Could redshift be wrong?

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That's correct, it's 50% longer at the greatest distances. That's a lot. It's not like a 1% difference that could be measurement error, it's a 2X4 in the face. <br /> Posted by MeteorWayne</DIV></p><p>Actually, I think it is a quite precise ratio.&nbsp; For example, at a redshift of z=1, the comoving distance is exactly double the angular size distance while the luminosity is twice as dim.&nbsp; In this case, a type Ia sn, instead of 20 days, would appear to take 40 days to reach peak luminosity. </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>

 

[JordiHeguilor]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;Either we are incredibly to be at the very center of some sort of explosion (highly unlikely) or everything is moving directly away from everything else.&nbsp; And general relativity, our best theory for gravity offers and explanation of how this not only might occur but how it almost is forced to occur.&nbsp; An expanding universe offers a stable solution to the field equations of general relativity.&nbsp; It also provides in that solution an explanation for red shift, the expansion of space.&nbsp; <br />Posted by DrRocket</DIV></p><p>&nbsp;This is a bit off topic, but it's something that has intrigued me for a while.&nbsp; If "...everything is moving directly away from everything else..."&nbsp; how can galaxies collide?<br /></p>

 

[UFmbutler]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;This is a bit off topic, but it's something that has intrigued me for a while.&nbsp; If "...everything is moving directly away from everything else..."&nbsp; how can galaxies collide? <br /> Posted by JordiHeguilor</DIV></p><p>&nbsp;The overall motion is "away from everything else" but locally galaxies can be moving toward each other just because of gravitational attraction. </p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;This is a bit off topic, but it's something that has intrigued me for a while.&nbsp; If "...everything is moving directly away from everything else..."&nbsp; how can galaxies collide? <br />Posted by JordiHeguilor</DIV></p><p>To add to what UFmbutler said, the Andromed galaxie and the Milky Way galaxy are expected to collide in the distant future, due to gravitational attraction.&nbsp; This is large a gravitational event, and is not a "train wreck".&nbsp; Galaxies are, after all, still largely empty space.</p><p>But if you factor out the relatively small "proper motion" the distant galaxies are, on average, moving directly away from us and that is strong evidence for the Big Bang and expansion of the universe.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>

 

[JordiHeguilor]

<p>Thank you, UFmbutler and DrRocket.&nbsp; One more question and I won't bug you anymore: what prevents a globular cluster to collapse on itself due to gravitational attraction?</p>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thank you, UFmbutler and DrRocket.&nbsp; One more question and I won't bug you anymore: what prevents a globular cluster to collapse on itself due to gravitational attraction? <br />Posted by JordiHeguilor</DIV><br /><br />The fast motion of the stars. They are actually in orbit around the center of mass of the cluster, just as in the solar system, the planets orbit around the center of mass of the solar system (which is in or very near the sun depending on where all the planets are at any given time). </p><p>Most of the solar system is in a flat plane, but there are also comets orbiting in all diections.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;This is a bit off topic, but it's something that has intrigued me for a while.&nbsp; If "...everything is moving directly away from everything else..."&nbsp; how can galaxies collide? <br /> Posted by JordiHeguilor</DIV></p><p>Just to add a bit more... It's actually galaxy <em>clusters</em> that are moving away from us.&nbsp; The galaxies within the clusters are gravitatioinally bound to each other.&nbsp; The distances between galaxies within clusters are small enough that gravitational forces can be 'felt'.&nbsp; The distance between clusters of galaxies are so great that Hubble's Law is the overriding factor... hence the metric expansion of space. </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>

 

[BoJangles]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>To add to what UFmbutler said, the Andromed galaxie and the Milky Way galaxy are expected to collide in the distant future, due to gravitational attraction.&nbsp; This is large a gravitational event, and is not a "train wreck".&nbsp; Galaxies are, after all, still largely empty space.<strong>But if you factor out the relatively small "proper motion" the distant galaxies are, on average</strong>, moving directly away from us and that is strong evidence for the Big Bang and expansion of the universe.&nbsp; <br />Posted by DrRocket</DIV><br /><br />Can we see proper motion of galaxies out side our own cluster? that would be a very fine measurement indeed, you would think. <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Can we see proper motion of galaxies out side our own cluster? that would be a very fine measurement indeed, you would think. <br />Posted by Manwh0re</DIV></p><p>According to this the only galaxy for which the proper motion has been measured is Triangulum in 2005.&nbsp; It is in our local group.</p><p>&nbsp;http://en.wikipedia.org/wiki/Triangulum_Galaxy</p><p>http://en.wikipedia.org/wiki/Proper_motion</p><p>&nbsp;</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Can we see proper motion of galaxies out side our own cluster? that would be a very fine measurement indeed, you would think. <br /> Posted by Manwh0re</DIV></p><p>Are you talking about proper motion as DrRocket is defining or are you asking about detecting radial velocities as defined by doppler redshift within recessional velocities as defined by cosmological redshift?&nbsp; I.E. Hubble's constant plus or minus peculiar velocities?</p><p>In the case of peculiar velocites, yes... I believe they can and do detect them.&nbsp; In galaxy clusters, they can detect minor redshift variations due to them doing their own graviational dance.&nbsp; Galactic rotations can even be detected due to one side being more redshifted than the other side.&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>

 

[BoJangles]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>According to this the only galaxy for which the proper motion has been measured is Triangulum in 2005.&nbsp; It is in our local group.&nbsp;http://en.wikipedia.org/wiki/Triangulum_Galaxyhttp://en.wikipedia.org/wiki/Proper_motion <br />Posted by DrRocket</DIV><br /><br />Thanks for the links.</p><p>I wonder why we cant measure the Proper motion of andromeda, our closest galaxy.</p> <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thanks for the links.I wonder why we cant measure the Proper motion of andromeda, our closest galaxy. <br />Posted by Manwh0re</DIV></p><p>Triangulum is not much farther away than Andromeda (2.9 vs 2.5 million light years)</p><p>I am personally amazed that they can measure proper motion at all.&nbsp; Light is pretty quick.&nbsp; 2.x million years is a long time,&nbsp; 2.x million light years is a long long way.&nbsp; Any motion perpendicular to the line of sight would look pretty small at that distance.&nbsp; It takes a pretty clever astronomer to pull off the measurement.&nbsp; The motion relative to the Milky Way was 190 +/- 59 km/s, which is well below the&nbsp;speed of light.&nbsp; </p><p><br />http://adsabs.harvard.edu/abs/2005astro.ph..3058B</p> <div class="Discussion_UserSignature"> </div>

 

[BoJangles]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Are you talking about proper motion as DrRocket is defining or are you asking about detecting radial velocities as defined by doppler redshift within recessional velocities as defined by cosmological redshift?&nbsp; I.E. Hubble's constant plus or minus peculiar velocities?In the case of peculiar velocites, yes... I believe they can and do detect them.&nbsp; In galaxy clusters, they can detect minor redshift variations due to them doing their own graviational dance.&nbsp; <strong>Galactic rotations can even be detected due to one side being more redshifted than the other side</strong>.&nbsp; <br />Posted by derekmcd</DIV></p><p>This one has always interested me, when they obtain this measurement is it a combined measurement or are they measuring star by star. I suppose that's how they figured out the flat rotation curve of galaxies.</p> <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[BoJangles]

<p>i was just reading <strong><font color="#1b4872"><font size="1">Dark Energy Signs Seen in Giant Clusters and Voids</font><font size="3"> </font></font></strong></p><p>What mechanism causes microwaves to vibrate faster under higher gravity. do we see that with observations on earth compared to space in our solar system. I.e. Gravity on earth is stronger than gravity on the ISS, do we see these affects in lab results.</p> <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This one has always interested me, when they obtain this measurement is it a combined measurement or are they measuring star by star. I suppose that's how they figured out the flat rotation curve of galaxies. <br /> Posted by Manwh0re</DIV></p><p>Unless there are Cephied variables on opposite sides of the galaxy, it is most likely a cumulative effect.&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>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thanks for the links.I wonder why we cant measure the Proper motion of andromeda, our closest galaxy. <br /> Posted by Manwh0re</DIV></p><p>I imagine it is because the two galaxies are travelling at similar velocities on a similar plane towards a point where we may collide.&nbsp; Like two cars on a collision course at a Y-shaped intersection.&nbsp; If, in the future, we can detect a proper motion, we can determine whether there will be a direct collision or brush by it with maybe only the halos interacting. </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'>i was just reading Dark Energy Signs Seen in Giant Clusters and Voids What mechanism causes microwaves to vibrate faster under higher gravity. do we see that with observations on earth compared to space in our solar system. I.e. Gravity on earth is stronger than gravity on the ISS, do we see these affects in lab results. <br /> Posted by Manwh0re</DIV></p><p>I'm guessing they are referring to the increase in frequency and shortening of the wavelength.&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>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This one has always interested me, when they obtain this measurement is it a combined measurement or are they measuring star by star. I suppose that's how they figured out the flat rotation curve of galaxies. <br />Posted by Manwh0re</DIV><br /><br />When you look at the spectrum of the whole galaxy, it will be a bell curve. The center frequency will be that of the galactic center, and the fringes will be the spectra of the outer regions coming towrd us on one side (blue shifted from the center frequency) and away from us (more red shifted) on the other side. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>i was just reading Dark Energy Signs Seen in Giant Clusters and Voids What mechanism causes microwaves to vibrate faster under higher gravity. do we see that with observations on earth compared to space in our solar system. I.e. Gravity on earth is stronger than gravity on the ISS, do we see these affects in lab results. <br />Posted by Manwh0re</DIV></p><p>Here are some tests that have been done to support general relativity, among them is a redshsift test done at Harvard.</p><p>http://en.wikipedia.org/wiki/Tests_of_general_relativity</p><p>And here is a description of that spedific experiment&nbsp; </p><p>http://en.wikipedia.org/wiki/Pound-Rebka_experiment</p> <div class="Discussion_UserSignature"> </div>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>When you look at the spectrum of the whole galaxy, it will be a bell curve. The center frequency will be that of the galactic center, and the fringes will be the spectra of the outer regions coming towrd us on one side (blue shifted from the center frequency) and away from us (more red shifted) on the other side. <br /> Posted by MeteorWayne</DIV></p><p>FYI, that was a very helpful, useful and concise explanation of the observed redshift spectra.&nbsp; Thanks.</p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[BoJangles]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Here are some tests that have been done to support general relativity, among them is a redshsift test done at Harvard.http://en.wikipedia.org/wiki/Tests_of_general_relativityAndhere is a description of that spedific experiment&nbsp; http://en.wikipedia.org/wiki/Pound-Rebka_experiment <br />Posted by DrRocket</DIV><br /><br /><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">Thanks for the links. And everyone who has contributed to date.</font></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">I think I asked this question earlier in the piece though not sure if it was answered directly.</font></p><ul><li><div class="MsoNormal" style="margin-top:0cm;margin-left:0cm;margin-right:0cm"><font face="Calibri" size="3">Has anyone tried to tweak redshift <span>&nbsp;</span>(Hubble&rsquo;s constant) to fit dark energy and dark matter? I.e. wouldn&rsquo;t it be easy to test if red shift was wrong, or validate it, by tweaking the value to fit the likes of dark energy and dark /&nbsp;matter. </font></div></li></ul><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">Basically what I'm suggesting is, trying to tweak redshift with the anomalies that dark matter and dark energy produce (acceleration, flat rotation curves and such). </font></p><ul><li><div class="MsoNormal" style="margin-top:0cm;margin-left:0cm;margin-right:0cm"><font face="Calibri" size="3">Additionally why does Hubble&rsquo;s constant have to be a constant, why not a function? Is there any reason why it has to be a constant (physics wise). I.e. replacing the constant with a function might solve dark energy / matter as well. Is there any studies done on&nbsp; tweaking / curve matching redshift values (as a function, for instance of time / distance) with the acceleration values, and red shift bell curve produced by galaxies?</font></div></li></ul><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">If you could design a function that works on both galactic and cosmological redshift, it would be evidence its wrong. It would be easy to design a bunch of curve matching algorithms if the data for evidence for acceleration and the galactic bell curve were available.</font></p><font face="Calibri"><font size="3">Maybe there is a paper in it, if you could include enough variables / data in regard to anomalies acceleration. </font><font size="3">Please note I'm just having a stab in the dark here.</font></font><font face="Calibri"> <p style="margin:0cm0cm10pt" class="MsoNormal"><font size="3">I suppose what I'm assuming is, that there is&nbsp;not a lot of empirical evidence that is otherwise somehow tainted by a broken Hubble&rsquo;s constant.</font></p></font><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal">&nbsp;</p> <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thanks for the links. And everyone who has contributed to date.I think I asked this question earlier in the piece though not sure if it was answered directly.Has anyone tried to tweak redshift &nbsp;(Hubble&rsquo;s constant) to fit dark energy and dark matter? I.e. wouldn&rsquo;t it be easy to test if red shift was wrong, or validate it, by tweaking the value to fit the likes of dark energy and dark /&nbsp;matter. Basically what I'm suggesting is, trying to tweak redshift with the anomalies that dark matter and dark energy produce (acceleration, flat rotation curves and such). Additionally why does Hubble&rsquo;s constant have to be a constant, why not a function? Is there any reason why it has to be a constant (physics wise). I.e. replacing the constant with a function might solve dark energy / matter as well. Is there any studies done on&nbsp; tweaking / curve matching redshift values (as a function, for instance of time / distance) with the acceleration values, and red shift bell curve produced by galaxies?If you could design a function that works on both galactic and cosmological redshift, it would be evidence its wrong. It would be easy to design a bunch of curve matching algorithms if the data for evidence for acceleration and the galactic bell curve were available.Maybe there is a paper in it, if you could include enough variables / data in regard to anomalies acceleration. Please note I'm just having a stab in the dark here. I suppose what I'm assuming is, that there is&nbsp;not a lot of empirical evidence that is otherwise somehow tainted by a broken Hubble&rsquo;s constant.&nbsp; <br />Posted by Manwh0re</DIV></p><p>The Hubble constant is a curve fit.&nbsp;&nbsp; I just happens that the fit for a straight line is pretty good.&nbsp;&nbsp; It also happens that a straight line is what&nbsp; you would expect from an expansion of space, and that fits with the general theory of relativity.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>