensional surface, such as in the hologram on a credit card, but now it is the entire Universe that is encoded in such a fashion.

“Our research is ongoing, and we hope to find more connections between flat space-time, negatively curved space-time and . Traditional theories about how the Universe operates go some way individually to describing its very nature, but each fall short in different areas. It is our ultimate goal to find a new combined understanding of the , which works across the board.”

The paper AdS/Ricci-flat correspondence and the Gregory-Laflamme instability specifically explains what is known as the Gregory Laflamme instability, where certain types of black hole break up into smaller black holes when disturbed – rather like a thin stream of water breaking into little droplets when you touch it with your finger. This black hole phenomenon has previously been shown to exist through computer simulations and this work provides a deeper theoretical explanation.

In October 2012, Professor Skenderis was named among 20 other prominent scientists around the world to receive an award from the New Frontiers in Astronomy and Cosmology international grant competition. He received $175,000 to explore the question, ‘Was there a beginning of time and space?”.

Read more at: http://phys.org/news/2013-05-mathematical-links-space-time-theories.html#jCp

Physicists Questioning Time as the Fourth Dimension

Physicists continue work to abolish time as fourth dimension of space

Apr 14, Physics/General Physics

 
Light clocks A and B moving horizontally through space. According to length contraction, clock A should tick faster than clock B. In a new study, scientists argue that there is no length contraction, and both clocks should tick at the same rate in accordance with special relativity. Image credit: Sorli and Fiscaletti.

(Phys.org) — Philosophers have debated the nature of time long before Einstein and modern physics. But in the 106 years since Einstein, the prevailing view in physics has been that time serves as the fourth dimension of space, an arena represented mathematically as 4D Minkowski spacetime. However, some scientists, including Amrit Sorli and Davide Fiscaletti, founders of the Space Life Institute in Slovenia, argue that time exists completely independent from space. In a new study, Sorli and Fiscaletti have shown that two phenomena of special relativity – time dilation and length contraction – can be better described within the framework of a 3D space with time as the quantity used to measure change (i.e., photon motion) in this space.

 

The scientists have published their article in a recent issue of Physics Essays. The work builds on their previous articles, in which they have investigated the definition of time as a “numerical order of material change.”

The main concepts of  – that the speed of light is the same in all inertial reference frames, and that there is no absolute reference frame – are traditionally formulated within the framework of Minkowski spacetime. In this framework, the three spatial dimensions are intuitively visualized, while the time dimension is mathematically represented by an imaginary coordinate, and cannot be visualized in a concrete way.

In their paper, Sorli and Fiscaletti argue that, while the concepts of special relativity are sound, the introduction of 4D Minkowski spacetime has created a century-long misunderstanding of time as the  of space that lacks any experimental support. They argue that well-known  experiments, such as those demonstrating that clocks do in fact run slower in high-speed airplanes than at rest, support special relativity and time dilation but not necessarily Minkowski spacetime or length contraction. According to the conventional view, clocks run slower at high speeds due to the nature of Minkowski spacetime itself as a result of both time dilation and length contraction. But Sorli and Fiscaletti argue that the slow clocks can better be described by the relative velocity between the two reference frames, which the clocks measure, not which the clocks are a part of. In this view, space and time are two separate entities.

“With clocks we measure the numerical order of motion in ,” Sorli told Phys.org. “Time is ‘separated’ from space in a sense that time is not a fourth dimension of space. Instead, time as a numerical order of change exists in a 3D space. Our model on space and time is founded on measurement and corresponds better to physical reality.”

To illustrate the difference between the two views of time, Sorli and Fiscaletti consider an experiment involving two light clocks. Each clock’s ticking mechanism consists of a photon being reflected back and forth between two mirrors, so that a photon’s path from one mirror to the other represents one tick of the clock. The clocks are arranged perpendicular to each other on a platform, with clock A oriented horizontally and clock B vertically. When the platform is moved horizontally at a high speed, then according to the length contraction phenomenon in 4D spacetime, clock A should shrink so that its photon has a shorter path to travel, causing it to tick faster than clock B.

But Sorli and Fiscaletti argue that the length contraction of clock A and subsequent difference in the ticking rates of clocks A and B do not agree with special relativity, which postulates that the speed of light is constant in all inertial reference frames. They say that, keeping the photon speed the same for both clocks, both clocks should tick at the same rate with no length contraction for clock A. They mathematically demonstrate how to resolve the problem in this way by replacing Minkowski 4D spacetime with a 3D space involving Galilean transformations for three spatial coordinates X, Y, and Z, and a mathematical equation (Selleri’s formalism) for the transformation of the velocity of material change, which is completely independent of the spatial coordinates.

Sorli explained that this idea that both photon clocks tick at the same rate is not at odds with the experiments with flying clocks and other tests that have measured time dilation. This difference, he says, is due to a difference between photon clocks and atom-based clocks.

“The rate of photon clocks in faster inertial systems will not slow down with regard to the photon clocks in a rest inertial system because the speed of light is constant in all inertial systems,” he said. “The rate of atom clocks will slow down because the ‘relativity’ of physical  starts at the scale of pi mesons.”

He also explained that, without length contraction,  exists but in a different way than usually thought.

“Time dilatation exists not in the sense that time as a fourth dimension of space dilates and as a result the clock rate is slower,” he explained. “Time dilatation simply means that, in a faster inertial system, the velocity of change slows down and this is valid for all observers. GPS confirms that clocks in orbit stations have different rates from the clocks on the surface of the planet, and this difference is valid for observers that are on the orbit station and on the surface of the planet. So interpreted, ‘time dilatation’ does not require ‘length contraction,’ which as we show in our paper leads to a contradiction by the light clocks differently positioned in a moving inertial system.”

He added that the alternative definition of time also agrees with the notion of time held by the mathematician and philosopher Kurt Gödel.

“The definition of time as a numerical order of change in space is replacing the 106-year-old concept of time as a physical dimension in which change runs,” Sorli said. “We consider time being only a mathematical quantity of change that we measure with clocks. This is in accord with a Gödel view of time. By 1949, Gödel had produced a remarkable proof: ‘In any universe described by the theory of relativity, time cannot exist.’ Our research confirms Gödel’s vision: time is not a physical dimension of space through which one could travel into the past or future.”

In the future, Sorli and Fiscaletti plan to investigate how this view of time fits with the broader surroundings. They note that other researchers have investigated abolishing the idea of spacetime in favor of separate space and entities, but often suggest that this perspective is best formulated within the framework of an ether, a physical medium permeating all of space. In contrast, Sorli and Fiscaletti think that the idea can be better modeled within the framework of a 3D quantum vacuum. Rather than viewing  as a medium that carries light, light’s propagation is governed by the electromagnetic properties (the permeability and permittivity) of the quantum vacuum.

“We are developing a mathematical model where gravity is a result of the diminished energy density of a 3D quantum vacuum caused by the presence of a given stellar object or material body,” Sorli said. “Inertial mass and gravitational mass have the same origin: diminished energy density of a quantum vacuum. This model gives exact calculations for the Mercury perihelion precession as calculations of the general theory of relativity.”

More information: Amrit Sorli and Davide Fiscaletti. “Special theory of relativity in a three-dimensional Euclidean space.” Physics Essays: March 2012, Vol. 25, No. 1, pp. 141-143. DOI: 10.4006/0836-1398-25.1.141

© 2012 Phys.Org

from:    http://m.phys.org/news/2012-04-physicists-abolish-fourth-dimension-space.html