Where is the big hole?

[Mee_n_Mac]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Ok I understand what you are saying about expansion being the cause of the phenomenom,&nbsp;but if points a through d represent the location of some mass then don't the masses represented by a and d have a relative velocity vector (i.e. they are moving at some speed and direction) in relation to each other that now exceeds C or does the expansion factor replace part of the relative velocity in this case.&nbsp; If yes have we developed a set of hypothesis or formula to account for the difference?&nbsp; <br />Posted by <strong>BrianSlee</strong></DIV><br /><br />I'm not sure what you're asking. Let me take a guess and hope I'm right.&nbsp; We can measure redshift.&nbsp; Movement of objects through spacetime (what we normally think of as motion)&nbsp;can produce redshift.&nbsp; Expansion of spacetime can produce redshift.&nbsp;There no way to measure how much of the observed redshift is due to one or the other effect. Because the redshift produced by expansion is small for "short" distances, any redshift we measure for objects within our galaxy is attributed to&nbsp;motion through spacetime.&nbsp; For far away objects the expansion factor&nbsp;outweighs any redshift due to motion through spacetime so all redshift is assume to be cosmological in nature.</p><p>&nbsp;</p><p>EDIT : I see once again I've taken too long too answer. At least I see derekmcd and I were on the same "wavelength" in interpreting the question.&nbsp; Still it seems we've not answered it.</p> <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>

 

[Mee_n_Mac]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Maybe we are talking about different thing.&nbsp; I am talking about the relative speeds of mass within the universe and I am&nbsp;thinking now&nbsp;that you are talking about space itself with no reference to mass.&nbsp; Yes? No? <br />Posted by <strong>BrianSlee</strong></DIV><br /><br />I believe that spacetime expanding is carrying the mass contained therein along for the ride, akin to a river carrying a log downstream.&nbsp; <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I'm not sure what you're asking. Let me take a guess and hope I'm right.&nbsp; We can measure redshift.&nbsp; Movement of objects through spacetime (what we normally think of as motion)&nbsp;can produce redshift.&nbsp; Expansion of spacetime can produce redshift.&nbsp;There no way to measure how much of the observed redshift is due to one or the other effect. Because the redshift produced by expansion is small for "short" distances, any redshift we measure for objects within our galaxy is attributed to&nbsp;motion through spacetime.&nbsp; For far away objects the expansion factor&nbsp;outweighs any redshift due to motion through spacetime so all redshift is assume to be cosmological in nature.&nbsp;EDIT : I see once again I've taken too long too answer. At least I see derekmcd and I were on the same "wavelength" in interpreting the question.&nbsp; Still it seems we've not answered it. <br />Posted by mee_n_mac</DIV><br /><br />mee_n_mac,</p><p>&nbsp; The best analogy I can come up with would equate to a gas&nbsp; bubble in a vacuum that suddenly lost containment.&nbsp; The molecules of gas would move to fill the vacuum at some velocity until another boudary were reached or accelerate continuously given no boundary.&nbsp; This may be a little too simplistic for what we are talking about but I think it covers the basic premise of the question.</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Maybe we are talking about different thing.&nbsp; I am talking about the relative speeds of mass within the universe and I am&nbsp;thinking now&nbsp;that you are talking about space itself with no reference to mass.&nbsp; Yes? No? <br /> Posted by BrianSlee</DIV></p><p>Special relativity tells us that 2 objects (with their own frame of reference) can not have inertial velocities at or exceeding C.&nbsp; I guess I'm a bit confused to what you are referring to.</p><p>I think the difference between what you are referring to and the metric expansion of space is there is no energy directly acting on the 2 galaxy clusters separating at superluminal velocities.&nbsp; There is nothing propelling these galaxies through space... it's space, itself, that is expanding.&nbsp; This is how the SR issues are avoided. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>mee_n_mac,&nbsp; The best analogy I can come up with would equate to a gas&nbsp; bubble in a vacuum that suddenly lost containment.&nbsp; The molecules of gas would move to fill the vacuum at some velocity until another boudary were reached or accelerate continuously given no boundary.&nbsp; This may be a little too simplistic for what we are talking about but I think it covers the basic premise of the question. <br /> Posted by BrianSlee</DIV></p><p>I think I got it now.&nbsp; Yes, someone outside the reference frame of the 2 receeding object could recognize that they are separating at speeds greater than C, but each object itself would not be moving greater than C.&nbsp; Nor could either object within it's own reference frame recognize velocities greater than C.</p><p>An example would be polar jets from black holes.&nbsp; The particles in the opposing jets have a combined separation speed greater than C, but the individual particles themselves do not achieve C.&nbsp; This, again, does not violate SR. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[nimbus]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>An example would be polar jets from black holes.&nbsp; The particles in the opposing jets have a combined separation speed greater than C, but the individual particles themselves do not achieve C.&nbsp; &nbsp;<br /> Posted by derekmcd</DIV><br />Good example. <div class="Discussion_UserSignature"> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think I got it now.&nbsp; Yes, someone outside the reference frame of the 2 receeding object could recognize that they are separating at speeds greater than C, but each object itself would not be moving greater than C.&nbsp; Nor could either object within it's own reference frame recognize velocities greater than C.An example would be polar jets from black holes.&nbsp; The particles in the opposing jets have a combined separation speed greater than C, but the individual particles themselves do not achieve C.&nbsp; This, again, does not violate SR. <br />Posted by derekmcd</DIV><br /><br />OK let me see now if I can answer my question.</p><p>Space/time is expanding at a speed greater than C.&nbsp; Mass internal to the space/time reference cannot exceed C.&nbsp; therefore the mass will not be able to keep up with the expansion and will lag behind at some speed less than C, so our physical laws are safe in this instance.</p><p>How's that sound ;O)</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[derekmcd]

<p><strong>Space/time is expanding at a speed greater than C.&nbsp; </strong></p><p>Only at large enough distances will it.&nbsp; Hubble's Constant is about 71 km per second per megaparsec (3.2 million light years distance).&nbsp;&nbsp; Objects that are currently ~13.5 billion light years distance are receeding at C. (13.5 is not precise, but should be really close). </p><p><strong>Mass internal to the space/time reference cannot exceed C.&nbsp; </strong></p><p>Correct.&nbsp; Local motion within your frame of reference cannot exceed C. </p><p><strong>therefore the mass will not be able to keep up with the expansion and will lag behind at some speed less than C, so our physical laws are safe in this instance.</strong></p><p>No.&nbsp; Mass is embedded in the spacetime manifold... it moves with the expansion.&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Space/time is expanding at a speed greater than C.&nbsp; Only at large enough distances will it.&nbsp; Hubble's Constant is about 71 km per second per megaparsec (3.2 million light years distance).&nbsp;&nbsp; Objects that are currently ~13.5 billion light years distance are receeding at C. (13.5 is not precise, but should be really close). Mass internal to the space/time reference cannot exceed C.&nbsp; Correct.&nbsp; Local motion within your frame of reference cannot exceed C. therefore the mass will not be able to keep up with the expansion and will lag behind at some speed less than C, so our physical laws are safe in this instance.No.&nbsp; Mass is embedded in the spacetime manifold... it moves with the expansion.&nbsp; <br />Posted by derekmcd</DIV><br /><br />Darn I really thoght I had it there for a minute </p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>