Does the Universe travel at the speed of light?

[dragon04]

<font color="yellow">There is absolute horizon of universe,that moves.</font><br /><br />In terms of the <b>observable</b> Universe, you are absolutely correct.<br /><br />That horizon would be constrained by Einsteinian physics. However, the observed <b>accelerating</b> expansion of the Universe implies that something "outside" what we can observe is happening. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[ajna]

With respect, I can't make sense of the question. How can there be any absolute in our universe such as c?<br /><br />C is 386,000m/s (i think). What is a mile? What is a second? They are not absolutes.<br /><br />C must be a ratio to other things, unseen as yet. When they change, so does C (C is a product of time and distance is it not?). Time. Distance. Gravity. They all change together right?<br /><br />I think we could be describing our expansion and C as a ratio to other things (eg the harmonics of the dimensions). Algebra fails us here, a greater knowledge of geometry will give us knowledge into the ratios that seem absolute, but are not.<br /><br />Invisi I think you are right, but I would say it undulates at the speed of light, whatever that may be within the local region of spacetime. The universal undulation is our own undulation, and we call that c.<br /><br />

 

[ajna]

I don't know Dragon04, 'To me, that implies a force acting from "outside" 4 dimensional space-time. That's trying to be explained by "dark energy" and "dark matter", which I find very inelegant.'<br />Our bodies expand from the inside out, yet we need external food. I think in the same way our universe is expanding but this is in concert with what we think is an external source. Ecologically, our food and us are one system. So the same with our universe and its 'system'.<br /><br />If the universe is 'all that is', then when we discover the true nature of the dimensional matrix, we will find that it sustains itself. If it can't, then it points to an even greater scheme of things, like multiverses. Do you think the universe is not self-sustaining?

 

[onesimple]

Scoop from Savo<br />According to this simple principle (the Savonian theory) the universe consists of only energy and space. Energy is the one and the same energy that has the ability to wrap up into denser space and the ability to open up into less dense energy in space, which does not expand or bend. You can perform an experiment by trying, how a single concentration of energy (you, in this case) can wrap up into smaller space (foetal position), in which less energy is released from you. Then you can try to think how the energy in the core of an atom is always denser and denser, depending on how close the energy is to the center of a separate energy concentration.<br /><br />Does history repeat itself? People, who believed that the earth was the centre of universe, thought erroneously that the earth stays in its own place and all the celestial objects circle us. Modern theories suggest that all visible objects of the universe mostly stay in a static area in space, which expands in such way that the universe does not expand outwards into existing space. This model requires an additional space dimension, which is rather impossible for people to understand.<br /><br /><br />The Big Bang<br />According to the Big Bang theory, in the beginning there was only a very dense concentration of energy and space was created inside this concentration in a big explosion. But what if all this energy begun to open up outwards to a space that already existed?<br /><br />We do not have to assume that all energy in that concentration opened up evenly. According to my theory, all energy in that concentration begun to push itself away from the center of the concentration while expanding at the same time. When all the energy tried to expand into every direction, it caused an enourmous pressure towards the center, and that pressure kept this energy hot and dense. The farther the energy traveled, the faster it could expand, and thus the faster the movement became.<br /><br />Let us assume that ther

 

[R1]

I need some input on the thought that the distant redshift could be the result of the<br />higher gravity field density when the observable universe had a smaller volume.<br /><br />A gravity field slows down clocks according to its strength, so when matter first existed in a more dense<br />universe time surely slowed down, so wouldn't light from this slow universe appear as redshifted<br />to the current un-dense universe 12 billion years later? <br /><br />for example I had a 56k modem 12 billion years ago over there, when time was slower from the<br />strong and dense gravity fields, I think that today, 12 billion yrs later when time is not as slow,<br />my modem signal would appear to you slowed down, like at 12k modem <div class="Discussion_UserSignature"> </div>

 

[tdamskov]

When atoms started forming (~1 mil. years), the universe was about as dense as the equivalent of our atmosphere if I remember correctly. When the gas started clumping into galaxies (the redshifted ones visible today) the average density was much less. The resulting gravity field would be too weak to have any detectable impact on red shift.

 

[SpeedFreek]

<i><font color="yellow">"I need some input on the thought that the distant redshift could be the result of the higher gravity field density when the observable universe had a smaller volume."</font>/i><br /><br />Whilst at first seemingly straightforward, the more I considered this concept, the more it confused me!<br /><br />Are we considering here that the universe <i>is</i> metrically expanding then, or not? Are the distant redshifts caused by the faster expansion of space early on and the light being stretched by that expansion, or are they purely caused by the mass of the observable universe residing in a smaller volume, causing all gravitational fields to be closer together?<br /><br />If so, the example still proposes expansion (if the universe was smaller, early on), but proposes that the redshifts aren't caused by that expansion, but by the light being affected by gravity.<br /><br />So we still have an expanding universe, but with redshifts corresponding how close together everything was, and not the light being stretched by that expansion?<br /><br />Or are we suggesting that redshift is not caused by expansion because there is no expansion, but everything was closer together earlier on? I.e. as if the big bang <b>was</b> an explosion into space that already existed, and all matter is moving away from a single point? Seeing as you use the term "smaller volume" I would assume you don't mean it this way?<br /><br />You can't mean a static universe, if the volume was smaller, earlier on...<br /><br />I need to know what the whole model is, to understand how gravity might affect observations. Actually, this reply of mine also confuses me! <img src="/images/icons/smile.gif" /><br /></i> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[adrenalynn]

<font color="yellow"><br />When atoms started forming (~1 mil. years), <br /></font><br /><br />Would you check and confirm that number? I'm standing on rocks older than that as I write this...<br /><br />I believe that current theory puts Recombination* at BigBang + 380,000yrs<br /><br />If we figure 13.7B - 380K, I come up with something like atoms forming some 13.32 <i>Billion</i> years ago.<br /><br />*Recombination was the period when Hydrogen and Helium atoms began to form and the density of the universe fell. Decoupling also probably occured during this period, when the atomic structures and photons separated. So this would also be the approximate age of the CMBR we observe. This is, of course, assuming current theory is correct. If you're operating under a different theory, would you disclose that?<br /><br /> <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>

 

[SpeedFreek]

He meant <i>approx</i> 1 million years after the big bang (t = ~1 million years). As you say, atoms started forming at recombination (t = ~380,000 years). We are now at t = ~13.7 billion years.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[Mee_n_Mac]

<font color="yellow">I need some input on the thought that the distant redshift could be the result of the <br />higher gravity field density when the observable universe had a smaller volume.</font><br /><br /><br />I can't answer your question but let me add another thought. Things may have been closer in the early universe but they were also more uniformly distributed. I'd think the latter is important because the warpage of space-time would have been less due to the symmetry. I think of it this way, gravity may be high near a star but at it's center there's none. So what won the battle in the early universe; lack of distance or uniformity ?<br /><br /> <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>

 

[R1]

Surely massive particles existed before atoms, and good points on the modeling, speedfreek<br />I would think my modeling should try to keep working on what we think we know, so<br />yes let's say the universe did and does expand, <br /><br />but perhaps much of the redshift value from these early times is at least in part due to this higher gravitational<br />density in the more dense early universe<br /><br />by the way I found a graphical timeline which seems to tell me that gravity separated very early in terms<br />of Planck time. Now then, gravity separated from something that doesn't exist?<br /><br />http://en.wikipedia.org/wiki/Graphical_timeline_of_the_Big_Bang<br /><br />the early universe surely had a higher density in the smaller more compact volume didn't it?<br />My first thought is that virtually every quark (or massive constituent of it)and/or gluon of every thing we observe in a<br />13 billion lightyr. radius plus everything swallowed by black holes might have once existed in an<br />area smaller than our sun<br /><br />from all the gravity that everything in the universe has, I would think time was extremely slow initially , the expansion<br />had to be powerful enough also to reach and exeed escape velocity of all mass too, but I think now<br />that the redshift noted from these early times surely is at least in part due to all the gravity of everyhting<br /><br />I have no clue what a reasonable ratio would be, but for distant objects with a redshift value of z=1500<br />what I'm wondering is could it be that z=900 of it due to expansion and z=600 of it due to the gravity of<br />the times?<br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[ajna]

John1R I get what you are saying. It implies that c has never been a constant and continues to change as the universe evolves. When Einstein proclaimed that c is a constant, everyone assumed that meant 'for all time'. We should have said 'at any one spacetime'.<br /><br />Any photon coming from billions of LY away would demonstrate the time/gravity of its origins in its redshift like John1R suggests, but it would be modified by the variable time/gravity environments during its passage to us. <br /><br />Q: Could the redshift data be used in the same way as the microwave data, to create a c anisotropy map? Would this allow us to a) map the change in c over 'time', and b) map local pockets of time/gravity anomalies?

 

[SpeedFreek]

Remember, that as light passes through a gravitational field, it is blueshifted on the way in to that field and redshifted by the same amount on the way out, leading to an overall change in redshift of zero. The only gravity that would have an effect on the redshift of that light would be the gravity of the object it started from, where it might be redshifted on the way out, and the gravity around the observer.<br /><br />Now, if gravity was so much "stronger" earlier on, wouldn't the early galaxies look different in structure (denser?) when compared to galaxies in more recent times? <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[yevaud]

<i>Now then, gravity separated from something that doesn't exist?</i><br /><br />That's mixing apples and oranges. At the temperatures at or before the Planck time, all four forces were unified. That symmetry was broken when the temperature decreased enough for the forces to begin to separate in their distinctive selves - gravity being the first force to do so. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[derekmcd]

"<i>b) map local pockets of time/gravity anomalies?</i>"<br /><br />Yes indeed. Using redshift as a tool helped confirm The Hole in the Universe.<br /><br />As light passed through the 'void' it was redshifted more than what is normally observed as the expansion of space does not have to compete with the regularly observed amount of matter/gravity.<br /><br />Conversly, when light passes by a region of space that is more dense than what is normally observed, the redshift is far less than normal.<br /><br /> <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>

 

[alokmohan]

Well said.

 

[R1]

<font color="yellow">Now, if gravity was so much "stronger" earlier on, wouldn't the early galaxies look different in structure (denser?) when compared to galaxies in more recent times? <br /></font><br /><br />good question. I don't know. maybe we can't discern individual galaxy density, but It probably should be<br />more densely populated with galaxies.<br /><br />But I'm noticing another thing, the first stars didn't begin to shine until 100 million years, so by now the <br />observable universe probably had a radius of at least 100 million lightyrs. So the redshift that could be<br />largely attributed to a high gravitational density component probably belongs to non-star related matter,<br />maybe something like simple free fermions and much earlier in the big bang timeline.<br /><br />I don't know, but this might be the beginning of the answer and maybe the galaxies with redshift values<br />in excess of z=1000 are mostly if not entirely due to expansion. I'm still left with the Background Radiation<br />to wonder about though, because now at this amount of earliness I would think that the observable universe had the significantly lower volume and higher density of gravity and fermions or whatever was needed<br />that could actually cause the universe to actually have a gravity value. In other words when in the timeline did<br />gravity actually exist? I see that gravity separated early as Yevaud pointed out.<br />But when did stuff actually exist that caused gravity to first exist? <br /><br />(I'm probably going to have lots of questions.) Withouth fermions or anything of mass then there's probably<br />no spacetime? (just imaginary spacetime?)<br /><br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[SpeedFreek]

<font color="yellow"> maybe we can't discern individual galaxy density, but It probably should be more densely populated with galaxies. </font><br /><br />Yes, the galaxies were a lot closer together then than now. But apart from local clusters, the galaxies were not close enough to be attracted towards each other, were they? And yet you suggest the voids between these galaxies have a high enough gravitational field to redshift light? <br /><br /><font color="yellow"> But I'm noticing another thing, the first stars didn't begin to shine until 100 million years, so by now the<br />observable universe probably had a radius of at least 100 million lightyrs </font><br /><br />I think the estimate for the radius of the observable universe when the first stars formed is a <b>lot</b> bigger than that. Consider that when the CMB (z=1089) was emitted at t = ~380,000 years, the observable universe is theorised to have been around 40 million light years in radius. By the time the first galaxies formed, the radius was already billions of light years!<br /><br />We theorise that no star or galaxy has a redshift over z=20. We have some evidence of galaxies having redshifts around z=10, but the highest "accepted" redshift for a galaxy is currently z=6.96. I often say the most distant, earliest structures would likely have a redshift around z=15. This would imply the universe was already pretty huge when the first stars formed (at least 3 billion light years radius).<br /><br /> A galaxy at a redshift z = 6.96 <br /><br />And I still say it doesn't matter how close together objects were, it is only the gravity of the emitter and receiver that could effect the redshift in the way you are suggesting. None of the other galaxies the light passes during its journey will add anything to the final redshift result - we currently only consider gravity to be a factor in the redshifts of objects like black holes or per <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[R1]

thanks speedfreek.<br />No, I'm no longer thinking galaxy light would be greatly time dilated gravitationally, simply from the size<br />of the universe when they formed, but I'm beginning to understand (I think) gravity in the early times,<br />such as when the observable universe was less than a kilometer in size, maybe even less than a meter.<br /><br />So now I'm thinking there should be background radiation which should be greatly time dilated gravitationally.<br /><br />I think I'm beginning to understand how there could be gravity before mass existed too.<br /><br />It seems like all that is needed are some high frequency strings that behave like spin 2 particles,<br />and I think it was highly likely that high energy and frequencies were there.<br /><br />but then I see time as having to exist necessarily, or else you can have no frequency, no spin.<br /><br />I don't think strings existed and all of a sudden decided to vibrate, I think they always vibrated, so<br />that would mean I believe time is infinite too.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[alokmohan]

I think gravitation is a force starting from birth of universe.All theories take gravitational for granted.Otherwise you canot speak of birth of star and galaxy.