Copernican Principle wrong? Do we live in a void?

[docm]

<h2><font size="1">Link....&nbsp;</font></h2><p><strong>Quote:&nbsp;</strong></p><p>The Cosmic Void: Could we be in the Middle of it?</p> <p>Written by Ian O'Neill</p> <div id="attachment_15730" class="wp-caption alignleft" style="width:260px"><img class="size-thumbnail wp-image-15730" src="http://www.universetoday.com/wp-content/uploads/2008/07/void_eso_edit-250x209.jpg" alt="Ian O'Neill" width="250" height="209" /><p class="wp-caption-text">Is our region of space unique? Is it a void? Can you hear the echo? Credit: ESO. Edit: Ian O'Neill</p></div><br /> On large scales, the Universe is homogeneous and isotropic. This means that no matter where you are located in the cosmos, give or take the occasional nebula or galactic cluster, the night sky will appear approximately the same. Naturally there is some 'clumpiness' in the distribution of the stars and galaxies, but generally the density of any given location will be the same as a location hundreds of light years away. This assumption is known as the Copernican Principle. By invoking the Copernican Principle, astronomers have predicted the existence of the elusive <em>dark energy</em>, accelerating the galaxies away from one another, thus expanding the Universe. But say if this basic assumption is incorrect? What if our region of the Universe <em>is</em> unique in that we are sitting in in a location where the average density is a lot lower than other regions of space? Suddenly our observations of light from Type 1a supernovae are not anomalous and can be explained by the local void. <em>If this were to be the case, dark energy (or any other exotic substance for that matter) wouldn't be required to explain the nature of our Universe after all&hellip;</em><br /> <br /> Dark energy is a hypothetical energy predicted to permeate through the Cosmos, causing the observed expansion of the Universe. This strange energy is believed to account for 73% of the total mass-energy (i.e. <em>E=mc</em>²) of the Universe. But where is the evidence for dark energy? One of the main tools when measuring the accelerated expansion of the Universe is to analyse the red-shift of a distant object with a known brightness. In a Universe filled with stars, what object generates a "standard" brightness? <div id="attachment_15733" class="wp-caption alignleft" style="width:253px"><img class="size-thumbnail wp-image-15733" src="http://www.universetoday.com/wp-content/uploads/2008/07/iaprogenitor-243x250.jpg" alt="NASA, ESA, and A. Field (STScI)" width="243" height="250" /><p class="wp-caption-text">The progenitor of a Type Ia Supernova. Credit: NASA, ESA, and A. Field (STScI)</p></div> <p>Type 1a supernovae are known as 'standard candles' for this very reason. No matter where they explode in the observable universe, they will always blow with the same amount of energy. So, in the mid-1990's astronomers observed distant Type 1a's a little dimmer than expected. With the basic <em>assumption</em> (it may be an accepted view, but it is an assumption all the same) that the Universe obeys the Copernican Principle, this dimming suggested that there was some force in the Universe causing not only an expansion, but an <em>accelerated expansion</em> of the Universe. This mystery force was dubbed <em>dark energy</em> and it is now a commonly held view that the cosmos must be filled with it to explain these observations. (There are many other factors explaining the existence of dark energy, but this is a critical factor.)</p> <p>According to a new publication headed by Timothy Clifton, from the University of Oxford, UK, the controversial suggestion that the widely accepted Copernican Principle is wrong is investigated. Perhaps we <em>do</em> exist in a unique region of space where the average density is much lower than the rest of the Universe. The observations of distant supernovae suddenly wouldn't require dark energy to explain the nature of the expanding Universe. No exotic substances, no modifications to gravity and no extra dimensions required.</p> <p>Clifton explains conditions that could explain supernova observations are that we live in an extremely rarefied region, right near the centre, and this void could be on a scale of the same order of magnitude as the observable Universe. If this were the case, the geometry of space-time would be different, influencing the passage of light in a different way than we'd expect. What's more, he even goes as far as saying that any given observer has a high probability of finding themselves in such a location. However, in an inflationary Universe such as ours, the likelihood of the generation of such a void is low, but should be considered nonetheless. Finding ourselves in the middle of a unique region of space would out rightly violate the Copernican Principle and would have massive implications on all facets of cosmology. Quite literally, it would be a revolution.</p> <p>The Copernican Principle is an assumption that forms the bedrock of cosmology. As pointed out by Amanda Gefter at <em>New Scientist</em>, this assumption <em>should</em> be open to scrutiny. After all, good science should not be akin to religion where an assumption (or belief) becomes unquestionable. Although Clifton's study is speculative for now, it does pose some interesting questions about our understanding of the Universe and whether we are willing to test our fundamental ideas.</p> <p>Sources: arXiv:0807.1443v1 [astro-ph], New Scientist Blog</p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p>The headlines are perhaps a bit overdone.&nbsp; This is interesting work, but one ought to read the real paper and not pay too much attention to the popularized article.</p><p>Bottom line:&nbsp; The authors have a&nbsp;TESTABLE hypothesis for our existence in a VERY large low density region of the universe.&nbsp; What is needed to test the hypothesis is a larger survey of type 1A supernovas.&nbsp; Once that is in place the data can be analyzed and a conclusion reached.&nbsp; This hypothesis is very speculative, and I think most people would bet against it, but the proof will come with additional data.&nbsp; Until then one ought not get too excited.</p> <div class="Discussion_UserSignature"> </div>

 

[nimbus]

Isn't illustrating the concept with a picture of a molecular cloud misleading? &nbsp;Both the scale and the composition are different from what the article talks about.<br /> <div class="Discussion_UserSignature"> </div>

 

[Philotas]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Isn't illustrating the concept with a picture of a molecular cloud misleading? &nbsp;Both the scale and the composition are different from what the article talks about. <br />Posted by nimbus</DIV><br /><br />Not to mention that&nbsp;a molecular cloud so dense that it blocks out most of the light is anything but a void, LOL. <div class="Discussion_UserSignature"> </div>

 

[silylene old]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Link....&nbsp;Quote:&nbsp;The Cosmic Void: Could we be in the Middle of it? ..........</p><p>Posted by docm</DIV><br /><br />This fictional concept was explored in <em>The Moat in God's Eye</em>, and excellent book.&nbsp; Of course the Moaties were the ones with their star stuck in the void, in the middle of the Coal Sack.</p> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[emperor_of_localgroup]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The headlines are perhaps a bit overdone.&nbsp; This is interesting work, but one ought to read the real paper and not pay too much attention to the popularized article.Bottom line:&nbsp; The authors have a&nbsp;TESTABLE hypothesis for our existence in a VERY large low density region of the universe.&nbsp; What is needed to test the hypothesis is a larger survey of type 1A supernovas.&nbsp; Once that is in place the data can be analyzed and a conclusion reached.&nbsp; This hypothesis is very speculative, and I think most people would bet against it, but the proof will come with additional data.&nbsp; Until then one ought not get too excited. <br /> Posted by DrRocket</DIV></p><p><font size="2">This is something for the first. DrRocket agrees with an outlandish theory which usually we crave for [a little good natured humor].</font></p><p><font size="2">But this is an interesting paper. I have said this a few times, we cannot possibly explain expansion of the universe correctly from activities takining place only within the&nbsp; universe. The 'stuff' outside our visible universe may also be responsible for its expansion. This void theory may have a leg. Although the paper is hard to read and contains too many unclear explanations, IMHO.</font></p><p><font size="2">The question is did big bang created the void or the 'outside materials' some how caused the void? If this theory is right, we should observe a few effects. The center of the void should have extremely low mass density, and regions away from the center should contain increasingly higher mass density. Even if our observable universe is the size of a peanut compared to the rest of the universe, shouldn't we observe a slight variation of mass density from center (or near center) to the edge of the observable void?</font></p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[kelvinzero]

<p>It would seem to be quite a coincidence if we were right in the middle of a void that was of the scale of the observable universe. In fact that is two coincidences.</p><p>wouldnt we be far more likely to find ourselves in an observable universe that was definitely denser than our location&nbsp;in one particular direction and&nbsp;perhaps actually&nbsp;sparser in the opposite?</p>

 

[emperor_of_localgroup]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>wouldnt we be far more likely to find ourselves in an observable universe that was definitely denser than our location&nbsp;in one particular direction and&nbsp;perhaps actually&nbsp;sparser in the opposite? <br /> Posted by kelvinzero</DIV></p><p><font size="2">Yes, I also don't see why distribution of matters around us are so uniform as observations show. One explanation can be our observable universe is a very small part of the rest.</font></p><p><font size="2">The reason I got curious about this paper is one of my own personal theories (yes, I have several, because no one's theory is so far correct) somewhat matches with this void theory. It is possible that the region we are in now was once filled with low density energy of unknown form just like the rest of the universe. Then something triggered formation of matter from this energy. Just as&nbsp; we make curds (solid) by curdling milk (liquid), the result is solid curds leaving diluted liquid. In this case we got matter and diluted space (zero point energy) or the void. The rest of the universe is still filled with original energy. What triggered this transformation? Big bang, big God, big daddy, or big Timmy of another universe whose mother always warned him not to play with matches.</font></p> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The Cosmic Void: Could we be in the Middle of it? Written by Ian O'Neill<br /> Posted by docm</DIV></p><p>Not according to these new findings.</p><h1 class="story"><font size="2">Earth Not Center Of The Universe, Surrounded By 'Dark Energy'</font></h1><p><font color="#333399"><em><span class="date">ScienceDaily (Dec. 19, 2008)</span> &mdash; Earth's location in the Universe is utterly unremarkable, despite recent theories that propose toppling a foundation of modern cosmology, according to a team of University of British Columbia researchers.</em></font></p> <p><font color="#333399"><em>[snip]</em></font></p><p><font color="#333399"><em>Now some advanced analysis and modeling performed by UBC post-doctoral fellows Jim Zibin and Adam Moss and Astronomy Prof. Douglas Scott is showing that this alternate "void theory" just doesn't add up.</em></font></p> <p><font color="#333399"><em>The researchers used data from the Wilkinson Microwave Anisotropy Probe satellite, which includes members from UBC on its international team, as well as data from various ground-based instruments and surveys.</em></font></p> <p><font color="#333399"><em>"We tested void models against the latest data, including subtle features in the cosmic microwave background radiation &ndash; the afterglow of the Big Bang &ndash; and ripples in the large-scale distribution of matter," says Zibin. "We found that void models do a very poor job of explaining the combination of these data."</em></font></p> <p><font color="#333399"><em>The team's calculations instead solidify the conventional view that an enigmatic dark energy fills the cosmos and is responsible for the acceleration of the Universe. "Recent advances in data collection have brought us to the era of precision cosmology," says Zibin. "Void models are terrible at explaining the new data, but the standard dark energy model works very well.</em></font></p><p>[snip] </p><p>Rest of article (with journal reference) here:</p><p>http://www.sciencedaily.com/releases/2008/12/081219032649.htm </p><p>&nbsp;</p><p>and here's the associated paper in Arxiv pre-print:</p><p>http://arxiv.org/abs/0809.3761 </p><p>&nbsp;</p><p>&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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The headlines are perhaps a bit overdone.&nbsp; This is interesting work, but one ought to read the real paper and not pay too much attention to the popularized article.Bottom line:&nbsp; The authors have a&nbsp;TESTABLE hypothesis for our existence in a VERY large low density region of the universe.&nbsp; What is needed to test the hypothesis is a larger survey of type 1A supernovas.&nbsp; Once that is in place the data can be analyzed and a conclusion reached.&nbsp; This hypothesis is very speculative, and I think most people would bet against it, but the proof will come with additional data.&nbsp; Until then one ought not get too excited. <br /> Posted by DrRocket</DIV></p><p>I think the main problem with the theory is that if *presumes* that there is something special about the location of our galaxy, and our galaxy cluster.&nbsp;&nbsp; If we're going to dump the principle, we could just *presume* that we are actually located at the middle of the universe.&nbsp; </p><p>I would also note that the the idea of "testability" is limited to a mathematical expression that can be compared to an *uncontrolled* observation.&nbsp; That is not the same as being able to duplicate the redshift phenomenon in controlled conditions.&nbsp;&nbsp; </p><p>I hear you about not getting too excited.&nbsp; I get the feeling that it's biggest obstacle to being "accepted" is due to the fact that it violates the Copernican principle.&nbsp; That principle allows us to assume a whole host of things about the universe that would otherwise not be required or supported without such an "assumption".&nbsp;&nbsp; If we're going to violate the priniciple, why not stick Earth at the center of the universe?</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>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think the main problem with the theory is that if *presumes* that there is something special about the location of our galaxy, and our galaxy cluster.&nbsp;&nbsp; If we're going to dump the principle, we could just *presume* that we are actually located at the middle of the universe.&nbsp; I would also note that the the idea of "testability" is limited to a mathematical expression that can be compared to an *uncontrolled* observation.&nbsp; That is not the same as being able to duplicate the redshift phenomenon in controlled conditions.&nbsp;&nbsp; I hear you about not getting too excited.&nbsp; I get the feeling that it's biggest obstacle to being "accepted" is due to the fact that it violates the Copernican principle.&nbsp; That principle allows us to assume a whole host of things about the universe that would otherwise not be required or supported without such an "assumption".&nbsp;&nbsp; If we're going to violate the priniciple, why not stick Earth at the center of the universe? <br /> Posted by michaelmozina</DIV></p><p>I tried, in vain, to come up with a definition for "uncontrolled observation".&nbsp;&nbsp; I fully understand the necessity for having experimental control.&nbsp; However, when none exists observational science is the only recourse.&nbsp; Simply because you can not experiment with something, does not mean you should quit persuing answers.</p><p>It appears the paper I linked to is addressing (though not directly mentioning it) the paper DOCM linked to.&nbsp; They use additional, independent methods of observatoinal data collection other than just type Ia SNe that seem to put the void model on very thin ice.</p><p>Additionally, an unfair assessment on my part;&nbsp; I find it rather amusing that someone from Jesus College Oxford would submit a paper trying to overturn the Copernican Principle.&nbsp; Coincidence? </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>Another argument against void theories...</p><p>&nbsp;</p><p><span class="BHL"><font size="3"><strong>What Can Swiss Cheese Teach Us About Dark Energy</strong></font></span></p><p><span class="BBL">by Staff Writers<br /></span> <span class="BDL">Pasadena CA (SPX) Dec 23, 2008</span> </p><table border="0" cellspacing="0" cellpadding="3" width="7" height="16" align="right"><tbody><tr><td><span class="BL"> </span><br />

 

[kg]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This is something for the first. DrRocket agrees with an outlandish theory which usually we crave for [a little good natured humor].Posted by emperor_of_localgroup</DIV><br /><br />I don't think DrRocket agreed with anything.&nbsp; He only said it was testable.

 

[Mee_n_Mac]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> The researchers at Fermi said these voids might lie between us and the supernovae being observed, acting like concave lenses to make the objects appear dimmer and farther than they really are.&nbsp; Posted by <strong>derekmcd</strong></DIV><br /><br />I'm curious about the snippet I extracted above.&nbsp; How would a void act like a lens ?&nbsp; And while I can understand the dimmer being interpreted as farther,&nbsp;I don't see a void affecting the time dilation curve for the SN.&nbsp; Wouldn't the mismatch peg that measurement of distance as being questionable ? <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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I tried, in vain, to come up with a definition for "uncontrolled observation".&nbsp;&nbsp; I fully understand the necessity for having experimental control.&nbsp; However, when none exists observational science is the only recourse.&nbsp; </DIV></p><p>I suppose it's the fact that "none exists" that presents the skeptic with the problem. If someone could empirically demonstrate that 'dark energy' has some tangible affect on light, the skeptic would have nothing to be be skeptical about.&nbsp; It's the fact the skeptic has to accept on "faith" that the two are related that creates the problem.&nbsp; </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>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I don't think DrRocket agreed with anything.&nbsp; He only said it was testable. <br />Posted by kg</DIV></p><p>Correct.&nbsp; Michael likes to distort and misrepresent my statements and that of others to promote his own wacko EU ideas. It is just a tactic of his, common among those who have no scientific leg to stand on.&nbsp; It is his way of getting attention in legitimate hard science forums for ideas that belong in The Unexplained.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I suppose it's the fact that "none exists" that presents the skeptic with the problem. If someone could empirically demonstrate that 'dark energy' has some tangible affect on light, the skeptic would have nothing to be be skeptical about.&nbsp; It's the fact the skeptic has to accept on "faith" that the two are related that creates the problem.&nbsp; <br />Posted by michaelmozina</DIV></p><p>This simply more of your continual carping at mainstream physicists because they don't pay attention to your EU nonsense, nor should they.&nbsp; As usual this is poorly veiled garbage that belongs in The Unexplained.</p><p>OF COURSE dark energy, if it exists, affects light.&nbsp; That is what it is all about.&nbsp; Expansion of the space-time manifold affects light through red shift, and dark energy is a hypothesis that attempts to explain the acceleration of thta expansion.&nbsp; The acceleration of expansion is the sole reason for the dark energy hypothesis, and the sole reason for the idea that the expansion is accelerating is based on the behavior of light.</p><p>You can question the data, You can question whether dark energy is the right explanation for the data.&nbsp; But&nbsp; to question whether the data is based on interpretation of the behavior of light is just plain idiotic.&nbsp; Light, photons, provides the only means&nbsp;at our disposal&nbsp;for obtaining any information at all about the cosmos.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Correct.&nbsp; Michael likes to distort and misrepresent my statements and that of others to promote his own wacko EU ideas. It is just a tactic of his, common among those who have no scientific leg to stand on.&nbsp; It is his way of getting attention in legitimate hard science forums for ideas that belong in The Unexplained.&nbsp; <br /> Posted by DrRocket</DIV></p><p>What the heck are you rambling on about?&nbsp; I didn't misrepresent anything, and the original comment about you agreeing with the idea did not even come from me.&nbsp;&nbsp; Holy cow, are you paranoid or what? </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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This simply more of your continual carping at mainstream physicists because they don't pay attention to your EU nonsense, nor should they.</DIV></p><p>Does every single one of your posts have to include some derrogatory and false comment about EU theory?&nbsp; Why is it that you are allowed to prattle on endlessly about that subject in this forum when I am not allowed to even mention anything remotely even associated with it?&nbsp; Talk about double standard nonsense.&nbsp; You get to endlessly "bash" the whole basis of plasma physics theory in every single post that you make and I'm supposed to just sit here and take it?</p><p>If you'd like to discuss this subject I suggest you go over to the new thread in the forum where I may discuss these ideas and the first thing I'm going to ask you is what you even believe EU theory be about, because clearly you don't have the first clue what it is really all about, and that's because you've never read the book I suggested to you.&nbsp; Your opinions on this topic are born of pure and complete and willfull ignorance on your part. </p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> As usual this is poorly veiled garbage that belongs in The Unexplained.</DIV></p><p>On crusade again over a comment that is related to pure sketicism (scientific doubt) and empricism, that is totally unrelated to any particular scientific theory?&nbsp; Hoy!&nbsp; I'm really tired of your pety insults and I resent the fact that I'm not even allowed to discuss these ideas here whereas you are given a free reign to bash and misrepresent them in every single post.&nbsp; You use every single posts as an excuse to launch a personal attack on me and my belief, even going so far as to accuse me of misrepresenting your beliefs when I'm not the individual he was even responding to, or who even made the original comments.&nbsp; You also used that post to bash and misrepresent EU theory yet again.&nbsp; What's with the blatent double standard around here?</p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>OF COURSE dark energy, if it exists, affects light. </DIV></p><p>If there was an emprical way to demonstrate the presumed affect, then the skeptic would not have any problem accepting the idea.&nbsp; All I noted is that the problem arises (the skepticism continues) because no physical method exists to verify this presumed affect.</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>

 

[franontanaya]

<p>I'd feel more confortable thinking that the cosmological redshift is just a measure of how much the photon wave has been pulled and pushed by gravity fields, until it spread like a thread of chinese pasta. </p><p>Then it would be easier to understand why we see roughly the same amount of mass in any direction, since it would need roughly the same amount of pulls and pushes to stretch beyond visibility.</p> <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I suppose it's the fact that "none exists" that presents the skeptic with the problem. If someone could empirically demonstrate that 'dark energy' has some tangible affect on light, the skeptic would have nothing to be be skeptical about.&nbsp; It's the fact the skeptic has to accept on "faith" that the two are related that creates the problem.&nbsp; <br /> Posted by michaelmozina</DIV></p><p>&nbsp;</p><p>My statement on "controlled observation" was, more or less, an indirect question.&nbsp; What is the difference between a controlled versus and uncontrolled observation? </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'm curious about the snippet I extracted above.&nbsp; How would a void act like a lens ?&nbsp; And while I can understand the dimmer being interpreted as farther,&nbsp;I don't see a void affecting the time dilation curve for the SN.&nbsp; Wouldn't the mismatch peg that measurement of distance as being questionable ? <br /> Posted by Mee_n_Mac</DIV></p><p>&nbsp;</p><p>Maybe someone with a better understanding of optics can answer this question.&nbsp; My understanding is that a gravitational lens (act like a convex lens focusing the light while voids act like concave lenses disbursing the light essentially making them dimmer.&nbsp; Light behind a massive object is initially travelling at a tangent to the curvature of space of object doing the lensing.&nbsp; In the case of a massive object, that light will begin to follow the curvature and be bent around to a focal point recieved by the observer.&nbsp; In a void, the light is bent in the opposite direction depending on the physical shape of the void. </p><p>I'm sure this doesn't answer your question, but I'd like to see this thread get back on track. </p><p>As for time dilation of SNe, I see it as confirmation of redshift.&nbsp; If the interpretation of observed redshift is wrong, then using time dilation to support the redshift data is no longer relevant.&nbsp; It would simply mean that type Ia SNa are not as standard as we think they are.&nbsp; If there is no redshift via cosmological expansion, then the durations of the light curves must be due to some other phenomena.</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>

 

[franontanaya]

<p>Type Ia SN are modeled as being binaries with one white dwarf. </p><p>Is it accounted that for far Ia SN producing binaries the non white dwarf star that provides mass for accretion may be statistically younger than for closer ones?</p> <div class="Discussion_UserSignature"> </div>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I'd feel more confortable thinking that the cosmological redshift is just a measure of how much the photon wave has been pulled and pushed by gravity fields, until it spread like a thread of chinese pasta. <br /> Posted by franontanaya</DIV></p><p>FYI, I agree with this idea 100%.&nbsp; I think that "way' of looking at the problem is helpful in many ways. </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>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;... but I'd like to see this thread get back on track....Posted by derekmcd</DIV></p><p>I think the thread ran out of track a while back.&nbsp; A testable hypothesis was put forward with some modeling to support its plausibility.&nbsp; The test was conducted and (in the links that you posted) the hypothesis was disproved.&nbsp; That is how research works,&nbsp; Back to the drawing board. <br /></p> <div class="Discussion_UserSignature"> </div>