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Questions for the 21st Century
- Vincent Icke
- Translated by Charlotte Lemmens
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- Book:
- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 94-102
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Summary
Where are we now, having covered four-and-a-quarter centuries of physics? At every point, what was the key observation or experiment? What was the problem associated with that? How did it get solved?
In 1585, Stevin performed his leaden ball experiment in Delft. The associated problems were the pronouncements inherited from Aristotle on falling objects. Stevin, a hero in the vanguard of ‘experimental philosophy’, was not impressed (or, in any case, not deterred) by this ancient stuff.
The solution of the problems surrounding falling objects was reached tactically by ‘separation of difficulties’. On one front, Galileo performed his lengthy studies of ‘natural’ motion by means of clever observations and experiments on objects falling freely or rolling along inclined planes. That approach was concluded by Huygens's radical statement on the relativity of motion. From this he derived the rules for collisions and the first mathematical equations in theoretical physics: the centrifugal acceleration, the oscillation period of the pendulum, fall along curved paths such as the famous cycloid, and more.
The other front focused on the origin and description of the acceleration in free fall. Newton rehabilitated the shaky concept of ‘force’ by casting it in the strict mathematical form of ‘universal gravity’ and devised a brilliant formalism for calculating the results of accelerations (a technique we now call differential and integral calculus, invented independently by Leibniz).
The success of this approach was phenomenal, but it left all questions about the origin of forces and the structure of matter unanswered. Matter cannot be stable if it is subject to gravity only, so other ingredients were needed. Chemistry provided some clues through the discovery of chemical elements and the fact that these combine in whole-number ratio. H2O is a chemical compound, where H1.8O would be just a mixture. Research into electromagnetism also offered some hope of understanding the inner forces of matter.
Maxwell's discovery that electromagnetic waves all propagate with the speed of light led to the 1887 Michelson-Morley experiment. This landmark observation showed that the speed of light does not depend on the motion of the emitter or the receiver of the light: the speed of light is invariant.
Thanks
- Vincent Icke
- Translated by Charlotte Lemmens
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- Book:
- Gravity Does Not Exist
- Published by:
- Amsterdam University Press
- Published online:
- 12 December 2020
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- 26 June 2014, pp 110-110
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Summary
Contrary to what the cynics may say, many non-scientists are captivated by the same Big Questions that keep physicists and astronomers so busy. This book is an attempt to share my fascination with them. I am grateful to the people at Amsterdam University Press for encouraging me to do so. Even though this book is primarily meant for the general public, I wish to hold it to the professional standards of a scholarly work. I am most grateful to six scientists for the time and effort they spent in assessing an earlier version of my book. It is customary that such referees remain anonymous, so that they are entirely free to tell the author their opinions. Therefore, I cannot thank them in person for their criticism and insight, but my gratitude remains undiminished nonetheless.
Fortunately, the seventh referee, Charlotte Lemmens, did not remain anonymous at all, which gives me the joyful opportunity to thank her once more for her detailed and intelligent assessment. I hope that she may consider this result as yet another bright feather in her guardian angel wings.
Small Moves, Ellie
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 103-109
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During one of my visits to CERN, the European research institute for particle physics in Geneva, I met Elmajid Nath-Kaci-Uvutmar, a Touareg from North Africa. As a boy, he fell seriously ill and was nursed back to health by the ‘White Fathers’ in a desert monastery. They renamed him Majid Boutemeur while he stayed there for his education until he was about 14 years old. He found work on a small boat, cleaning fish, until one day in Marseille he decided to stay in France to be trained in physics. I met him at CERN where he was working on the development of software for particle accelerators. I asked him: ‘You were fourteen when you decided to become a physicist. Suppose that you meet a thirteen- or fourteen-year-old boy or girl, asking you: please give me one good reason to go and study physics. What would you reply?’ He looked into my eyes and said:
Physics is the most wonderful thing. You should be so lucky to go home in the evening and still have a problem to solve.
Brilliant, the true grit of the scientist knowing that the primary product of research is failure. ‘The conditions of nature give us no alternative’, Huygens warned us. Even a ‘failed’ experiment or theory is useful when mapping new land. How awful would it be if I were to come home one evening and say to my wife and daughter: ‘Darlings, physics is finished.’ Fortunately, such a disaster will never happen. We should be so lucky.
That which we call ‘gravity’ is one of the consequences of the structure of space-time. Einstein asserted that the mass-energy-momentum of matter contributes to that structure. But how? What is the interaction? What mechanism is hidden in the = of the Einstein equation? Or, more plainly: how does the Sun tell space-time around it that it's supposed to be curved, and by how much?
The present generation of physicists hasn't found an answer yet, or even a formulation that is clearly a good starting point. Possibly younger folk must give it a go. I hope that they will not have the wrong image of advancement in the sciences. Contrary to street wisdom, great advances in physics are not revolutionary but stepwise.
Acceleration
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 35-41
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If I ask the train personnel, ‘Conductor, does the Cambridge railway station pass by this train?’ I’m being a bit strange, but not wrong, because velocities are relative. However, saying, ‘Conductor, does the Cambridge railway station stop at this train?’ makes no sense in our Universe.
Because position is relative, we must use the change of position in order to describe motion. This change we call velocity. But velocity is relative as well; therefore we must use the change of velocity in order to describe motion. This change we call acceleration. This is, in fact, an observable, as every cyclist knows who has had to brake for a traffic light.
The word is a bit specialized, because in physics we use the word ‘acceleration’ for every kind of change in velocity: an increase or a decrease of speed as well as a change in direction are all called by this name. Velocity has a direction and a magnitude, so that a change of direction counts as an acceleration too, even if the speed (number of metres travelled per second along a path) remains the same.
That is precisely the case with Galileo's circular motion. The speed remains constant, but the direction changes steadily. The question then is: how does that feel? In a brilliant sequence of arguments, Huygens equated the acceleration of uniform circular motion to the steady acceleration of a falling object. Thus, he could relate the pull which is felt on the string of a slingshot directly to the acceleration of gravity.
From Galileo's work, Huygens knew that the speed of a falling object increases linearly with time. If the amount of acceleration is arbitrarily set to 1, and an object starts at speed zero, then in 2 units of time it reaches speed 2. The mean speed in that interval is then (0+2)/2=1. The mean speed in the next interval is 1+2=3, so that the mean velocity follows the sequence of odd numbers: 1, 3, 5, 7… at successive instants of time. The distances travelled at these times are then the sums of the numbers: 1, 1+3, 1+3+5,… which add up to 1, 4, 9, 16… These are all square numbers: 1×1, 2×2, 3×3, 4×4…, from which it follows that the distance travelled by a falling object increases quadratically with time.
Absoluteness Theory
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 45-49
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Classical mechanics is a true theory of relativity. Motus inter corpora relativus tantum est; position and velocity are not properties of an object, only relative positions and velocities are observable. The equations of motion, called ‘second-order differential equations’, are the expression of this observation. It follows, too, that constant-velocity motion is the ‘ideal’, ‘natural’ or ‘inertial’ state of motion.
In Huygens's relativity, it makes no difference whether one is moving with constant velocity or standing still: according to the motus line, there is no way to decide between the two. The mere existence of an object is indistinguishable from its moving with constant velocity.
Unless, that is, our Universe has the property that some objects in it cannot stand still. In our everyday world, we are never aware of objects that cannot stand still with respect to us. It may take some effort, but it is perfectly possible to fly alongside a jet plane such that the velocity difference between you and the jet is zero.
But in a very surprising experiment in 1887, Michelson and Morley discovered that there is, in fact, something in our Universe that cannot stand still: light. Up to that moment, it was thought that light – of which Huygens had successfully argued that it is a shock-wave phenomenon – must move with respect to some carrier medium, like waves on the surface of water are moving with respect to the underlying water volume. To their immense surprise, Michelson and Morley found that light does not behave like that. The speed of light – traditionally called ‘c’ – is invariant. That is to say, light always moves with the same speed, no matter what the speed of the emitter or the receiver of the light is. Light rays cannot stand still with respect to anything. Huygens's assertion that the same object that some say to be at rest, may be said to move with respect to other objects turned out to be false after all, at least for light.
A little thought shows that, therefore, all light moves with the same speed. In summary: the speed of light is not relative, but absolute. Had he known this, Huygens would have written Motus inter corpora relativus tantum est, praeter lumen– movement between objects is relative in all aspects, with the exception of light.
Contents
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 5-6
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Gravity
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 42-44
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In classical mechanics, the acceleration of objects has to be prescribed before the resulting motions may be computed. In fact, the mathematical formula that specifies how objects respond to forces, the ‘equation of motion’, can be read in this way: The acceleration experienced by any object is equal to the net force exerted on that object, divided by its mass.
The cause of the acceleration is not part of the system proper. It must be specified separately, put in from the outside, so to speak. When the science of mechanics was developed, this requirement led to a wild variety of hypotheses about the properties and causes of accelerations, to the tune of fierce and often acrimonious debate. In fact, the whole concept of ‘force’ had a bad reputation. It was much too vague, and carried the odium of magic and arbitrariness.
Of course every blacksmith, carpenter and bricklayer of that time knew that the forces among material objects were somehow related to their structure. The opinions of craftspeople and engineers, however, were not held in high esteem, except by people like Stevin and Huygens, who were very skilled in engineering and practical work.
Nor did it help that Descartes made a fine mess of it with his vortices of hypothetical ghost particles. Armchair philosophers could, and usually did, invent a new particle for every phenomenon in the world, resulting in a Shakespearean ‘sound and fury, signifying nothing’.
So when Newton declared that ‘gravity’ was the ‘universal’ source of accelerations, he did something quite daring. To his and our good fortune, he also cast the expression for his ‘universal force’ in an astonishingly simple mathematical form: the acceleration is inversely proportional to the square of the distance and independent of the accelerated object's mass. The latter requirement was absolutely necessary because of Stevin's experiment in 1585, about a century before Newton's work.
Scientists who are sensitive to such things find this simplicity a source of great beauty. It seems instantly convincing because it is the diametrical opposite of all the vague Cartesian stuff about ethereal particles and vortices, which contains no more physics than the ‘epicycles’ of antiquity.
A Twist to the Tale
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 84-93
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Summary
The paper-cutting experiment above illustrated Einstein's General Theory of Relativity. It showed that the motion of an object is determined by the structure of space-time: curved space gives curved orbits. The relationship between matter and space-time is mutual. On the one hand, the orbit of an object is due to the structure of space-time. On the other hand, that structure is determined by the arrangement of the massenergy- momentum of matter. We also saw that the state of motion of quantum particles is determined by the coupling at a Feynman vertex.
This raises the question: what determines this coupling? Or, in the language of our large-scale world: what determines the properties of forces?
The observation of reflection-and-transmission of light in a windowpane shows that quantum particles behave in ways that are radically different from the motions of big objects. Orbits in classical mechanics are fixed when all initial positions and velocities of the particles are prescribed together with a recipe for the accelerations. In quantum mechanics, we must determine the transition probability that connects a given initial state to a specified final state. These probabilities are computed by means of the Feynman diagrams introduced above.
The key to interaction in a Feynman diagram is the vertex, the point in space-time (called an event in relativity theory) at which particles are coupled. The interactions at a vertex are determined by symmetries. Before discussing how this works, let us look a little more closely at what is meant by ‘symmetry’.
A symmetry may be loosely described as ‘a change that leaves something unchanged’. Rotation is an example of a symmetry. A sphere is unchanged when it is rotated about its centre. Mathematicians say that a sphere is invariant under rotations. You might say that a sphere is in fact produced by a symmetry, because a sphere is the set of all points that have the same distance to a given point, and that ‘same distance’ is the ‘something that does not change’.
Galileo thought that the rotational symmetry of a circle implies that the ‘natural motion’ of planetary orbits is composed of circles, but Huygens proved that circular motion requires an acceleration. As we saw above, Huygens formulated a very different symmetry: the universe remains unchanged if everything in it were displaced over a fixed distance, and also if a fixed velocity were added to the velocities of all objects.
The Process of Measurement
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 9-13
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With measured tread, Johan Cornets de Groot climbed the many steps to the first tier of the tower. He did so solemnly, as seemed proper for his rank as burgomaster of Delft in southern Holland. De Groot had been invited to witness a physics experiment proposed by Stevin, the Flemish engineer, polymath and private physics instructor to Maurits, Prince of Orange.
This is the way it happened in my imagination. What these two men actually did has not been recorded, except for the setup and outcome of their experiment. The year was 1585, in an era when the scientific acceptance of observations and experimental evidence was beginning to grow in the minds of the intelligentsia (the illiterate stonemason and the shipwright had always respected facts, of course). In our 21st century, surrounded at all times and in all places by the products of science, it is difficult to appreciate how radically new it was to conduct an experiment that brushed aside nineteen centuries of philosophical opinion and, indeed, to devise such a test in the first place.
High above the ground, the experimental apparatus was held ready: two leaden balls, one ten times heavier than the other, prepared by Simon Stevin of Brugghe. He was a scientist in the best modern sense of the word: his brain held a vast amount of knowledge; he was familiar with all the classical works on physics and mathematics known in his time; his own work advanced science and engineering; and he informed non-scientists about the wonders of the world – among them Maurits, Prince of Orange, for whom he composed a fat compendium of theoretical and practical physics and mathematics entitled Wisconstige gedachtenissen (Flemish for something between ‘mathematical musings’ and ‘mathematical inventions’).
Stevin knew a lot, but he also understood that science is not so much about knowing as it is about searching. Of course it is necessary to be aware of the state of knowledge, but mostly to determine one's point of departure on a voyage into terra incognita, and possibly to get some idea about what direction to take in that immeasurable land. Like Galileo, Huygens, Newton and others, Stevin was one of the founding fathers of science, known as ‘natural philosophy’ at the time.
Feynman's Web
- Vincent Icke
- Translated by Charlotte Lemmens
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- Book:
- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 76-83
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Stevin's leaden ball experiment, the theme that runs through this story, has now broken up into two parts: the equal acceleration of the two different masses, and the structure and behaviour of matter. The equal-acceleration behaviour of ‘gravity’ is explained by the properties of space-time discovered by Einstein. Next on the agenda are those leaden balls or, more generally, any matter.
To understand the structure and behaviour of matter, we must delve a bit more deeply into the world of particle physics that is too small to be seen with an optical microscope. This will give us more insight into the nature of forces, and the possible beginning of a connection between the space-time world at large with the particle world on small scales.
The interaction of light with matter, such as in the case of the glass of a windowpane, takes place via an infinity of alternatives. These alternatives, when added together by means of the rolling-wheel process, produce effects collectively known as interference. For example, the ‘choices’ that light rays have in reflection-and-transmission at surfaces (such as glass or water) can produce visible interference, as they do when producing the shimmering colours in a soap bubble.
With a little effort it can be shown that, in empty space, the most probable path of a quantum is a straight line. At least this aspect of Huygens's relativity is nicely built into quantum mechanics. But what about curved paths? How are accelerations introduced?
Let us go back to the presentation of the rolling phase wheel associated with the motion of a quantum. The shape of the most probable path is determined by the addition of the phases of all possible paths between two points. It stands to reason, then, to introduce accelerations (and thus curved paths) by means of a prescription of the phases along the paths.
If the shape of the most probable path is curved, Huygens would have said that the object moving along that path has been accelerated. In the quantum world, the shape of the most probable path is governed by the arrow-addition of the phases of the quantum wheel along all possible paths. Thus, what we experience as an acceleration in our large-scale world is due to the behaviour of the phases of the quanta.
Jes’ Rollin’ Along
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 68-75
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Computing the net result of all possible alternatives is a monumental task, even in apparently simple cases. This is not a physics textbook, but it may be useful here to give some indication of how quantum motion is computed. This will show how far from everyday experience quantum behaviour is, and how unlike the classical motion we saw in Galileo's parabola and Huygens's spinning circle.
Motus inter corpora relativus tantum est, said Huygens: movement between objects is relative in all aspects. The absolute velocity of an object does not exist. Any dispute about the ‘true’ state of motion of a single object is meaningless. In particular, it makes no sense to distinguish between ‘rest’ and ‘motion’, provided that this motion proceeds with constant velocity.
A classical particle moves with constant velocity in the absence of accelerations, which are caused by forces. But what does a quantum do?
Picking just one path for the quantum to follow makes no sense in our Universe, because the windowpane experiment tells us that the same causes do not always have the same effects. In fact, we must do exactly the opposite: each path that is not explicitly forbidden, and that is not distinguished from other paths in any way, must be allowed. All force-free paths are to be considered collectively as equal-rights alternatives.
Now we are faced with the following problem. If all paths have equal rights, do they all have equal probability? It turns out that the answer is ‘no’. How must we compute the various probabilities? The answer to that is rather curious and totally contrary to everyday intuition. This is so bizarre, that it took scientists something like half a century to work it out.
A quantum on a path behaves like a rolling wheel. Imagine that we have a wheel with a given circumference. On the wheel, an arrow drawn from the axle to the air valve on the rim is called the amplitude of the quantum. When the wheel rolls along, that arrow rotates about the axle. The angle through which the wheel has rotated is called the phase of the quantum.
Frontmatter
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 1-4
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Laws Ain’t
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 17-22
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One of the beauties of Stevin's setup is that it uses a familiar, everyday effect. The result of the test triggers the most basic characteristic of the brilliant researcher. This isn't curiosity, as is commonly thought, but perceptiveness: the ability to see what everyone else can see, too, only better, or more connected to other things, more cleverly abstracted from circumstantial clutter, or more broadly generalized.
As an example, consider the statement The sky is dark at night. This truism is, on closer inspection, quite remarkable and non-obvious. Another example of a fact that is so strange that it borders on the bizarre: I am not the average of my parents, especially if we see it together with the fact I resemble both of my parents. The darkness at night is due to a subtle combination of effects. The most prominent of these are: stars cannot emit more light than a certain maximum; the Universe expands; the Universe has a finite age. That people are not the average of their parents, even though they resemble both of them rather closely, turns out to be mostly due to the fact that we are built out of elementary particles.
Everyday phenomena are almost completely incomprehensible in their raw appearance, so they are a very bad guide to physics. The world is messy, and there is not a single observation – whether in the days of Archimedes or in the days of the European Extremely Large Telescope – that is free from the interference of side effects. To make matters worse, if we speak about physics, we are obliged to use words that have an established common meaning already, such as ‘energy’, ‘force’ or ‘symmetry’.
It is useful to return one final time to the subject of ‘laws of nature’. I will argue that these do not exist if, by ‘law’, we mean some sort of Ultimate Truth that will never change once we have discovered it. If science were a methodical process that zooms in on ‘natural laws’ by steps big and small, then we would expect that it would always be fairly clear what course to take. But the quest for the mechanisms of the Universe has led us to a point from which there is no visible road ahead.
Reflections
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 60-67
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The main reason why mechanics was a very good candidate for the title ‘Theory of Everything’ is probably that it feels so definitive, not only in its strict and transparent mathematical structure, but also in its workings. If we want to know the future, all we have to do is specify the positions and velocities of all material at some initial time, and then the remainder of eternity can be computed, at least in theory. With a theory of everything, we can say with Leibniz: let's calculate! Calculemus! Voltaire wrote:
All occurrences are produced by one another. […] Under the same circumstances, the same causes produce the same effects.
Einstein's relativity theories did not change that; again, at least in principle. The computations become vastly more complicated, but the fact remains that, in relativistic mechanics, the future follows uniquely from the past.
Everyday mechanical events usually show that this is an acceptable point of view. In practice, the fact that the Universe consists of an unruly number of particles makes that initial specification and its subsequent computation difficult, but not necessarily impossible (plus the problem that the computer must be part of what it computes, but never mind that).
However, there is a danger lurking under this seemingly calm surface. Because mechanics demands that we specify the whereabouts of all material in the Universe at an initial time, the question arises what that ‘material’ is and, in particular, what its internal constitution is.
It had long been clear that gravity cannot be the only force in the Universe, because gravity is a purely attracting force, so it cannot produce stable objects by itself. But research into electricity had shown that an electric charge can be positive as well as negative, and that charges with the same sign repel each other. The experiments and theories of Faraday and Maxwell, developed in the 19th century, showed that the forces of electricity and magnetism can be in equilibrium. Therefore, electromagnetic forces were good candidates for the explanation of the structure of matter.
Then, in the first quarter of the 20th century, it was discovered that matter is not continuous, but built out of discrete particles. These particles form families, analogous to the well-established ‘chemical elements’, and within a given family the particles are precisely identical. Faraday's electric current turned out to be a stream of an immense number of electrons.
Motion
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 23-25
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With five centuries of hindsight, it seems that the development of mechanical theories proceeded predictably. In the year 1600, however, it was by no means clear where to begin, what to study or what questions to ask. One of the key items on the physics agenda was change. The ancient Greek philosophical dictum, panta rhei (‘everything flows’), lacked precision and was unacceptable in experimental philosophy as an explanation for change.
Change presents itself in many ways, the most obvious being the motion of objects. In 1600, common sense seemed to show that motion needs an agent to produce and to maintain it, and everything seemed to move towards the ground, unless something interfered. The first person in the history of our planet to make serious headway on this subject was Galileo. He did this by replacing the philosophical question, ‘What is motion?’ with the experimental-philosophical inquiry, ‘How does motion behave?’
With his immense perception and talent for precise and systematic experimentation, Galileo began to study the behaviour of spherical balls that were set up to roll down inclined planes so that they moved more slowly than simply dropping vertically. In a long series of experiments, he discovered most of the basics of falling motion.
First: the velocity increases in direct proportion to time (in the absence of perturbations such as the resistance of the air). That is to say: free fall is uniformly accelerated motion. Second: the speed that an object acquires when released is always the same after it has fallen a given vertical distance, in free fall as well as when constrained to move on an inclined plane. Third: Galileo deduced and verified that it follows from the first finding (speed is proportional to time) that the distance an object traverses when falling is proportional to the square of the time. Fourth: horizontal and vertical motions occur independently. From this, he concluded that the path of a thrown mass is a parabola.
In parallel with these experiments, Galileo developed a view of the more general and abstract properties of motion. The consensus at the time was that motion requires something to keep it going, with the exception of motion ‘above the Moon’, that is, the motions of the planets.
Gravity Does Not Exist
- Vincent Icke
- Translated by Charlotte Lemmens
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- Gravity Does Not Exist
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- Amsterdam University Press
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- 12 December 2020
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- 26 June 2014, pp 50-59
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The speed of light is always the same. Because this speed is absolute, time is relative: a moving clock is seen to tick more slowly than the same clock standing still with respect to the observer. This is called time dilation, and the equation describing it shows that the speed of light is the maximum speed attainable in the Universe.
Consequently, instantaneous actions or connections over a finite distance are impossible. In our Universe, all things are always under way, whatever they are. No two events in space-time may be linked instantly; the news that something has happened always takes some time before it has reached other places.
Likewise, the properties of space-time itself cannot be linked instantly across finite distances. This implies that space-time properties may vary from place to place and from time to time. If, for some reason, space-time were not exactly uniform, meaning that its properties differed from event to event, it would be impossible to smooth everything out instantaneously.
When the structure of space can vary in the course of time, we are justified in saying that space-time has its own dynamical behaviour, so that space-time may be seen as real stuff with its own structure, like the Oude Kerk in Delft. Unlike that old church, space-time doesn't just stand there, but it is dynamic. Space-time is not some sort of invisible graph paper on which the paths of all things are drawn, the way Newton said it is. Space-time is stuff, with a dynamic structure.
The invention of the mathematical equation that expresses this astonishing result was Einstein's greatest contribution to physics, even greater than his other enormous achievements, according to just about all physicists. The formulae have a stark beauty of their own, but they need not be presented here. Translated into plain language, they state that the structure and dynamics of space-time are determined by the arrangement of mass, energy and momentum.
Astonishing indeed, because it follows from this equation that, first, gravity does not exist; second, it is now clear why Stevin's experiment showed what it did.
If there is no such thing as gravity, what then is the reason why the orbits of the planets are curved?
Gravity Does Not Exist
- A Puzzle for the 21st Century
- Vincent Icke
- Translated by Charlotte Lemmens
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- Published by:
- Amsterdam University Press
- Published online:
- 12 December 2020
- Print publication:
- 26 June 2014
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Every scientific fact was born as an opinion about the unknown - a hypothesis. Opinion gradually becomes fact as evidence piles up to support a theory. But what if there are two theories, each of which has produced a myriad of things that correspond perfectly to the phenomena but can't be combined into one? One theory replaced the mystery of gravity with a precise model of space and time. The other theory replaced the mystery of matter with a description of quantum particles. As we understand our universe, we keep each in its own domain: space and time for very large things, particles for the very small ones. However, 13.8 billion years ago, those two incompatible domains belonged to a single realm. Who in the current or future generations of physicists will crack this seemingly impossible puzzle? This, contends the author, is not just a big question, but the biggest question in physics in our century. Combining Ickes's first-hand knowledge with a robust argument and intellectual playfulness, this fascinating book succeeds in making a notoriously difficult subject accessible to all readers interested in a better grasp of our universe.
The Process of Progress
- Vincent Icke
- Translated by Charlotte Lemmens
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- Book:
- Gravity Does Not Exist
- Published by:
- Amsterdam University Press
- Published online:
- 12 December 2020
- Print publication:
- 26 June 2014, pp 14-16
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Summary
Do facts exist? Simon Stevin would have answered ‘yes’ without any hesitation. He did an enormous number and variety of experiments, including the crucial one on that tower in Delft: this is a historical fact. His experiments were quite repeatable, both during his time as well as today, and were often repeated and improved. These are physical facts.
Do laws of nature exist? Not that we know of. Theories evolve, facts remain. Stevin's demonstration of the most remarkable property of falling bodies is as striking today as it was four centuries ago, even though in our time we see it demonstrated in the form of the so-called ‘weightlessness’ of astronauts in their spacecraft. I will follow the historical evolution of the concepts and theories related to Stevin's experiment. Along the way we see theories of motion, collision, accelerated motion, mechanisms that produce acceleration, gravity, space-time curvature, and the bizarre properties of matter in the form of quanta that are described by quantum field theory.
At the point when history becomes present, the path of this research bogs down in a marshy landscape where, at night, will-o’-the-wisps called ‘supergravity’ or ‘string theory’ spread a feeble and misleading light. I fervently hope that this book will inspire someone to find a way ahead. Arthur pulled a sword from a stone, helped by his tutor, Merlin. Maybe a 21st-century girl or boy will perform a comparable feat in physics, helped by a physics professor who teaches her or him that theory is the art of the possible. When we follow the long and winding road from Stevin's beautiful experiment to present observations with giant telescopes and immense particle accelerators, we are confronted squarely with the evolution of scientific understanding: the same observation gives rise to an evolving sequence of explanations and theories. This demonstrates the provisional and temporary character of all results in physics. The phrase ‘law of nature’ is misleading, unless ‘law’ is meant to be similar to laws in society, which are made and amended as needed.
What is commonly called a ‘natural law’ is actually an intermediary link between the makeup of the Universe and our understanding thereof.
Foreword
- Vincent Icke
- Translated by Charlotte Lemmens
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- Book:
- Gravity Does Not Exist
- Published by:
- Amsterdam University Press
- Published online:
- 12 December 2020
- Print publication:
- 26 June 2014, pp 7-8
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Summary
This is a Small Book about a Big Question, not a textbook of known physics. Or perhaps it's about a Big Opinion – or a small opinion, depending on one's perspective. It's a book about unknown physics. Every scientific fact was born as an opinion about the unknown, often called a ‘hypothesis’. Opinion gradually becomes fact when evidence piles up. By perceptive and diligent work, it is
… possible to attain a degree of probability that quite often is hardly less than complete certainty. Namely, when the things that one has deduced from the supposed principles correspond perfectly to the phenomena that observations show us,
as Huygens wrote. It has been so ever since, except that instead of ‘supposed principles’ we now say ‘theory’. But what if there are two theories, each of which has produced a myriad of ‘things that correspond perfectly to the phenomena’ but that cannot be combined? One theory replaced the mystery of gravity by a precise picture of space and time. The other replaced the mystery of matter by a description of quantum particles that is so exact that some of its predictions have been verified to eleven decimal places. At the present time in our Universe, we may keep these two separate, each in its own domain: space and time for very large things, particles for the world of the very small. However, 13.8 billion years ago, these two incompatible theories referred to a single realm. Many scientists think that they can be united only by a minuscule group of hyper-specialists. I think differently. The mathematics of the ultimate answer will be as arcane as always, but that formulation will have to follow upon some original perception. Insight is freely distributed; all you’ve got to do is pick it up. I hope that somewhere a girl or boy will do so, because the generations of physicists who made the existing brilliant theories will soon be extinct. We will never understand the beginnings of our Universe until this puzzle has been cracked. That is why I hold the opinion that this is not just a big question, but the Biggest Question in physics of the 21st century.
Huygens's Relativity
- Vincent Icke
- Translated by Charlotte Lemmens
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- Book:
- Gravity Does Not Exist
- Published by:
- Amsterdam University Press
- Published online:
- 12 December 2020
- Print publication:
- 26 June 2014, pp 26-34
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Summary
Christiaan Huygens was the first to prove explicitly that Galileo's argument about ‘natural motion’ is wrong. He replaced this idea through a number of steps. First, he postulated a ‘principle of relativity’ that he supposed to be valid for all motions. He did not introduce this item as an axiom, like a mathematician or a classical philosopher would, but as a summary of what he perceived as the most striking characteristic of motion – without, of course, including some sort of ‘natural motion’ from the start.
From that, he deduced what later came to be called the ‘law of inertia’: free or ‘natural’ motion is motion with a constant velocity, that is, motion in a straight line with constant speed, flatly contradicting Galileo’s assertion about circular motion. Next, he computed geometrically what the difference is between Galileo's two forms of ‘ideal’ motion: the circle and the straight line. In the process he derived the first-ever algebraic equations in theoretical physics, describing the centrifugal acceleration and the oscillation time of the ideal pendulum.
Huygens's main conclusion forms the next step on the path leading from Stevin to modern physics: a curved orbit is an accelerated orbit. An object maintains a constant velocity (fixed speed in a fixed direction) with respect to other objects, unless – through some outside agent to be specified – an acceleration interferes.
But let me start at the beginning. As I have argued above, the primary characteristic of a great scientist is not curiosity, but perceptiveness: the ability to see what others have also seen, but from a different angle. The vision of ‘what motion is’ was vaguely present in some of the writings of Galileo and Descartes, but Huygens provided the clear and definitive formulation. It occurred to him that motion does not mean that an object changes its position in space, but that its position changes relative to other objects in the Universe. The sentence he wrote in his notes reads:
Motus inter corpora relativus tantum est.
Movement between objects is relative in all aspects.
That is two symmetry principles rolled into one. First: nothing changes if you change all positions in space by shifting all positions by the same amount. Second: nothing changes if you add a fixed velocity to all velocities throughout space.