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Ripples in the Universe COSMOLOGY IS IN crisis. The 'big bang' theory of point of zero time and zero matter. to uhich an origin of the universe in a 'singularity: a version of the big bang theort: Science Forum Science exists within the ideologies and prejudices of class-based society 260 MIR the origin of the universe is currently the prevailing orthodoxy amongst cosmologists. But it is under challenge from many directions. A grouing minority: for example, question ubether the cosmic background radiation and the all-round recession/red shift of stars, the main physical evidence claimed in support of the current orthodoxy, does bear out the big bang interpretation. Many scientists, moreorer, have fundamental theoretical-philosophical objections to the big bang theory: They reject the extrapolation backuards in time of the expansionary model to gire ON APRIL 2÷. The Independent carried a big front-page story under the headline: How the U'niverse Began'. That Sunday: The Observer asked 'Has Man conquered the U'niverse? It field of quoted Steven Hawking.
nowned cosmologist. Claiming that this was the "discovery of the century, it not of all time." with What was this discovery? What truth. if any, lay behind the hype? What should our attitude be to scientific discoveries? For some good reasons, and some bad. scientists and the more abstract sciences are viewed sceptically: Education. and even knowledge itself. has been jealously guarded by a select few through the centuries. The elitism of science is. however. partly an illusion created by our lack of familiarity with the subject. For instance. in dealing with modern cosmological modbelief. the possibility of creation. els. a reader new to the subject can't expect to read this article in the same way as they might an article about things they are familiar with. Science. like any requires knowledge.
study, reflection. discussion. application, and more study: before you can become tamiliar its concepts. Hopefully. this article will serve as an introduction to this process. But if you are willing to put in the time, there is no reason why you be.
can't develop your understanding to a high degree - if that's what you want!
But in any societ! Which is divided into haves and havenots. from slave societies to modern-day capitalism. science cannot be examined without asking political questions. For instance. what sort of scientific research is funded? What sort of ideas manage to get any further currently knoun physical lau's cannot be applied and ubich leares open, expecially for those uho attempt to combine science with religions Clearly: the big bang theory: Which has itself been through a number of major reformulations in successive attempts to account for neull-discovered physical phenomena, largely' consists of theoretical modelling and scientific speculation. This debate, uhich will undoubted!! intensify in the next feu pears, is of great interest to Marvists. In this issue, Pete Mason argues the case for a than a few scribbled notes? Also. science lives within the ideologies. the presuppositions. the prejudices of class-based society. Scientists are often blind to the real forces at work. Einstein later bitterly regretted that his work had prepared the way for the development of the atomic bomb. Scientists dont always appreciate the exploitative nature of capitalism and what the end result of their research will Of course. this is not true for all. The class struggle will always be echoed in the laboratory rooms. Even well known cosmologist Steven Hawking. hard. ly a lowly scientist. gave an ex acting. very perceptive and powerful condemnation of the Tories. in one of the How I will vote newspaper articles prior to the last election.
And this also means that in a
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socict! riven by clashes between the opposing torces of right and might. and especially where revolutions are ever!where overthrowing old ruling elites and everything is up for question. just in such a climate the most revolutionar ideas are likely to burst forth. As the aspirof the downtrodden ations reach their highest hopes and some scemingly god-given eternal regime seems to be tottering. What was unthinkable becomes reality: and thought is inspired to examine things previously considered impossible. It is also true that the more capitalism can encourage creat ivity and treedom of thought. the more it will be able later to harness the ideas that emerge. The invention and derclopment of personal computers by young hippies and hackers in garages has been harnessed to home promote working.
super-exploitative bonus capitalism.
But fundamentally: when it comes down to the end result. the value. or at least the immediate value. of a scientific discovery depends on who has control over it — who funds it. who owns it Ven technology in the workplace is often resisted because it seems only to make things harder. hours longer. conditions worse. and at the same time, impoverish us more by work. Hardly an advancement! Today:
this is the result of science in the hands of the bosses.
WHAT IS THE big bang! And what is the present state of cos mology? One of the paradoxes unexplained since time. was why gravity was not causing the universe to collapse in on itself. Newton had sugg ested a force of repulsion which exactly balanced out the gravitational effect of the stars. was clearly an arbitrary addition to his theory, and anyway. didn't work. But Einstein did more or less the same thing. introducing a constant into his equations to stop them predicting the collapse of the universe. A static universe was an unquestioned assumption for centuries. Hubble proposed that it was expanding in 192t This expl ained a number of paradoxes for that were arising as scientists looked out into the universe. It was (and still is ) the best model to explain the observations, and from it a host of predictions could be tested It removed the need for the constant that Einstein had introduced into his equations.
Hubble discovered that every galaxy is receding from us. The further away the galax!. taster it is moving. It is as if we were at the very centre of this putting more people out of expansion. In reality: the situation is analogous in three dimen- Steven which is being inflated. Every other point seems to be moving away from it. and the further away the observed point. the faster it will be moving away. You can trace bach such an Newton's expansion and make certain predictions universe must have looked like before. Theories of a 'big bang' arose. to explain the beginnings of our universe and its expansion. Initially this theory was greeted with derision - in fact it was its opponents who coined the term big bang. It was later postulated that the radiation from such a big bang should still be around. although ver! ver! much colder. Theories predicted what such radiation would look like and where it could be found. At the same time. in 196+. Penzias and Wilson. who were trying to measure something else. reported having trouble from radiation of the sort described With the discovery of this background radiation'
bang theorctical model of the universe began to gain acceptance. and in time became the new orthodoxy. Now the many alternative theoretical models found themselves in the position the of being the challengers to the given orthodox!:
THIS TAKES IS to the latter part sions to a point on a balloon Hawking, left and above.
George Smoot of Berkele!
University:
announcing the COBE satellite findings.
about what the A static universe was an unquestioned assumption for centuries the big MIR 027
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280 MIR Autumn 1992 Cosmology'
roblems for le big bang
theoretical model were
making
scientists
uneasy
of this century. The discovery of the background radiation' which had seemed to give so much support to the big bang model. was now providing new sets of problems for this theory.
Nothing added up. Perhaps 99% of the universe is absent without leave - no one can find it. Scientists named this stuft 'dark matter' because they can't see it. although they can see it's effects, on galaxies, and clusters of galaxies, for example.
Increasingly, particle physicists, studying atoms and subatomic particles, were participating in the studies of the cosmos. They spawned a dozen difterent theoretical models incorporating the behaviour of the early matter in the proposed big bang. from which all present matter was formed.
And yet the 'standard model of particles of matter and the forces that act on them, is still a model in it's very early stages bits and pieces have yet to be seen, and other bits. called virtual particles, can't be seen, by definition! Composing electrons and protons are a range of strange creatures named in an almost flippant way. 'Quarks' ot different 'flavours'. called for instance charm', 'up', and down' and then there is the mysterious 'higgs boson' on which all mass depends. The names appear to suggest the scientists are saying well, this is what the theories and observations suggest. but.' These subatomic particles began to appear in the theories about the beginnings of the universe. But yet quantum mechanics. a very successtul model of the behaviour of subatomic particles, and Einstein's theory of relativity: which had revolutionis. ed our understanding of events on a very large scale. could not be combined. Quantum mechanies uses statistical methods. defining events by probability. But relativity is a classical theory. using methods going back to Newton's time. While in general application in their own fields they hekd good. if they were both brought in to the problems of cosmology: there arose circumstances in which they contradicted each other.
For instance general relativity
suggested that under the effect of gravity: all the matter in the universe would be reduced to a point infinitely small. a Singularity. and that all known phys ical laws would cease to apply. This 'singularity' seemed to be a paradox — a mathematical hoax - and presented a big problem. It is really treading on the toes of quantum mechanics anyway. which deals with things at an atomic level, and which rules out such a possibility:
And perhaps the most important single part of general relativity, gravity, is completely disregarded by quantum mechanics. This is because it is so weak when dealing with sub-atomic particles. as to be negligible. However, in models of the big bang and black holes. whose gravitational effect was so great that even light cannot escape. this is not the case. The search for a quantum mechanics theory of gravity is on, to give a different interpretation of what happens when general relativity equations no longer apply and tend to infinity: And for these reasons. it was becoming necessary to somehow combine quan tum mechanics and general rel ativi
OTHER PROBLEMS FOR the big bang theoretical models made the scientists uncast. Why has the universe got so much matter in it? The time scale was wrong - things could not have developed as far as they have in the time suggested. The universe was too uniform. For instance. the temperature is the same throughout the universe. so far as we can tell from things like the background radiation. How could there be the same observable features all round the universe. when big bang models predicted that radiation trom one part of the early universe would not be able to traverse it. so as to bring about the unitornit! we observe?
The background radiation was remarkably smooth. confounding all predictions How could such an explosion have given off such a smooth radiation? Experimentation since 1961 had been attempting to find regularities or ripples in the background
radiation without success. Furthermore. we know that the universe is highly structured. with great walls of galavies. Hor could matter have clumped tog ether so quickly, it by some strange event. the explosion was such a smooth one!
Even worse, calculations suggested a tremendous fluke. or series of remarkable coincidences at the beginning of the universe. that must have held for the universe to expand as it had without quickl! collapsing in on itself
Then finally the massively expanding knowledge of our universe was giving a larger and larger figure for the amount of matter which we simply can't find. The end result of all this was that the simple model of an expanding universe started oft by i big bang was beginning to spawn a dozen different versions. some with quite arbitrary assumptions yet to be contirmed. It was beginning to look like the period prior to Copernicus. when models trying to explain the movement of the planets became more and more complet and arbitrary.
Even the calculations on which the big bang are based were by no means certain. For instance. measurements of the expansion of the universe are extremely uncertain. giving figures for the age of the universe of anything between eight and twenty billion years. And then. after all. the background radiation might be a product ot some intermediate and or local incident which coincidentally produced radiation of the uniformity: temperature and freq vency of that observed.
AT THIS TIME a theory studying apparently chaotic events. called chaos theory: developed One such event studied Was d special effect which had been observed in general in nature. an example of which occurs when there is a disturbance of water. such as the splash caused by a stone. Under special circumstances. instead of a chaotic and quite short dispersion of the energy of the splash, one spec ially shaped ware is formed which is very stable. and travels
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for some distance: retamng 1s shape and overcoming the locat irregularities of the splash. thus smoothing out the original spl ash into the special characterist ics of this wave form The mathematics of such a wave shape had now been work ed out. The initial conditions of such a rapid and unitorm expan sion. it applied to the big bang lay within the range of possibil ities still being investigated by scientists. The suggestion that such an event may have happen ed in the big bang helped solve a number of the problems with which scientists were grappling It gave predictions for the disturbances or ripples in the back ground radiation without which galaxies could not have formed. and these lay within the range still not ruled out by experi ment.
The remarkable smoothness of the universe. its remarkable balancing act between the point of collapse and the point of chaotic dissipation, its rapid development. could be answered if there was experimental confirmation of the predictions it gave. It was suggested that our universe was the result of i period of very rapid expansion or inflation' which had the sort of properties of the wave caused by the splash.
The tirst tenuous results of the NASA satellite. Cosmic Back ground Radiation Explorer (COBE). first launched in 1980 after years of delay: supports the big bang theory be detecting ripples. These are the sensation. al observations which the news. papers reported carlier this year. They had been collated throughout last year and the results ver ificd over the first threc months of this rear. Jasper Wall. of the Royal Greenwich Observatory is quoted in the let scientist as saying: "I COBE hadnt found the fluctuations. we would have had to rethink a lot of our basic theories - including general rel- Since Einstein's thcor of gen eral relativity is now incorporated into calculations in satellite navigation systems and used routinely as a basis for our gen eral understanding of large-scale events this would have present ed i ten headaches'
But more than this. the results provide support for the inflation model a theory which uses quantum mechanics to predict the behaviour of subatomic particles in this period of inflation. thus combining general relativiwith quantum mechanics. Quantum mechanics predicts certain minute fluctuations from which form the necessary ripples. around which the galaxies form.
It has been suggested that in the original chaos of the big bang. there would be regions in this chaos. which due to these minute fluctuations in the fog of primordial matter, would contain particles which reach a value which repelled each other like gravity in reverse. This would cause this region of space to expand at an ever increasing rate. until it eventually cooled enough for the effect to wear off. and what we now sce as our universe resulted still expanding at the near critical rate. In this process an enormous amount of matter is produced, but this particular model does not need any special circumstances to have taken place in the big bang, for our universe to have ended up as it is.
OF COURSE. UNLIKE the newspapers. the scientists (in general) are very cautious — "the cata therefore supports the inflation model. though it does not prove it." according to British cosmologist Martin Rees (Ven Scien- (ist). The experiments can now be followed up by instruments on the ground. and a further satellite is planned which is 100 times as sensitive to the radiation frequencies being detected I ntil this work is done. the results of the COBE satellite remain open to question. Nevertheless. it is not difficult to understand the excitement of the scientists in linding that they now have a model which gives i coherent explanation of events since the big bang, and which also works towards the combining of quantum mechanics and general relativity - and for which they now have some. at least tenuous. experimental from support evidence!
Finally: the theory gives a fig ure for the amount of dark matter. so-called simply because we can't see it. that should abound in the universe. It is perhaps not surprising that scientists have yet to detect everything that exists in the universe. When it was first noted in the 1930s that the gravitational etfect observed was far greater than the estimated amount of mass around on a galactic and intergalactic scale. no-one was desperately con cerned - new things were being found all the time, and black holes, for instance, were yet to be postulated, let alone found. Dead stars. black holes. 'cosmic string: there were plenty of possibilities. Recently: calculations have suggested that there may be millions of black holes in every galaxy. Other recent calculations have suggested that specific conditions may allow hydrogen mixed with some heavier elements to solidify, forming enormous invisible ice clouds round galaxies Further investigation into the details of the fluctuations in the background radiation may help to fathom this mystery: A popular theory supported by the evidence so far is that the dark matter is composed of weakly inter. acting massive particles - or WIMPs for short. These are subatomic particles. although relatively big (for a sub-atomic particle that is - don't expect to see one doing a ton down the MI). but the! rarel! interact with other particles.
It could be suggested that since this dark matter is said to comprise some ninet! per cent of the mass of the universe. that this is a prime site for further unexpected discoveries which will throw a different light on all the theories and models that we presently have. perhaps throwing into question some of our fondest held theoretical models. like the big bang and relativity. in the same way as relativity did previously to Newtonian physics. Vevertheless, experiments are beginning. primarily in a salt mine in Britain. to see whether such theoretical particles will actually interact in the specific ways proposed by scientists with existing matter.
MIR D29 Autumn 1992 Cosmology The first tenuous results of COBE support the big bang theory
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