The science behind RHCs liver thread

Potential bollocks those

 

Specifics? You surely don't mean the great Eagleman himself, do you?

 

Mathematicians sum up the big questions of our time

Tom Whipple, Science Editor
Saturday June 12 2021, 12.01am, The Times

please log in to view this image

Eight of the mathematician David Hilbert’s original 23 problems have been sloved since 1900
Share
Save
As a wish list, no one could accuse it of lacking ambition. There’s the problem of free will, the quest for truly intelligent AI and the mathematical basis of mortality. There’s a theory of quantum gravity, of course. And, as befits any collection of great unsolved mathematical problems, there is the Riemann hypothesis.

In 1900 the great mathematician David Hilbert published a list of 23 problems he wanted the world’s mathematicians to apply themselves to.

More than a century on, the London Institute for Mathematical Sciences has published its own. They range from finding a unifying theory of mathematics to providing a rigorous underpinning to quantum field theory, to determining the laws of genetic information processing. Some, such as tackling free will, seem as though they are barely mathematics at all.



That, said Thomas Fink, director of the independent not-for-profit organisation modelled on Princeton’s famous Institute for Advanced Studies, is partly the point. “Sometimes just to pose a problem mathematically means you understand a fair bit about it already,” he said. Serious researchers, such as the Nobel laureate Roger Penrose, have tried to formulate a neurological basis for free will. Fink’s own work has looked at the theoretical basis of mortality.

“Why do we age? Is it a ticking time bomb? For a long time we have just thought it is the accumulation of errors in how our body stores information. But there’s increasing evidence that ageing is not an essential component to life itself.” He has been looking at whether it is a consequence of the mathematics of natural selection.


The institute, based in the Royal Institution in London, produced the list in part because of the creation of Aria, a funding body for blue skies research. “Now’s a great time to focus on the great challenges of our time,” said Fink. “We thought, let’s brainstorm and think what are the great problems of our time.”

Of Hilbert’s original 23 problems, eight are judged solved and 12 partially solved. The solved Hilbert problems include the question of whether if you have two polyhedra — straight-edged shapes — of equal volume it is always possible to chop one up into polyhedral pieces to make the other (it isn’t), and what’s the best way of densely packing spheres such as oranges. The latter problem was solved only in 1998.

Despite 120 years of attempts, three are little closer to completion, among them the Riemann hypothesis, a classic theory that relates to the distribution of prime numbers. Solving that, said Fink, would be revolutionary.

“Countless theorems begin, ‘If the Riemann hypothesis is true, then the following holds’. So, first of all, proving it true or false would have immediate knock-on effects.” Doing so would also, he suspects, yield a revolution. Just as uniting quantum mechanics and general relativity to create a “theory of everything” — a longstanding goal, also on the list — would require new physics, the same would be true here. “I think the Riemann hypothesis is going to require a new type of mathematics,” he said.



But will we get it? Riemann remains intractable. Many of the other problems feel impossible to formulate, let alone solve. How does he think his list will do, compared with Hilbert’s? “This will be a map for 100 years,” he said. “If we can make a start on half or two thirds, I think that would be incredible.”

please log in to view this image

Head scratchers

1 Theory of everything
We lack a single theory that describes the universe. Gravity, described by general relativity, is not consistent with our quantum field theory of the other three forces. Will this be resolved by string theory, loop quantum gravity, or something new? What are the testable consequences of such a theory, which is beyond the limit of human experimentation?

2 Riemann hypothesis
Attempts to settle the Riemann hypothesis have inspired new branches of mathematics. For example, the Riemann zeta-function is the simplest kind of L-function, and these seem to play a role in modern mathematics similar to polynomials in ancient mathematics. What new concepts are needed to resolve this most important of open problems?

3 Thermodynamics of life
According to Darwin’s theory, evolution is the result of mutation, selection and inheritance. But from a physics perspective, we do not understand how life began in the first place. What is the thermodynamic basis for emergent self-replication and adaptation, of which biology is just one instance? Can it be used to create digital artificial life?

4 The structure of innovation
Despite advances in our understanding of evolution, what drives innovation remains elusive. Technological innovation operates in an expanding space of building blocks, in which combinations of technologies become new technologies. Can we characterise innovation in a mathematical way, so that we can predict it and influence it through interventions?

5 Physics of self-assembly
Self-assembly is how proteins fold, snowflakes form and viruses assemble. It can be used to manufacture complex and nanoscale objects at low cost. As a physical embodiment of computation, it is deeply linked with decidability. Can statistical physics be combined with computability theory to build a comprehensive theory of self-assembly?

6 Cosmological constant
Only a small fraction of the observable universe is made up of known matter. The majority is conjectured to be dark matter and dark energy, for which there is no consensus in explanation. Why does the zero-point energy of the quantum vacuum not cause a large cosmological constant? What cancels it out? Is new fundamental physics needed to reformulate gravity?

7 Langlands Program
There is evidence of a grand unified theory for mathematics, called the Langlands Program. It seeks to relate automorphic forms in geometry and number theory to representation theory in algebra. Wiles’s proof of Fermat’s Last Theorem can be viewed as just one instance of it. How can we advance and extend this theory, and what fruit would it bear?

8 Intelligent AI
Far from approaching artificial general intelligence, AI has not progressed beyond high-dimensional curve fitting. What mathematical insights could lead to more intelligent AI, such as causal reasoning, functional modules or a representation of the environment? Are there fundamental limits to AI and what might this tell us about human intelligence?

9 Repairable instead of robust To be sure of success in the face of uncertainty, we make plans that can cope with the unexpected. One way is to be robust: able to absorb a known setback. Another is to be repairable: easily modifiable in the face of unknown setbacks. Our approaches to threats, such as war or climate change, tend to be robust. What would a theory of repairability look like?

10 The operating system of life Networks of gene regulation govern morphogenesis and determine cell identity. The concision of viruses suggests that this genetic software uses subroutines like digital software. What are the laws governing genetic information processing? Can they shed light on the operating system of life, setting the stage for a biological analogue of the silicon revolution?

11 The mathematical universe Wigner noted the unreasonable effectiveness of mathematics in physics. Today, we are seeing the reverse: attempts to advance physics, such as string theory, are driving mathematics. Is there a convergence between these two disciplines, and should this inform how much we fund and advance mathematics? Can Tegmark’s mathematical universe be made rigorous?

12 Bridging networks and graphs Network science, which tries to extract meaning from real world networks, is popular but unsophisticated. To realise its potential, it must build on more rigorous concepts from graph theory. Can we develop a formal notion of network geometry and a thermodynamics to describe deviations away from it? How can we characterise network modules and other substructures?

13 Theory of free will The existence of free will has no grounding in the known laws of physics. Some attempts have been made to link it to quantum phenomena, but a theory of free will remains elusive. Is it a phantom, a consequence of life, or a more general attribute of the present moment? What new physics is required to understand this seemingly vital concept?

14 Collective creativity Collective creativity started 300 years ago when the scientific paper sped up research by enabling fast marginal advances over slow major ones. Today, anonymous collaboration platforms such as Wikipedia suggest we can speed up much more. But why and when does collective creativity work? Can platforms like Gowers’s Polymath transform the process of discovery?

15 Programmable matter We can cause surfaces and volumes to change shape on command using polymers that respond to temperature and current. What are the scope and limits of such programmable matter? Can we use differential geometry, recent advances in algorithmic origami and other mathematical tools to provide a language for reverse engineering useful shapes and mechanisms?

16 Foundation of QFT Can quantum field theory, which describes all elementary particles and interactions, be made rigorous? An open problem is to prove that for any compact gauge group, a Yang-Mills theory exists in four dimensions and predicts a lightest particle with positive mass. This will likely require new kinds of mathematics and offer a new perspective on physics.

17 Mathematical dualities Dualities play a key role in how we form insights in physics and mathematics. Examples include the Geometric Langlands correspondence, dualities across quantum field and string theories, and the ADE classification. Are dualities an artefact of how we decipher new theories, or do they have a more fundamental cause? Can we systematise them to discover more?

18 Engineerable AI Evolution and innovation both make use of interoperable functional modules to increase the odds of successful tinkering. But deep learning algorithms, by contrast, are globally wired. This makes them difficult to build up in a hierarchical way, as well as hard for humans to understand. Can we formulate a framework for AI that is engineerable?

19 Theory of simplicity In an increasingly complex world, we seek simplicity in how we organise technology and society. But we don’t know how to describe simplicity, much less construct it. Physicists have developed various models of complexity, but what would a theory of simplicity look like? Is it connected to being able to readily reconfigure to new environments?

20 AI-assisted conjectures
Good conjectures, through spotting patterns and applying instinct, can inspire new branches of mathematics. Because mathematics is exact and coincidences can be interrogated, automated pattern detection is immune from the bias normally found in high dimensional search. Can machines help identify candidate conjectures and speed up theoretical research?

21 Mathematics of causality Causality is fundamental to how we make predictions and structure society. Yet our mathematics for describing it is poor. Can a more sophisticated theory of causality help unlock challenges such as intelligent AI, the operating system of life and even how we build physical theories? How can we move from a microscopic to a macroscopic notion of causality?

22 Emergence of virtue The fully-informed rational agent view of economics is inadequate for describing real world behaviour, especially virtuous activity. Can insights from the microscopic view of behavioural science and the macroscopic view of thermodynamics form the basis of a co-operative game theory that accounts for the emergence of virtue in human behaviour and enterprise?

23 Theory of immortality Ageing is ascribed to the accumulation of errors — an inevitable consequence of the increase of disorder. But mounting experimental evidence suggests that ageing is not a fact of life. Is ageing a thermodynamic necessity, or is it instead favoured by natural selection? Does it emerge in artificial life? Is it possible to slow ageing or even stop it?

 

Andromeda’s and the Milky Way’s black holes will collide. Here’s how it may play out
Supermassive black holes will merge less than 17 million years after galaxy merger

please log in to view this image

The Milky Way galaxy will merge with neighboring Andromeda (pictured) about 10 billion years from now — a bit later than previously estimated.

DAVID (DEDDY) DAYAG/WIKIMEDIA COMMONS (CC-BY-SA-4.0)

Share this:

• Email
• Facebook
• Twitter
• Pocket
• Reddit
• Print

By Sid Perkins

MARCH 5, 2021 AT 8:00 AM

The supermassive black holes at the centers of the Milky Way and Andromeda galaxies are doomed to engulf each other in an ill-fated cosmological dance.

Astronomers have long known that Andromeda is on a collision course with our galaxy (SN: 5/31/12). But not much has been known about what will happen to the gargantuan black holes each galaxy harbors at its core. New simulations reveal their ultimate fate.

The galaxies will coalesce into one giant elliptical galaxy — dubbed “Milkomeda” — in about 10 billion years. Then, the central black holes will begin orbiting one another and finally collide less than 17 million years later, researchers propose February 22 at arXiv.org and in an earlier paper published in Astronomy & Astrophysics. Just before the black holes smash into each other, they’ll radiate gravitational waves with the power of 10 quintillion suns (SN: 2/11/16). Any civilization within 3.25 million light-years from us that has gravitational wave–sensing technology on par with our current abilities would be able to detect the collision, the researchers estimate.

The latest data suggest Andromeda is approaching us at about 116 kilometers per second, says Riccardo Schiavi, an astrophysicist at the Sapienza University of Rome. Using computer simulations that include the gravitational pull of the two spiral galaxies on each other as well as the possible presence of sparse gas and other material between them, Schiavi and his colleagues played out how the galactic collision will unfold.

A computer simulation shows how the Milky Way (left) and Andromeda (right) galaxies will brush past each other about 4 billion years from now before merging into a single galaxy roughly 6 billion years later. The numbers along the sides denote distance in kiloparsecs (1 kiloparsec equals 3,260 light-years).
Previous simulations have suggested that Andromeda and the Milky Way are scheduled for a head-on collision in about 4 billion to 5 billion years. But the new study estimates that the two star groups will swoop closely past each other about 4.3 billion years from now and then fully merge about 6 billion years later.

The team’s estimate for Milkomeda’s merger date “is a bit longer than what other teams have found,” says Roeland van der Marel, an astronomer at the Space Telescope Science Institute in Baltimore who was not involved in the research. However, he notes, that could be due in part to uncertainty in the measurement of Andromeda’s speed across the sky.

 

Where is Sisu and his entertaining, if somewhat nonsensical graphs nowadays?

Planet is likely to warm far more quickly than expected, bombshell UN report warns | Daily Mail Online

The peoples of Greece and Turkey could do with a laugh just now.

 

13 things we learned from the landmark IPCC climate report
ENVIRONMENT 9 August 2021
By Adam Vaughan

please log in to view this image

A coal power plant in Bełchatów, Poland

Bartek Sadowski/Bloomberg via Getty Images



The world’s top climate scientists today released their first major review in eight years on the physical science of climate change, in a report approved by 195 countries. Here are 13 things we learned from the 4000-page Intergovernmental Panel on Climate Change (IPCC) report, about 3000 pages of which are simply a list of citations for the 14,000 scientific papers assessed.

1. The world has warmed by 0.1°C more than previously thought

The amount the world has already warmed has been revised upwards compared with the last version of the IPCC’s report, released in 2013. This shift is due to improved observational records and a series of very warm years in the past decade. Earth’s global average surface temperature is now 1.09°C above 1850-1900 levels. The rate of warming since the industrial revolution is unprecedented in at least 2000 years.


2. We have even greater certainty that our fossil fuel burning and activities are to blame

“It [the report] tells us that it is indisputable that human activities are causing climate change,” says Hoesung Lee, chair of the IPCC. The report itself says: “It is unequivocal that human influence has warmed the atmosphere, ocean and land.” In 2013, the IPCC said human influence was only “clear”.

3. Earth is expected to reach or breach 1.5°C of warming within two decades


All five emissions scenarios evaluated by the IPCC suggest we will miss the Paris Agreement’s toughest target, of holding warming to 1.5°C, within the next 20 years. The central estimate is for the early 2030s. Even in the very lowest of scenarios for future greenhouse gas emissions, the threshold is “more likely than not” to be hit.

4. Staying below 1.5°C in the longer term is still possible

In the very lowest emissions scenario, temperatures are expected to fall back to 1.4°C by 2100 after reaching 1.5°C. “If we rapidly reduce greenhouse gas emissions, if we can reach global net zero carbon dioxide emissions by around 2050, it is extremely likely we can keep global warming well below 2°C,” says Valérie Masson-Delmotte of the IPCC. That will require much stronger policies and measures than governments have in place now, though.


5. We have already locked in climate changes that will last thousands of years

Emissions to date mean some changes to the environment are now unavoidable, but we can slow them by cutting emissions faster. “Deep ocean warming, acidification and sea level rise are committed to ongoing change for millennia after global surface temperatures initially stabilize and are irreversible on human time scales,” the report says.

6. Some air pollution cuts are likely to increase climate change

Some of the warming to date has been masked by the aerosols, or pollution, we have put into the air. The IPCC estimates a cooling effect of 0-0.8°C so far. Cleaning up air pollution in the short term is good idea for human health and often also addresses some of the root causes of climate change. Nonetheless, doing so is “very likely” to cause further warming in the next two decades, because pollution – aerosols – have a cooling effect on global warming.

7. Each fraction of warming and every extra tonne of CO2 matters

Every additional 0.5°C of global warming will cause “clearly discernible increases” in the intensity and frequency of heatwaves, heavy rainfall, and droughts in some regions. That means we will still feel the benefits of efforts to reduce emissions even if we breach 1.5°C or 2°C. Passing such thresholds doesn’t mean we should give up on net zero.

8. The pandemic has had little impact on climate change

The covid-19 pandemic led to a huge drop in global emissions last year but it hasn’t changed the big picture on climate change. The impact of reduced emissions caused by lockdowns and economic slowdowns were “undetectable” beyond natural variability due to their temporary nature, said the IPCC.


9. CO2 removals are going to be important

Using technology and tree-planting to remove CO2 from the atmosphere does work, and is a plausible way of stabilising global temperature rises. The report concludes that CO2 removal can work, and that it would actually reverse warming, says Joeri Rogelj at Imperial College London, an IPCC author. “So that is good news.” However, each tonne of CO2 removed could be 10 per cent less effective at cooling than each tonne of CO2 emitted is at warming – in other words, we can’t simply take CO2 out of the atmosphere and pretend we never emitted it.

10. We cannot rely on nature as an excuse for business as usual

Forests, oceans and other “carbon sinks” will get less efficient at absorbing CO2 if we continue with high emissions. “While natural land and ocean carbon sinks are projected to take up, in absolute terms, a progressively larger amount of CO2 under higher compared to lower CO2 emissions scenarios, they become less effective, that is, the proportion of emissions taken up by land and ocean decrease with increasing cumulative CO2 emissions,” says the report.

11. Geoengineering the planet is probably a bad idea

One proposed solution to climate change, putting particles in the atmosphere to reduce the amount of the sun’s energy reaching Earth, is probably a bad idea. The report says the approach, and other ones under a suite of “solar radiation modification” options, could offset global warming but is likely to cause abrupt changes to water cycles, could have regional climate impacts and poses a risk because suddenly stopping would cause “rapid climate change.” Amanda Maycock at the University of Leeds, UK, and an IPCC author, says such strategies “have a huge number of risks associated with them”.

12. There is no longer any doubt about the links between climate change and extreme weather

Heatwaves, floods and other events have all been blamed on climate change in recent years. In 2013, the IPCC said it had “detected changes in some climate extremes” due to human influences such as burning fossil fuels. Today the IPCC said “it is now an established fact” that the increased frequency and intensity of such events is due to humanity’s emissions.

13. The Arctic is likely be ice-free at points in coming decades

Even in a net zero world where emissions follow the lowest of the IPCC’s five scenarios, the Arctic is likely to fall to a “practically ice-free state” (meaning there are less than a million square kilometres of ice) at least once before 2050. Under the highest emission scenarios, that ice-free state will become the norm for late summer by the end of the century.

Sign up for Countdown to COP26, our free newsletter covering this crucial year for climate policy

 

Worrying ****

 

well none of it is unexpected.

We knew it and we keep on (not kept on) consuming and polluting so the news is its "too late"

the important wording is business as usual.

Every effort made thus far has been to maintain lives as is, happy consuming profitable lives. When companies green wash products they don't care what happens next. 99% of their efforts continue to flow into the non circular economy irrespective of what they claim on carbon footprints.

you can be absolutely assured this will be ignored.

 

Why the big bang may not have been the beginning of the universe
SPACE | COMMENT 23 June 2021
By Chanda Prescod-Weinstein

please log in to view this image

David Kashakhi/Alamy

PART of what turned me into a theoretical cosmology enthusiast as a child was watching the documentary A Brief History of Time and hearing about the mystery around the big bang. It showed how the equations that we use to describe space-time broke down into a singularity when we ran time all the way back to the beginning. What does this imply about the origins and history of space-time – about the ultimate cosmological tale?

When the film came out in 1991, popular science books and magazines used the term big bang to refer to the moment when our universe came to be. It was the beginning of time and the beginning of space, and thus the beginning of space-time. In a very basic way, this wasn’t super hard to relate to. For example, in my family’s own Jewish tradition, our origin story for the universe begins quite similarly.

I am now a professor of physics and when I attend physics conferences, I have a very different relationship to the idea of the big bang than I did back in the early 90s. One might expect that this is because I have gone through extensive technical training, including passing intense postgraduate exams on general relativity and quantum field theory in relativistic space-times. And it’s true, my understanding of what that mysterious singularity represented deepened.


But actually, what lay people like me didn’t know 30 years ago is that a transformation was already happening in the physics community. How people were thinking about the big bang was shifting. The big bang no longer necessarily referred to the beginning. And there may not have been a beginning at all – at least not in the traditional terms.

There have been two changes to the way physicists think about this cosmological timeline. The first is that research on inflationary models, which study the exponential expansion of space-time, indicate that inflation may be an eternal process. As in, the universe may not have had a beginning moment, and we may live in what is called an eternally inflating universe, one that was expanding exponentially even before what we call the big bang. Mathematically, this seems the most likely scenario – assuming inflation is correct.

“The universe may not have had a beginning and we may live in what is called an eternally inflating universe”


Second, these days, people often use “hot big bang” to refer to a time period, rather than a single moment. The story goes that in the early stages of our corner of space-time, what we might call the visible universe, the universe was very hot and dense. This hot big bang era was filled with an energetic goo from which atoms would eventually emerge and begin to cluster, along with dark matter, into the structures we observe today: stars, galaxies, planets and, yes, people.

In a recent email to me and my editor, one of these people structures – a thoughtful reader – sent in a question that points to this transformation in how we think about the big bang. The reader noted that, for a while, it was fashionable to publish articles about the big bang and these days there are fewer. While I can’t speak to publishing choices by the editors at this magazine or any other, I can say that in recent years, there has been more (if not total) consensus in the cosmology community about the likely scenario for the inflationary universe – that our space-time went through a period of rapid, exponential expansion. A plethora of data supports the inflationary picture, which mathematically favours an eternal scenario.

There are, of course, detractors. Paul Steinhardt, one of the early thinkers on inflation, has since become one of its most vocal critics. But even in his competitor model of the universe, the big bang is replaced by a big bounce and a cyclic universe. The key point, ultimately, is that physicists don’t like singularities, and the search has always been on for a more satisfying model. Much as the idea of a “beginning moment” might satisfy the intuition we have developed in a world where some of the most dominant religious traditions teach us that there is a definitive beginning, from a scientific point of view, the singularity is a mathematical problem to be solved.

Models of the very early universe are hard to test directly. That doesn’t stop people from trying. For example, an eternally inflating universe implies that we live in one space-time bubble of many. Astrophysicist Hiranya V. Peiris, famous for her work on the cosmic microwave background (CMB) radiation, has with co-authors proposed that CMB data can be used to test interactions between our space-time bubble and others.

If I had to theorise why it is less popular to write about this in popular publications, I’d say it is because there haven’t been any new splashy ideas about it recently. The question of whether there was a beginning, of course, remains infinitely interesting!

 

How to Mars review: Sci-fi satire about reality TV on the Red Planet
HUMANS 4 August 2021
By Clare Wilson

please log in to view this image

In How to Mars, the Red Planet is so boring that TV ratings have tanked

gorodenkoff/Getty Images



How to Mars

David Ebenbach

Tachyon Publications


IN 2012, a Dutch group announced a novel plan for financing the literally astronomical costs of setting up a base on Mars: the firm would sell the TV rights for the selection and training of the would-be astronauts and the colonisation process too.

While there was massive public interest and more than 4000 people worldwide applied to be part of what was admitted to be a one-way mission, the company involved, Mars One Ventures, seemed out of its depth and went bankrupt in 2019. Now the idea lives on in fiction, in the form of How to Mars, the debut sci-fi novel from David Ebenbach.

The book explores with both humour and pathos the consequences of humanity leaving the challenging task of extraterrestrial colonisation to a TV company focused on ratings and sponsorship opportunities. The pitfalls are obvious from the start. During the selection process, the firm, Destination Mars!, seems less interested in finding people with the “right stuff” than in creating a telegenic melting pot.


Scandinavian Stefan, who speaks almost accentless English, is secretly told to “sound more Danish”, leaving him suspicious of the accents of his competitors. During the training programme in an Australian desert, another applicant is ejected for making the mistake of “breaking the fourth wall”, or speaking to the camera.

“The Mars settlers are in a vulnerable position: their survival depends on the goodwill of a TV company”

As the book opens, the six scientists at the colony are two years into their mission and all is not well. The crew members have become bored – of each other, the monotonous food and the never-changing scenery.

Perhaps unsurprisingly, viewers are bored too, which means the team suffers the indignity of the show being cancelled for poor ratings. The TV company has no incentive to move to Stage Two: sending out the next batch of colonists and terraforming Mars. The crew’s handlers on Earth have been suspiciously quiet about that side of things for a while.

The settlers are in a vulnerable position: their survival depends on the goodwill of a company on which they are now just a financial drain. When they disagree about something with a handler, she sets them straight: “Do you realize that you don’t even get to eat unless we send you food?”

Fortunately for the story, the colonists’ lives soon take a more interesting turn, bringing fresh challenges as well as the return of TV viewers.

The humour has shades of Douglas Adams, whose The Hitchhiker’s Guide to the Galaxy series excelled at satirising the frustrations of ordinary people battling faceless bureaucracy. In Ebenbach’s novel, Destination Mars! saddles the colonists with towels that aren’t absorbent because they bear enormous company logos.

But on the whole, How to Mars is a more serious read than Hitchhiker’s, exploring themes such as bereavement and mental illness. One crew member’s turmoil in particular is portrayed with convincing realism.

Indeed, a genuine fear for Earth’s real-life space agencies is that future missions to Mars may be jeopardised by the astronauts coming to hate each other. This has been investigated in mock missions, where crews are isolated for months in sealed habitats.

So far, no space agencies have turned any such projects into reality TV. If How to Mars is any guide, let’s hope they never do.

 

It's another theory......

 

As in 'May'.

 

Fazackerley

 

https://www.bbc.co.uk/news/science-environment-58498676

should be interesting to see how many images we get out of this one.

please log in to view this image

 

Actually, I think it's more of a hypothesis. Scientific theories usually have some evidence to back them up. "Pre-Big Bang existence" is hypothetically possible, but until there is some sort of evidence can't be called a theory.

 

A posultation?

You are right though, a theory is built on some data about something.

A hypothesis has no data at all.

 

Actually, I think it's all semantics.

 

What's Israel got to do with it?

 

Stephon Alexander interview: Is the universe a self-learning AI?
To solve the big mysteries in physics, we need to embrace fresh perspectives, says cosmologist Stephon Alexander. Here he explains why intuition is so important – and outlines one of his own wild ideas

PHYSICS 8 September 2021
By Thomas Lewton

please log in to view this image

Jennie Edwards



AS A child, Stephon Alexander was awestruck by the broken-down, graffiti-covered train carriages in the depot opposite where he waited for the yellow school bus each morning. Graffiti artists were his heroes, as were urban philosophers. Later, he joined a hip-hop group. “I used to beatbox in rap battles. They called it dropping science too,” he says.

Growing up in the Bronx in New York City in the 1980s might not be the typical training for a theoretical physicist, but it helped shape Alexander’s distinct style. “That collision of all these different cultures was valued because we saw the product,” he says. Alexander learned to embrace the discomfort of difference and saw the ideas that sprung from it. But as a young Black scientist, he was snubbed by colleagues. His speculative ideas were deemed outlandish by some of his peers.


Alexander sought refuge in jazz clubs, cafes and Zen Buddhist centres. Making friends with biologists, musicians and artists, he forged his own approach to the big questions about the nature of reality – one that valued diverse viewpoints, intuition and imagination.

Today, Alexander is a cosmologist, string theorist and jazz musician. He heads a research lab at Brown University in Providence, Rhode Island, seeking to unite the smallest and largest entities in the cosmos and unearth what came before the big bang. He is also president of the National Society of Black Physicists.

In his new book, Fear of a Black Universe: An outsider’s guide to the future of physics, Alexander argues that welcoming new voices into the “club of physics” will be essential to breaking new ground. Scientists could learn a lot from graffiti artists, once regarded as vandals but now revered by the art establishment, he says. “They recognise that it’s important to keep a foot on the outside and to keep on talking to others. It’s at that interface that we can expect new innovations to come,” he says. In this way, he hopes off-road thinking can put physicists back on the right track.


Thomas Lewton: Alongside theoretical physicist Lee Smolin, virtual reality pioneer Jaron Lanier and others, you recently proposed that the universe learned its own laws in the same way that artificially intelligent neural networks teach themselves. What is the appeal of a self-learning universe?

Stephon Alexander: I’ve asked the why question throughout my career: why is our universe special? String theory tells us something about how the laws of nature emerge. You start out with a string – there’s no gravity or particle physics – but then these forms and forces appear. But string theory doesn’t answer the why question. It lacks a mechanism to select which of the slot machine of 10500 possible universes is our universe.

If the forces in our universe were slightly different, then stars wouldn’t be able to burn hydrogen. You couldn’t make carbon, and if you can’t make carbon, then where are we? Why are the laws as we see them today? So we’re trying to come at this another way. A self-learning universe provides a mechanism to select those laws.

How could the universe be self-learning?

Learning is accumulating information and then making decisions based on this. It also needs some kind of stability; it must build and be sustained through time. So you start off with a set of very simple primordial rules, which are also a set of learning rules. These are prior to the laws of nature. If the rules can learn some of the laws we now know exist, like the laws of gravity, that’s a good learning system.

We have the universe of learning architectures and machine learning and artificial intelligence. And then, in the other universe, we have the laws of physics as we know them. It’s two sides of the same coin.

Which fundamental laws might have a learning architecture built in?

“Matrix models” are one example. You can picture these as chequerboards with different colours in each square that are constantly changing. Each matrix can have billions of columns and rows. Let’s assume this matrix theory is the mother of all theories, that it contains all possible laws. How does it realise the specific laws necessary for our world?

The mathematics of matrix theory seems to have some of the ingredients of a particular type of neural network. The idea then is to show that at least one of these neural network architectures can learn one of those laws. That correspondence would be an indicator. That’s what’s wild and beautiful about this idea, because if that’s nature at its most fundamental, then nature itself is like a neural network.

Wouldn’t it be a leap to go from this correspondence between the laws of physics, matrix theory and neural networks to then saying that the universe actually is a neural network?

It is a leap. It would be analogous to a neural network. We’re still playing with the idea, and it might end up taking us in another direction.

It also wouldn’t necessarily mean a neural network in the sense of a hardwired computer. A computer is just the substrate for neural networks. There could be something more biological going on. The universe itself produced brains, so why couldn’t the universe itself be a superbrain?

If you find enough of these correspondences, would we have to consider neural networks to be as “real” as physical laws?

I think we would have to. It would be real in the same way that we think electric or magnetic fields are real. Or think about when Paul Dirac predicted antimatter. You have a mathematical equation that seems to say something absurd about reality – that antimatter exists – and it then turned out to be a hidden part of reality.

How does a self-learning universe differ from an evolving universe?

Evolution depends on the idea of fitness within an environment. In evolution, species get killed off. In the same way, an evolving universe depends on there being a large population of universes and only the fittest ones – say with the right constants of nature – will survive.

Learning means that you have an opportunity to make a mistake without getting wiped out. These matrix models have a lot of space in which to store information. So you store that mistake as a memory and keep moving forward. It’s akin to jazz improvisation.

Why are bold ideas like this such an important part of doing physics?

I’m this kind of physicist who thinks these wild ideas. I even have ideas that I’m afraid to tell for fear of not being taking seriously or respected as a physicist. It certainly doesn’t help that I’m Black, and the biases and presumptions that go with that.

“The universe produced brains, so why couldn’t the universe itself be a superbrain?”

I went into this book asking: why do I do physics this way? Then I realised Max Planck thought consciousness subsumes everything. That Niels Bohr was studying Confucianism and Taoism. Then, wait a minute: Wolfgang Pauli was doing dream analysis?

It’s good for the advance of science. History has proven that to be the case. You need it all, because we’re dealing with the unknown. We’re dealing with nature that’s much smarter than we could ever be.

In your new book, Fear of a Black Universe, you write about the “club of physics”. What is that?

We form groups, we form social bonds, and I don’t think scientists are devoid or excused from that. These bonds are surrounded by certain social forces that can penalise or benefit you. It’s a very human thing.

There’s also an intellectual confidence and arrogance that makes physics hard for some people. We live in a Western society where people of colour and women have been stereotyped to be lazy or emotional or less intellectually endowed. I have my own personal experience of it. This is not saying: “Oh, give me a pass, because I’m suffering.” It’s actually the exact opposite. If you’re not fitting in, you’ve got to work hard.

Who introduced you to physics?

My high-school teacher Mr Kaplan told me that “intuition is the lifeblood of a great physicist”. It’s Einstein’s thought experiments, it’s Schrodinger’s cat. We intuit first, then confirm with math.

In my first physics lesson with Mr Kaplan, I didn’t know a damn thing about physics. But from watching him throw a ball up and down, I intuited the conservation of energy. That opened up my eyes that I could do physics. You don’t have to be some genius. It’s a human thing, it’s our birthright.

A revolution in theoretical physics – akin to the discovery of general relativity or quantum mechanics – seems long overdue. Do you attribute this to an unwillingness to embrace people from a variety of backgrounds?

I’m going to put my sword in the ground and say yes. I’m not saying we should just bring everyone in and [sing] Kumbaya. But we should look into this and empower those who are doing good work.

Given how deeply mathematical theoretical physics has become, do you think that makes it harder to apply intuitive thinking?

It does make it harder, but that’s why these things should be done collaboratively. Some people might play the role of being speculative while the others are more grounded. By the way, that’s what happens in jazz improvisation. When you’re improvising your solo, you’re exploring, but it’s kind of weird if there’s no background band supporting that. Then everyone else takes their turn to solo. We need both the grounding and the exploration.

How do you improvise when doing physics?

My intellectual training has not just been learning mathematics and the concepts of physics, but also learning philosophy.

You still need those mathematical tools. You need to find yourself within the tradition of physics. I believe in experiments. But you also need to explore wild ideas and be brave. You need to talk to others who you’ve been taught not to respect. They might have something to teach you.

please log in to view this image

Physicists can learn from graffiti artists, says Alexander

Shutterstock/Stock Store



I’ve had the fortune to train with Zen masters. I also trained in dream analysis with [theoretical physicist] Chris Isham. That’s where a lot of the magic started to happen. It’s like the Zen proverb of emptying your cup. How do you empty your mind so that it can contain new ideas? Ideas are going to come from irrational, illogical places sometimes.

“Koans” are these Buddhist riddles and paradoxes that are thrown at you. My entire life, as a physicist, I’ve trained my mind to be mathematical and to think logically. But you can’t get insight into these koans with that kind of thinking. It’s before thinking. The creativity in physics also lives in that place. For many years, I didn’t talk about any of this.

So what initially seems implausible can actually turn out to be what reality is deep down?

Absolutely. Take quantum mechanics: a particle can be a wave and a particle. But our experiences of waves and particles seemed to be separate. It’s an impossibility that then became a reality. Or look at the new interface between consciousness, physics and artificial intelligence. Scientists are writing papers about it. We’re now embracing what was once thought to be absurd.

In your book, you write about how Bantu-Kongo philosophies have led you to new ideas about quantum cosmology.

I was talking about my craft with the legendary bassist Melvin Gibbs, and afterwards he sent me a book about African cosmology. I realised that some elements of the origin story of the Bantu-Kongo people of West Africa fit very nicely into a problem in quantum cosmology.

Quantum cosmology is about applying the laws of quantum mechanics to the entire universe. Stephen Hawking and James Hartle came up with this idea of the wave function of the entire universe: that the entire universe is a quantum-mechanical system containing the potential of all things.

If you accept this, then you have to deal with the measurement problem. If there are no observers out there to measure the wave function of the universe and so collapse it, what do you do about that? The idea is that the universe observes itself. But how does it observe itself? Well, if there’s some form of protoconsciousness associated with this wave function, then that observer doesn’t have to be at a specific point in space. The observer is non-local. But through that observation, the universe disintegrates into local observers.

This is a Bantu-Kongo idea called mbungi. In the state of mbungi, both physical and conscious awareness are complementary. They are a duality – just like wave-particle duality in quantum mechanics, where a particle is a localised version of a non-local wave.

How can physics welcome people from a wide range of backgrounds while still embracing their differences?

I’ve created a group for young Black theoretical physicists and scientists called NeXus. There are still so few Black theoretical physicists. In my time, when I was a postdoc, there was only me and somebody else around the globe.

The idea is, everybody is a different kind of theorist. We have researchers in quantum gravity and machine learning, we have black hole physicists and theoretical biologists. They meet to share techniques and to do research projects together. And when they meet, they’re all thrown out of their comfort zones.

We need to embrace discomfort. If you are hiking up a mountain and you are uncomfortable, are you just going to hike back down? If you hear a different way of thinking about something, what are you afraid of? That’s Fear of a Black Universe.

More on these topics:

• PHYSICS

 

Not reading all that but why does he think the universe is artificial ?