Question about gravity
in [Relativity]
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From: mpc755 on 18 Mar 2010 12:19 On Mar 18, 12:04 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Mar 18, 10:06 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > On Mar 18, 9:51 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Mar 18, 7:01 am, "J. Clarke" <jclarke.use...(a)cox.net> wrote: > > > > > On 3/17/2010 9:19 PM, Tom Roberts wrote: > > > > > > mpc755 wrote: > > > > >> On Mar 16, 11:43 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > > > > >>> mpc755 wrote: > > > > >>>> 'curved spacetime' is meaningless nonsense in terms of a physical > > > > >>>> description of nature. What is physically being 'curved'? [...] > > > > >>> Nothing "physical" is involved, this is GEOMETRY. > > > > > >> Not only do we have the absurd nonsense [...] > > > > > > The "absurd nonsense" is your thinking that you can discuss modern > > > > > physics without any understanding of it whatsoever. > > > > > I think it's perfectly valid to ask if the curvature of spacetime is > > > > something real or if it's a useful fiction, however asserting a priori > > > > that it is "meaningless nonsense" or that "nothing 'physical' is > > > > involved" are both quite premature. One trouble I have with > > > > philosophers is that they assert such things and run with them and you > > > > have to whack 'em with a two-by-four to get them to look at their > > > > premise. Unfortunately the ranks of philosopher wannabees seem to be > > > > considerably larger than then ranks of physicist wannabees who are > > > > actually serious about it. > > > > And in this particular case, MPC has a preconceived notion about what > > > makes sense and what is absurd, and there is no need (at least in his > > > mind) to test whether that categorization is appropriate. > > > > PD > > > And in your mind in order to maintain support of a failed theory you > > have to resort to the future determining the past. > > > In your mind since you really do not understand what is physically > > occurring in nature your resort to labels such as 'fields' and > > 'virtual' particles. > > > Yes, I realize you think 'virtual' particles physically exist out of > > nothing and I realize you think a 'field' is physically real. But in > > the reality of nature they are not. > > See? You've already made decisions in your mind about what is real and > what is not, what makes sense and what is not, what is absurd and what > is not. And you've not figured out how to test whether those decisions > are right or not. You just make the decisions and go with it. > > Scientists don't do that. > 'Scientists' decide the future determines the past because they do not understand what occurs physically in nature? 'Scientists' invent 'virtual' particles which exist out of nothing because they do not understand what occurs physically in nature? 'Scientists' use the term 'field' because they do not understand what occurs physically in nature?
From: G. L. Bradford on 18 Mar 2010 12:40 "Sam Wormley" <swormley1(a)gmail.com> wrote in message news:8P-dnWl1SYFyvT_WnZ2dnUVZ_q4AAAAA(a)mchsi.com... > On 3/18/10 6:10 AM, G. L. Bradford wrote: > >> >> Wormy it is not space that is expanding. It is the objects in the >> medium that are moving apart wrt each other. >> > > The metric expansion of space is the averaged increase of metric (i.e. > measured) distance between distant objects in the universe with time. > > It is an intrinsic expansion—that is, it is defined by the relative > separation of parts of the universe and not by motion "outward" into > preexisting space. (In other words, the universe is not expanding "into" > anything outside of itself). > > Metric expansion is a key feature of Big Bang cosmology and is modeled > mathematically with the FLRW metric. This model is valid in the present > era only at relatively large scales (roughly the scale of galactic > superclusters and above). At smaller scales matter has clumped together > under the influence of gravitational attraction and these clumps do not > individually expand, though they continue to recede from one another. The > expansion is due partly to inertia (that is, the matter in the universe is > separating because it was separating in the past) and partly to a > repulsive force of unknown nature, which may be a cosmological constant. > Inertia dominated the expansion in the early universe, and according to > the ΛCDM model the cosmological constant will dominate in the future. In > the present era they contribute in roughly equal proportions. > > While special relativity constrains objects in the universe from moving > faster than the speed of light with respect to each other, there is no > such theoretical constraint when space itself is expanding. It is thus > possible for two very distant objects to be moving away from each other at > a speed greater than the speed of light (meaning that one cannot be > observed from the other). The size of the observable universe could thus > be smaller than the entire universe. > > It is also possible for a distance to exceed the speed of light times the > age of the universe, which means that light from one part of space > generated near the beginning of the Universe might still be arriving at > distant locations (hence the cosmic microwave background radiation). > > Ref: http://en.wikipedia.org/wiki/Metric_expansion_of_space > ========================== The Big Crunch / Big Bang infinite Singularity is a subsurface constant (one entity, or side, of a dual entity) you take for Creation (and in an Orwellian manner give a slight twist to delude yourself that you aren't Creationist ("In the beginning....."). The surface horizon, or the (constant) horizon of surfacing, is the constant of the Planck universe. Did you miss the "constant", the constancy? Of course you did, as if an infinite Universe could lose or drop the other side of its duality, an infinite Singularity. Infinity itself has to be a constant. It can't be anything other than a constant. YOU don't have anything to measure your single-sided only, nakedly singular, universe against. YOU say sure you do, itself! Like isolating a meter stick from all surrounding universe, period, and saying, God-like simply, it measures that length. Measures against what else? Against nothing. Infinity, that could be said of. Finite? No way! GLB =========================
From: Tom Roberts on 18 Mar 2010 13:12 mpc755 wrote: > On Mar 17, 9:19 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: >> mpc755 wrote: >>> On Mar 16, 11:43 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: >>>> mpc755 wrote: >>>>> 'curved spacetime' is meaningless nonsense in terms of a physical >>>>> description of nature. What is physically being 'curved'? [...] >>>> Nothing "physical" is involved, this is GEOMETRY. >>> Not only do we have the absurd nonsense [...] >> The "absurd nonsense" is your thinking that you can discuss modern physics >> without any understanding of it whatsoever. > > Do you understand geometry is a mathematical representation of nature > and is not responsible for gravity? It's obvious from your > 'understanding' of nature where geometry is responsible for gravity > you are full of absurd nonsense. As I said, "... without any understanding of it whatsoever." I am discussing MODELS of nature, and make no attempt to describe what is "responsible" for any physical phenomenon like gravity, because I know that can never be known to humans. The absurdity and nonsense is all yours. You will remain mystified until you actually STUDY modern physics. Tom Roberts
From: PD on 18 Mar 2010 14:48 On Mar 18, 11:19 am, mpc755 <mpc...(a)gmail.com> wrote: > On Mar 18, 12:04 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Mar 18, 10:06 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Mar 18, 9:51 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Mar 18, 7:01 am, "J. Clarke" <jclarke.use...(a)cox.net> wrote: > > > > > > On 3/17/2010 9:19 PM, Tom Roberts wrote: > > > > > > > mpc755 wrote: > > > > > >> On Mar 16, 11:43 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > > > > > >>> mpc755 wrote: > > > > > >>>> 'curved spacetime' is meaningless nonsense in terms of a physical > > > > > >>>> description of nature. What is physically being 'curved'? [....] > > > > > >>> Nothing "physical" is involved, this is GEOMETRY. > > > > > > >> Not only do we have the absurd nonsense [...] > > > > > > > The "absurd nonsense" is your thinking that you can discuss modern > > > > > > physics without any understanding of it whatsoever. > > > > > > I think it's perfectly valid to ask if the curvature of spacetime is > > > > > something real or if it's a useful fiction, however asserting a priori > > > > > that it is "meaningless nonsense" or that "nothing 'physical' is > > > > > involved" are both quite premature. One trouble I have with > > > > > philosophers is that they assert such things and run with them and you > > > > > have to whack 'em with a two-by-four to get them to look at their > > > > > premise. Unfortunately the ranks of philosopher wannabees seem to be > > > > > considerably larger than then ranks of physicist wannabees who are > > > > > actually serious about it. > > > > > And in this particular case, MPC has a preconceived notion about what > > > > makes sense and what is absurd, and there is no need (at least in his > > > > mind) to test whether that categorization is appropriate. > > > > > PD > > > > And in your mind in order to maintain support of a failed theory you > > > have to resort to the future determining the past. > > > > In your mind since you really do not understand what is physically > > > occurring in nature your resort to labels such as 'fields' and > > > 'virtual' particles. > > > > Yes, I realize you think 'virtual' particles physically exist out of > > > nothing and I realize you think a 'field' is physically real. But in > > > the reality of nature they are not. > > > See? You've already made decisions in your mind about what is real and > > what is not, what makes sense and what is not, what is absurd and what > > is not. And you've not figured out how to test whether those decisions > > are right or not. You just make the decisions and go with it. > > > Scientists don't do that. > > 'Scientists' decide the future determines the past because they do not > understand what occurs physically in nature? > > 'Scientists' invent 'virtual' particles which exist out of nothing > because they do not understand what occurs physically in nature? > > 'Scientists' use the term 'field' because they do not understand what > occurs physically in nature? Actually, no, they don't decide that. They put it up as a testable model, and then they test it with experiment. They don't decide anything until the experimental tests are in. You see the difference between when scientists make decisions and when you do? PD
From: PD on 18 Mar 2010 14:50
On Mar 18, 11:18 am, mpc755 <mpc...(a)gmail.com> wrote: > On Mar 18, 12:03 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Mar 18, 10:03 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Mar 18, 9:46 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Mar 17, 5:06 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > On Mar 17, 5:59 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Mar 17, 4:51 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > The poster I was responding to has finally made it to the step of > > > > > > > understand something physical causes gravity. The poster is a QM true > > > > > > > believer so it must be excused if the best step the poster can offer > > > > > > > is 'quanta is responsible' for gravity. > > > > > > > > The point I was trying to make, which you completely misinterpreted, > > > > > > > is if quanta is responsible for gravity then whatever you want to > > > > > > > consider the quanta to physically exist as in order for it to be > > > > > > > responsible for gravity, light from the sun is physically propagating > > > > > > > in quanta. > > > > > > > This is so cute. Note he says that quanta must be physically real, but > > > > > > that quantum mechanics (which describes the behavior of quanta) is not > > > > > > about stuff that is physically real. > > > > > > You're making my point. > > > > > > Gravity is physically real. > > > > > > Only in your interpretation of the absurd nonsense of QM can gravity > > > > > not be physically real. > > > > > > If quanta is responsible for gravity then quanta is physically real > > > > > Of course they are real. And quantum mechanics describes those real > > > > things. Quantum mechanics is the study of how quanta (those real > > > > things) behave. Thank you. > > > > So, you are walking down the street and you are 'tied' to the Earth > > > because quanta is responsible for gravity. > > > Yes, this seems likely. > > > > Now it is a bright sunny > > > day outside and you are being bombarded by light quanta. > > > Yes. > > > > How does > > > light quanta interact with gravity quanta? > > > We don't know for sure, because we don't have a solid model yet for > > how gravitational quanta work. This doesn't mean we know nothing. We > > do know they interact, and we have observational measurements of how > > much. > > In AD, the 'quanta' responsible for gravity and the 'quanta' > responsible for light is aether. If you conceptualize the aether as > consisting of quanta you will advance your understanding of nature. > > > > Are they one in the same? > > > No. > > Then you will never understand nature. Light waves propagate through > the aether and the pressure associated with the aether displaced by a > massive object is gravity. > Well, let's see. You asked a bunch of questions about quantum mechanics, since you didn't know anything about it. Then when I told you the answers, you responded that quantum mechanics is not a good model of nature, because it is not your model. Aha. PD |