The Theory of Everything.
https://en.wikipedia.org/wiki/Theory_of_everything
https://www.youtube.com/watch?v=ExapC3nPzNE ((Special Presentation (Featuring Theoretical Physicist Eugene Bagashov): The Theories of Everything))
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“Theory of Everything” Tested – NASA’s Chandra X-Ray Observatory Probes String Theory
A supermassive black hole in the Perseus galaxy cluster located about 240 million light-years from Earth. The main image is about 550,000 light-years across and was imaged by Chandra from X-ray light. Credit: NASA/CXC/Cambridge Univ./C.S. Reynolds
Astronomers used Chandra to perform a test of string theory, a possible “theory of everything” that would tie all of known physics together.
One of the biggest ideas in physics is the possibility that all known forces, particles, and interactions can be connected in one framework. String theory is arguably the best-known proposal for a “theory of everything” that would tie together our understanding of the physical universe.
Despite having many different versions of string theory circulating throughout the physics community for decades, there have been very few experimental tests. Astronomers using NASA’s Chandra X-ray Observatory, however, have now made a significant step forward in this area.
By searching through galaxy clusters, the largest structures in the universe held together by gravity, researchers were able to hunt for a specific particle that many models of string theory predict should exist. While the resulting non-detection does not rule out string theory altogether, it does deliver a blow to certain models within that family of ideas.
“Until recently I had no idea just how much X-ray astronomers bring to the table when it comes to string theory, but we could play a major role,” said Christopher Reynolds of the University of Cambridge in the United Kingdom, who led the study. “If these particles are eventually detected it would change physics forever.”
The particle that Reynolds and his colleagues were searching for is called an “axion.” These as-yet-undetected particles should have extraordinarily low masses. Scientists do not know the precise mass range, but many theories feature axion masses ranging from about a millionth of the mass of an electron down to zero mass. Some scientists think that axions could explain the mystery of dark matter, which accounts for the vast majority of matter in the universe.
One unusual property of these ultra-low-mass particles would be that they might sometimes convert into photons (that is, packets of light) as they pass through magnetic fields. The opposite may also hold true: photons may also be converted into axions under certain conditions. How often this switch occurs depends on how easily they make this conversion, in other words on their “convertibility.”
Some scientists have proposed the existence of a broader class of ultra-low-mass particles with similar properties to axions. Axions would have a single convertibility value at each mass, but “axion-like particles” would have a range of convertibility at the same mass.
“While it may sound like a long shot to look for tiny particles like axions in gigantic structures like galaxy clusters, they are actually great places to look,” said co-author David Marsh of Stockholm University in Sweden. “Galaxy clusters contain magnetic fields over giant distances, and they also often contain bright X-ray sources. Together these properties enhance the chances that conversion of axion-like particles would be detectable.”
To look for signs of conversion by axion-like particles, the team of astronomers examined over five days of Chandra observations of X-rays from material falling towards the supermassive black hole in the center of the Perseus galaxy cluster. They studied the Chandra spectrum, or the amount of X-ray emission observed at different energies, of this source. The long observation and the bright X-ray source gave a spectrum with enough sensitivity to have shown distortions that scientists expected if axion-like particles were present.
The lack of detection of such distortions allowed the researchers to rule out the presence of most types of axion-like particles in the mass range their observations were sensitive to, below about a millionth of a billionth of an electron’s mass.
“Our research doesn’t rule out the existence of these particles, but it definitely doesn’t help their case,” said co-author Helen Russell of the University of Nottingham in the UK. “These constraints dig into the range of properties suggested by string theory, and may help string theorists weed their theories.”
The latest result was about three to four times more sensitive than the previous best search for axion-like particles, which came from Chandra observations of the supermassive black hole in M87. This Perseus study is also about a hundred times more powerful than current measurements that can be performed in laboratories here on Earth for the range of masses that they have considered.
Clearly, one possible interpretation of this work is that axion-like particles do not exist. Another explanation is that the particles have even lower convertibility values than this observation’s detection limit, and lower than some particle physicists have expected. They also could have higher masses than probed with the Chandra data.
A paper describing these results appeared in the February 10th, 2020 issue of The Astrophysical Journal. In addition to Reynolds, Marsh, and Russell, the authors of this paper are Andrew C. Fabian, also from the University of Cambridge, Robyn Smith from the University of Maryland in College Park, Maryland, Francesco Tombesi from the University of Rome in Italy, and Sylvain Veilleux, also from the University of Maryland.
Reference: “Astrophysical Limits on Very Light Axion-like Particles from Chandra Grating Spectroscopy of NGC 1275″ by Christopher S. Reynolds, M. C. David Marsh, Helen R. Russell, Andrew C. Fabian, Robyn Smith, Francesco Tombesi and Sylvain Veilleux, 12 February 2020, The Astrophysical Journal.
DOI: 10.3847/1538-4357/ab6a0c
arXiv: 1907.05475
We're not the only entity on the hunt for a unified theory of physics...
Creator of Wolfram Alpha Has a Bold Plan to Find a New Fundamental Theory of Physics
Stephen Wolfram is a cult figure in programming and mathematics. He is the brains behind Wolfram Alpha, a website that tries to answer questions by using algorithms to sift through a massive database of information. He is also responsible for Mathematica, a computer system used by scientists the world over.
Last week, Wolfram launched a new venture: the Wolfram Physics Project, an ambitious attempt to develop a new physics of our Universe.
The new physics, he declares, is computational. The guiding idea is that everything can be boiled down to the application of simple rules to fundamental building blocks.
What's the point of the 'new physics'?
Why do we need such a theory? After all, we already have two extraordinarily successful physical theories.
These are general relativity – a theory of gravity and the large-scale structure of the Universe – and quantum mechanics – a theory of the basic constituents of matter, sub-atomic particles, and their interactions. Haven't we got physics licked?
Not quite. While we have an excellent theory of how gravity works for large objects, such as stars and planets and even people, we don't understand gravity at extremely high energies or for extremely small things.
General relativity "breaks down" when we try to extend it into the miniature realm where quantum mechanics rules. This has led to a quest for the holy grail of physics: a theory of quantum gravity, which would combine what we know from general relativity with what we know from quantum mechanics to produce an entirely new physical theory.
The current best approach we have to quantum gravity is string theory. This theory has been a work in progress for 50 years or so, and while it has achieved some success there is a growing dissatisfaction with it as an approach.
How is Wolfram's approach different?
Wolfram is attempting to provide an alternative to string theory. He does so via a branch of mathematics called graph theory, which studies groups of points or nodes connected by lines or edges.
Think of a social networking platform. Start with one person: Betty. Next, add a simple rule: every person adds three friends. Apply the rule to Betty: now she has three friends. Apply the rule again to every person (including the one you started with, namely: Betty). Keep applying the rule and, pretty soon, the network of friends forms a complex graph.
A simple rule multiple times creates a complex network of points and connections. (Author provided)
Wolfram's proposal is that the universe can be modelled in much the same way. The goal of physics, he suggests, is to work out the rules that the universal graph obeys.
Key to his suggestion is that a suitably complicated graph looks like a geometry. For instance, imagine a cube and a graph that resembles it.
(Author provided)
Above: In the same way that a collection of points and lines can approximate a solid cube, Wolfram argues that space itself may be a mesh that knits together a series of nodes.
Wolfram argues that extremely complex graphs resemble surfaces and volumes: add enough nodes and connect them with enough lines and you form a kind of mesh. He maintains that space itself can be thought of as a mesh that knits together a series of nodes in this fashion.
What does this have to do with physics?
How can complicated meshes of nodes help with the project of reconciling general relativity and quantum mechanics? Well, quantum theory deals with discrete objects with discrete properties. General relativity, on the other hand, treats the universe as a continuum and gravity as a continuous force.
If we can build a theory that can do what general relativity does but that starts from discrete structures like graphs, then the prospects for reconciling general relativity and quantum mechanics start to look more promising.
If we can build a geometry that resembles the one given to us by general relativity using a discrete structure, then the prospects look even better.
Space may be a complex mesh of points connected by a simple rule that is iterated many times. (Wolfram Physics Project)
So is it time to get excited?
While Wolfram's project is promising, it does contain more than a hint of hubris. Wolfram is going up against the Einsteins and Hawkings of the world, and he's doing it without a life spent publishing in physics journals.
(He did publish several physics papers as a teenage prodigy, but that was 40 years ago, as well as a book A New Kind of Science, which is the spiritual predecessor of the Wolfram Physics Project.)
Moreover, his approach is not wholly original. It is similar to two existing approaches to quantum gravity: causal set theory and loop quantum gravity, neither of which get much of a mention in Wolfram's grand designs.
Nonetheless, the project is notable for three reasons.
First, Wolfram has a broad audience and he will do a lot to popularise the approach that he advocates. Proponents of loop quantum gravity in particular lament the predominance of string theory within the physics community. Wolfram may help to underwrite a paradigm shift in physics.
Second, Wolfram provides a very careful overview of the project from the basic principles of graph theory up to general relativity. This will make it easier for individuals to get up to speed with the general approach and potentially make contributions of their own.
Third, the project is "open source", inviting contributions from citizen scientists.
If nothing else, this gives us all something to do at the moment – in between baking sourdough and playing Animal Crossing, that is. 
Sam Baron, Associate professor, Australian Catholic University.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
“Downright Weird” New Findings Suggest Laws of Nature Not as Constant as Previously Thought
Scientists examining the light from one of the furthermost quasars in the universe were astonished to find fluctuations in the electromagnetic force.
Not only does a universal constant seem annoyingly inconstant at the outer fringes of the cosmos, it occurs in only one direction, which is downright weird.
Those looking forward to a day when science’s Grand Unifying Theory of Everything could be worn on a t-shirt may have to wait a little longer as astrophysicists continue to find hints that one of the cosmological constants is not so constant after all.
In a paper published in the prestigious journal Science Advances, scientists from UNSW Sydney reported that four new measurements of light emitted from a quasar 13 billion light years away reaffirm past studies that found tiny variations in the fine structure constant.
UNSW Science’s Professor John Webb says the fine structure constant is a measure of electromagnetism – one of the four fundamental forces in nature (the others are gravity, weak nuclear force and strong nuclear force).
“The fine structure constant is the quantity that physicists use as a measure of the strength of the electromagnetic force,” Professor Webb says.
“It’s a dimensionless number and it involves the speed of light, something called Planck’s constant and the electron charge, and it’s a ratio of those things. And it’s the number that physicists use to measure the strength of the electromagnetic force.”
The electromagnetic force keeps electrons whizzing around a nucleus in every atom of the universe – without it, all matter would fly apart. Up until recently, it was believed to be an unchanging force throughout time and space. But over the last two decades, Professor Webb has noticed anomalies in the fine structure constant whereby electromagnetic force measured in one particular direction of the universe seems ever so slightly different.
“We found a hint that that number of the fine structure constant was different in certain regions of the universe. Not just as a function of time, but actually also in direction in the universe, which is really quite odd if it’s correct … but that’s what we found.”
Looking for clues
Ever the skeptic, when Professor Webb first came across these early signs of slightly weaker and stronger measurements of the electromagnetic force, he thought it could be a fault of the equipment, or of his calculations or some other error that had led to the unusual readings. It was while looking at some of the most distant quasars – massive celestial bodies emitting exceptionally high energy – at the edges of the universe that these anomalies were first observed using the world’s most powerful telescopes.
“The most distant quasars that we know of are about 12 to 13 billion light-years from us,” Professor Webb says.
“So if you can study the light in detail from distant quasars, you’re studying the properties of the universe as it was when it was in its infancy, only a billion years old. The universe then was very, very different. No galaxies existed, the early stars had formed but there was certainly not the same population of stars that we see today. And there were no planets.”
He says that in the current study, the team looked at one such quasar that enabled them to probe back to when the universe was only a billion years old which had never been done before. The team made four measurements of the fine constant along the one line of sight to this quasar. Individually, the four measurements didn’t provide any conclusive answer as to whether or not there were perceptible changes in the electromagnetic force. However, when combined with lots of other measurements between us and distant quasars made by other scientists and unrelated to this study, the differences in the fine structure constant became evident.
A weird universe
“And it seems to be supporting this idea that there could be a directionality in the universe, which is very weird indeed,” Professor Webb says.
“So the universe may not be isotropic in its laws of physics – one that is the same, statistically, in all directions. But in fact, there could be some direction or preferred direction in the universe where the laws of physics change, but not in the perpendicular direction. In other words, the universe in some sense, has a dipole structure to it.
“In one particular direction, we can look back 12 billion light-years and measure electromagnetism when the universe was very young. Putting all the data together, electromagnetism seems to gradually increase the further we look, while towards the opposite direction, it gradually decreases. In other directions in the cosmos, the fine structure constant remains just that – constant. These new very distant measurements have pushed our observations further than has ever been reached before.”
In other words, in what was thought to be an arbitrarily random spread of galaxies, quasars, black holes, stars, gas clouds and planets – with life flourishing in at least one tiny niche of it – the universe suddenly appears to have the equivalent of a north and a south. Professor Webb is still open to the idea that somehow these measurements made at different stages using different technologies and from different locations on Earth are actually a massive coincidence.
“It raises a tantalizing question: does this ‘Goldilocks’ situation, where fundamental physical quantities like the fine structure constant are ‘just right’ to favour our existence, apply throughout the entire universe?”
“This is something that is taken very seriously and is regarded, quite correctly with skepticism, even by me, even though I did the first work on it with my students. But it’s something you’ve got to test because it’s possible we do live in a weird universe.”
But adding to the side of the argument that says these findings are more than just coincidence, a team in the US working completely independently and unknown to Professor Webb’s, made observations about X-rays that seemed to align with the idea that the universe has some sort of directionality.
“I didn’t know anything about this paper until it appeared in the literature,” he says.
“And they’re not testing the laws of physics, they’re testing the properties, the X-ray properties of galaxies and clusters of galaxies and cosmological distances from Earth. They also found that the properties of the universe in this sense are not isotropic and there’s a preferred direction. And lo and behold, their direction coincides with ours.”
Life, the universe, and everything
While still wanting to see more rigorous testing of ideas that electromagnetism may fluctuate in certain areas of the universe to give it a form of directionality, Professor Webb says if these findings continue to be confirmed, they may help explain why our universe is the way it is, and why there is life in it at all.
“For a long time, it has been thought that the laws of nature appear perfectly tuned to set the conditions for life to flourish. The strength of the electromagnetic force is one of those quantities. If it were only a few percent different to the value we measure on Earth, the chemical evolution of the universe would be completely different and life may never have got going. It raises a tantalizing question: does this ‘Goldilocks’ situation, where fundamental physical quantities like the fine structure constant are ‘just right’ to favor our existence, apply throughout the entire universe?”
If there is a directionality in the universe, Professor Webb argues, and if electromagnetism is shown to be very slightly different in certain regions of the cosmos, the most fundamental concepts underpinning much of modern physics will need revision.
“Our standard model of cosmology is based on an isotropic universe, one that is the same, statistically, in all directions,” he says.
“That standard model itself is built upon Einstein’s theory of gravity, which itself explicitly assumes constancy of the laws of Nature. If such fundamental principles turn out to be only good approximations, the doors are open to some very exciting, new ideas in physics.”
Professor Webb’s team believes this is the first step towards a far larger study exploring many directions in the universe, using data coming from new instruments on the world’s largest telescopes. New technologies are now emerging to provide higher quality data, and new artificial intelligence analysis methods will help to automate measurements and carry them out more rapidly and with greater precision.
Reference: “Four direct measurements of the fine-structure constant 13 billion years ago” by Michael R. Wilczynska, John K. Webb, Matthew Bainbridge, John D. Barrow, Sarah E. I. Bosman, Robert F. Carswell, Mariusz P. Dąbrowski, Vincent Dumont, Chung-Chi Lee, Ana Catarina Leite, Katarzyna Leszczyńska, Jochen Liske, Konrad Marosek, Carlos J. A. P. Martins, Dinko Milaković, Paolo Molaro and Luca Pasquini, 24 April 2020, Science Advances.
DOI: 10.1126/sciadv.aay9672
