The fate of the Earth?
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From: dow on 18 Sep 2009 10:48 On Sep 17, 9:26 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > You seem hung up on rotation implying there is some external frame of > reference which does not rotate which can be used a reference. No such > reference frame is necessary. If I was on that rotating children's > roundabout, but it had walls all around it so I couldn't see the outside > world, I could still determine that I was on a rotating platform using > experiments entirely on the roundabout. No outside world is needed to > provide a non-rotating frame for comparison purposes. > > I am not surprised that the measurements show that the Universe is not > currently rotating to any significant degree. If it is rotating now, then by > conservation of angular momentum it must always have rotated with that same > angular momentum. When the Universe was very young and very small, even a > small amount of angular momentum translates into a very high rotation speed > indeed. This would seriously screw up models of the early Universe, a lot > would have to be changed if the Universe was determined to have non-zero > angular momentum. It is possible, but unlikely. A "frame of reference" is an abstraction. It has no physical reality. There may be real objects in it that are stationary. It may even be defined by reference to real objects, but the frame itself is no more than a conceptual convenience. I agree with you that you could determine if a roundabout on which you are riding is rotating without being able to see any external objects, but that does not invalidate the *concept* of a non-rotating frame of reference. Of course, if the universe was rotating at the instant of the Big Bang, when the whole universe was (according to many theorists) no bigger than a proton is today, then the rotation would have been slowed down immensely by the expansion that has occurred since. It's not surprising that we can't detect it today. But I suspect there would be observable traces. Things might look different in the directions of the rotational "poles" than toward the "equator", for example. The fact that no such anisotropy is observable suggests that there is no rotation, but it doesn't prove it. Theorists are still working on this issue... dow
From: G=EMC^2 Glazier on 18 Sep 2009 10:58 Peter Every thing rotates in the universe. Its naive thinking that the universe need not rotate.Galaxies rotate. Universe rotates relative to its center. So that is how it relates. Its size makes this possible Bert PS Its Center could be a black hole with more mass density than all of the universe around it. Black hole came out of the implosion of the big bang,and universe with all that is rotates around it. This is one of my theories that have posted in alt. astronomy many years ago. Bert PS BB explosion& implosion is natures first and biggest balancing act
From: Sam Wormley on 18 Sep 2009 11:16 G=EMC^2 Glazier wrote: > Universe rotates relative to > its center. Herb, the universe does NOT have a single center. Every point in the universe is effectively the center. To say that the universe a whole rotates, begs the question: Rotates with respect to what? I know that you won't (or can't) read these as you are too ____ to try. You are not to old to learn something new under the sun, Herb. you just don't want to. No Center http://www.astro.ucla.edu/~wright/nocenter.html http://www.astro.ucla.edu/~wright/infpoint.html Also see Ned Wright's Cosmology Tutorial http://www.astro.ucla.edu/~wright/cosmolog.htm http://www.astro.ucla.edu/~wright/cosmology_faq.html http://www.astro.ucla.edu/~wright/CosmoCalc.html WMAP: Foundations of the Big Bang theory http://map.gsfc.nasa.gov/m_uni.html WMAP: Tests of Big Bang Cosmology http://map.gsfc.nasa.gov/m_uni/uni_101bbtest.html
From: alien8er on 18 Sep 2009 15:26 On Sep 17, 2:20 pm, dow <williamsdavi...(a)gmail.com> wrote: > On Sep 17, 3:59 pm, alien8er <alien8...(a)gmail.com> wrote: > > > > > > > > No it isn't. It's an observed fact that a frame of reference in which > > > distant galaxies are not revolving is, at least very nearly, the same > > > as the frame that is absolutely rotationally stationary. > > > What do you mean "very nearly"? Either it is, or it isn't. > > > > Mach proposed > > > that somehow distant galaxies define the absolutely stationary frame, > > > but the mechanism by which they might do so is still highly > > > conjectural. > > > Do you realize that you stated this as "an observed fact" in the > > above paragraph? > > > Do you have a cite for this claim? > > > Mark L. Fergerson- Hide quoted text - > > > - Show quoted text - > > From:www.physics.adelaide.edu.au/itp/staff/pcwd/Guardian/1994/940922Mach.html 404 Not Found. > Also See:http://www.jse.com/haisch/zpf.html 404 Not Found. > Further evidence in favour of Mach's principle comes from cosmology. > If rotational motion is purely relative It isn't. Look up "Foucalt pendulum". Mark L. Fergerson
From: alien8er on 18 Sep 2009 16:08
On Sep 15, 12:58 pm, oriel36 <kelleher.ger...(a)gmail.com> wrote: > On Sep 15, 7:49 pm, alien8er <alien8...(a)gmail.com> wrote: > > > On Sep 15, 3:32 am, oriel36 <kelleher.ger...(a)gmail.com> wrote: > > > > On Sep 14, 11:06 pm, alien8er <alien8...(a)gmail.com> wrote: > > > > > On Sep 14, 1:36 pm, dow <williamsdavi...(a)gmail.com> wrote: > > > > > > > The bottom line is that there's no fixed reference anywhere against > > > > > > which to measure the Earth's rotation period; it isn't even measurable > > > > > > against itself, though its absolute rotation _rate_ is measurable. > > > > > > Ummm.. There is (or at least there is thought to be) an absolutely non- > > > > > rotating frame of reference, independent of observations of stars, > > > > > etc.. It's the frame in which there are no centrifugal or Coriolis > > > > > forces. Theoretically, the absolute speed of rotation of he earth is > > > > > its speed relative to this frame. > > > > > No, there's no such external reference. > > > > > Besides, I said its _period_ (length of a day) is not independently > > > > measurable. > > > > Grow up for godness sake and think like a man. > > > You are an arrogant prick. You must be French. > > > You asked what you apparently assumed was a simple question (it > > wasn't) and I gave you the most honest answer I know. That evidently > > wasn't good enough to satisfy you. Too bad for you. > > > > The Earth , as a sphere, will rotate at different speeds from a > > > maximum speed at the Equator down to zero at the geographical > > > poles.The values for an observer at the Equator is 1669.8 km for every > > > 15 degrees of rotation covering the complete 40,075 km circumference > > > through 360 degrees,at 60 degrees latitude,the rotational speed is 837 > > > km for every 15 degrees/1 hour and the same for all latitudes in the > > > table - > > > >http://www.ncgia.ucsb.edu/education/curricula/giscc/units/u014/tables.... > > > > There is a cause and effect of different latitudinal speeds which > > > would be fairly easy to acknowledge in an era of air travel where most > > > people are aware of the rapid transition from daylight to darkness > > > the further towards the Equator and obversely,the longer twilights > > > experienced towards the geographical poles.At any given moment,a > > > location at the Equator is transiting at 1669.8 km per hour through > > > the circle of illumination generating a swift transition to darkness > > > while at 60 degrees latitude,the transition is longer due to the speed > > > of 837 km or 833 km less than the Equator speed. > > > Blah, blah, blah. Yes, I know all that. > > Good !,that makes you my first attentive student now go teach the rest > what you just comprehended. I didn't "just" comprehend it, I certainly am not your "student", and everyone else already knows it as well. I said as much when I described the three kinds of "day". Weren't you paying attention? My point is that you cannot measure the Earth's rotation _period_ without using an external reference, and THEY ALL MOVE. > > > A reasonable > > > person,and there are not many at the moment,accepts the cause and > > > effect with the values reflecting rotation through 360 degrees in 24 > > > hours and then teaches their students or kids properly. > > > 360 degrees _measured against what_? You _cannot_ measure the > > rotation of the Earth against itself only. > > The transition from daylight to darkness You cannot measure the rotation of the Earth against the sun because IT MOVES. > > You appear to be _assuming_ that the solar day is the only "proper" > > day. That's all very nice, but it varies through the year and is > > therefore a poor standard. It is also completely useless for aiming > > astronomical telescopes. > > Grow up for goodness sake Don't just deliver vague attempts at insult, contradict me with facts, if you can. > > >> Its _rate_ (or speed, if you prefer) _is_ independently > > > > measurable (say in a hermetically sealed room) with a Foucalt > > > > pendulum. Why a Foucalt pendulum doesn't exactly measure the length of > > > > a day is complicated and I won't try to explain; I'll refer you here > > > > instead: > > > > >http://en.wikipedia.org/wiki/Foucault_pendulum > > > > > To say we've measured its period, its rotation must be timed against > > > > an _external_ measurement point, but they all _move_. That's why I put > > > > quotes around "fixed" stars. > > > > What you do is quarantine the 'sidereal time' concept as it represents > > > a catastrophic lapse of reasoning which tries to force right ascension > > > into daily rotation as an independent motion.The values which explain > > > latitudinal variations in twilight or the transition through the > > > circle of illumination via daily rotational dynamics require definite > > > values which the 'sidereal time' junk cannot hope to supply insofar as > > > an observer at the Equator turns through a 40,075 km distance every 24 > > > hours or 1669.8 km per hour or 111.32 km every 4 minutes . > > > You appear to have some bizarre fixation on Earthly measurements of > > time. That's all very nice for you, but there _are_ other people, with > > other interests on the planet. Some of them are astronomers, who need > > to be able to aim their telescopes properly. > > I am considered a madman for promoting the rotation of the Earth once > in 24 hours or 15 degrees per hour Measured against what, the sun? IT MOVES! Also, the _rate_ of rotation of the Earth IS NOT constant; it varies over many time scales hence your claim is falsified. You are indeed insane, right up there with the Einstein-haters. > That is extremely > > > difficult to do using only the solar day; there are a slew of > > correction factors that would need to be applied, and they change > > through the year. For that matter, they change with the centuries. The > > length of the solar day, the length of time it takes the Sun to > > reappear at a given maximum height above the horizon, increases with > > time. The day (all of them, actually) is getting longer and will > > continue to do so. GET USED TO IT. > > You are arguing against planetary geometry/geography which states that > the Equatorial Earth rotates through 1669.8 km every 15 degrees and > its entire 40,075 km circumference in 24 hours You keep asserting that as if you have some evidence. What is it? > > > > > However, there is no existing way in which this speed can be measured > > > > > to more than a few digits of precision, so for practical purposes we > > > > > have to use the "fixed" stars, even though we know they are not really > > > > > fixed. > > > > > Horsefeathers. > > > > Horsefeathers you say !,take off that late 17th century powdered wig > > > and start thinking like a man or be left behind.You do not need to be > > > too smart to appreciate how the planet ,as a sphere, rotates through > > > 360 degrees at different speeds with definite values for each > > > latitudinal location with definite effects following from basic > > > planetary facts of dimensions and rotational characteristics so drop > > > that nonsense of the 'fixed stars' and a really,really stupid > > > 'sidereal time' reasoning. > > > Yes, horsefeathers. There is NO non-moving external standard against > > which to measure the Earth's rotation period. > > > There is no way to measure the Earth's rotation period on the > > surface of the Earth, without using an external reference. > > > That's all there is to it. The solar day is as arbitrary as the > > others. They each have their uses and each is COMPLETELY INAPPROPRIATE > > for other uses. > > > Nobody cares about your idea of "smart" and "stupid", or what you > > think it means to be "a man". You have your fixation; enjoy it. > > No,humanity has a holocaust I suspect that word does not mean what you think it does. > which sees people who do not know their > limitations and enforce contrived speculative junk on the wider > population under the guise of 'astronomy'. What are you talking about? The "wider population" doesn't care about astronomy, it cares about filling its belly with cheap booze, and killing anyone who is (or might be) in any way different. > It is not an understatement > but rather an unfortunate fact that even the Earth's shape which is > contained in the following set of geodetic values is lost so that we > literally exist,at least in matters relating to planetary > dynamics,structural astronomy and terrestrial effects at the level of > flat Earthers,this is no exaggeration for what people can wilfully > ignore common sense and all the history of > timekeeping,clocks,longitude and planetary geography/geometry. > > http://www.ncgia.ucsb.edu/education/curricula/giscc/units/u014/tables... You are very good at producing disjointed, rambling sentences. Did the foregoing have a point? > Now,remind me how long it takes the Earth to turn once. I have already told you that there is no way to measure it except against moving external references, but you aren't really interested. You'd rather rant about some supposed vague conspiracy theory of yours. Mark L. Fergerson |