One of the great mysteries of our times is Dark Matter. In various forms, it makes up most of reality, somewhere between 85 and 98 per cent, yet we know almost nothing about it, including the particles of which it is composed, because we can't see it (it neither emits nor scatters light). Scientists assume it exists because they can detect its mass and gravitational pull (see a piece at I09 on Dark Matter here and an explanation from Scientific American here). Now there are speculations that there might have been (might still be?) stars and potentially alternate, unseen galaxies, a coexistent unseen universe, composed of Dark Matter.
First, the distinction between Dark Matter and Antimatter: Dark Matter is unlike regular matter, which has its own oppositely-charged nemesis in Antimatter (both matter and Antimatter are part of the observable universe, while Dark Matter is not). Antimatter mirrors regular matter in that its particles have an opposite charge. At one time, there was an oppositely-charged Antimatter particle for every particle of matter. If, after the Big Bang, this perfect symmetry had played out, then each particle would have collided with its corresponding anti-particle, resulting in mutual cancellation. But since the universe exists, there must have been an imbalance that favoured matter. Physicists do not know why.
The relationship between matter and Antimatter is now considered to be asymetrical. There is much less Antimatter than there is matter, and hence no Antimatter universe to act as our universe's inverted twin. Wiki: "There is considerable speculation as to why the observable universe is apparently almost entirely matter, whether there exist other places that are almost entirely antimatter instead, and what might be possible if antimatter could be harnessed. At this time, the apparent asymmetry of matter and antimatter in the visible universe is one of the greatest unsolved problems in physics. The process by which this asymmetry between particles and antiparticles developed is called baryogenesis." Some scientists believe that concentrations of Antimatter could be too far away for us to see. Other researchers believe that there are no Antimatter galaxies, stars and solar systems, because Antimatter particles have been exponentially destroyed. Antimatter is currently being studied at the Large Hadron Collider in Switzerland (see my post on that here). One clever yin-yang theory uniquely posits that the universe's missing Antimatter became Dark Matter.
Dark Matter - Dark Stars
Unseen Dark Matter, unlike matter and Antimatter, must constitute both positive and negative versions of itself, and form its own own Annihilations. I09: "One of the unusual properties about most candidates for the dark matter particle is that they are their own antiparticle, meaning any two dark matter particles interacting in close proximity would annihilate each other in a matter/antimatter reaction." It is even possible that at one time in the universe, there were stars made of Dark Matter, formed from giant globs of Dark Matter particles reacting with each other. These would be Dark Stars. Whether Dark Stars ever existed (or exist?) would depend on what type of particle hypothetically makes up Dark Matter. From 2006 to the present, a string of news reports have appeared on the particles that make up Dark Matter, and how close scientists are (or are not) to discovering them (here, here, here, here, here, here). Scientific American:
"Could there be a whole sector of hidden particles? Could there be a hidden world that is an exact copy of ours, containing hidden versions of electrons and protons, which combine to form hidden atoms and molecules, which combine to form hidden planets, hidden stars and even hidden people?
The idea is truly tantalizing. Could it be that what we see as dark matter is really evidence for a hidden world that mirrors ours? And are hidden physicists and astronomers even now peering through their telescopes and wondering what their dark matter is, when in fact their dark matter is us?
Other reports indicate that the Milky Way galaxy is surrounded by several Dark Matter galaxies, shadow galaxies, that we can't see. Dark Matter is also being used to explain why time moves forward:Unfortunately, basic observations indicate that hidden worlds cannot be an exact copy of our visible world. For one, dark matter is six times more abundant than normal matter. For another, if dark matter behaved like ordinary matter, halos would have flattened out to form disks like that of the Milky Way—with dramatic gravitational consequences that have not been seen. Last, the existence of hidden particles identical to ours would have affected cosmic expansion; compositional measurements rule that out. These considerations argue strongly against hidden people.
That said, the dark world might indeed be a complicated web of particles and forces. In one line of research, several investigators, including one of us (Feng) and Jason Kumar of the University of Hawaii at Manoa, have found that the same supersymmetric framework that leads to WIMPs allows for alternative scenarios that lack WIMPs but have multiple other types of particles. What is more, in many of these WIMP—less theories, these particles interact with one another through newly postulated dark forces. We found that such forces would alter the rate of particle creation and annihilation in the early universe, but again the numbers work out so that the right number of particles are left over to account for dark matter. These models predict that dark matter may be accompanied by a hidden weak force or, even more remarkably, a hidden version of electromagnetism, implying that dark matter may emit and reflect hidden light. This "light" is, of course, invisible to us, and so the dark matter remains dark to our eyes."
The potential impact of Dark Matter upon time provokes an unsettling thought: in the push to define and find Dark Matter, there's even less understanding of how it interacts with ordinary matter, with which it is so tightly interwoven. The video below shows a time lapse footage of the construction of a camera intended to photograph Dark Matter at Fermilab."Last year, the Hubble telescope photographed indirect evidence in the form of a ghostly halo around a distant galaxy, caused by clumps of dark matter bending light from stars as it passed by. A year before that, scientists led by the British astronomer Richard Massey, at the California Institute of Technology, published the first 3D map of dark matter, which revealed how it clung around galaxies and held clusters of them together.Dark matter is likely to be made up of a variety of invisible particles that not only explain the missing mass of the universe, but shed light on some of the most profound mysteries in science. Some dark matter particles could explain why ordinary matter is not radioactive, while others may help scientists understand why time – so far as we know – always runs forward.'The real impact of this is psychological, in that it shows we're getting close to being able to do a whole new kind of physics,' Gilmore said. 'We know there are properties of the universe that should correspond to new families of particles. One of the great mysteries is why time only goes in one direction, and one candidate to explain that is a dark matter particle.'Many scientists believe dark matter particles will turn out to be proof of a theory called supersymmetry, which predicts that every kind of particle in the universe is paired with a heavier twin. Finding evidence for supersymmetry is one of the major goals of the Large Hadron Collider at Cern, in Switzerland."
Construction of dark matter camera: Fermilab. Video Source: Brightcove.com.
The estimated proportions of Dark Energy, Dark Matter, and matter in the universe. Image Source: NASA via Wiki.
Caption for the above image (comment from Dr. Dave Goldberg): "Breaking it down by the fraction of the cosmic inventory, ordinary matter makes up about 5% of the total, Dark Matter makes up about 25%, and Dark Energy makes up about 70%. And don't even get me started about Dark Energy. It's the stuff that accelerates the universe, and if you think you've got a problem with Dark Matter, wait'll you see Dark Energy. It's no so much that we don't understand where Dark Energy could come from; it's just that the "natural" value (the one that comes out of reasonable assumptions based on vacuum energy) is about 10^100 times the density that we actually observe."
The mysteries of Dark Matter are compounded in that it is accompanied by a force called Dark Energy, which makes up an even larger portion of the universe and is described as a "mysterious substance ... which causes the universe to accelerate" and "the closest thing that we have to anti-gravity," although that's not what it is. The term was coined in 1998 by theoretical cosmologist Michael Turner. Scientists are trying to determine if there is a causal relationship between Dark Matter and Dark Energy.
Can scientists' ideas be partly viewed through the cultural lens of their times? Dark Matter was conceived in 1933 by Swiss astronomer Fritz Zwicky. He was examining the Coma Cluster, which is estimated to be about 90 per cent Dark Matter. While the phenomenon he observed is still accepted, how Zwicky understood the phenomenon may have reflected his cultural context.
The 1930s saw concepts which had been brewing since the turn of the century and through the First World War finally come to fruition, publication and public attention. Some twenty-five years of discoveries and new ideas circulated in the heady post-War atmosphere. By the late 1920s, "enthusiasm for science and technology was very strong." A British children's book, This World of Shadows, published c. 1928, conveys the mood and the contemporary willingness to believe in mysterious unseen forces, in this case, the history of X-rays (discovered in 1895) and the secrets of atomic power. The passage below and illustration at the top of this post are from that book:
The onset of the Great Depression in 1929 then had an impact on how those earlier scientific concepts were received and interpreted. In that cultural context, the notion that science could unlock and harness invisible forces was popular, but in some cases it began to take an ominous tone:"A THING is happening in the world which is almost beyond men's dreams. Slowly but surely the veil is lifting from the invisible foundations upon which this world rests, and the invisible world, with all its powers and hopes for the future of mankind, is revealing itself to the human mind. ... The process of their knowledge of electricity, and magnetism (the two great invisible forces that influence our lives in a thousand ways) is the most striking piece of exploration of this unseen world. Its value is plain. An invisible force, which our five senses cannot detect, carries a cry for help for hundreds of miles over lonely, stormy seas, and hundreds of passengers on some sinking ship are rescued.
The same invisible force is now used in another form for saving life in our hospitals. It is turned into an unseen ray which strikes through the flesh of our bodies and leaves photographs which enable doctors and surgeons to see what is going on inside us and discern what can be done to cure us if we are ill. The X-ray and the wireless telegraph are both forms of the same unseen energy, which science calls electro-magnetism. And this force is employed in other ways to help us and work for us. It runs our trams and many of our trains, it drives our machines, it makes chemicals for us, it helps to send our motor-cars along, it helps to propel our aeroplanes faster than the fastest bird can fly.
We are, in fact, living in the age of electricity - the most wonderful of the new forces of the invisible world. But modern men of science know other new things besides this unseen form of energy. They have found out that man is in some ways blind, and that he cannot even see many objects in the broad sunlight. For they have taken the sunlight and broken it up by passing it through a prism of glass, which spreads it out into a rainbow band of colour.
Our eyes can see only a little ribbon of colours with long bands of darkness stretching away at either end. Both these long, dark parts of the band are composed of real sunlight; one is a part that acts on a photographic plate, the other is the part that acts on an instrument for measuring heat. But our eves can see neither of these parts of ordinary sunshine, because our optic nerve works in a very limited way and does not use this part of light. We are surrounded by invisible forces - strange, glorious colours that we cannot see, delicate perfumes that we cannot smell, sounds that we cannot hear, and powerful things that our sense of touch cannot feel. Yet the things in this invisible world are of more practical importance, than the things we see.
The visible world is a land of myths and legends and phantoms. If it were the whole reality we could not live in it. The Earth would be a desert, emptied of all forms of life, or, rather, the Earth would not exist, it would be blown into bits of rock whirling in wild and scattered ruin around the Sun. Unseen forms of life work in the soil beneath our feet and make it fertile. If these invisible things did not exist, not a tree or a blade of grass would grow; there would be no food for animals or men.
The real world of power and infinite life around us is an invisible world. Before we become the lords of the Earth we must be awake and alive to the miracles that our eyes cannot perceive.
To see a World in a grain of sand,
And a Heaven in a wild flower;
Hold Infinity in the palm of your hand,
And Eternity in an hour,
was the dream of an English poet a hundred years ago - a poet who was looked upon as a madman. But the dreams of William Blake have now become the realities of the man of science. He does not want a grain of sand in which to see the world. He can divide that grain into more than a million parts, and in one of these parts he finds a universe as complicated as our solar system. ...At present our wisest men are only standing on the edge, as it were, of the new world of invisible forces. They grope, they guess they fumble, but they cannot tell us much about it. Some of the greatest discoveries are happy accidents - things men hit upon by mistake when seeking something else. A scientist in these days feels somewhat like a child in a fairy tale wandering through an enchanted forest. Somewhere in the depths of the forest is the great treasure of invisible power. If it is found it will abolish poverty from the world. But the seekers after this wonderful treasure never boast even to themselves that they will find it. They do not even go so far as to proclaim that some man, some day, before life perishes from our planet, will find the great secret power. All they do is to work on in hope, amazed at their own ignorance of invisible things, yet joyful at the unknown fields of adventure that stretch before them awaiting discovery. ...
A quick and easy way of breaking up an atom into the electrical energy of which it is composed would entirely change the fortunes of the human race. Man would then be, indeed, lord of the Earth. And that day will come. Slowly but surely the truth is dawning upon mankind that the invisible forces of the world are the great reality, and that the things our eyes can see are but the dim shadows of the wonderful unseen Universe."
- In 1929, Albert Einstein published his Unified Field Theory in the Journal of the Prussian Academy of Physics, "an attempt to explain the nature of gravity and all the known phenomena of the physical universe in terms of the laws of electromagnetism." This publication and related publications on the topic led to wild speculation about anti-gravity devices. This non-quantum effort to unify gravity with electro-magnetism edged Einstein closer to uniting gravity with the Standard Model. His results have been rejected by quantum physicists, who do not consider it to be a successful Theory of Everything. (See here, here, here and here.)
Image Source: Einstein's World.
Caption for the above image: "In 1928, [Einstein] embarked on a new approach to a unified field theory... involving what he called 'distant parallelism'... By early 1929 he had solved the main problems involved in writing down field equations for his unified field theory. On the day of official publication of the third of a formidably technical series of nine articles on the theory... excited headlines appeared in foreign newspapers throughout the world... In this frenzied, unscientific atmosphere, Einstein's new theory was hailed in the press as an outstanding scientific advance. Yet Einstein had stated in his article that this was still tentative; and soon he found he had to abandon it"
- In 1932, John Cockcroft and Ernest Walton split the atom's nucleus. (See here.)
- In 1932, Guglielmo Marconi discovered microwaves.
- From the 1920s to the 1940s, invisible force fields become a staple trope in science fiction, starting with E.E. 'Doc' Smith's 1928 story, The Skylark of Space, first published in the famous pulp magazine Amazing Stories. The Skylark series ran until 1963.
Jung, illustration from The Red Book (pg. 129). Image Source: NYT.
- Carl Jung wrote The Red Book from 1914 to 1930; publication was suppressed until 2009; the book develops the concept that the psyche has independent elements not produced by one's own mind, in other words, Jung argued for the objective or extra-subjective existence of the Unconscious. It's been described as "the Holy Grail of the Unconscious." A contemporary who saw the book thought it the product of a psychotic mind. See scans of it here and here.
- Artist Salvador Dalí worked from 1929-1932 on a piece entitled The Invisible Man (see an explanation and scan of the painting here); the work involves his belief that schizophrenics had an ability to see the latent existence in manifested reality. The artist remarked, "I believe that the moment is near when by a procedure of active paranoiac thought, it will be possible . . . to systematize confusion and contribute to the total discrediting of the world of reality."
- Universal Studios adapted H. G. Wells's 1897 novel of the same name, The Invisible Man, for the screen in 1933.
- Crypto-histories (mostly anachronistic projections back on the 1930s), are filled with assumptions that the Nazis rose to power in 1933 via their obsession with occult symbols that allowed them to tap invisible forces (or made them think that they had). Remove the magic from this view of the Nazis, and it's still plain that they spent this period spreading the fiction that the ills of society could be attributed to invisible Jewish conspiracies.
Millennial Dualism and Doomsday
Image Credit: Kamioka Observatory, ICRR (Institute for Cosmic Ray Research), The University of Tokyo via Wired.
Caption for the above photograph at the University of Tokyo: Physicists paddle around the Super Kamiokande detector in a rubber raft as it fills with water. The detector was designed to hunt neutrinos and decaying protons, but could catch the signatures of Particle X. ... Proton decay isn’t allowed by the standard model of particle physics, but some theories that go beyond the standard model allow it. An enormous underground tank of water in Japan, called SuperKamiokande, was designed to look for the decaying protons, but has so far found nothing. If physicists at SuperKamiokande went back through their data and looked at slightly different energies, they may be able to find traces of dark matter.
The current cultural mood involves a conviction, partly inspired by the meaning we draw from our calendars, that we are plunging into a turn-of-the-Millennium process of catastrophic transformation. This change must be two-sided, signifying a clash of opposites, or 'before' and 'after' states; the former is tangible and discernible, the latter is not. Invisible forces clashing with detectable realities appeals to the mood of Millennial dualism and doomsday in equal measure. These ideas can be interpreted as literal metaphors for the collision of what we know and what we don't know (but can only guess at). Many of these theories that are being investigated are postulated to fill in what we don't know and highlight the contrast with what we do. Supersymmetry? The God Particle? Dualistic cosmologies are alive and well.
Undoubtedly, these ideas will fuel the imaginations of 2012 conspiracy theorists. What if Planet X Nibiru is made of Dark Matter, and can't be detected as it hurtles toward us? What if it's already here? Given that Dark Matter has detectable gravitational effects, this is impossible. But as purely cultural phenomena, the physicists' queries and pseudoscientific fears are two sides of the same coin."This is an old question, which has come up again in a discussion that includes Russell Blackford, Jerry Coyne, John Pieret, and Massimo Pigliucci. (There is some actual discussion in between the name-calling.) Part of the impetus for the discussion is this new paper by Maarten Boudry, Stefaan Blancke, Johan Braeckman for Foundations of Science. ...
Something doesn't have to be directly observable to be part of science — it only has to have definite and testable implications for things that are observable. (Quarks are just the most obvious example.) Dark matter is unambiguously amenable to scientific investigation, and if some purportedly supernatural concept has similar implications for observations we do make, it would be subject to science just as well.
It's the final category, things that don't obey natural laws, where we really have to think carefully about how science works. Let's imagine that there really were some sort of miraculous component to existence, some influence that directly affected the world we observe without being subject to rigid laws of behavior. How would science deal with that?"