Showing posts with label dark energy. Show all posts
Showing posts with label dark energy. Show all posts

Saturday, October 7, 2017

The Basis of the Universe May Not Be Energy or Matter but Information

via BigThink:

There are lots of theories on what are the basis of the universe is. Some physicists say its subatomic particles. Others believe its energy or even space-time. One of the more radical theories suggests that information is the most basic element of the cosmos. Although this line of thinking emanates from the mid-20th century, it seems to be enjoying a bit of a Renaissance among a sliver of prominent scientists today.

Consider that if we knew the exact composition of the universe and all of its properties and had enough energy and know-how to draw upon, theoretically, we could break the universe down into ones and zeroes and using that information, reconstruct it from the bottom up. It’s the information, purveyors of this view say, locked inside any singular component that allows us to manipulate matter any way we choose. Of course, it would take deity-level sophistication, a feat only achievable by a type V civilization on the Kardashev scale.

Mid-20th century mathematician and engineer Claude Elwood Shannon, is thought the creator of classical information theory. Though few know of him outside of scientific circles, he’s being hailed today as the “father of the digital age.” Shannon’s spark of genius came in 1940 at MIT, when he noticed a relationship between Boolean algebra and telephone switching circuits.

Soon after, he was hired by Bell Labs to devise the most efficient way to transfer information over wires. In 1948, he penned “A Mathematical Theory of Communication,” essentially laying the foundation for the digital age. Shannon was the first to show that mathematics could be used to design electrical systems and circuits.

Before him, it was done through expensive model-making, or mere trial and error. Today, Boolean algebra is used to design communication and computer systems, hardware, software, and so much more. Basically, anything that generates, stores, or transfers information electronically, is based on Shannon’s tome.

That's not all. Shannon defined a unit of information, the binary unit or bit. Bits are a series of 0s and 1s, which help us to store and recall information electronically. Moreover, he was the first to transform data into a commodity. Its value he said was proportional to how much it surprised the consumer. 

In addition, he connected electronic communication to thermodynamics. What's now called “Shannon entropy,” measures the disorder or randomness inherent in any communications system. The greater the entropy, the less clear the message, until it becomes unintelligible. As for information theory, he developed that during World War II, while trying to solve the problem of sending an encrypted message over a static-ridden telephone or telegraph line.

To look at information theory from a quantum viewpoint, the positions of particles, their movement, how they behave, and all of their properties, give us information about them and the physical forces behind them. Every aspect of a particle can be expressed as information, and put into binary code. And so subatomic particles may be the bits that the universe is processing, as a giant supercomputer. Besides quantum mechanics, since Shannon elucidated it, information theory has been applied to music, genetics, investment, and much more.

Science writer James Gleick, author of The Information, contends that it wasn’t Shannon, but early 19th century mathematician Charles Babbage, who first called information the central component of all and everything. Babbage is credited for first conceptualizing the computer, way before anyone had the ability to even build one.

The eminent John Archibald Wheeler in his later years was a strong proponent of information theory. Another unsung paragon of science, Wheeler was a veteran of the Manhattan Project, coined the terms “black hole” and “wormhole,” helped work out the “S-matrix” with Neils Bohr, and collaborated with Einstein on a unified theory of physics.

Wheeler said the universe had three parts: First, “Everything is Particles,” second, “Everything is Fields,” and third, “Everything is information.”

In the 1980s, he began exploring possible connections between information theory and quantum mechanics. It was during this period he coined the phrase “It from bit.” The idea is that the universe emanates from the information inherent within it. Each it or particle is a bit. It from bit.
In 1989, Wheeler produced a paper to the Santa Fe institute, where he announced "every it--every particle, every field of force, even the space-time continuum itself--derives its function, its meaning, its very existence entirely--even if in some contexts indirectly--from the apparatus-elicited answers to yes-or-no questions, binary choices, bits."

A team of physicists earlier this year announced research conclusions that would make Wheeler smile. We might be caught inside a giant hologram they state. In this view, the cosmos is a projection, much like a 3D simulation. What’s weird is that the laws of physics operate well in a 2D quantum field within a 3D gravitational one.

It’s important to note that most physicists believe that matter is the essential unit of the universe. And information theory’s proof is limited. After all, how would you test for it?

If the nature of reality is in fact reducible to information itself, that implies a conscious mind on the receiving end, to interpret and comprehend it. Wheeler himself believed in a participatory universe, where consciousness holds a central role. Some scientists argue that the cosmos seems to have specific properties which allow it to create and sustain life. Perhaps what it desires most is an audience captivated in awe as it whirls in prodigious splendor.

Modern physics has hit a wall in a number of areas. Some proponents of information theory believe embracing it may help us to say, sew up the rift between general relativity and quantum mechanics. Or perhaps it’ll aid in detecting and comprehending dark matter and dark energy, which combined are thought to make up 95% of the known universe. As it stands, we have no idea what they are.

 Ironically, some hard data is required in order to elevate information theory. Until then, it remains theoretical.

To learn more about information theory as the basis of the universe, click here:


Monday, October 26, 2015

No Big Bang? Quantum equation predicts universe has no beginning

 via phys.org

The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein's theory of general relativity. The model may also account for dark matter and dark energy, resolving multiple problems at once.

The widely accepted age of the universe, as estimated by general relativity, is 13.8 billion years. In the beginning, everything in existence is thought to have occupied a single infinitely dense point, or singularity. Only after this point began to expand in a "Big Bang" did the universe officially begin.

Although the Big Bang singularity arises directly and unavoidably from the mathematics of general relativity, some scientists see it as problematic because the math can explain only what happened immediately after—not at or before—the singularity.

"The Big Bang singularity is the most serious problem of general relativity because the laws of physics appear to break down there," Ahmed Farag Ali at Benha University and the Zewail City of Science and Technology, both in Egypt, told Phys.org.

Ali and coauthor Saurya Das at the University of Lethbridge in Alberta, Canada, have shown in a paper published in Physics Letters B that the Big Bang singularity can be resolved by their new model in which the universe has no beginning and no end.

Old ideas revisited

The physicists emphasize that their quantum correction terms are not applied ad hoc in an attempt to specifically eliminate the Big Bang singularity. Their work is based on ideas by the theoretical physicist David Bohm, who is also known for his contributions to the philosophy of physics. Starting in the 1950s, Bohm explored replacing classical geodesics (the shortest path between two points on a curved surface) with quantum trajectories.

In their paper, Ali and Das applied these Bohmian trajectories to an equation developed in the 1950s by physicist Amal Kumar Raychaudhuri at Presidency University in Kolkata, India. Raychaudhuri was also Das's teacher when he was an undergraduate student of that institution in the '90s.

Using the quantum-corrected Raychaudhuri equation, Ali and Das derived quantum-corrected Friedmann equations, which describe the expansion and evolution of universe (including the Big Bang) within the context of general relativity. Although it's not a true theory of quantum gravity, the model does contain elements from both quantum theory and general relativity. Ali and Das also expect their results to hold even if and when a full theory of quantum gravity is formulated.

No singularities nor dark stuff

In addition to not predicting a Big Bang singularity, the new model does not predict a "big crunch" singularity, either. In general relativity, one possible fate of the universe is that it starts to shrink until it collapses in on itself in a big crunch and becomes an infinitely dense point once again.

Ali and Das explain in their paper that their model avoids singularities because of a key difference between classical geodesics and Bohmian trajectories. Classical geodesics eventually cross each other, and the points at which they converge are singularities. In contrast, Bohmian trajectories never cross each other, so singularities do not appear in the equations.

In cosmological terms, the scientists explain that the quantum corrections can be thought of as a cosmological constant term (without the need for dark energy) and a radiation term. These terms keep the universe at a finite size, and therefore give it an infinite age. The terms also make predictions that agree closely with current observations of the cosmological constant and density of the universe.

New gravity particle

In physical terms, the model describes the universe as being filled with a quantum fluid. The scientists propose that this fluid might be composed of gravitons—hypothetical massless particles that mediate the force of gravity. If they exist, gravitons are thought to play a key role in a theory of quantum gravity.

In a related paper, Das and another collaborator, Rajat Bhaduri of McMaster University, Canada, have lent further credence to this model. They show that gravitons can form a Bose-Einstein condensate (named after Einstein and another Indian physicist, Satyendranath Bose) at temperatures that were present in the universe at all epochs.

Motivated by the model's potential to resolve the Big Bang singularity and account for dark matter and dark energy, the physicists plan to analyze their model more rigorously in the future. Their future work includes redoing their study while taking into account small inhomogeneous and anisotropic perturbations, but they do not expect small perturbations to significantly affect the results.

"It is satisfying to note that such straightforward corrections can potentially resolve so many issues at once," Das said.