Thursday 21 May 2009

Dimensionisation

All hinges on the definition of dimensions in the model and the real world. The ant walking around the orange may know about its local up and down, without realising that the straight line it is walking is not really straight but is curving gently forever downwards. It is too busy not veering to left or right to wonder about the meaning of its horizon. But the local 'down' and the horizon 'down' are the same dimension, the 3rd after#1) left-right and #2) front-back.

So as with our toroid, its invention by taking the cylinder of the rotating rubber belt, and joining the ends of its axis, is just the macro version of a dimension in which a piece of the cylinder exists in.

This is a trick, because the premise of discovering the 3rd dimension was that the ant lives in a 2D world, we have a "number of dimensions" ambiguity.

Having scotched pseudoscience, alchemy (sorry Sir Isaac), astrology and general expedient guessing, I still have to mention barmy ideas because they are the origins of out-of-the-box thinking. They include:

- Our development of logic has to put things in neat boxes, eg each dimension is distinct, whereas in reality the edges between one dimension and the next may be blurred. After all, matter and energy are connected by the shady wave-particle duality. And the computers of our brains are soft and sludgy, not a set of straight lines and switch nodes as our computers still are.

- Space as a medium, or "ether" was disproved by Newton and many after him, yet energy travels through 'something', and masses interact at a distance through nothing but space. The basis of my wondering about the shape of the universe is the dual impossibility of existence, and non-existence, and my barmy thought of the month (May 2009 AD) is that space is the realisation of the tension (I will think of a better word) between these two impossible conditions. (I keep recalling thhgttu "Improbability Drive" but I consider that to be more humour than sense, and my 'reconciliation of impossibilities' concept is independent and unconnected to good old Douglas Adams, bless him.)

- The rotation of space creating its distortion by the masses it is constantly accelerating, relates directly to the dimension of time. What a huge conundrum though, to our linear minds, to grasp the start and end of time as the same thing.

Yes these are pseudoscience (if that!), but alchemy led Newton towards real science so we shouldn't be knocking things out of court too soon.

I came to the toroid shape without knowing how cosmologists got to theirs. If the amateur model works in this case, maybe it can work in others. I need to find what cosmologists think space is - in terms that I might understand. But time - I don't expect anyone to have worked that out. It will have to wait till June . . .

Tuesday 12 May 2009

Jump to a familiar shape

The rubber belt or cylinder is a useful model to show how masses can appear to attract one another even though they don't. With the cylinder at rest and the masses scattered randomly around the inner surface, nothing attracts anything. But if the whole lot is spinning around the axis of the cylinder, then the masses, which as Newton found want to keep moving in a straight line, are being constantly forced by the elastic surface to follow its circular path, and because it is elastic, the surface is distorted, ie each mass makes its own bump in the sheet. Masses nearby each other have their own local bump, but there is also a combined effect where the place between their bumps is lower than the area outside them, and so they are pushed towards each other by the "outside" gradient being larger than the "inside" gradient. This can easily be understood whether the masses are similar or very different.

Newton found that the force of "attraction" followed the inverse square law, and it will be interesting to calculate how the bump gradients of the distorted elastic medium match up to the inverse square law.

The cylinder needs developing because (a) I think the total angular momentum should equal zero (b) the cylinder has an axis, presently a straight line (c) don't forget the 2D surface is our model of 3D space. We have to park (c) while we work on the others.

By joining the ends of the axis together it becomes finite but unbounded (necessary to avoid the impossibility of real infinity) though in so doing we have invented a new dimension (it is not the same dimension as the one we add to the 2D surface to restore 3D space). But joining the axis gives another possible benefit - is it possible that the resulting toroid, its surface rotating in the direction through its hole, has zero net angular momentum? Actually I doubt it, I need to get into toroids. Fascinating that the area of a torus (surface area of the toroid) is the same as the area of cylinder of same r and length equal to the large circumference.

Although I knew that cosmologists say the universe could be toroidal, I didn't know why, so this little discussion, with its convenient jumps, gives some ideas of how this shape can be arrived at.

Using some obviology we can put a boundary to one problem of the torus. The major axis of the torus (the line through the hole) is not relevant. This is because, if it was, we would have to join its ends (to avoid real infinity) but in a new dimension, creating a new torus, with its own major axis - we are back to "turtles all the way down". For my simple mind, one torus is all it takes. We don't have to worry about "what's outside the torus" - that is taken care of by the fact that the torus is only a 2D model, it represents 3D space.

So if we come back to the world we can see, progressing through time with the three familiar dimensions forward-back, left-right and head-feet, we can say that real space is finite but unbounded ie looking in any direction with our ultra-powerful telescope and waiting long enough we will see the back of our own head. The space we are looking through is not emptiness but has elastic properties like a rubber sheet, which is bent by resisting masses and is rotating in a way which puts a constant force on all masses yet conserves angular momentum.

I'd like to suggest that the missing "dark energy" is related to the net angular momentum of the universe system, and the associated work being done to accelerate all masses, of which the work done in gravitational attraction between masses is just a tiny fraction. Well, suggesting is easy . .

Thursday 30 April 2009

The Work of Gravity

I have no intuition about the ultra-small – apart from a yet-unanswered question about how transparent objects slow light in a profound and perfect interaction (refraction), I will leave alone quanta and nuclear physics. My interest is gravity, and in developing a model understandable to our 3-dimensional conciousness.

To rehash a previous post, the balls of lead shot on the surface of a rubber balloon do well up to a point. Looking for a model that demonstrates the characteristics of gravity, using a trick of removing one of the four dimensions of space-time to enable us to envisage it (as a 2-D photograph or painting represents a 3-D scene). A rubber balloon is elastic. Although the balloon exists in three dimensions, it is the macro dimension inclding the whole balloon which represents the real-world 4th dimension, and of the local space dimensions, only north-south and east-west are present, up-down is missing hence the locally "flat" membrane.

In our gravity-free laboratory, lead balls rest at the outside surface. As the balloon is inflated, the balls resist, and cause indentations. Adjacent balls find themselves sharing an indentation, and roll down the slope towards each other. The model is a simplification through removal of the radial dimension (the direction of inflation), so we have to imagine that although elastic and having no thickness, the membrane is perfectly strong ie cannot be punctured. (Its “puncturability” is where the models for black holes will come in.) The main conundrum with this model is that work is needed to inflate the balloon, which gets thinner. Before assuming this, I am searching for a shape and motion of membrane which can cause the lead shot to move and therefore resist against and distort the membrane, without requiring the membrane itself to absorb energy or become increasingly stretched. In particular, the model needs the elastic medium to exert a continuous and constant force on the masses without doing work on them.

The answer is a continuous belt-shaped rubber membrane. If it is spinning like the tyre of a bicycle wheel, with the lead balls on the inside, the rotation and their inertia will force them to resist and cause them to indent the membrane, with pairs in the same “well” apparently attracting each other. The attractive force originates not with the pair of balls which are completely passive, but the fact that both are being pulled away from the straight line by the rotating rubber membrane, as they are forced into orbit around the centre of the ring’s rotation.

This is an elegant model because the size of the ring can remain constant, or it may expand or contract according to other influences. (Astronomers report that the universe is expanding, though it could reverse in the future.) And the driving force of the active or shining universe is in angular momentum. Once a bicycle wheel is turning, every part of the tyre experiences centripetal force away from the centre, determined by its mass and the speed of rotation, yet with no air and frictionless bearing will do so indefinitely and with no further input of energy.

Interesting though that rotation is around an axis (a line); the orbit exists in a plane which is two-dimensional. The dimension we have stripped off to simplify the model is the radial one (the dimension containing the spokes of the ‘wheel), not the dimension above and below the plane. Is the universe flat? I find it difficult to imagine the reinsertion of all dimensions to show how the model represents the real universe, especially when dimensions invent themselves. I think the rubber belt model is extremely elegant but it throws up a bunch of new conundrums. Of course we need two of them counter-rotating in the same plane to sum to zero angular momentum. Or could the belt be a Mobius shape? Wow! A two-sided belt with only one surface – relevance not clear, just a thought.

Friday 24 April 2009

Help from the Masters

So far these have been the random jottings of a complete amateur, deliberately untainted by any significant research. The initial contributions were thoughts I have collected over some decades of idleness; and more recently the development of ideas recently occurred as a result of writing this blog. Of most note, and of significance even after a month or two of cogitation, are 1) that the force of gravity experienced between masses is tiny compared to the force with which all masses are being dragged along by (or decelerated by?) dynamic and elastic space; and 2) the mystery of refraction - the fundamental speed of light is reduced by 20% or so when travelling through transparent material. I have not yet found adequate explanations of either pheonomenon on the web.

The ancients had little opportunity for experimentation and 'thought-out' the meaning of what they were seeing. But it was the work of Galileo, Newton and many others who used experimentation and mathemantics to demonstrate and prove, and thereby develop, their findings, and move from philosophy and occult into science.

My ideas are that there are elements of pure thinking that still have merit. There is something about our awareness and analytic capability that is missing - we can have vivid dreams but have barely no recollection of the details just seconds after awakening from them. We all took gravity for granted until just a few hundred years ago, just as we still take for granted the properties of our molecules - and of the fact of the existence of the Universe, which is impossible to exist and impossible not to exist (for what is non-existence?). In my naivity I am happy to call this the The Ultimate Paradox.

It is as if science claims a monopoly of truth, but if there areas it cannot deal with, like asking fundamental questions, it forces us to ignore them - true ignorance. My experience on a recent holiday, chatting about the origin of the universe with an ordinary guy met at random, suggest that lots of people secretly think and even worry about this, but realise it is too big a subject to deal with. We need a channel to ask and expound the problems without the constraints of formal science, but also without recourse to astrology, sacred science, demons or total anarchy.

An example of a free process is my "proof" that the universe is finite but unbounded - the intuitive statistical impossibility of another world exactly like ours. It is confused, but not dis"proved" by the other reason for the impossibility - quantum mechanics, which says that there cannot even be two billiard balls identical to each other.

I want to use this "obviology" to tackle fundamental questions too hard for science. How can a world exist with laws and physical constants so exact not have been designed, yet if it was, who designed and built the designer? How arrogant for atheists to say it happened by accident from nothing, and for theologists to say it is God's creation, and he was always here. It's turtles all the way down!

Traditional paradoxes pale in comparison, yet serve to illustrate. The 17th century battles between Newton and Hooke about whether light was a wave or a particle - and turned out to be both. In fact, it depends on how you look at it. We realise that the ultra small (and the ultra large) are outside our intuitive experience or understanding, and accept the experiments and wave equations (ie of wave-particle duality) to build the model we cannot really see.

So a brief review - we should ask the difficult questions and think about them, and structure a free-form scaffolding for the solution model around possibilities like: - creation joins the three elements of 1) the physical universe, 2) God, and 3) our awareness of those two; - just as our earth's surface is finite but unbounded, so is the volume of the universe; - our understanding of time is key, and we need to manage somehow that the beginning and end of time are (like the East and West edges of the Earth and the "Up" and "Down" edges of the universe), the same thing.

The main point of this post is to say that I need to do some research, and am reading first the biography of Sir Isaac Newton - thinker, recluse, philosopher, mathematician, alchemist, physicist, theologeon, practical scientist - in my view the father of science. He questioned everything, took nothing for granted, shied away from no problem, he worked out for himself what he was seeing from first principles and with his own practical and mathematical tools. But it is as if by opening the door to analytical proof, he helped close the door to free uncluttered thinking. Even in my naivity I know this is trivial, so just for fun I'll call this the Paradox of Newton. The serious point is that Newton thought outside his box; his successors like Stephen Hawking also have to show us outside theirs.

Tuesday 3 March 2009

Omniology is not for the faint-hearted

Douglas Adams has made this subject a cliche in thhgttu. The answer to the question of Life, the Universe and Everything is 42. Well I don't think 42 is a special number, (though it does divide by seven, six times to be precise), but he realised it had to be simple. Why? If we stick to our linear (flat earth) model of time the starting point had to be vanishingly simple. We are trying to get away from linear time, but the answer still has to be glaringly obvious once we have worked out the true shape of time.

Just as the flat earth (the one "we could see") involved some impossible structures (giant elephants and turtles), the way lies beget more lies, until we realised that the earth was in fact spherical like an orange. Or the knots the early philosopher-astronomers tied themselves in with the geocentric solar system, solved in a trice by placing the sun at its centre.

Could the laws of physics, and the perfectly-tuned physical constants (eg Boltzmann, Planck, mass of electron, permittivity and permeability of free space etc) have evolved, ie every set of laws and constants that didn't "work" disappeared, and left us with this perfect one? (I realise that a whole range of these ideas have been rehearsed by clever and learned people, but this is just a layman trying to get his head around it.)

We need a few ground rules otherwise a wide-ranging discussion like this can get out of control. They are my rules, others may disagree, but if their rules involve the term "energy" in a form that can't be measured in ergs, joules or kWH, they are no use to me.

So I am not saying black is white, or everything is nothing, or God is the creator of everything by definition, therefore God is the answer. I make it a premise that we are real, hence our origin is real, hence it must be explicable. (As a reminder, it is the God-given gift of free will that I am exercising here . .) So I rule out astrology, an example of illogical claims that particular heavenly bodies exerting a negligible effect can influence our behaviour or fortune. The moon is different, it is big and close and is exerting a significant effect on the development of life on earth. As of course is the sun, a primary factory and our primary power station. Maybe we are influenced by what time of year we were born or conceived, in the annual cycle of climate, or the education system, but not Mars in Uranus.

I don't rule out spirituality. In my early 2os I had a near out-of-body experience. I knew what it was, having read the subject some years previously, but the event was so spontaneous that it could not have been suggested, and it was real. I have no proof, but am prepared to accept there is another world not bounded by our physical constraints. And it can be detected (apparently) by temperature changes or images on photo paper. The existence of the spiritual world is an intriguing connection between the everyday physical, life and humanity, and God.

But another bogey is UFOs. Serious scifi writers like Clarke and Azimov have argued the statistical likelihood of life elsewhere, along with the great likelihood that we are ordinary, ie not the most advanced but somewhere on the scale of advancement. However, I don't accept that some are so advanced that they have cracked the speed of light barrier, are constantly watching, occasionally visiting and sometimes crashing into us. Of course we love mysteries and conspiracies, but the idea that all these extra-terrestrials are toying with us in a game of "now you see me, now you don't", or "wait till they develop an organic supercomputer, then we'll pop in and introduce ourselves" is to me ridiculous. Wouldn't at least one of these visitors have broken ranks and let us know for sure we are not alone. There is probably life elsewhere but time and space are real communications and transport barriers, and we will probably have to sort things out for ourselves.

In short, I think the basic shape of the universe is simple, and complex models involving faster than light, or space-time shunts, or string theory for that matter, are equivalent to our philosopher ancestors digging in their minds through our plate-shaped earth and gazing down on huge elephants standing on the back of that poor giant turtle.

Omniology is going to need some more closely defined rules and methods, based on the science of statistics, a subject I know little about but (you've guessed it), have plenty to say about. If I can get my snaggled ideas together.

Saturday 21 February 2009

Yes, but why bother

I need to clarify, if only for myself, why I am writing this. Obviously an interested but lightly-informed amateur is not going to find the secret of life, the universe and everything by thinking or blogging about it. Even if physics appears to be mired in fog and complexity, thousand of physicists and billions of dollars says to me 'why bother?'.

Blogging may be the key, not to finding direct answers, but to increasing awareness, first that awareness itself is something special, secondly that impossible questions like the infinite universe or the nature of gravity can be answered and understood by many in terms of familiar models. Thirdly our use of the world's resources is at an unsustainable level, our progress is unstable, and there has to be a mass realisation of our privileged position as intelligent life, and our greater responsibility. As civilisation has developed our wars have moved from nearby tribes, to city states and fiefdoms, to countries and continents, to our present clash between cultures. I think it's a common belief that if we encountered an external threat like an alien invader, the world would unite against it. Well, we may not meet the Clingons or Zargons around here, but we are facing a threat as great as any science fiction writer imagined from LGM, and equally need to unite.

Prof Brian Cox's programme recently showed that an equitable energy target of 5kW per person is impractical by known fossil and renewable sources, it requires viable fusion power. But more was spent on cellphone ring tones last year than on fusion power research, we have some priorities to sort out.

It is impossible for most people to reach professional standard in disciplines they are not apt in and trained for and experienced in, yet we enjoy directly the results of their teaching, writing, acting, cooking, art and music, engineering, doctoring and building. Of course big science also benefits us in pharmaceticals and technology, but physics research and physical fundamentals remain largely inaccessible. String theory, huge accelerators, big telescopes etc appear to us on Horizon TV programmes, yet I think most people would know Hubble for its beautiful images rather than its contribution to our physics knowledge.

I think there is a need for the Big Questions to be simplified, and made accessible and natural by techniques such as familiar models.

Thursday 19 February 2009

Two things - no, three things

There are two kinds of people - those who divide people into two kinds, and those who don't. Trivialities aside, there are several fundamentals that look quite different from opposite approaches. Our perception of reality depends on how it is perceived.

Sub-atomic particles can be observed and counted individually, most have an exact mass, and yet if you send them through two adjacent slits they behave as only waves can. Particle or wave - let's have a fight! The development of our species on earth is known to scientists to have evolved over billions of years, but to followers of certain faiths over a period of 5 days at some point over just 5,000 years ago. In the first case scientists observe and measure the phenomena and reconcile different behaviour in a complex set of equations, so that a particle and a packet of energy are expressions of the same thing. In the second, a scientist believes the geological fossil evidence and reconciles the scriptures by using a loose interpretation, and their purpose of teaching an early awareness of creation. I have heard it expressed as "the science says what, and the scriptures say why. Why is not just a matter of cause and effect, but a search for a reason that we are here and asking questions.

Well, two is a special number (it is the only even non-zero prime) but three is quite special as well. I am actually looking to connect three things - the facts of the physical universe, the spiritual world which includes God and his reason for our existence; and our perception and awareness of them. Why should our speck of flawed humanity figure alongside the magnificence of the first two? Certainly the physical universe was here long before us (in our linear view), and I am not suggesting God only exists because we invented him. It is because we (intelligent life) are the instruments of awareness and knowledge of both, and in this way we connect these warm star-baked molecules with the God who made them. And we connect them in such a way that the people who care cannot agree whether the universe came about by some freak accident and has no purpose, or it was designed by a God with a master plan in which we are an early prototype life form. Both answers are fairly improbable if you try to think about it. Yet here we are. Why? Don't ask! But the glib answer is hinted above.

Saturday 14 February 2009

Qualifications, and method

What I have put up so far is the result of some decades kicking around ideas and firming them up, and there are some more of those to come, but from now on I'll mainly be dotting around new territory.

What am I doing writing about this (arguably) biggest subject of all? Apart from a long-term and prevailing interest, I did a short Philosophy of Science course in my engineering degree in the 70s, I attended church regularly as a youth and for some brief periods since, I have read much science fiction (again mainly in the late 70s) of the practical kind of Arthur C Clarke and Isaac Azimov. In a 1st year University science course I did modules on relativity, and thermodynamics. I have to admit that both were beyond me academically, but some principles stuck, in particular the stunning simplicity of the energy-mass relationship e=m c^2, and the fact that the entropy (degree of chaos) of the universe is increasing. The existence of the Internet, for example, appears to belie that, but who can argue against the principles of thermodynamics? (I abbreviated it to TDS (=T(temperature)deltaS(entropy)) = tedious or TDM = tedium = Te Deum. Obscure coincidental connections, or what?) But I'd be the first to admit that I am not academically qualified to find answers in Cosmology. I just got tired of waiting for the professionals to get results from their very large particle accelerators. Hubble mus be the best telescope we have, there will be huge amounts of scientific data obtained, but the best value I have seen is in images showing the beauty of the distant universe.

Regarding method, I am using this blog to attract interest and discussion from people who are prepared to keep content at a level that ordinary but informed people can follow. The Internet gives this capability of the first time, to reach a very large number of people (and hence a fair number of active contributors) with a reasonable quality of discussion. We may not be well-informed about the scientific evidence, but have a deep pool of intuition and imagination.

For clues about where I'm going with this, I'll close now with the observations (a) that human perception is key to this part of the universe's understanding of itself - it is not the facts that matter, but what they mean to us. And (b) that religion plays a major part of our understanding. People can reconcile Science and Religion, but only by agreeing to disagree, I would suggest.

Wednesday 11 February 2009

Why blog?

In case anyone is wondering why I am writing this, let me try and explain, it might help me too . . I find myself wondering about what came before the Big Bang, and the whole impossibility (from our 3-dimensional viewpoint) of everything appearing from nothing. Especially when you think about what nothing really is. Because empty space is not nothing.

Early man lived outdoors, many early cultures tracked the movements of the stars and planets, the evidence of the correct shape of the solar system (and the correct shape of the earth) was there to see. Yet they did not become common knowledge till just a few hundred years ago. Understanding the basics should not need fine scientific measurements; the main tools are an open interpretation of the evidence, an agile imagination, and some simple models.

One of Arthur C Clarke's stories is of the world's telephone network being developed to the point where is has a comparable number of links and nodes as a brain, and gains intelligence which it then engages to control all the telecommunications and power infrastructure. Even with the internet and the computers it interconnects this hasn't happened yet, but maybe the people connected to those computers on that network will put their heads together and distil out a simple route to solving an impossible conundrum. It's about time this new supertool, the internet, was exploited for something grand, other than SETI.

Well, we need an objective, and the first one is to think of a simple model for the shape of the universe, which has to include its fourth dimension, time. Does it matter? Not really, it's just an interesting challenge.

Tuesday 10 February 2009

Some big ideas

We are talking about the shape of the universe, so let's waste no time in bringing God into the discussion. I hesitate however, because God is a matter of faith and nothing I say should deepen or lessen anyone's faith. For those for whom God is fact, and not just a belief, let me say that he gave us free will, and this includes the ability of each of us to believe, or not to believe. If knowing him was somehow compulsory, then we would not be human. So one person may know God, and another may not, and neither can say the other is wrong.

The method I use to show the shape of the earth to a flat-earther, or the shape of the universe to an "infinite universer", can also be used to illustrate how God is there for those who want to find him. But I don't want to trivialise something so meaningful to many people, and will leave this for the moment as an exercise for the student . . . Meanwhile God may or may not guide me as I exercise my free will to write these random jottings.

Going back again to my teens, a very good friend told me something very profound. I don't know if it was original or whether he got it from Mr Tomkins in Wonderland (ISBN 0-521-44771-2) but it goes as follows "Through us, humankind, the universe is aware of itself". It is our awareness, as compared to being alive or being conscious, that sets us apart from all other life on earth, and is the foundation of our curiosity, the development of our skills and talents, and our independent thought.

Another "so what" moment. Well, I've sidestepped religion, I've avoided emotions, I am a layman and am not going to get into complex dimensions or string theory etc. However complex the laws of physics, I think the basics have to be quite simple, and I reckon that awareness is a good starting point to move off from, as it is the connection or interface between the universe and our (and therefore its) understanding of it.

Monday 9 February 2009

Too soon to state objectives, lets just set down a few relevant discussions/arguments. Always start with the obvious (though it was not always so . . )

Why did it take us until the middle ages to begin to realise that the earth was spherical? Everyone believed the earth to be flat, and then wrestled with the problems that creates, of what happens at the edges - won't the sea run off? And what is beneath this plate-shaped earth. And why is the horizon apparently a fixed distance, dependent on only the height ASL of the observer? Just looking at a peeled orange has all the clues of a sphere with poles, and lines of longitude. Was the moon also a flat disc, which just happened to present its surface normal to the earth?

People were trapped in their local view of the world, and so oranges could be spherical but planets must be flat. And then the great navigators proved the earth's true shape by sailing around it in one direction and ending up where they started. The earth's surface has finite area, and it has no boundaries. Like an orange, you (or an ant) can travel around it without ever stopping, but its area is only 4PiR^2/3. For someone with a two-dimensional view, where there is only forward/reverse and left/right, the gentle downwards curvature of the globe does not exist and to return to where you started without falling off the edge is a total mystery. Slot in the third dimension, the same one that up and down exist in, and all fits into place.

How many people think the universe is infinite? In any case it is unimaginably large, so why not? Cosmologists (using the term broadly) know it is not, in fact its total mass has been estimated, I have seen a figure of 10^40kg give or take some orders of magnitude. They see evidence of the Big Bang and can measure the age and the speed of expansion.

I worked out as a teenager that the universe must be finite. The method was simply that if it were infinite, there must be another earth exactly like ours, but for that to happen there must be a near-infinite number just like it except for one molecule etc etc, even thinking about an infinte universe is scary. Fortunately we have a model from our two-dimensional world - as the surface of a sphere is finite but unbounded, so the volume and mass of the universe is finite but unbounded. In this case whichever direction you set off in (forward/back, left/right or up/down), and think you are travelling in a straight line, you will end up where you started.

So where is the hidden dimension, the forgotten up/down of the flat earther? Let's say that is time (I haven't a better idea), something we are familiar with in our local view, but find it hard to imagine on a cosmic scale. And something which links cosmic distances and the speed of light.

I once failed an interviewing course, and one reason was a dumb question I gave a bright test interviewee - what would you reply to a precocious nephew who asked you why we are attracted to the ground. (I did not ask him to explain gravity, just how he would reply to a cute question.) I think his answer was to ask his dad - or someone who understood big things. But he copped out. What do you say - shut up and eat your porridge? But if we can't be expected to understand the size of the universe, why should we question why gravity exists. There are far more pressing mysteries, like whether UFOs are real.

But there is a model for gravity that lay people should be able to understand, that involves slipping off the tricky dimension and going back to just three. Take a rubber toy balloon, stick some pieces of lead shot around its surface, what happens? (Don't forget, gravity doesn't exist yet, we can do without the sticky stuff). Nothing happens. But start to blow up the balloon, and the pieces of lead shot will resist the movement, and make indents in the surface of the balloon. And if two of the pieces of lead shot are close together, their indentations will tend to be lower in the region between them, and they will roll (or gravitate?) towards one another. We have a model of masses being attracted to each other when being accelerated in an elastic medium.

Put back the magic dimension, the one that takes us from a 2-D surface to a 3-D volume, and we have the elastic medium of space with masses in it. If the space is static the masses don't bend it and there is no gravity. But if the elastic space is expanding, the masses resist by making indents in the space. Two masses nearby each other 'share' an indent, and roll down its 'sides' towards each other - hence gravity. Astronomers make measurements of stars by observing how light from distant stars is bent around planets as they 'line up' to our view. Space is elastic, and it bends as it pushes masses along in its expansion.

So what? If you didn't know before, then you've learned something fundamental. And if you did, well let's move to the next step. Yes, all of us.

Sunday 8 February 2009

I've seen a few good blogs, generally about the individual. That's fine if you think you are interesting (whether you are or not), and the best blog I have seen is of an individual now deceased, whose issue is his experience in the war to end all wars.

I am more interested to blog an issue, rather than myself. What I have in mind is nothing trivial, in fact it is far too complex for the layman, but something that needs understanding at a popular level to be useful to us.

A subject full of paradox and mystery, contradiction, and controversy no doubt. A subject which is impossibly complex, yet common sense says has to be fundamentally simple. Can you see what it is yet?
Starting out with this blog, something to say, decided to say it in real time rather than advance prep.