Archive for the ‘Research studies’ Category

Why we don’t see extra dimensions

Wednesday, April 29th, 2009

Science is a process of objectification and the generation of models creates a duality- versus a phenomenological or ontological awareness of being. Phew. Which may be why I find it irresistible when the models themselves take on an almost mystical quality that is tantalizingly suggestive or difficult. I suspect someone like Baudrillard would have regarded this as a fetish- as if the technical jargon of string theorists, or whoever, makes a sort of gizmo that stands in for spirituality. I find the mechanics and language of these theories almost as wondrous as what’s being said with them. Maybe the fetish thing is right and it’s all about the words and numbers. I could just forget about everything else and, say, make big silver words and symbols like h or D-Space and polish them to the point where you can barely see the forms, just everything else reflected in them.

Discover Blog Cosmic Variance has a good piece on a topic I get a kick out of- extra dimensions. It reports on research into the question that a five year old would ask about extra dimensions- “if there are all these extra dimensions, how come we don’t see them?” The Calibau-Yau manifild in string theory, which I’ve posted about before, is a sort of torus that’s too small to see. In electromagnetism, solutions are also provided by wrapping an extra dimension into a circle, that’s too small to see. At this point the question becomes, “why are the dimensions we see so large, and the rest so small?”

The post reports on an academic paper that finds a “multiverse” as part of a possible solution;

Upping the number of dimensions to D, it is possible to find black branes that do exactly this – when you cross an event horizon, you enter a region in which some number of the extra dimensions have become compact. The number of compact dimensions is determined by the symmetry of the event horizon. If the event horizon has (D-4)-dimensional spherical symmetry, then the region inside of the black brane is effectively four dimensional. Further, the 4 dimensional region has a natural “slicing” into space and time, that yields a cosmology. The big-bang in this 4-dimensional cosmology corresponds to the event horizon of the black brane.

These black branes can be embedded in a D-dimensional de Sitter space, which has some very interesting properties itself. Most relevant for us is that energy conservation does not work in de Sitter space, since it has a finite temperature. This means that every once in a while, a fluctuation will occur that produces one of the black brane solutions, and therefore a 4-dimensional universe. This is a mechanism of dynamical compactification.

The devil is now in the details. First off, the brane needs to be charged under the gauge field for there to be one of these interesting solutions. For each value that the charge can take, a slightly different lower-dimensional universe will be produced, and if there are different types of gauge fields, then universes with different numbers of dimensions will be produced as well. There is a “landscape” of many possible lower-dimensional vacua, just like in string theory. Dynamical compactification will be happening all over the place in the D-dimensional de Sitter space, realizing all of these possibilities in different spacetime regions, and yielding what is referred to as a “multiverse.”

The zeroth order question is if any of these universes look like ours. This involves having an early time epoch of inflation and late-time evolution towards a universe dominated by a small cosmological constant. We found that the answer can be yes on both counts for the models we studied.

Choice Blindness

Wednesday, April 22nd, 2009

“Could we be forgiven for being wrong about the limits of our skills as experts of ourselves?” is the question at the beginning of an excellent New Scientist article that looks at “Choice Blindness”;

We have been trying to answer this question using techniques from magic performances. Rather than playing tricks with alternatives presented to participants, we surreptitiously altered the outcomes of their choices, and recorded how they react. For example, in an early study we showed our volunteers pairs of pictures of faces and asked them to choose the most attractive. In some trials, immediately after they made their choice, we asked people to explain the reasons behind their choices.

Unknown to them, we sometimes used a double-card magic trick to covertly exchange one face for the other so they ended up with the face they did not choose. Common sense dictates that all of us would notice such a big change in the outcome of a choice. But the result showed that in 75 per cent of the trials our participants were blind to the mismatch, even offering “reasons” for their “choice”.

The authors go on to speculate that confabulation (the story telling we do to justify things after the fact) may play a role in obsessive-compulsive disorder.

Depending on what our volunteers say in response to the mismatched outcomes of choices (whether they give short or long explanations, give numerical rating or labelling, and so on) we found this interaction could change their future preferences to the extent that they come to prefer the previously rejected alternative. This gives us a rare glimpse into the complicated dynamics of self-feedback (“I chose this, I publicly said so, therefore I must like it”), which we suspect lies behind the formation of many everyday preferences.

Quantum Biology

Saturday, March 14th, 2009

olfactorybulb

Olfactory bulb of an adult mouse © Dr Adam Puche

The story of Schrödinger’s cat was invented to illustrate the inherent paradox of entanglement, using the simultaneous life and death of a familiar domestic animal to ram home the absurdity of the concept. For me, the device is lame compared to the story of an actual experiment such as the classic Double-slit experiment. The dual nature of energy and of matter naturally evokes many questions about reality and about life and the workings of consciousness.

I remember reading a story in the excellent Faber Book of Science, years ago, about worms that live in the tideline and come out of the sand onto the beach, to photosynthesize, at low tide. They are, apparently, the only creature that’s part animal, part plant, since they have photosynthesizing cells in their skin. The pay-off of the story is that when scientists took them out of the beach and put them in a lab under a constant light-source, they continued to follow the tide times. Which led the scientists to suspect that they may be responding to the gravitational force of the moon. High level physics and biology seemed to merge even in the simplest of creatures.

Discover magazine has an interesting article about the relatively new field of Quantum Biology- slightly ridiculously titled “Is Quantum Mechanics Controlling Your Thoughts?” The title, incidentally, made me think of Major General Albert Stubblebine, commanding general of the United States Army Intelligence Security Command from 1981 to 1984. Who may have been under the influence of Quantum Mechanics when he tried repeatedly to walk through the wall of his office, in his bid to create super-soldiers using parapsychology and pseudo-science. Objects do pass through other objects in quantum mechanics, although Brian Greene, in his book “The Elegant Universe”, estimates that to have a good chance of walking through a wall, it would be necessary to try it every second for approximately the current age of the universe.

Anyway, the article reveals that new tools such as femtosecond lasers and nanoscale precision positioning are opening up biological processes to quantum-scale observation. The incredible efficiency of photosynthesis, the sense of smell, consciousness and even the beneficial effects of green tea, are all variously thought to arise from quantum processes; “…many human experiences… from dreams to subconscious emotions to fuzzy memory, seem closer to the Alice in Wonderland rules governing the quantum world than to the cut-and-dried reality that classical physics suggests. Discovering a quantum portal within every neuron in your head might be the ultimate trip through the looking glass…”

Dualism and God

Thursday, March 5th, 2009

Arts and letters Daily has a link to an interesting New Scientist article (click on SKIP, lower right corner of subscribe box), about how our brains are predisposed to religious or creative thinking. The article centers around research by Paul Bloom, a psychologist at Yale;

So how does the brain conjure up gods? One of the key factors, says Bloom, is the fact that our brains have separate cognitive systems for dealing with living things – things with minds, or at least volition – and inanimate objects.

This separation happens very early in life. Bloom and colleagues have shown that babies as young as five months make a distinction between inanimate objects and people. Shown a box moving in a stop-start way, babies show surprise. But a person moving in the same way elicits no surprise. To babies, objects ought to obey the laws of physics and move in a predictable way. People, on the other hand, have their own intentions and goals, and move however they choose.

Bloom says the two systems are autonomous, leaving us with two viewpoints on the world: one that deals with minds, and one that handles physical aspects of the world. He calls this innate assumption that mind and matter are distinct “common-sense dualism”. The body is for physical processes, like eating and moving, while the mind carries our consciousness in a separate – and separable – package. “We very naturally accept you can leave your body in a dream, or in astral projection or some sort of magic,” Bloom says. “These are universal views.”

There is plenty of evidence that thinking about disembodied minds comes naturally. People readily form relationships with non-existent others: roughly half of all 4-year-olds have had an imaginary friend, and adults often form and maintain relationships with dead relatives, fictional characters and fantasy partners. As Barrett points out, this is an evolutionarily useful skill. Without it we would be unable to maintain large social hierarchies and alliances or anticipate what an unseen enemy might be planning. “Requiring a body around to think about its mind would be a great liability,” he says.

You have to admire these scientists- I’ve never seen a baby that doesn’t look surprised. The article goes on to talk about the other essential ingredient in the construction of religion; an overdeveloped sense of cause and effect. There’s reference to an extremely interesting experiment published late last year;

Jennifer Whitson of the University of Texas in Austin and Adam Galinsky of Northwestern University in Evanston, Illinois, asked people what patterns they could see in arrangements of dots or stock market information. Before asking, Whitson and Galinsky made half their participants feel a lack of control, either by giving them feedback unrelated to their performance or by having them recall experiences where they had lost control of a situation.

The results were striking. The subjects who sensed a loss of control were much more likely to see patterns where there were none. “We were surprised that the phenomenon is as widespread as it is,” Whitson says. What’s going on, she suggests, is that when we feel a lack of control we fall back on superstitious ways of thinking. That would explain why religions enjoy a revival during hard times.

Grids

Tuesday, March 3rd, 2009

1. Structure

berndhilla1

© Bernd & Hilla Becher

2. Anonymity

studiowe1

© Walker Evans

3. Nebulas

icb

4. Identity

exactitudes

© Ari Versluis

5. Movement

muybridge_race_horse_gallop

© Eadweard Muybridge

6. Nature

birds

© Dora Balla

7. Expression

pollak_faces_emotion_grid02

© Seth Pollack

8. Simulation

sims01

© Karl Sims

Edge- Art and Human Reality

Friday, February 27th, 2009

A few weeks ago there were quite a few articles floating around about Dennis Dutton’s book “The Art Instinct; Beauty, Pleasure and Human Evolution”. At the time I couldn’t find anything really good on it, but Edge has a great talk with him; a video interview and transcript. My favorite quote from it;

We have to consider the spontaneity of the arts—the way they spontaneously arise, beginning in childhood experience, across the globe. Think of the ways in which children, by the time they’re three years old, can engage in make-believe and keep imaginary worlds separate from one another. A small child playing with its teddy bears at a tea party. If you knock over a cup and spill the pretend tea in it, the child will not be in the least confused as to which of the three empty cups to refill. In fact, if you refill the wrong empty cup, and insist it was the one that spilled, the child may well break out in tears. The child then goes from the tea party over to the television, and watches a Bugs Bunny cartoon, or “Sesame Street.” From there, it’s on to reading a book, entering into its make-believe world, and then to have dinner with mommy and daddy. Even a three year old can keep all of these real and fictional worlds coherently separate from each other. Such spontaneous intellectual sophistication—try to imagine teaching it from scratch to a three year old—is a mark of an evolved adaptation.

Delusion and multiple realities

Sunday, February 22nd, 2009

3 Quarks Daily has an interesting interview looking at a new theory on the nature of delusion. Current theories fall in to “top-down” or “bottom-up” models, where the phenomenon is seen as either a consequence of a disturbance in high level understanding, or of false perceptions. In his article “Delusional Realities”, Shaun Gallagher, a professor of Philosophy at the University of Central Florida, suggests several inadequacies with previous explanations and gives his own;

So, Gallagher proposes an alternative description, which incorporates both top-down and bottom-up components and emphasizes the influence of bodily and social factors. On this view, “in the spirit of embodied, situated and phenomenological views of cognition,” the delusional subject “does not live in the one unified world of meaning that is defined objectively (in a view from nowhere), but in multiple realities, sub-universes or finite provinces of meaning.” He likens the experience of these realities to being “in-the-world” of a book, movie, or video game, but says that “unlike other multiple realities…[delusional ones] may be ‘firmly sustained…’”

Conceiving of delusional states in this way, Gallagher argues, allows us to account for previously unexplained aspects of delusion. For instance, it has been noted that some delusional patients actually find it strange when others express agreement with their delusional claims. This may be because they see themselves as responding to a distinct reality.

The interviewer, Olivia Scheck, asks the question that this begs at the end of the interview; “This is a philosophical approach to answering a psychiatric question, but do you also think it has implications for other areas of philosophy? For instance, does showing that people can experience alternate realities suggest that to some extent aspects of objective reality are just shared beliefs about the world, and does this suggest that our ideas about the world are more constructed than we normally think of them as being?” Imagine a world in which the nature of reality was generally agreed upon. It’s easy to think of vast swathes of the world’s population that are living “in the world” of various books. The interview also links to a great TED talk by Vilayanur Ramachandran entitled “A journey to the center of your mind”, which looks at the brain’s most basic mechanisms and gives an entertaining bottom-up explanation for Capgras Delusion;

Calabi-Yau manifold

Sunday, February 15th, 2009

image

calabi-yau1calabi-yau21

©Paul Nylander

More otherworldly geometry, this time from the simulations of string theorists. These shapes may or may not occur naturally and could contain other dimensions. If string theory is proved to be right (by experiments in the Large Hadron Collider at CERN), then these geometries help shape the physical universe- in the way that a musical instrument shapes a note. If you have time, definitely check out this TED talk by Brian Greene, who is really a gifted speaker, here explaining string theory for those of us who don’t know much about physics;

Defence spending lifts economy? Depends how big the war is…

Monday, February 9th, 2009

DoD Buzz writes that non-partisan Congressional Research Service economists have recently examined military spending and it’s effect on the economy;

As the CRS economists explain, World War II stands in a class all its own. Trying to compare a period when military outlays from 1943 to 1945 reached 37 percent of GDP and the structure of the American economy was fundamentally altered, to other post-war economic events is foolish. During the Korean War years, military spending reached 14 percent of GDP, and real GDP grew during the early 1950s. After Korea, the evidence is murky at best. “Vietnam, the Reagan military buildup, and the two wars in Iraq were not large enough to dominate economic events of their time,” CRS says.

The CRS economists conclude that it takes a really big war to stimulate aggregate demand in an economy the size of the US. Even if it were an option to increase defence spending by hundreds of billions of dollars to replace consumer demand (and from 2000 to 2009 there was already a 62% increase in military spending), there aren’t many places to spend the money.

Moral absolutists prefer symbolic gestures to reason or money

Saturday, January 3rd, 2009

Not Exactly Rocket Science reports on a study from the New School for Social Research, which surveyed 1,800 people picked from Jewish Israeli settlers, Palestinian refugees and Palestinian students, in Israel and the Palestinian territories. About half of the Palestinian students in the study were members of Hamas or related organizations. The study asked the participants to consider compromise over issues that were relevant to them (land for peace, giving up the right to land, claim to Jerusalem).

They found that participants on both sides fell into two groups- the moral absolutists and the non-absolutists. And the interesting part of the experiment came when they introduced incentives to sweeten the deal. Faced with the prospect of the same compromise, only with a rational or financial incentive to make it more attractive, the two groups behaved completely differently. The incentives included peace, resulting from the end of hostilities, and money in the form of donations from the EU or the US. Whilst the moderates responded well to these incentives, the absolutists reacted vehemently, with more of them recommending a violent response than before.

Symbolic gestures had the opposite effect. It didn’t matter if these symbolic gestures altered the costs or benefits of the compromise, and in fact it didn’t even matter if these deals would be successfully carried out.

The only thing the study doesn’t seem to have gone into, is whether or not violence itself constitutes a symbolic gesture. If you fire rockets blindly into Israeli territory, or take out Hamas targets and then post the results on YouTube, what are you actually doing? The videos and images of violence from these places are absolutely stuffed full of symbolism.