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Natural Science Forum / Physics / Relativity / March 2007Neophyte question.
I have been nagged for years by the following: Let's say that the earth started spinning really fast on it's axis. So fast that we all flew off because of centripetal force. What would it have to be spinning relative to in order for this to happen? The Sun? The "Universe"? It's own sub atomic particles? If the earth was the only thing in the universe, would it be possible for it to spin? Dave Reckoning Indiana >I have been nagged for years by the following: > [quoted text clipped - 9 lines] > Dave Reckoning > Indiana You've answered your own question. It's own [sub atomic] particles, although why they have to be "sub atomic" is mysterious. Two rocks tied together with string will still spin until the string breaks. Did you want confirmation of your correct finding? You have it. >>I have been nagged for years by the following: > [quoted text clipped - 12 lines] >> Dave Reckoning >> Indiana >You've answered your own question. >It's own [sub atomic] particles, although [quoted text clipped - 3 lines] >Did you want confirmation of your correct finding? >You have it. Am I correct in assuming that if the rock-string configuration were the sum total of the universe that it could still manage to "spin" relitive to itself and therefore cause tension in the string? Humbley, Dave Dear Dave Reckoning: ... > Am I correct in assuming that if the rock-string > configuration were the sum total of the universe > that it could still manage to "spin" relitive to itself and > therefore cause tension in the string? Ernst Mach did not think so. If the total mass of the Universe were two rocks and string, whatever configuration the total was in would be "inertial", and variations from this would be "non-inertial". David A. Smith > Dear Dave Reckoning: > [quoted text clipped - 9 lines] > > David A. Smith Mr. Smith, thanks for the great reference, that helped define the problem much better. Are there those who would disagree with Mach? Dave Reckoning Noblesville, Indiana Dear Dave Reckoning: >> Dear Dave Reckoning: >> [quoted text clipped - 13 lines] > > Are there those who would disagree with Mach? Oh, sure. Some people feel that inertia resides in the object being accelerated alone. The Universe is just an uninterested bystander. There are those that say that Mach just wasn't quantitative enough to be helpful. His arguments are / were "emotionally satisfying", but all they managed to do was point in a particular direction. Science is all about making quantitative predictions, and he made none that were testable. No matter how cool I think his ideas were... David A. Smith >> Dear Dave Reckoning: >> [quoted text clipped - 14 lines] > > Are there those who would disagree with Mach? Yes, Einstein. I already gave you the reference. Cheers, Harald > Dave Reckoning > > Noblesville, Indiana >>> Dear Dave Reckoning: >>> [quoted text clipped - 16 lines] > > Yes, Einstein. I already gave you the reference. Your dog, this "Einstein" character, is it? >>>I have been nagged for years by the following: >> [quoted text clipped - 28 lines] > > Dave You do not need to assume or propose non-existent universes. We live in this universe with this universe's laws of physics. What goes on in your imaginary universe will have whatever imaginary laws you dream up for it and nobody can check it. Thus I can imagine two universes, one in which the string is taut and the other in which the string is slack, but who cares what I imagine? In this universe the behaviour of the bolas is known. In this universe the behaviour of the Earth is known. In this universe the behaviour of the Moon is known. There is only one universe, by definition. Try to separate reality from your imaginations. The rocks are going in opposite directions in straight lines and meet a double noose hanging in space. The nooses snag the rocks, the forward motion is halted and circular motion commences. The string then breaks, circular motion ceases and reverts back to forward motion. the rocks fly apart and never see each other ever again. >I have been nagged for years by the following: > > Let's say that the earth started spinning really fast on it's axis. So > fast > that we all flew off because of centripetal force. Likely more correct, is to say that it is because of inertial force. > What would it have to be spinning relative to in order for this to happen? > The Sun? The "Universe"? It's own sub atomic particles? We measure that it is spinning relative to the distant stars. From there on we move to metaphysics. After some reflection, Newton and also Einstein held that this implies some kind of physical "space". As Einstein put it in 1920: "the mechanical behaviour of a corporeal system hovering freely in empty space depends not only on relative positions (distances) and relative velocities, but also on its state of rotation, which physically may be taken as a characteristic not appertaining to the system in itself. In order to be able to look upon the rotation of the system, at least formally, as something real, Newton objectivises space. [...] this conception of the ether to which we are led [...] not only conditions the behaviour of inert masses, but is also conditioned in its state by them." - http://www.mountainman.com.au/aether_0.html > If the earth was the only thing in the universe, would it be possible for > it > to spin? It depends on what you mean with "thing". If there is nothing else (not even "space"), obviously it cannot spin. Harald On Mar 30, 9:04 am, "harry" <harald.vanlintelButNotT...@epfl.ch> wrote: > >I have been nagged for years by the following: > [quoted text clipped - 27 lines] > > Harald Harry,how do you manage it,how do you manage to go all these years being clever when a single paragraph from Newton makes you look a lot less clever than even Albert was.Is there some legal requirement for people over 50 to carry on waltzing to a 1905 tune long after the party is over. Albert said Newton objectives space hence aether/absolute space but the powdered wig went out of his way to explicitly state what he thought about aether - "The fictitious matter which is imagined as filling the whole of space is of no use for explaining the phenomena of Nature, since the motions of the planets and comets are better explained without it, by means of gravity; and it has never yet been explained how this matter accounts for gravity. The only thing which matter of this sort could do, would be to interfere with and slow down the motions of those large celestial bodies, and weaken the order of Nature; and in the microscopic pores of bodies, it would put a stop to the vibrations of their parts which their heat and all their active force consists in. Further, since matter of this sort is not only completely useless, but would actually interfere with the operations of Nature, and [314] weaken them, there is no solid reason why we should believe in any such matter at all. Consequently, it is to be utterly rejected." Optics 1704 I actually think it is amazing the way you and your buddies here can still carry on and have Albert dump aether back on Newton as 'absolute space' and then reject it all over again - " In order to be able to look upon the rotation of the system, at least formally, as something real, Newton objectivises space. Since he classes his absolute space together with real things, for him rotation relative to an absolute space is also something real. Newton might no less well have called his absolute space ``Ether''; what is essential is merely that besides observable objects, another thing, which is not perceptible, inust be looked upon as real, to enable acceleration or rotation to be looked upon as something real. " Albert. The joker in the pack is actually John Flamsteed insofar as Johnny took a particularly awful shortcut in his quest to hitch the Earth's rotation to celestial sphere geometry.While it is nice and all to see where Newton took that shortcut,the good news is that the actual principles which correlate clocks with axial rotation at exactly 24 hour/360 degrees do two wonderful things - they restore much of Copernican heliocentricity and its refinements and they highlight what happens when people lose the plot. > I have been nagged for years by the following: > [quoted text clipped - 9 lines] > Dave Reckoning > Indiana Love your nickname by the way. Dear,oh dear oh dear,what am I to do with the lot of you,a simple error made by Flamsteed who announced in 1677 that he proved axial rotation is constant by using the return of the star Sirius to his location in 23 hours 56 minutes 04 seconds to justify the axial/ orbital motion of the Earth - "... our clocks kept so good a correspondence with the Heavens that I doubt it not but they would prove the revolutions of the Earth to be isochronical... " John Flamsteed Now,whether you are an aetherist,relativist or good old Newtonian,you will take that 23 hour 56 minute 04 second value as sacrosanct,the problem is that the value does not prove axial rotation is constant for the simple reason that it only works with a 1461 day calendrical cycle split into 3 years of 365 days and 1 year of 366 days. Albert's space is indeed 'warped' but it is the familiar warping of celestial sphere/constellational geometry all wrapeed up in that 23 hour 56 minute 04 second value,I will even show you what it looks like - http://www.opencourse.info/astronomy/introduction/02.motion_stars_sun/celestial_ sphere_anim.gif Of course when you take the appreciation of the great astronomical cycles from observation of celestial phenomena you spend 100 years of wasted effort promoting a 1898 science fiction novel by H.G. Well's - "'Scientific people,' proceeded the Time Traveller, after the pause required for the proper assimilation of this, 'know very well that Time is only a kind of Space" http://www.bartleby.com/1000/1.html To think that I used to spend a lot of time in this forum and now only stay long enough to remind neophytes that none of it is worth it,not relativity which is merely an extreme sysmptom,but rather the late 17th century disease itself. >> I have been nagged for years by the following: >> [quoted text clipped - 24 lines] > Now,whether you are an aetherist,relativist or good old Newtonian,you > will take that 23 hour 56 minute 04 second value as sacrosanct, Yes indeed, less the gradual slowing over eons as energy is lost to tidal forces. > the > problem is that the value does not prove axial rotation is constant If it were not constant you'd soon know as the ground accelerated and decelerated beneath you and the oceans sloshed over the continents, you idiotic moron. > for the simple reason that it only works with a 1461 day calendrical > cycle split into 3 years of 365 days and 1 year of 366 days. Bullshit, you ignorant imbecile, that is an approximation good enough to convert from the Julian to Gregorian calendar, it is not a exact figure. > Albert's space is indeed 'warped' but it is the familiar warping of > celestial sphere/constellational geometry all wrapeed up in that 23 > hour 56 minute 04 second value,I will even show you what it looks like > - > > http://www.opencourse.info/astronomy/introduction/02.motion_stars_sun/celestial_ sphere_anim.gif That's a joke, the Earth is not turning. Your mind is warped. > Of course when you take the appreciation of the great astronomical > cycles from observation of celestial phenomena you spend 100 years of [quoted text clipped - 10 lines] > relativity which is merely an extreme sysmptom,but rather the late > 17th century disease itself. You are almost as dumb as Dork Van de merde, but you are right about one thing. You are not worth replying to further. *plonk* (again). On Mar 30, 6:10 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > >> I have been nagged for years by the following: > [quoted text clipped - 27 lines] > Yes indeed, less the gradual slowing over eons as energy is lost > to tidal forces. > > the > > problem is that the value does not prove axial rotation is constant [quoted text clipped - 18 lines] > > That's a joke, the Earth is not turning. Your mind is warped. http://www.opencourse.info/astronomy/introduction/02.motion_stars_sun/celestial_ sphere_anim.gif Every star in that animation will return in 23 hours 56 minutes 04 seconds but only when there are 3 years of 365 days and 1 year of 366 days hence the joke that got out of hand. There are no external references for the correlation which keep clocks in sync with axial rotation at 15 degrees per hour making exactly 24 hours through 360 degrees,it is just a complimentary human devised creation via the Equation of Time correction (equable 24 hour day) overlayed on the secondary Copernican principle that axial rotation generates the daily cycle. So much fuss for centuries over a silly mistake by Flamsteed.At least the guys in the last century pulled it off as did the Newtonian disciples.We get to pick up the pieces. > > Of course when you take the appreciation of the great astronomical > > cycles from observation of celestial phenomena you spend 100 years of [quoted text clipped - 16 lines] > > - Show quoted text - > On Mar 30, 6:10 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 58 lines] > Every star in that animation will return in 23 hours 56 minutes 04 > seconds Yes, that's the sidereal day. > but only when there are 3 years of 365 days and 1 year of 366 > days hence the joke that got out of hand. It has to do with the rotation of the earth and nothing to do with the 365.23 day orbital period. On the other hand, the fact that the solar day is longer does have to do with the orbital period, since the earth has to rotate 361 degrees for the sun to be in the same location in the sky. > There are no external references for the correlation which keep clocks > in sync with axial rotation at 15 degrees per hour making exactly 24 > hours through 360 degrees, No, the external reference (the sun) makes exactly 24 hours in about 361 degrees. - Randy > > On Mar 30, 6:10 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > > wrote: [quoted text clipped - 82 lines] > > - Show quoted text - Look Randy,just for you I will explain how the 24 hour day and subsequently equable hours,minutes and seconds were created by men,Then I will explain how it was adapted to axial rotation when Copernicus discovered axial rotation causes the daily cycle. It is just a once off thing unlike all those times before but be prepared for the first accurate explanation of how clocks keep in sync with axial rotation at precisely 4 minutes for each degree of rotation making 24 hours/360 degrees exactly. > > > On Mar 30, 6:10 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > > > wrote: [quoted text clipped - 84 lines] > > Look Randy,just for you I will explain how the 24 hour day Don't bother. Sidereal day, solar day. In 50 million messages you have never shown any glimmer of understanding why there are these two different periods, despite being linked to pictures many times. Your explanations are nonsense. The earth is in orbit around the sun. That means that after a 360 rotation, the sun will not be in the same position in the sky. - Randy >> On Mar 30, 6:10 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> >> wrote: [quoted text clipped - 80 lines] > > - Randy Even you are not as stupid as Kellerher, who constantly sticks his stupid oar in every thread where he thinks someone as stupid as he is will think the Earth doesn't turn on its own axis 360 degrees (or 2pi radians) in 23h 56m 4.1s with a constant rate of rotation. I used to think he was salvageable, but he's a total loon. I swear he really thinks the universe revolves around the Earth. Then the moron wonders why nobody listen to him. Good luck if you can dent that thick skull of his with a glimmer of logic. Incidentally, the sun does not go noon-to-noon in 24 hours. http://antwrp.gsfc.nasa.gov/apod/ap061223.html Absolute, true, and mathematical time, of itself, and from its own nature flows equably without regard to anything external, and by another name is called duration: relative, apparent, and common time, is some sensible and external (whether accurate or unequable) measure of duration by the means of motion, which is commonly used instead of true time; such as an hour, a day, a month, a year. - Sir Isaac Newton. On Mar 30, 4:21 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > >> On Mar 30, 6:10 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > >> wrote: [quoted text clipped - 94 lines] > > http://antwrp.gsfc.nasa.gov/apod/ap061223.html Interesting. No, I didn't think that the position was *exactly* the same in the sky, but I was trying to convey as simply as possible the reason why solar day and sidereal day are different. I'm not quite sure why this pattern is a figure-8, but I suspect it is related to another figure-8. Long ago I was doing satellite orbital calculations, and one validation of my program was that the ground track of a geosynchronous satellite with an inclined orbit is a figure-8. - Randy > On Mar 30, 4:21 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 101 lines] > as possible the reason why solar day and sidereal day are > different. Not to Kellerher you can't, as you've seen. He wants to explain the 24-hour day the way Roberts wants to explain speed. "Imagine a train leaving one city at 12:00 and arriving in a city 60 miles to its west at 12:01. Do you really think that train traveled 3,600 miles per hour? Of course not! This example used two _different_ coordinate systems for "time", the two timezones of those two cities. To obtain the speed you _must_ use a single coordinate system; then you'll realize it traveled just under 60 miles per hour." -- Screwball Roberts. Is that a joke, or what? Factually correct, but sheesh...you can see why he is no longer employed by Lucent Technologies. Who knows why these goofballs think they are smarter than anyone else and then display such stupidity? > I'm not quite sure why this pattern is a figure-8, but > I suspect it is related to another figure-8. Long ago [quoted text clipped - 4 lines] > > - Randy It's pretty simple. The height results from the tilt of the Earth, we all know the sun is higher in the sky at noon in summer than in winter. The width results from the eccentricity of the Earth's orbit. It just so happens that in our epoch (in the fullness of time) perihelion is only days away from solstice (Dec 23 to Jan 2nd/4th) which is a quirk, not a general rule. What you should NOT do is imagine the points are equidistant in time, even if they are roughly equidistant spatially. I have the analemma of Mars (clearly computed) saved at http://www.androcles01.pwp.blueyonder.co.uk/Analemmae/Analemmae.htm Moreover, I've computed (and demonstrated) the analemma of a cepheid. It is from such data that I *KNOW* Einstein was a goofball. Think 3D. We have only just begun since Copernicus. > On Mar 30, 4:21 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 121 lines] > > - Randy Isn't it a loop that crosses itself (figure 8) because the orbit is not a circle but an ellipse? Dave Reckoning > On Mar 30, 4:21 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 113 lines] > > - Show quoted text - There is actually a badge of pride in being able tio find your way out of the analemmatic fudge of the late 17th century,that notorius figure-8 that was brought in as an act of vandalism,specifically the idea that the Earth has a variable axial tilt. Easy enough to get rid of the analemma nonsense even if you have no idea why . What does the analemma look like at the Equator where there is a constant daylight/darkness symmetry over the course of an annual orbit.The answer is that variable axial inclination of the Earth to the Sun is a wild goosechase and the answer lies in Keplerian orbital geometry and the orbital path of the Earth. Of course you give all your effort ot supporting the symptoms of the Newtonian disease,otherwise known as relativity therefore I do not hold out much hope of you finding your way out of the late 17th century labyrinth which created these ridicilous analemma notions and the facile attempts to explain the Equation of Time via axial tilt. > On Mar 30, 4:21 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 113 lines] > > - Show quoted text - A few loose ends to tidy up. You ,as representative of the major institutions , require the Sun to return to a meridian in exactly 24 hours in order to justify why a star returns in 23 hours 56 minutes 04 seconds - http://hypertextbook.com/facts/1999/JennyChen.shtml The actual graphic for this shows a ,986 degree/3 minute 56 second orbital displacement - http://www.pfm.howard.edu/astronomy/Chaisson/AT401/IMAGES/AACHCIR0.JPG Now the Total length of each individual cycle as determined at noon has been known since antiquity hence the noon Equation of Time correction to equalise to 24 hours and from there to checking the accuracy of a 24 hour clock yet you find the greatest difficult in understanding this. The Equation of Time is a global astronomical correction meaning it has nothing whatsoever to do with hemispherical daylight/darkness asymmetry nor that pseudo-dynamic of variable axial tilt.The natural inequalities in the daily cycle have to do with the change in the solar radiation/orbital shadow (SR/OS) boundary is accordance with Keplerian orbital geometry .The shift from taking the orbital path of the Earth into account thereby jettisoning this pseudo-dynamic of variable axial tilt would not be for people who make the effort to understand the Newtonian conceptions let alone the later early 20th century exotic extensions. Such a simple mistake is Flamsteed's,that wonderful way to sound like an authority while forgetting that the 1461 calendar cycle split into 3 years of 365 days and 1 year of 366 days is a terrible way to promote the axial and orbital motions of the Earth.It is however a great convenience for numbskulls who think astronomy is solely exercise in magnification and their goto telescopes.For everyone else it is a disaster. You are right,it feels like 50 million messages to promote the idea that clocks keep in sync with axial rotation at 15 degrees per hour making 24 hours through 360 degrees but with all due respect I can walk away with a more pure appreciation of the once great astronomical heritage,even where Flamsteed/Newton jumped the tracks,but I cannot account for why people who have such wondeful data in this era cannot find their way out of contrived notions which are neither productive or interesting. The next generation may be the first in centuries to appreciate the two step process which links the pre-Copernican principle of the 24 hour day to the heliocentric adaption to clocks and axial rotation and this is ultimately what people should strive towards. After many years,that is that,at least in this forum. ----- Original Message ----- From: "oriel36" <kelleher.gerald@gmail.com> Newsgroups: sci.physics.relativity Sent: Friday, March 30, 2007 3:36 PM Subject: Re: Neophyte question. > On Mar 30, 6:10 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 93 lines] >> >> - Show quoted text - Hmmm, I thought that the earth spun around on it's axis either 366 or 364 times a year, the extra day being taken up in rotation around the sun. Am I not right about this? Is there not one more or less (I forget now) celestial day than there is solar day a year? I suspect that is what you are saying but I am just a bit too dense to understand :( Dave Reckoning Noblesville. >I have been nagged for years by the following: > [quoted text clipped - 4 lines] > What would it have to be spinning relative to in order for this to happen? > The Sun? The "Universe"? It's own sub atomic particles? An inertial frame. > If the earth was the only thing in the universe, would it be possible for > it > to spin?] Yes. Bill > Dave Reckoning > Indiana Original Message ----- From: "Dave Reckoning" <John@smith.com> Newsgroups: sci.physics.relativity Sent: Thursday, March 29, 2007 6:48 PM Subject: Neophyte question. >I have been nagged for years by the following: lotsa great ideas and controversy snipped here So, the conclusions it seems that I can draw from the answers this group gave are: 1) No one really knows (because if they did it would not take 45 messages and some fine insults to answer) 2) This news group is a highly entertaining and enlightening forum and is not well suited to answer this type of question in a concise manner I learned a lot about physics and sociology here, a hearty and sincere thank you to all of you for your tutelage. Dave Reckoning Noblesville, Indiana > Original Message ----- > From: "Dave Reckoning" <John@smith.com> [quoted text clipped - 10 lines] > > 1) No one really knows Ok, you've been answered, now f.ck off. > So, the conclusions it seems that I can draw from the answers this group > gave are: [quoted text clipped - 4 lines] > 2) This news group is a highly entertaining and enlightening forum and is > not well suited to answer this type of question in a concise manner Number 2 is largely correct, but number 1 is not. Ignoring all the irrelevant blather about aether and "physical space" and the other nonsense that was presented, the answer to your query according to relativity is the following. http://www.lepp.cornell.edu/spr/2000-11/msg0029419.html ---Tim Shuba--- |
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