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From: doug on 29 Nov 2008 13:59 Juan R. González-Álvarez wrote: > Sam Wormley wrote on Sat, 29 Nov 2008 18:39:30 +0000: > > >>Juan R. González-Álvarez wrote: >> >> >> >>>From the Nobel commite: >>> >>>(\blockquote >>> The Royal Swedish Academy of Sciences has decided to award the Nobel >>> Prize Physics for 1993 jointly to Russell A. Hulse and Joseph H. >>> Taylor, Jr, both of Princeton University, New Jersey, USA *FOR* the >>> discovery of a new type of pulsar, a discovery that has opened up new >>> possibilities for the study of gravitation >> >> Ref: >> http://nobelprize.org/nobel_prizes/physics/laureates/1993/press.html >> >>The press release continues: >> >> >>The significance of the discovery of the binary pulsar >> >>The discovery of the first binary pulsar is primarily of great >>significance for astrophysics and gravitational physics. Gravity is the >>oldest known natural force, the one we are most aware of in daily life. >>At the same time it is in one sense the force that is hardest to study >>since it is so much weaker than the other three natural forces: the >>electromagnetic force and the strong and the weak nuclear forces. The >>development of technology and science since the second World War with >>rockets, satellites, space voyages, radioastronomy, radar technology and >>the precise measurement of time using atomic clocks has led to a >>renaissance of the study of this earliest-known natural force. The >>discovery of the binary pulsar represents an important milestone in this >>historical development. >> >>Relativity theory and gravitational physics >> >>According to Albert Einstein's general theory of relativity, gravity is >>caused by changes in the geometry of space and time: space-time curves >>near masses. Einstein presented his theory in 1915 and became a world >>celebrity when in 1919 the English astrophysicist Arthur Eddington >>announced that one of the predictions of the theory, the deflection of >>starlight passing near the surface of the sun - "the light is drawn >>towards the sun" - had been verified during solar eclipse expeditions. >>This deflection of light. together with a small general-relativity >>contribution to the perihelion motion of Mercury (a slow rotation of >>Mercury's elliptical orbit round the sun), was for several decades the >>only, partly rather uncertain, support for Einstein's theory. >> >>For a long time the theory of relativity was considered aesthetically >>very beautiful and satisfying, probably correct, but of little practical >>significance to physics except in applications in cosmology, the study >>of the origin, development and structure of the universe. >> >>Attitudes to the general theory of relativity changed, however, during >>the 1960s when both experimental and theoretical developments made >>gravitational physics a topical part of physics. New opportunities for >>precise experiments, based on satellite and radar technology, opened up. >>In particular, the research of the Americans R. Dicke and I. Shapiro >>contributed to this. Dicke performed precision experiments in which the >>sun's gravitational field on the earth was used for verifying what is >>termed the equivalence principle, the identity between gravitational and >>inertial mass - one of the basic principles of the general theory of >>relativity (and also of several alternative gravitation theories). >>Important contributions were also Shapiro's theoretical prediction and >>experimental verification, using radar echoes from Mercury, of a new >>consequence of the general theory of relativity - a time-delay effect >>for electromagnetic signals passing through gravitational fields. >> >>All these experiments, however, were confined to our solar system with >>its very weak gravitational fields and consequently small deviations, >>hard,to measure, from the Newtonian theory of gravity. Hence it was >>possible to test the general theory of relativity and other theories >>only in the first post-Newtonian approximation. >> >>The discovery of the binary pulsar >> >>Hulse's and Taylor's discovery in 1974 of the first binary pulsar, >>called PSR 1913 + 16 (PSR stands for pulsar, and 1913 + 16 specifies the >>pulsar's position in the sky) thus brought about a revolution in the >>field. We have here two very small astronomical bodies, each with a >>radius of some ten kilometres but with a mass comparable with that of >>the sun, and at a short distance from each other, only several times the >>moon's distance from the earth. Here the deviations from Newton's >>gravitational physics are large. As an example may be mentioned that the >>periastron shift, the rotation of the elliptical orbit that the pulsar >>(according to Kepler's first law from the beginning of the 17th century) >>follows in this system, is 4 degrees per year. The corresponding >>relativistic shift for the most favourable example in our solar system, >>the above-mentioned perihelion motion of Mercury, is 43 seconds of arc >>per century (this is less than a tenth of the very much larger >>contributions to the perihelion motion caused by perturbations from >>other planets, chiefly Venus and Jupiter). The difference in size >>between the shifts is partly due to the orbital speed in the binary >>pulsar, which is almost five times greater than Mercury's, and partly >>due to the pulsar performing about 250 times more orbits a year than >>Mercury. The orbiting time of the binary pulsar is less than eight >>hours, which can be compared with the one month our moon takes to orbit >>the earth. >> >>A very important property of the new pulsar is that its pulse period, >>the time between two beacon sweeps (0.05903 see) has proved to be >>extremely stable, as opposed to what applies to many other pulsars. The >>pulsar's pulse period increases by less than 5% during 1 million years. >>This means that the pulsar can be used as a clock which for precision >>can compete with the best atomic clocks, This is a very useful feature >>when studying the characteristics of the system. >> >>The very stable pulse period is in fact a mean of the pulse period >>observed on earth over the time of one orbit of the pulsar system. The >>observed period actually varies by several tens of microseconds, i.e. by >>an amount that is much greater than the variation in the mean value. >>This is a Doppler effect, and led to the conclusion that the observed >>pulsar moves in a periodic orbit, meaning that it must have a companion. >>As the pulsar approaches the earth, the pulses reach the earth more >>frequently; as it recedes they arrive less frequently. From the >>variation in pulse period, conclusions can be drawn about the pulsar's >>speed in its orbit and other important features of the system. >>Demonstration of gravitational waves >> >>A very important observation was made when the system had been followed >>for some years. This followed theoretical predictions made shortly after >>the original discovery of the pulsar. It was found that the orbit period >>is declining: the two astronomical bodies are rotating faster and faster >>about each other in an increasingly tight orbit. The change is very >>small. It corresponds to a reduction of the orbit period by about 75 >>millionths of a second per year, but, through observation over >>sufficient time, it is nevertheless fully measurable. This change was >>presumed to occur because the system is emitting energy in the form of >>gravitational waves in accordance with what Einstein in 1916 predicted >>should happen to masses moving relatively to each other. According to >>the latest data, the theoretically calculated value from the relativity >>theory agrees to within about one half of a percent with the observed >>value. The first report of this effect was made by Taylor and co-workers >>at the end of 1978, four years after the discovery of the binary pulsar >>was reported. >> >>The good agreement between the observed value and the theoretically >>calculated value of the orbital path can be seen as an indirect proof of >>the existence of gravitational waves. We will probably have to wait >>until next century for a direct demonstration of their existence. Many >>long-term projects have been started for making direct observations of >>gravitational waves impinging upon the earth. The radiation emitted by >>the binary pulsar is too weak to be observed on the earth with existing >>techniques. However, perhaps the violent perturbations of matter that >>take place when the two astronomical bodies in a binary star (or a >>binary pulsar) approach each other so closely that they fall into each >>other may give rise to gravitational waves that could be observed here. >>It is also hoped to be able to observe many other violent events in the >>universe. Gravitational wave astronomy is the latest, as yet unproven, >>branch of observational astronomy, where neutrino astronomy is the most >>direct predecessor. Gravitational wave astronomy would then be the first >>observational technique for which the basic principle was first tested >>in an astrophysical context. All earlier observational techniques in >>astronomy have been based on physical phenomena which first became known >>in a terrestrial connection. > > > > Both received a Nobel for discovering of the famous binary pulsar, just > that. > > 1) Gravitational waves have been never detected. Everything about > pulsar is about indirect tests. The indirect tests agree with relativity. If they did not, you would be here screaming that relativity is disproved. > > 2) Last high precision observations reveals that binary pulsar is > better > described by non-geometrical theory of gravity which gives the same > prediction than GR more a 1% excess cannot be explained using GR. > You keep saying this but give no reference. > >
From: "Juan R." González-Álvarez on 29 Nov 2008 14:16 doug wrote on Sat, 29 Nov 2008 10:59:47 -0800: >> Both received a Nobel for discovering of the famous binary pulsar, just >> that. >> >> 1) Gravitational waves have been never detected. Everything about >> pulsar is about indirect tests. > > The indirect tests agree with relativity. If they did not, you would be > here screaming that relativity is disproved. In science an indirect test is not a substitute for a direct test. This is why *direct* tests to detect GR predicted gravitational waves are done :-) >> 2) Last high precision observations reveals that binary pulsar is >> better >> described by non-geometrical theory of gravity which gives the same >> prediction than GR more a 1% excess cannot be explained using GR. >> > You keep saying this but give no reference. Already replied :-) -- http://www.canonicalscience.org/
From: doug on 29 Nov 2008 14:40 Juan R. González-Álvarez wrote: > doug wrote on Sat, 29 Nov 2008 10:59:47 -0800: > > >>>Both received a Nobel for discovering of the famous binary pulsar, just >>>that. >>> >>>1) Gravitational waves have been never detected. Everything about >>> pulsar is about indirect tests. >> >>The indirect tests agree with relativity. If they did not, you would be >>here screaming that relativity is disproved. > > > In science an indirect test is not a substitute for a direct test. > > This is why *direct* tests to detect GR predicted gravitational waves are > done :-) > > >>>2) Last high precision observations reveals that binary pulsar is >>> better >>> described by non-geometrical theory of gravity which gives the same >>> prediction than GR more a 1% excess cannot be explained using GR. >>> >> >>You keep saying this but give no reference. > > > Already replied :-) > > Maybe but with all the posts I must have missed it. How about repeating it.
From: Juan R. on 30 Nov 2008 07:51 On 30 nov, 03:55, eric gisse <jowr.pi.nos...(a)gmail.com> wrote: > On Sat, 29 Nov 2008 19:27:48 +0100 (CET), "Juan R." González-Álvarez > > > > <juanREM...(a)canonicalscience.com> wrote: > >eric gisse wrote on Sat, 29 Nov 2008 08:29:18 -0900: > > >> On Sat, 29 Nov 2008 18:01:33 +0100 (CET), "Juan R." González-Álvarez > >> <juanREM...(a)canonicalscience.com> wrote: > > >>>Sam Wormley wrote on Sat, 29 Nov 2008 14:52:52 +0000: > > >>>> As I said, you misunderstand the significance of Russell Hulse and > >>>> Joseph Taylor's work with PSR 1913+16. > > >>>Both received a Nobel for discovering of the famous binary pulsar, just > >>>that. > > >> No, they recieved the Nobel for discovering that the pulsar's components > >> were decaying exactly in accordance with general relativity's prediction > >> of gravitational radiation. > > >Crackpot, why do you insist on trying to find a mistake in my posts? > > >Do you feel some need to be permanently ridiculed in public? :-) > > >From the Nobel commite: > > >(\blockquote > > The Royal Swedish Academy of Sciences has decided to award the Nobel > > Prize Physics for 1993 jointly to Russell A. Hulse and Joseph H. Taylor, > > Jr, both of Princeton University, New Jersey, USA *FOR* the discovery of > > a new type of pulsar, a discovery that has opened up new possibilities > > for the study of gravitation > >) > > http://nobelprize.org/nobel_prizes/physics/laureates/1993/press.html > > > > >>>1) Gravitational waves have been never detected. Everything about > >>> pulsar is about indirect tests. > > >>>2) Last high precision observations reveals that binary pulsar is > >>> better > >>> described by non-geometrical theory of gravity which gives the same > >>> prediction than GR more a 1% excess cannot be explained using GR. > > >> Let's see the literature reference. > > >Why would waste time with a crackpot liar as you? :-) > > You always have an excuse, but never a citation. You always find mistakes in others' posters, but never are real :-)
From: Eric Gisse on 30 Nov 2008 09:02
On Nov 30, 3:51 am, "Juan R." <juanrgonzal...(a)canonicalscience.com> wrote: [...] > You always find mistakes in others' posters, but never are real :-) How would you know? You never discuss anything - you snip my arguments, insult me, and then repeat the claims as if they were true. |