Communion Of Dreams


Hawking’s Conundrum

From Chapter 3 (page 50 of the paperback edition) of Communion of Dreams:

Apparent Gravity was the third major application of the theories set forth in Hawking’s Conundrum, the great opus of Stephen Hawking which was not published until after his death in the earlier part of the century. He hadn’t released the work because evidently even he couldn’t really believe that it made any sense. It was, essentially, both too simple and too complex. And since he had died just shortly before the Fire-Flu, with all the chaos that brought, there had been a lag in his theory being fully understood and starting to be applied.

But it did account for all the established data, including much of the stuff that seemed valid but didn’t fit inside the previous paradigms. Using his theories, scientists and engineers learned that the structure of space itself could be manipulated.

In the news today:

Stephen Hawking’s ‘breathtaking’ final multiverse theory completed two weeks before he died

A final theory explaining how mankind might detect parallel universes was completed by Stephen Hawking shortly before he died, it has emerged.

Colleagues have revealed the renowned theoretical physicist’s final academic work was to set out the groundbreaking mathematics needed for a spacecraft to find traces of multiple big bangs.

Currently being reviewed by a leading scientific journal, the paper, named A Smooth Exit from Eternal Inflation, may turn out to be Hawking’s most important scientific legacy.

I frighten myself sometimes.

 

Farewell, Professor Hawking. Challenged in body, you challenged us with your mind.

 

Jim Downey

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The shape of things to come.

From Chapter 3 of Communion of Dreams:

Apparent Gravity was the third major application of the theories set forth in Hawking’s Conundrum, the great opus of Stephen Hawking which was not published until after his death in the earlier part of the century. He hadn’t released the work because evidently even he couldn’t really believe that it made any sense. It was, essentially, both too simple and too complex. And since he had died just shortly before the Fire-flu, with the chaos that brought, there had been a lag in his theory being fully understood and starting to be applied.

But it did account for all the established data, including much of the stuff that seemed valid but didn’t fit inside the previous paradigms. Using his theories, scientists and engineers learned that the structure of space itself could be manipulated. The first major application led to practical, safe, and efficient fusion power. Rather than forcing high-energy particles together, the forces keeping them apart were just removed. Or, more accurately, the manifestation of space between them was inverted. It took very little energy, was easy to control, but only worked in a very localized fashion

Then there’s this excellent non-technical explanation of a new theory of Shape Dynamics. An excerpt or two:

Their latest offering is something called “shape dynamics.” (If you’ve never heard of shape dynamics, that’s OK—neither have most physicists.) It could, of course, be a dead end, as most bold new ideas in physics are. Or it could be the next great revolution in our conception of the cosmos. Its supporters describe it as a new way of looking at gravity, although it could end up being quite a bit more than that. It appears to give a radical new picture of space and time—and of black holes in particular. It could even alter our view of what’s “real” in the universe.

* * *

In most situations, shape dynamics predicts what Einstein’s theory predicts. “For the vast majority of physical situations, the theories are equivalent,” Gryb says. In other words, the two frameworks are almost identical—but not quite.

Imagine dividing space-time up into billions upon billions of little patches. Within each patch, shape dynamics and general relativity tell the same story, Gryb says. But glue them all together, and a new kind of structure can emerge. For a concrete example of how this can happen, think of pulling together the two ends of a long, narrow strip of paper: Do it the usual way, and you get a loop; do it with a twist and you get a Möbius strip. “If you glue all the regions together to form a kind of global picture of space and time, then that global picture might actually be different.” So while shape dynamics may recreate Einstein’s theory on a small scale, the big-picture view of space and time may be novel.

Another prediction come true?

Not really — there were intimations of this theory when I was working on CoD, and it is a *very* long way from being accepted as valid, as the Nova article discusses.

But still …

 

Jim Downey

PS: new review of Communion of Dreams was put up yesterday. Check it out.

 



So I wander into this nuclear reactor . . .

I had reason to look up this item the other day, and was surprised that I hadn’t ever posted it to the blog. So, in honor of St Pat’s Day (well, OK, not really, but there is a connection…), here’s a little something from my old archives from a few years ago.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So I wander into this nuclear reactor . . .

This morning’s news that the NRC has declined to force nuclear power plants to take additional precautions to prevent the breach of a nuclear reactor’s core by attack with a jetliner comes as little surprise, given the Bush administration’s attitudes about actual security issues.

But, as always when I hear such news reports, I was taken back to a sunny spring morning some 30 years ago, when me and a couple of college buddies wandered into a nuclear reactor.

It was the weekend of St. Pats day, and we were at the University of Missouri – Rolla to party with a friend of ours who was an engineering student there.  I think it was Friday morning, and our friend had some classes he had to attend, so myself and my two friends decided to just explore the campus a bit (we all attended schools elsewhere).

I had considered Rolla for school myself a few years previously, when I had been thinking of going into physics (a dream derailed by poor higher-math skills).  So when we came across the research reactor building, I wanted to have a look.

We just wandered in.  No, seriously.  We just wandered into the building, through a couple of sets of doors, and soon found ourselves standing at a railing, looking down at the glowing blue core of the nuclear reactor.  In this day and age it is hard to imagine such a thing – and even at the time it seemed more than a little odd.

A few minutes after we came in, a nice fellow who fit the stereotype image of a science professor came over to us.  Short, grey, bearded, balding, wearing a white lab smock over his shirt and jeans.  He sort of looked us over, asked what we were up to . . . and then gave us an impromptu tour of the place (after tagging us with personal dosimeters).

It was fascinating, to me at least.  The reactor core at this facility sits at the bottom of a large swimming pool, about 20 feet down.  That provides all the necessary protection from the radiation generated from operation of the fission reactor (which doesn’t produce much power, and doesn’t use the sort of fuel used in nuclear weapons).  Herr Doktor explained all this to us non-scientists, and also explained the eerie blue glow coming off the reactor (which was then in operation).

It was a color like I’ve never seen before or since – a soft electric blue that was both intriguing and repulsive.  I knew what it was, having been interested in physics:  Cherenkov radiation, caused when the radioactive particles generated by the fission reactions are faster than the speed of light in the water.  But it’s the sort of thing that lasts in the memory, embedded there in a way not unlike a religious experience – hard to describe, or explain, or convince others of, yet extremely vivid for the one who experienced it.

Now, I’m not religious.  I’m an atheist, in fact.  I understand what that blue glow is – yet, whenever someone claims that they have had a religious experience, I can tie it to that same feeling I had on first seeing that other-worldly blue glow.

Well, anyway, I had to share that personal experience, and add a bit of perspective on the changes we’ve seen in terms of security over the last 30 years.

Jim Downey



Location, location, location.

It really does seem to be a pretty universal law:

On the role of GRBs on life extinction in the Universe

As a copious source of gamma-rays, a nearby Galactic Gamma-Ray Burst (GRB) can be a threat to life. Using recent determinations of the rate of GRBs, their luminosity function and properties of their host galaxies, we estimate the probability that a life-threatening (lethal) GRB would take place. Amongst the different kinds of GRBs, long ones are most dangerous. There is a very good chance (but no certainty) that at least one lethal GRB took place during the past 5 Gyr close enough to Earth as to significantly damage life. There is a 50% chance that such a lethal GRB took place during the last 500 Myr causing one of the major mass extinction events. Assuming that a similar level of radiation would be lethal to life on other exoplanets hosting life, we explore the potential effects of GRBs to life elsewhere in the Galaxy and the Universe.

 

What that means is summed up in this article. Here’s the conclusion:

Astronomers have long known that the Earth occupies a unique position in the solar system that allows life to flourish. This idea of a habitable zone now allows them to focus search for exoplanets that might also have conditions that are right for life. Now they can take this further by excluding inhospitable regions of the galaxy, and searching only those stars and galaxies that exist in the universe’s habitable zones.

 

Of course, that’s just for life as we know it

 

Jim Downey

 



A state of matter, or a state of mind?

From page six of Communion of Dreams:

His expert was one of best, one of only a few hundred based on the new semifluid CPU technology that surpassed the best thin-film computers made by the Israelis. But it was a quirky technology, just a few years old, subject to problems that conventional computers didn’t have, and still not entirely understood. Even less settled was whether the experts based on this technology could finally be considered to be true AI. The superconducting gel that was the basis of the semifluid CPU was more alive than not, and the computer was largely self-determining once the projected energy matrix surrounding the gel was initiated by another computer. Building on the initial subsistence program, the computer would learn how to refine and control the matrix to improve its own ‘thinking’. The thin-film computers had long since passed the Turing test, and these semifluid systems seemed to be almost human. But did that constitute sentience? Jon considered it to be a moot point, of interest only to philosophers and ethicists.

 

And, perhaps, physicists:

And while the problem of consciousness is far from being solved, it is finally being formulated mathematically as a set of problems that researchers can understand, explore and discuss.

Today, Max Tegmark, a theoretical physicist at the Massachusetts Institute of Technology in Cambridge, sets out the fundamental problems that this new way of thinking raises. He shows how these problems can be formulated in terms of quantum mechanics and information theory. And he explains how thinking about consciousness in this way leads to precise questions about the nature of reality that the scientific process of experiment might help to tease apart.

Tegmark’s approach is to think of consciousness as a state of matter, like a solid, a liquid or a gas. “I conjecture that consciousness can be understood as yet another state of matter. Just as there are many types of liquids, there are many types of consciousness,” he says.

 

Good article. Read the whole thing.

 

Jim Downey

Via MetaFilter.



One reality or t’other.

From Chapter 3 of Communion of Dreams:

Apparent Gravity was the third major application of the theories set forth in Hawking’s Conundrum, the great opus of
Stephen Hawking which was not published until after his death in the earlier part of the century. He hadn’t released the work because evidently even he couldn’t really believe that it made any sense. It was, essentially, both too simple and too complex. And since he had died just shortly before the Fire-flu, with the chaos that brought, there had been a lag in his theory being fully understood and starting to be applied.

But it did account for all the established data, including much of the stuff that seemed valid but didn’t fit inside the previous paradigms. Using his theories, scientists and engineers learned that the structure of space itself could be manipulated.

Of course, that is the reality of St. Cybi’s Well, not our own. In our reality, there’s been no fire-flu (at least yet), Stephen Hawking is still alive, and the laws of physics are still the same.

Well, maybe

Black holes are in crisis. Well, not them, but the people who think about them, theoretical physicists who try to understand the relationship between the two pillars of modern physics, general relativity and quantum physics. Judging from the current discussions, one of the two must go, at least in their present formulation. On January 22nd, Stephen Hawking posted a paper where he bluntly stated that black holes, in the sense of being objects that can trap light and everything else indefinitely, are no more. And that’s a big deal.

Sometimes I wonder what reality I am actually plugged into, since it seems that I keep getting leaks from the other one.

 

Jim Downey



Cue the mad scientist laugh …

This is a really interesting idea: that fundamental thermodynamic forces lead very naturally to the the beginning and evolution of life. From the start of the article:

Why does life exist?

Popular hypotheses credit a primordial soup, a bolt of lightning and a colossal stroke of luck. But if a provocative new theory is correct, luck may have little to do with it. Instead, according to the physicist proposing the idea, the origin and subsequent evolution of life follow from the fundamental laws of nature and “should be as unsurprising as rocks rolling downhill.”

From the standpoint of physics, there is one essential difference between living things and inanimate clumps of carbon atoms: The former tend to be much better at capturing energy from their environment and dissipating that energy as heat. Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula that he believes explains this capacity. The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.

It’s important to note that this is not in any way in conflict with current understanding of evolution — rather, as the article says: “England’s theory is meant to underlie, rather than replace, Darwin’s theory of evolution by natural selection, which provides a powerful description of life at the level of genes and populations.”

Take a few minutes to read the article; it’s well written and non-technical but assumes a basic scientific understanding of both evolution and thermodynamics.

And if proven true, implies that the universe should be full of biological life as a manifestation of basic physical processes.

*Very* interesting, indeed.

 

Jim Downey