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Bruno Kamdem - Newton's Laws of Motion
I've been listening to "In our Time" online for the past year. I'm a graduate student in Mathematics here at the University of Maryland, Baltimore County, U.S.A. The episod on Newton was very revealing. Your guests have an admirable insight on the histotry of Physics and on Physics itself. If Descartes' laws were wrong, how could Newton be inspired by them? Please, is there any way you can make available CD of your program for sale? I'd buy them right now. They would constitude tremendous ressources to many universities faculties here in the U.S. If you can make those subjects archives on CD and sale them, it would be a marvelous way to promote knowledge. Since many drive, they would listen to the programs while driving. Think about the immense effect that would have! Please think about it!
Terry Noonan. Robert Hooke
I really enjoyed the latest program on sir Isaac Newton but was wondering if a program about the often overlooked and over-shadowed Robert Hooke might not be in order?
Alex Bellamy Newton's Laws of Motion
Oh dear ! The untenable fairy-tales of Newton hagiography and Enlightenment-positivist philosophical zeal seem to have combined to produce surely the very worst programme in this excellent series, and whose profoundly misleading infallibilist misrepresentations of the explanatory power of science, the nature of scientific development and Newton’s achievement surely require extensive correction in this forum at least inasmuch as the programme is now used as a teaching resource for students of the history of science and ideas and indeed of other subjects. The headline claim of the programme, which was never substantiated, was that "In 1687 Isaac Newton attempted to explain the movements of everything in the universe, from a pea rolling on a plate to the position of Pluto. It was a brilliant, vaultingly ambitious and fiendishly complex task; it took him three sentences." Whilst this is nice Enlightenment-positivist rhetoric, in fact the fallibilist truth of it is that far from attempting to explain the movements of everything in the universe, an impossible task which science never has attempted nor surely ever will, in fact Newton's ‘Principia’ attempted to explain very little indeed by its laws of motion and gravitation in terms of actual empirical predictions, and definitely not the motions of peas rolling on plates nor certainly of Pluto, which was not even discovered until 1930. Moreover, those very few empirical predictions in celestial mechanics it did attempt in order to try and prove its theory of universal mutual gravitation - namely its novel predictions or novel explanations of tidal motion and high-tide times, the precession of the equinoxes, mutual perturbation of Jupiter and Saturn at their orbital conjunctions, moving aphelia of inner planetary orbits, the oblate figure of the Earth with a 17 mile equatorial bulge, the lunar orbit and the return of Halley's comet - were either refuted or else unconfirmed or just simply fiddled, even by its 1726 third edition. This is evident in the more intelligent analytical literature in such as Curtis Wilson's article 'Newton and Celestial Mechanics' [in 'The Cambridge Companion to Newton' Cohen & Smith (Eds) CUP 2000] and in Westfall's 'infamous' 1973 paper 'Newton and the Fudge-Factor'
Newton (reply)
It is precisely the kind of casual - and almost certainly misguided - speculation about the empirical nature of the cosmos (dark matter etc.) that James Baring invites us to make that has characterised the modern idea of a route towards a correct scientific theory. Such pop science pays scant regard to the virtue of devising axiomatic truths and instead assumes them (in the Newtonian axioms) and proceeds, as did Einstein, by modifying them - a practice that is fundamentally offensive to logic. Incidentally, 'force' being equal mv^2 was first devised by Huygens (1656), prior to Newton's Principia.
Prof. Mike Disney, Newton's Laws
Lacking from the discussion of Newton's Laws was their modern explanation, which is both profoundly satisfying, and comprehensible. The 3 laws can be reformulated as 3 Conservation Laws: the conservation of Linear Momentum, of Angular Momentum and of Mechanical Energy. In 1917 the mathematician Emmy Noether(worthy of a program in herself) showed that each conservation law followed from a fundamental Symmetry Principle, a principle that HAD to be true, otherwise science would be impossible. Thus the Conservation of Linear Momentum follows directly from the requirement that scientific laws must be true, irrespective of one's position in Space. In that sense Newtons Laws are truisms, forced upon us if we are to make scientific sense of our world.
James Baring NEWTON
Good stuff philosophically and scientifically explained, except that objects in extremes of the observed universe do NOT exert even the smallest attractive force on each other either in theory or in practice. This is not just because of Einstein's update but because the apparent force of attraction is a regional effect, caused by the uneven arrangement of matter (including so called 'dark'). The fundamental force gravitational force is repulsive, the apparent attraction being a result in spaces of relative mass-density, which ironically can be thought of as Newtonianly equal and opposite in toto on the cosmic scale. But to understand it properly you need to get to grips with the multidimensional cosmos. Once you have sorted it, Newton and Einstein both make much more sense. Also worth noting: although E=1/2MV-squared was (as mentioned) a 1710AD post-Newtonian equation, he must take credit for providing the building blocks for it. Einstein's E=MC-squared follows inevitably from it as soon as we realise that light leaves a source immediately at its full speed. The 1/2, needed in the earlier equation to find the average velocity caused by acceleration over time, is no longer required. Therefore all mass converted to radiant energy must be subject to that equation without waiting for Einstein to tell us. So Newton stretches into Special Relativity, General Relativity deals with the geometry in 4 dimensions, and the next theory (which will presumably be named after someone who can explain it better than I can, with the required mathematical academic background, will make it all much more comprehensible in a package. Won't be long now.
Newton's Laws, Ed Traviles
You say in your email that "you can derive the laws of motion without experimental evidence", and that "As long as you get the measurements right, what happens happens." This may be so, but presumably the laws of motion are supported by observational evidence, and would be discarded (except, perhaps, as a curiosity) if they were shown not to describe correctly the way motion works? Could someone better qualified than I comment on this, please?
Joe Kerr - Newton's Laws of Motion
A Little off topic, but related. Richard S Westfall's cracking biography of Newton, "Never at Rest" contains the following quotation: "A Vulgar Mechanick can practice what he has been taught or seen done, but if he is in an error he knows not how to find it out, and if you put him out of his road, he is at a stand; Whereas he that is able to reason nimbly and judiciously about figure, force and motion, is never at reft till he gets over every rub." [Isaac Newton to Nathaniel Hawes, 25 May 1694]
John Archer
Dear Melvyn, Nice programme. Thank you. You say in your newsletter, "One thing that still intrigues me is the idea that you can derive the laws of motion without experimental evidence." One could argue about the word 'derive' here not being correct but leaving that aside (you'll see what I mean below), there's nothing peculiar in this. First, it is important to note that one cannot derive a (unique) theory from experimental data. In general, for any given amount of data, there are innumerable theories that could fit the bill, in theory at least (ha ha). Putting it crudely, it works something like this: you spot certain regularities, patterns or relationships in the data and then you try to find a set of ideas (axioms or postulates, if you want) that will 'explain' them, i.e. a set of ideas from which it is possible to derive (typically mathematically) the observed patterns etc from those postulates and certain initial conditions of the system you are looking at. If you can manage this then you have a candidate theory (and ONLY a candidate theory) which then needs subsequent testing against new data and different setups. A good candidate theory will also make some surprising predictions or surprising connections between phenomena previously considered not particularly related or not related at all. If these predictions etc bear out then you are on to a winner, maybe.
niall devlin Newton's laws
I was very taken by the idea of Newton wanting to have God’s objective eye view of nature and the vulgarity having a more subjective relativist eye view. In the end it was the vulgarity that came to dominate the 20th century. It is the subject/relativist perspective that is present in the uncertainty principle and in the theories of relativity. I was taught that the difference between Newton and Einstein was that for Newton time was a constant and the speed of light was relative whereas for Einstein the opposite was true. I wonder if Einstein had had as much a debt to Nietzsche , with the death of God and the birth of man, as to Newton. That is the freedom not to have the objective eye view and to recognise that the individual is part of the phenomena being investigated or perhaps the relocation of the individual from the outside looking in to the inside looking around. How often does radio inspire such thoughts misguided or otherwise.
Chris Newton's Laws and Gravity
Thank you for a very interesting programme. However you may be excited to learn of another possible re-interpretation of the Newton's Laws as recounted in the following book:"Light-Speed, Gravitation and Quantum Intstantaneity" by Anthony D Osborne & Vivian Pope.I have read it from cover to cover and so far can't fault the mathematics. But of course, that doesn't mean it is correct.....and neither can we assume that our current theories are correct just because the sums seem to add up!The aforementioned book starts from basic axioms and simply argues that current physics has over-complicated many observations and that all that is really needed to explain many phenomena including "GRAVITY" is a higher importance to be attached to angular momentum. The upshot is that all current observations will still fit AND some new predictions can be tested. It also means that we don't get silly black hole singularities etc. or need extra dimensions, dark matter and maybe need to rethink aspects of the big bang!Maybe its wrong, maybe its right, I thought I knew a lot about science but despite my personal shortcomings, I think this alternative (and still rigorous) approach to modern science is well worth a very serious look. Thanks for reading this
Newton's Laws
(Steve carbert, Wakefield)An exceptional piece of broadcasting! Newton has been a hero of mine since the late 60's when I sat in front of a dusty blackboard and watched the physical universe unfold. Conservation of momentum and energy, impulse momentum, work energy, rocket science, calculus! To the young mind this was mind bending stuff. But it wasn't until the nineties that I realised his Laws were actually insights into the nature of existence. The programme observed that there is very little of a technical nature in his laws. They are verbose and short on technicalities but encompass the essence of human experience of the physical universe. Newton obviously thought this was important, to summarise the experience, rather than to pursue such abstruse concepts as "What is force?". His summation in the form of these 3 short sentences was as much a cry to stop the chatter and concentrate on what is important as it was to push forward human understanding. The Buddha in 500BC did a similar thing by summarising the totality of human experience with the Four Noble Truths except that he was referring to the mental phenomena to which we are all subject. Exactly like Newton's Laws they are not complicated but somehow seem to embrace the totality of human experience. Newton left us Calculus with which to explore the universe he had revealed in his 3 Laws. Gautama the Buddha left us Samatha meditation practice so we could investigate our mind. Quantum Theory is now daring to investigate mind, awareness and consciousness. Perhaps we will some day get a true Unified Theory of Everything when the mind and the physical universe are finally united.That's assuming we don't get a slow burning Black Hole coming out of CERN which would make it all rather pointless.suggestions for future programme - an exploration of Buddhist philosopy and meditation as a tool for exploring our experience of existence and not as a religion.
Andrew, Newton's 3 laws
Simon Schaffer might have done well to see in this archive (dating from the programme on Popper), "if you study the original version of Newton's Second Law - not the modern F=ma - you realise that Newton regarded force as a function of time, equivalent to the modern notion of an impulse. It was change of momentum: mass *or* velocity; thus even if mass increases with increased velocity so does the force required, and Newton holds." The insertion of 'rate' in 'rate of change of motion (momentum)', giving F=ma, isn't a flaw of Newton's - it's a mistranslation of 'mutationem motus'.
Tom Milner-Gulland - Newton
Newton maintained that he was modelling gravitation, not hypothesizing ('hypothesis non fingo'), and as such it would be eccentric to suppose he could be supplanted by an empirical hypothesis. Nevertheless, Newton did speculate that his metaphysics led to the reasoning, gravity therefore God. The transcendent unity represented by gravitation has led me to conclude that the cosmos encapulates celestial bodies as a concomitant to the capacity the conscious mind has for encapsulating ideas. The constitution of God is the source of both the innate constitution of conscious minds and also of the cosmos. When assemblages of God's various 'instincts' - if such be an appropriate term - are encapsulated in the form of the constitution of a mortal mind, so the objects of the cosmos are rendered palpable - via the fundamental constants of nature, the very immutability of which underlies physicality. Moreover, such an imposition of a determinate arrangement of the parts of God thrusts them out of their more natural, unified state, and this is the source of the perpetual tensions evidenced by Newtonian dynamics.-- (Mostly paraphrased from my book 'The Birth of Three Sides: A Theory of Dimensionality' (Ashgate, 1997)
Dennis Apple
I never cease to be grateful that in the UK we have programmes of such high intellectual standard as Melvyn Bragg's In Our Time, which do not shrink away from discussing subjects of minority interest for fear of alienating listeners. Today's programme concerning Newton's Three Laws of Motion was an excellent illustration of this attitude.As a retired Physics teacher I was always highly impressed by the apparent simplicity of the statements of the three laws and of the most profound consequences which follow from them. As a 10-year child they seemed so obvious to me. But, as was stated in the program, so was Darwin's equally commonsense views on Natural Selection - after they were proposed!My only slight criticism of the program was that the mention of Descartes' misleading ideas of motion might confuse listeners who perhaps are not very familiar with Newton's Laws.One consequence of the success of Newton's Laws of Motion was the idea that the Universe is not controlled by supernatural entities operating in benevolent or wrathful manner, but rather that it is natural laws which govern motion, from the most humble objects to the orbiting of planets around the Sun, and by using these laws we can predict the behaviour of all mechanical systems. Similar laws, which are waiting to be discovered, must exist in other fields of study. This new approach caused a shift from mystical thinking and lead to a change in attitude which still exists today, and which has been so very beneficial for the advancement of scientific progress since Newton’s time.I was very pleased that none of the programme’s contributors put forward the usual chestnut that Einstein proved Newton wrong. Indeed the program made it quite clear that Newton’s laws are still the bedrock of modern mechanics and need only be refined under the most extreme conditions of gravity and velocity.Alexander Pope's familiar couplet eulogized Newton: "Nature and Nature's Laws lay hid in Night./God said, Let Newton be! and All was Light."
Newtons laws
I hope you will find space to include an extract from In our time 'Newton's Laws of Motion'. The academics proved they can translate difficult ideas into plain english to help this non scientific mear mortal gain a better understnding of Newtons achievements.When I get the opportunity to listen 'In Our Time' has become for me one of the BBC gems of broadcasting. It would be good if they could be made available for future students through CDs.Mike Bunyan
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