A rotating frame is non-inertial because it doesnt follow Newtons law that says that only when a force is applied an acceleration will be produced in direction of force application. now acceleration is a vector.since while rotating acceleration changes constantly,(because of it direction changed) without any force instantaneously being applied,thus a non-inertial frame. A pseudo force called centri-fugal force is assumed to have been applied to make the frame inertial,in order to tackle the problems . if i am wrong James kindly rectify me... bye!
"With the first one, alarm bells started ringing as soon as I read the qualification of the author (from the "Association for Biblical Astronomy"). It then goes on to quote a 1938 paper for the supposed incompatibility of the effect with relativity. (Nothing more recent?) ........................." i didn't read it myself just quickly looked, saw Ph.D (not the Association for Biblical Astronomy) --> bad link, sorry "I haven't read Babin's paper in full, but reading the conclusion is sufficient to show that he does not understand special relativity, because he refers to a "universal reference frame" or similar defined by the speed of light." i know but there're quite a lot of submitted papers to read had just a quick look myself just found that link myself "Lindner (MD) seems to be more concerned with philosophy more than physics. (Does he have any physics training?) While I agree with your point that relativity is based on some axioms which could be considered a kind of philosophy, the veracity of those axioms is supported by an enormous body of experimental and observational evidence. Thus, relativity cannot be considered to be a philosophical construct. It is solid science." there is the possibility at the university to study Physics without any maths and is mainly concerned with the philosophical implications etc. I think it is called 'metaphysics' when you hear of debates between physicians and philosophers, then it is about that kind of philosophers and they NEVER agree in debates, both say of each other that the other side just doesn't understand it! (the recent debate on Time for example) If you want my opinion, it is the philosophers who understand the matter better: philosophy is the basis of physics physicians tend to think that they can be an objective observer, conducting experiments, reading the data, confirming it, etc. all without philosophical implications --> this is absolutely wrong: otherwise there wouldn't be any discussion going on in any science field philosophy is primary, not physics now, when you say Solid science I will have to interrupt you it's true: E = mc² is great formula and is correct but what about decay processes: they had to postulate a new neutral particle "neutrino" because the observed amount of energy output was not in accordance with Special relativity now, afterwards, they claim the neutrino has been found and that is still very much open to debate unlike many would like to have it also, the principle of equivalence which is ABSOLUTELY vital for BOTH special and general relativity is according to me not at all correct and I gave a simple example (to which no one responded) previously to explain why I think this is so --> mass-energy conservation is ALWAYS valid, also for gravitational acceleration!!! also, the Lorentz equation are mathematical correct but not PHYSICALLY! (see Carezani at http://www.autodynamics.org ) lastly, relativity explains phenomena with things like "time dilation", "length contraction" etc. (because of Lorentz transformations) which simply do not feel like the BEST explanation to me, and when you find that people like Marmet explain this easily with De Broglie equations, etc. then these extroadinary claims of relativity are utterly useless I find it also incredible that so many clever scientists out there erronously believe that time is what a clock displays .. A clock does not measure time!! when such people read data from a clock and from that derive that time must have slowed down then I wonder where their sense of reason is.
"Bear in mind that the speed of light measured by an inertial observer outside the Sagnac apparatus or in an inertial frame co-moving with a particular point on the rotating apparatus is the same." but the MEASURED speed of light IS different as the formula easily proofs it doesn't matter what the real speed is the measured speed is still different and the measured speed of an observer outside the rotation will measure a different speed (just c normally) so your claim is easily proofed wrong you should have said that the speed is always the same not the MEASURED speed BUT i ask again: if you say we have calculated a Relative velocity "V", then what is the local inertial frame in this specific example? I would like to know of which one you are thinking and I am not talking about an apparatus but about the earth here "There are no absolute frames of reference." according to relativity that is
Just a question: which force makes the earth rotate on its axis ???? and if there's no force doing that, what is the cause ...
c'est moi, Thanks for your post. I am glad you didn't dig in and assert that the three sites you linked about were gospel, which you could easily have done, forcing me to go to extra effort to show them wrong. Metaphysics is concerned largely with the basis of being - what it means for things to exist, why there is something rather than nothing, what we can be sure is real - that sort of thing. Those questions are technically outside the scope of science. I'm not saying that they are not worth asking. I agree that philosophy is an important discipline in its own right. Science is more concerned with describing how things work than explaining the true underlying nature of things; that is a job for metaphysics. Thus, science has a good description of time, but cannot explain things like why time exists in the first place. <i>If you want my opinion, it is the philosophers who understand the matter better: philosophy is the basis of physics</i> As I said, I think they deal with different things. Many philosophers don't understand physics. Many physicists don't know much philosophy. Some people in both disciplines have a good knowledge of both. Let's look at some of your science issues, which I can provide some definite answers to (there are no definite answers in philosophy): <i>E = mc² is great formula and is correct but what about decay processes: they had to postulate a new neutral particle "neutrino" because the observed amount of energy output was not in accordance with Special relativity now, afterwards, they claim the neutrino has been found and that is still very much open to debate unlike many would like to have it</i> The existence of the neutrino was postulated on the grounds of energy and momentum conservation issues in various nuclear processes. Energy and momentum conservation are fundamental concepts of physics. The problems raised could be fixed in two ways - throw away energy and momentum conservation OR postulate a new particle. Much less "damage" came from postulating a new particle. Countless subsequent experiments have tended to confirm the existence of the neutrino. I am interested to know why you think its existence is still an open question. <i>also, the principle of equivalence which is ABSOLUTELY vital for BOTH special and general relativity is according to me not at all correct</i> Yet no experiment has contradicted it (despite certain claims you may see strewn around the internet). <i>the Lorentz equation are mathematical correct but not PHYSICALLY!</i> Autodynamics has been refuted by others, so I won't get into that here. <i>lastly, relativity explains phenomena with things like "time dilation", "length contraction" etc. (because of Lorentz transformations) which simply do not feel like the BEST explanation to me</i> Much of physics is counter-intuitive. I personally find quantum mechanics much more bizarre than relativity. But history has shown (in physics at least) that common sense is no guide to a good scientific theory. We must be led by the evidence. <i>...and when you find that people like Marmet explain this easily with De Broglie equations, etc. then these extroadinary claims of relativity are utterly useless</i> At some stage, I will probably have to critique Marmet in detail. Unfortunately, there is a lot of information there and I have limited time. Suffice it to say that I have serious doubts about the correctness of Marmet's theories, but I admit I have not looked at them in detail yet. If they were sound, why have they not been published in peer-reviewed journals? <i>I find it also incredible that so many clever scientists out there erronously believe that time is what a clock displays...</i> They don't. When relativists say "clock" they mean "any device which can measure time". That includes you pulse, your digital watch, a swinging pendulum, the rate at which you age, your heart rate, and so on. Regarding the Sagnac effect: the usual inertial frame used is the frame of the "fixed stars". The rotating frame is often the Earth. Did you know that 747s rely on the Sagnac effect for navigation? They use laser gyroscopes, which work according to the Sagnac effect. <i>which force makes the earth rotate on its axis ???? and if there's no force doing that, what is the cause ...</i> The Earth was spinning when it formed out of the dust cloud which formed the solar system. Since there are very few friction effects in space, it just hasn't slowed down very much yet. There is no force needed to keep it spinning.
Which is precisely why philosophers still are inconclusively opining wholesale on the very same indefinite indeterminates with which they long ago started their process. Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image!
"Science is more concerned with describing how things work than explaining the true underlying nature of things; that is a job for metaphysics." you are partially wrong, and your own answer later on clarifies this: you said: "They don't. When relativists say "clock" they mean "any device which can measure time". That includes you pulse, your digital watch, a swinging pendulum, the rate at which you age, your heart rate, and so on." again, the fundamental question is: WHY does ANY of the things you name (they simply show uniform motion) MEASURE time? where is the argument, where is the proof? You can say this is business for metaphysics but look how important this is for science. One of those last debates between philosophers and physicians I read about was about this: Does time really exist or not (and all other things related to time issues.) Of course, it ended with a huge disagreement between each other, also between the physicians!! So, when I read that time slows down then my little alarm bell ringes also. IT is an empty claim. Let me go into this deeper: Let us say that with a device which performs an uniform motion we can really measure time. What does this IMPLY: it implies that Time is Something that FLOWS. Whether it is a continuous flow or in pieces, it doesn't matter. Time must be something that is "flowing" by, otherwise this device cannot measure this "amount" of time. But is there anything, apart from your feelings maybe, that tells us that time "flows"? Nope. and that is for me a very big objection against the interpretation of relativity concerning "time dilation". You name the aging of my body as a "clock". This is entirely an assumption: the "aging" can simply be explained with motion alone. Time is used as a parameter or as an "excuse" for the motion, but motion is primary. If we say something is old, like an old building: is it time that caused this? why would it be time --> the building has basically been damaged by motions, not by time Is time needed for motion to occurre? I don't know but i wouldn't be to sure of the big YES. Time might very well be a man-made concept, which appears to be usefull in mathematics. "Thus, science has a good description of time, but cannot explain things like why time exists in the first place." thus science has basically no description of time, it can't say what it is, what it does and why it would change of rate at great speed it tells us almost nothing "The existence of the neutrino was postulated on the grounds of energy and momentum conservation issues in various nuclear processes. Energy and momentum conservation are fundamental concepts of physics." and yet not compatible with relativity, and this is very true, conventional scientist have said this equivalence pr. is not compatible with mass-energy conservation "The problems raised could be fixed in two ways - throw away energy and momentum conservation OR postulate a new particle. Much less "damage" came from postulating a new particle." no: trow away relativity or introduce a particle it was the predition of relativity that appeared wrong autodynamics claims to be in perfect agreement without any neutrino, you might want to verify that "Countless subsequent experiments have tended to confirm the existence of the neutrino." I've read about the experiments and why they don't provide the proof, but can't remember where if i'm correct, autodynamics website has a small section on that basically there a other things that are also neutral (like gamma rays) and which will penetrate and confuse the experiment the claim that this is 100% prevented is not true "Yet no experiment has contradicted it (despite certain claims you may see strewn around the internet)." not compatible with mass-energy conservation i gave an example from marmet earlier: inertial acceleration the mass aquirers energy, i can stand here submitted to earth's gravity all day and i don't increase my energy "Autodynamics has been refuted by others, so I won't get into that here." marmet says lorentz equation are correct but interpreted wrongly, i.e. the lenght of an object really physically changes (due to kinetic or gravitational energy) and not space(time) "Much of physics is counter-intuitive. I personally find quantum mechanics much more bizarre than relativity." It is not "bizarre" that holds me: it is the feeling that there's an easier way to explain it (and my thoughts on time I gave earlier in this post) the world, the universe, i find everything bizarre when i think about it life is strange "At some stage, I will probably have to critique Marmet in detail." probably yes "Unfortunately, there is a lot of information there and I have limited time." idem ditto "If they were sound, why have they not been published in peer-reviewed journals?" i think that question answers itself! we all know how research in science should be and how it IS look back in history and see: nothing has changed though many (honestly) think it has "Regarding the Sagnac effect: the usual inertial frame used is the frame of the "fixed stars". The rotating frame is often the Earth. Did you know that 747s rely on the Sagnac effect for navigation? They use laser gyroscopes, which work according to the Sagnac effect." the stars are not fixed, we know that this is the objection that autodynamics puts forward: you don't need a third observer (frame whatever), it's not usefull imagine the earth alone in space, nothing else: just you with your Sagnac experiment equipment and the earth: you do your thing, and are able to calculate the velocity of the earth's rotation why would i need something else, why calling in "fixed" stars? i think this issue has also a great deal to do also with Mach's principle fort the record: i would like to find myself a descent book on relativity which must: - explain all the principles of general and special relativity with great clarity - for each principle an experiment is provided which shows why they are correct: no gedanken experiment --> real ones who have been done - maths are welcome: but not too much and clear enough - the history must also be explained: why came relativity, what was it with Lorentz, Maxwell, etc. in not in three sentences! IS THERE SUCH A BOOK OUT THERE??? (hope so)
I've seen the term "counter-intuitive" all over the place. It's ridiculous. Through billions of years of evolution, we have existed according to physical laws of our universe. Our intuition is absolutely and irrefutably entwined with physics, in one way or another. I think the term "counter-intuitive" is used as a pseudo-philosophical back-up to support equations which seem to fit what is known yet are not actually absolute proofs. I suspect every true law of physics will turn out to be 100% in accord with our intuition. We have billions of years of life to back that up.
Years ago this hamster and a physicist built an Orbital Maneuvering Vehicle simulator. One exercise was to dock with the Hubble Space Telescope. Paradoxically, to overtake the telescope from some orbits one had to slow down. This dropped the OMV into a lower orbit allowing the OMV to rotate around the earth faster than the telescope. Then the OMV could accelerate and dock with the telescope at the higher orbit. Intellectually this was not hard to understand. However, looking through a camera and just knowing what to do was not so easy. As the physicist described it, “It’d be easy if one had grown up as a fly on the whirling blades of a fan.” It takes an astronaut about a day to adjust to the changed dynamics of the shuttle. At first their actions and movements are slow and stumbling. By the second day they are jumping around, grabbing things, and working at almost normal speed. This hamster feels many aspects of General Relativity and Quantum Mechanics are counterintuitive. Quantum entanglement and ambiguities in “cause and effect” are two examples. The behavior of super cooled helium also seems bizarre to most people. Intuition is formed from experience with normal events. Abnormal events seem counterintuitive. Part of becoming expert in a field is developing intuition for the special weirdness in that field. With extensive experience an expert just feels that a certain concept is right. Then a new phenomenon comes along and the expert’s intuition isn’t any better than a child’s.
In NASA shuttle experiments involving astronauts playing with tennis balls and such, the astronuats demonstrate an almost inborn ability to judge how the ball will move in the microgravity of orbit. (Was all in New Scientist a few months back.) The people studying humans in space were starting to get the idea that we have a natural understanding of physocal laws even if only subconsciously. I have piloted a 2,500-odd ton frigate. It can be surfed along a big enough wave just like a surfboard on smaller waves near the beach. I could do this almost as soon as I began piloting the vessel; it only took enough time for me to learn the motions of the vessel itself. If something appears counter-intuitive, it is in my opinion because the idea is not properly understood. We are working with incorrect ideas which seem to fit but may not be the best solution. And when a moresuitable explanation is thought up, I suspect it will be perfectly intuitive. Only a day to adjust to moving in space? After decades on the ground? Seems rather intuitive to me. Intuition is more than learning by experience. In psychology, one of the rather famous experiments you might study involves having babies crawl along ashort corridor which has two different sides; on one side the floor is solid, while on the other the floor is a thin cover over a hollow area (the thin floor is stong enough to support the weight). The babies almost without exception crawl along the solid side, skirting around the hollow area. Other animals in the same experiment do the same. Pick a forest animal, and wonder why it will run from a forest fire. It has not been burnt alive before. Why does a young gazelle run from predators? Intuition. Not learning from experience.
This hamster applauds anyone wishing to develop more understandable theories. Evolution operated in the macroscopic earth environment. Would that evolutionary “learning” help an animal or a human understand Relativity or Quantum Mechanics? To the degree those theories describe everyday physics it might. But near the speed of light or at nanometer scale? Or exotic substances near absolute zero? Perhaps. Animal evolution has embedded innate survival information that in humans may form a component of intuition. However humans are far more guided by learning than by instinct. Instinct and early cultural training might have to be un-learned before new intuition could develop for an unusual subject. (A human might have to learn that it is safe to walk across a narrow bridge over a chasm. Some humans may never overcome that instinctive fear.) (This hamster may have a differing meaning for “intuition”. This hamster includes the insight that develops in chemistry, biology, mathematics, engineering, etc. that is acquired through the experience of working and thinking with concepts for years.)
c'est moi: <i>WHY does ANY of the things you name (they simply show uniform motion) MEASURE time?</i> Can't we avoid this whole problem by defining time as "what clocks measure"? If clocks don't measure time, what are they for? Interestingly, relativity doesn't describe time as "flowing". Time is just a co-ordinate, similar to a spatial co-ordinate. Why humans perceive time as flowing is an interesting philosophical question. <i>thus science has basically no description of time, it can't say what it is, what it does and why it would change of rate at great speed it tells us almost nothing</i> The scientific definition of time is linked into all areas of physics. Physics wouldn't exist without the concept of time. I'd say science says a lot about time. It doesn't answer the big question of "why time?", but then, it doesn't answer those sorts of questions at all. <i>Energy and momentum conservation are fundamental concepts of physics. ... and yet not compatible with relativity, and this is very true, conventional scientist have said this equivalence pr. is not compatible with mass-energy conservation</i> Which scientists said that? They are wrong. <i>i gave an example from marmet earlier: inertial acceleration the mass aquirers energy, i can stand here submitted to earth's gravity all day and i don't increase my energy</i> You are in the same non-inertial frame as the Earth whilst you stand on its surface. <i>the stars are not fixed, we know that</i> The term "fixed stars" really means "distant stars and galaxies" - all the other "stuff" in the universe. Mach's principle is very relevant here, as you say. <i>just you with your Sagnac experiment equipment and the earth: you do your thing, and are able to calculate the velocity of the earth's rotation</i> No. If there was nothing but the Earth in the universe, how would you know it was rotating? All rotation is with respect to something (i.e. relative). <i>i would like to find myself a descent book on relativity which must</i> The general relativity bible is probably Wheeler's <i>Gravitation</i>, though it is pitched at a reasonably high level. It has everything you've asked for. Maths and relativity are closely linked, so if you want the details it's hard to avoid the maths.
This hamster intends studying gravitation when the comic book version is released. John Wheeler’s book is way too thick, not light reading for an evening. It’s also thirty years old. Is it still relatively up to date? Know any good online tutorials?
"No. If there was nothing but the Earth in the universe, how would you know it was rotating? All rotation is with respect to something (i.e. relative). " I know this because of the difference in time I measured it's that easy you still haven't dealt with Marmet .............. Please Register or Log in to view the hidden image!
c'est moi: I just had a look at Marmet's book (on the web) about Classical mechanics vs. Einstein's relativity. He goes to a lot of trouble to establish the Lorentz transformations and so on, which are exactly the same as Einstein's equations. However, in the process, Marmet builds into his theory an idea of an absolute rest frame. I went looking for a point of conflict between Marmet's theory and relativity. Sure enough, in section 3.9 he writes: <i>Contrary to Einstein's claim, the energy given to a mass accelerated with respect to [a] train must depend on the direction of its velocity with respect to the direction of the velocity of the train. When the directions are opposite, the two velocities (whose magnitudes are equal) cancel out and the mass of the body must come back to its original value in the [absolute] rest frame. Otherwise we would discover that atoms of matter having traveled to another frame would have a different mass after their return to the initial frame. We must conclude that two frames cannot be equivalent when there exists a relative motion between them.</i> This conclusion is experimentally testable. In essence, Marmet is saying that the length contraction and time dilation effects are not seen equally in two reference frames moving at a constant relative speed to each other. He says that observers in both frames would see one of the frames' clocks slowed down with respect to the other frame. Einstein, on the other hand, says that <i>both</i> observers will see the other's clock slowed down. Experiment supports Einstein, not Marmet. No more reading is necessary.
A photon does indeed have a mass. Light is made of Photons and if one were to pass light by a black hole the light would refract (bend)into the black hole, this is due to the "mass" of the light or the Photon, Black Holes only attract things that do indeed have a mass. A Photomic mass is quite small but that is because it is a sub atomic particle, meaning "Being able to *live* or stay inside an atom" or "smaller than an Atom"
S Dalal A photon does indeed have a mass. That is quite an interesting claim. Can you provide any evidence? Light is made of Photons and if one were to pass light by a black hole the light would refract (bend)into the black hole, this is due to the "mass" of the light or the Photon, Black Holes only attract things that do indeed have a mass. Another outrageous claim. I'm beginning to get the feeling you don't know what you're talking about. Can you produce evidence? A Photomic mass is quite small but that is because it is a sub atomic particle, meaning "Being able to *live* or stay inside an atom" or "smaller than an Atom" Now I'm convinced you have no idea what you're talking about. What is a "photonic mass?" How does it *live* inside of an atom?
Hi, I was wondering...is earth an inertial frame of reference?if so why?(it should not be,i think)because of revolutions that change velocity(in terma of directions i mean)...Please Register or Log in to view the hidden image! bye!
