looking at the start of the universe

It appears to be more a function of the imagination.

There isn't and they aren't, the space betwixt them is expanding. Kinetic energy is a moot point.

This is incorrect.

It would appear that YOU are the only one who knows about that. Is that a new pet theory of yours? What is it with you and kinetic energy? It means nothing here.

 

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Fraggle:

I posted a response to you earlier, but I'll post it again, but first let me pose a thought [gedanken] experiment for Q.

If I were to construct a rocket ship that travelled at 90% of the speed of light, after a few million years it would catch up with many of the nearby galaxies we see receding from us, right? If that rocket ship were to continuously be beaming a laser beam in the visible light spectrum [in the rocket-ship's reference frame] back to Earth, intense enough that it could always be detected, that laser beam would be red-shifted in our Earth reference frame.

Now, the question to you, Q, is this: Would the rocket ship, at the mid-point that it reached a receding galaxy [passing by at a high speed], have kinetic energy relative to Earth? Knowing the initial mass of the rocket, and the amount of mass expended for acceleration, would we be able to calculate it's kinetic energy based upon the red-shift of the laser beam aimed at us? [Hint: The answer to both questions is 'yes'].

So, if some other object in the vicinity of a galaxy, having a red-shift indicating its recessional velocity, has kinetic energy relative to the Earth, why would the galaxy itself not have kinetic energy if it too has a recessional velocity indicated by its red-shift?

---------

Fraggle:

In response to your question, if you were to get in a rocket ship and travel at 0.9999991 c towards the CMB-emitter, keeping a close-eye on a single point, always aiming for it, it would take some 14 billion years to reach that point. Once you got there [and you would see that that point was contained in a galaxy that was some 14 billion years evolved from the original hot-plasma you had initially been keeping your careful eye on - indeed you would have seen, in a very short period of time while on the rocket, that point evolve into a point within a galaxy system, surrounded by other galaxy systems similar to what we see from Earth], you would have barely aged [due to relativistic effects], but when you looked around, you would see even more galaxies much further away than you could have seen when you departed. Looking back towards Earth, you'd see it aged by some 14 billion years. So, what would be the diameter of the Universe then, at that future point in time?

 

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You're talking about two different things here, one is under acceleration while the other is not. Big difference.

 

Fraggle:

That's the way I see it too.

What I believe is being spoken about in those sites that say the "diameter" or
"radius" of the Universe being some 7-fold greater is that under some theories, they have postulated that there was a rapid "inflation" of space in the earlier history of the universe [ergo, in the region of the CMB-emitter], but we don't see that, and they therefore infer the diameter, or radius, to be much greater. As I indicated, however, I believe that such is a mathematical construct, not supported by physical evidence. Seeing is believing.

What we see at circa 14 billion light-years distant is a hot plasma [mostly electrons, protons, and deuterons] that is cooling and expanding, at a measureable temperature of roughly 2,700 degrees K. We do not see separate, identifiable galaxies; though there are hints of slight differences in energies [anisotropies], which we presume will cause local variations in Hydrogen densities as it continues to expand and cool, allowing for it to form into local clusters of galaxies over time [very similar to what happened in our Milky Way neighborhood, or in other galactic neighborhoods we see receding from us], in our reference frame. Within its own reference frame, it has undoubtedly already formed into stars, galaxies, etc.; we just can't see that yet due to the finite speed of light. We also cannot see 'through' that plasma, but we infer that it is even hotter, and of greater mass, and that over time [in our reference frame] it will become visible as it continues to expand and cool, initially as a future CMB-emitter, and even further in the future, as separate galaxies seen in their earliest stages of existence. Of course, that matter has also undoubtedly, within its own reference frame, expanded, cooled, and coalesced into galaxies which we can't yet see even as a CMB-emitter.

Indeed, it indeed appears that there are "worlds without end"; we just can't see them yet; though we can see quite a large number of them nowadays right here in our backyard, the good ol' Milky Way.

Because it is at the "edge" [which is a misnomer; there is no edge - perhaps a better term is 'limit'] of what we can see, that plasma is receding at circa .9999991 c, giving a red-shift of circa 1,000, so that the light we see from that plasma is received in the microwave region, rather than in the visible light or infra-red region, of the electromagnetic spectrum. This exactly mimics, mathematically, the spectrum of emission of a stationary black-body at 2.7 degrees K at the same distance. We do not, however, believe it is stationary, but rather that it is receding at tremendous velocity.
[Q will say that it is the 'space' between us that is "expanding"]

I believe Q prefers to use artificial mathematical constructs, and refers to the "space" betwixt the CMB-emitter and us as "expanding", and the CMB as being emitted thereby from a stationary black-body. To me, that drastically confuses the matter [no pun intended].

As to Q's comment regarding the gedanken experiment I proposed, asserting that there is a difference in the two scenarios I proposed, because 1) the rocket ship was under acceleration, and 2) the galaxy was not, what I forgot to mention is that the rocket ship slowed to the speed of the galaxy, and then cut its engines, when it reached the galaxy, and it was just drifting along with the galaxy at the exact same recessional velocity, no longer under acceleration. It's laser beam aimed at Earth, red-shifted because the rocket is receding from Earth at great velocity, exactly mimics the red-shift of the galaxy. Q claims that the red-shift of the galaxy is caused not by physical recession from Earth [and hence there is no kinetic energy of that galaxy, in Earth's reference frame, due to its recession], but due to the expansion of "space" between the galaxy and us here on Earth; but that the red-shift of the rocket's laser beam aimed at Earth is caused by its recession from Earth, but that the expansion of "space" between the rocket and Earth does not add an additional red-shift. I guess he's concluding this because the rocket was man-made, and not natural. Anyway, I can't figure out where he's coming from, because his statements appear to defy the laws of physics.

Thanks for weighing in on the topic. 2Inquisitive's posts of the dwarf galaxy merger with the Milky Way was an interesting aside. Now I'm wondering if Earth and our solar system spent much of its earlier history in the much smaller dwarf galaxy that's mostly merged with the Milky Way, and not in the Milky Way itself, and how this 'recent' merger might have been impacting our geo-history, if at all. Likely it's had no impact, due to the great distances between stars.

Regards,


Walter

 

Fraggle and 2Inquisitive:

Q's posts are usually quite good. I've read many of them. However, he's wrong here.

I believe he's taken a personal affront, not due to this, but due to one of my earliest posts regarding Uranium. As it turns out, I challenged in a public forum [news-media]a personal friend/associate of his regarding the health-risks associated with the usage of Uranium as a glazing agent in the 1920s and 1930s on tiles of many types, including bathroom and kitchen tiles. As it turned out, those tiles are present even in grade schools, giving small beta-radiation exposures to the students. We did some preliminary calculations, and were essentially agreed it was not a major health threat, but nevertheless it would be a good idea to minimize the exposure. To me, it was more interesting that no one seemed to know, or more properly, remember, that several hundred thousand TONS of Uranium were glazed onto tiles in the 1920s to 1930s, long before it was discovered that Uranium could also be used in nuclear reactors.

Anyway, it appeared then that he had a chip on his shoulder about it, and I believe he thought he had a way to challenge me on this thread.

 

For those that would like a source, other than the posters opinions, as to whether space expands or not, here is a link to a wikipedia article on the metric expansion of space. While I usually prefer sources other than wiki, this is a good article and it gives further references at the bottom.

http://en.wikipedia.org/wiki/Metric_expansion_of_space

Here is the main part that deals with the reasons it is currently accepted as valid.

Observational evidence

It was not until the year 2000 that scientists finally had all the pieces of direct observational evidence necessary to confirm the metric expansion of the universe. However, before this evidence was discovered, theoretical cosmologists considered the metric expansion of space to be a likely feature of the universe based on what they considered to be a small number of reasonable assumptions in modeling the universe. Chief among these were:

* the Cosmological Principle which demands that the universe looks the same way in all directions (isotropic) and has roughly the same smooth mixture of material (homogeneous).
* the Copernican Principle which demands that no place in the universe is preferred (that is, the universe has no "starting point").

To varying degrees, observational cosmologists have discovered evidence supporting these assumptions in addition to direct observations of space expanding. Today, metric expansion of space is considered by cosmologists to be an observed feature on the basis that although we cannot see it directly, the properties of the universe which scientists have tested and which can be observed provide compelling confirmation. Sources of confirmation include:
Edwin Hubble presented the first observational evidence of an expanding universe.
Edwin Hubble presented the first observational evidence of an expanding universe.

* Edwin Hubble demonstrated that all galaxies and distant astronomical objects were moving away from us ("Hubble's law") as predicted by a universal expansion.[2] Using the redshift of their electromagnetic spectra to determine the distance and speed of remote objects in space, he showed that all objects are moving away from us, and that their speed is proportional to their distance, a feature of metric expansion. Further studies have since shown the expansion to be extremely isotropic and homogenous, that is, it does not seem to have a special point as a "center", but appears universal and independent of any fixed central point.
* In studies of large-scale structure of the cosmos taken from redshift surveys a so-called "End of Greatness" was discovered at the largest scales of the universe. Until these scales were surveyed, the universe appeared "lumpy" with clumps of galaxy clusters and superclusters and filaments which were anything but isotropic and homogeneous. This lumpiness disappears into a smooth distribution of galaxies at the largest scales in much the same way a Jackson Pollock painting looks lumpy close-up, but more regular as a whole.
* the isotropic distribution across the sky of distant gamma-ray bursts and supernovae is another confirmation of the Cosmological Principle.
* The Copernican Principle was not truly tested on a cosmological scale until measurements of the effects of the cosmic microwave background radiation in the dynamics of distant astrophysical systems. As reported by a group of astronomers at the European Southern Observatory, the radiation that pervades the universe is demonstrably warmer at earlier times.[3] Uniform cooling of the cosmic microwave background over billions of years is explainable only if the universe is experiencing a metric expansion.

Taken together, the only theory which coherently explains these phenomena relies on space expanding through a change in metric. Interestingly, it was not until the discovery in the year 2000 of direct observational evidence for the changing temperature of the cosmic microwave background that more bizarre constructions could be ruled out. Until that time, it was based purely on an assumption that the universe did not behave as one with the Milky Way sitting at the middle of a fixed-metric with a universal explosion of galaxies in all directions (as seen in, for example, an early model proposed by Milne).

Additionally, scientists are confident that the theories which rely on the metric expansion of space are correct because they have passed the rigorous standards of the scientific method. In particular, when physics calculations are performed based upon the current theories (including metric expansion), they appear to give results and predictions which, in general, agree extremely closely with both astrophysical and particle physics observations. The spatial and temporal universality of physical laws was until very recently taken as a fundamental philosophical assumption that is now tested to the observational limits of time and space. This evidence is taken very seriously because the level of detail and the sheer quantity of measurements which the theories predict can be shown to precisely and accurately match visible reality. The level of precision is difficult to quantify, but is on the order of the precision seen in the physical constants that govern the physics of the universe.



Of course, people are free to believe what they wish. I've ask for supporting links or references to support the opposing view and have been ignored. Once again, I request some support for the opposing view. If I fail to receive any, then I will assume the opposing view is nothing more than opinion.

Wilgory

 

And every other cosmologist, too.

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Correcting your inaccuracies and misunderstandings has nothing to do with a chip.

 

It is, Walters opinion. And of course, there is an entire array of websites and articles that will confirm the above article from wiki, despite Walters opinion.

 

This is simple ballisitics.
We have the gun residue and a rapidly expanding shockwave. In more detail the back ground radiation of the universe is fading little by little.( like an explosion) All matter in the universe is rapidly moving appart.

Those are the facts. Was there an explosion? I tend to believe yes. There was.

How ever we also know that the present state of the universe is not entirely the result of the explosion. Currently we know the space time fabric of the universe is expanding at an accelerated rate, independent from the background radition of the universe it'self.

Quintessence plays apart. Quintessence is force generated by the mutal annihilation of virutal particles.

Gravity has also played apart as energy condessend into matter

Dark Matter: We really don't know what Dark Matter is but we've got lots of theories. Brown Drawfs stars we can't see like Jupiter in abundance, neutrionos, photons and host of particles that may have a minute amount of mass may have caused stellar uneveniness.

Anitmatter: There's also another question. Where is all the animatter that must have been created in equal porion during such an explosion. (If it was equal. we've no basis to asume it was.) Where ever antimatter may exist is large portions may also explain our universe.

The Great Attractor: Some belive that the Great Attractor does not exist. A large super super super massive cluster of Galaxies that that our Local cluster and several other clusters seem to be racing toward. Or they may be racing toward somewhere else.

There are many factors. Scientist don't have all the answers and the answers they do have don't all fit together snuggley. But it searching an the discovery that is so scintillating.

 

Wilgory and Q:

I do not disagree with the article cited by Wilgory. Indeed let me quote from it as to evidence that supports an "expanding" universe with physical motion of galaxies moving away from the Milky Way:

"[2] Using the redshift of their electromagnetic spectra to determine the distance and speed of remote objects in space, he [Hubble] showed that all objects are moving away from us, and that their speed is proportional to their distance, a feature of metric expansion. Further studies have since shown the expansion to be extremely isotropic and homogenous, that is, it does not seem to have a special point as a "center", but appears universal and independent of any fixed central point."

Indeed, such is exactly what I've stated - that distant galaxies are receding from us ["moving away from us], and the farther away they are, they faster they are receding. Further, anywhere in the Universe would give essentially the same general view of galaxies receding away from one's reference point. That is, of course, a feature of GR and the finite speed of light.

That quote describes, in fact, physical motion through space. It is not necessarily "space expanding"; however, mathematically, it can be treated the same. Of recent, however, the "space expanding" concept has apparently been elaborated upon, in which the expansion is believed by some not to have been uniform, but much more rapid in the earliest eras of the Universe, which gives rise to the answer to Fraggle's question. However, as to that particular version, there appears to be no firm evidence.

The other "models" with a "fixed metric" referenced in the article have the Milky Way at the center of the Universe. However, under GR, there is no center; or alternatively, anywhere in the Universe is a "center". Thus, any inhabitants in the galaxies we presume to exist in that region of the Universe that constitutes the CMB-emitter would have the same type of world-view [universe-view] that we have - - namely galaxies receding from them, with their speed of recession increasing with increasing distance. GR requires no less.

Nowhere does that article affirm what Q has been stating - that the nearby galaxies we see receding from us do not have a kinetic energy relative to Earth.

That is why I consider the "space-metric" approach, of referring to space as "expanding" as a poor model - because it leads to confusions such as concluding that a receding galaxy has no kinetic energy associated with its recession, relative to us, as Q stated earlier in this thread.

In its own rest-frame, such receding galaxy has no kinetic energy, true; just like the Milky Way has no kinetic energy [other than that obtained from local graviational perturbations, such as being attracted to nearby galaxies] in its own rest-frame. However, those distant galaxies are part of our universe, and in our rest-frame, they have high kinetic energy, as demonstrated in the gedanken experiment posted above.

What I was summing up in this thread is that, in our rest-frame, the CMB-emitter material [electrons, protons, deuterons, etc.] likewise has a high kinetic energy [even though within any particular point within its rest frame, there would be no local kinetic energy, just as here in the Milky Way we are "at rest"] due to its high recessional value, in addition to its high thermal energy.

Now, Q, do you disagree with that last paragraph, or not?


The matter further beyond the CMB-emitter, that we can't see yet but will see in our future, is accordingly even hotter, of greater total mass, and of greater recessional velocity. As we sum up all of that matter/energy, going back to the singularity origin of the Universe, the summation approaches infinity.


This is also not something new to me. I've been stating this [and printing this] since the mid 1970s, long before we began examining the CMB in greater detail to ascertain small local anistropies [dimples] on its "surface". Those dimples are what we would expect, and likely represent the earliest precursors of distant galactic clusters, though that is still under further investigation. If we could see the cold clouds of Hydrogen that such devolve into [located closer to us than the CMB-emitter, but further away than the most distant galaxies we can detect], before they coalesce into stars and galaxies, we'd have a better handle on it, but we can't yet see that virtually invisible, cooled Hydrogen gas unless it contracts into denser clouds and/or stars/galaxies that emit light [unless that's what's causing the dimpling, uneven clouds of cooled Hydrogen?!].

And, if you want references, go back to Hubble's original works. He concluded that the galaxies were physically receding from us, due to their red-shifts. Likewise, look to Penzias and Wilson, who concluded that their Bell laboratory discovery of a constant microwave "static" noise, coming from all directions, was in fact the "remnants" of the BB explosion. I'll look up some of my other references, cited in my papers, when I get back to my other office.

Regards,


Walter

--------------

 

Saquist:

All very good points, well taken.

 

Walter said:

"And, if you want references, go back to Hubble's original works. He concluded that the galaxies were physically receding from us, due to their red-shifts. Likewise, look to Penzias and Wilson, who concluded that their Bell laboratory discovery of a constant microwave "static" noise, coming from all directions, was in fact the "remnants" of the BB explosion. I'll look up some of my other references, cited in my papers, when I get back to my other office."

If your view of the universe is from these references, I suggest you update it. You seem to be stuck on what you learned in the seventies.

I could support the believe that the earth is the center of the universe by referencing Ptolemy but science has progressed slightly since then.

Wilgory

 

Saquist,

Ballistically speaking, there is a center to an explosion. There is no place you can point to as being the center of the universe. Even Walter agrees there. I can't understand how one continues to insist on the expansion being like that of an explosion when that point alone tells us it can't be.

Wilgory

 

Horsepucky! You've been claiming that those distant objects are hurtling THROUGH space with HUGE kinetic energies and HUGE masses. That isn't anything as to what the article refers.

No, it can't, it is entirely different. Your explanation would yield very different observations than that which IS observed.

Yes, there is evidence, the NASA's Cosmic Background Explorer, the Degree Angular Scale Interferometer (DASI) and the Balloon Observations of Millimetric Extragalactic Radiation and Geophysics (BOOMERANG) all have provided very strong evidence in favor of inflationary theory.

I've not disputed that, only your explanation of that.

It makes no such claim due to the fact that kinetic energy has nothing to do with receding galaxies. The space is expanding between the galaxies, they are NOT hurtling through space. Their kinetic energies will be almost zero.

No, it is your opinion that is causing confusion, especially considering it is not observed.

No, it didn't demonstrate that at all.

It's gibberish.

And more.

Huh? What does that have to do with anything?

Again, I don't dispute that, only your explanation of their observations, which is wrong.

 

Well, it appears we have a disagreement.

In the gedanken experiment I proposed, I believe that if we send a rocket ship to a nearby galaxy that we see receding from us, cut the engines, and let it drift along with that galaxy [go real fast from Earth to catch up, then decelerate to the speed of the galaxy], it will have the same red-shift as the galaxy [in the laser beam aimed back at Earth, compared to the star light of the galaxy], and likewise the rocket ship will have large kinetic energy [relative to Earth], even though drifting along in the galaxy.

You believe otherwise, claiming that the receding galaxies do not have kinetic energies associated with their recession from Earth, but man-made objects placed into such distant receding galaxies so that they are receding at the same speed [drifting along in the galaxy], with a high recessional velocity equal to that of the galaxy, would have kinetic energies.

That doesn't make sense.

Oh well, all those who believe that that makes sense, please raise your hand, or otherwise post your comments here.

As to your statement below:

"Yes, there is evidence, the NASA's Cosmic Background Explorer, the Degree Angular Scale Interferometer (DASI) and the Balloon Observations of Millimetric Extragalactic Radiation and Geophysics (BOOMERANG) all have provided very strong evidence in favor of inflationary theory."

What those experiments provide evidence for is a very slight anisotropic distribution amongst an otherwise relatively uniform isotropic distribution of the CMB. How that is interpreted is another matter. Those experiments are confirming evidence that the CMB is a black-body spectrum of an approximately 2,700 degree receding hot black-body [that in our reference frame spherically surrounds us at a distance of circa 14 billion light years], with a red-shift of about 1,000 due to the high recessional velocity, so that we see it in the microwave frequencies.

So, any more horsepucky you want to post?

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Wilgory:

I cited old references to show that essentially the BB theory remains the same today, but with greater detail, from the earliest of days when it was first discovered that galaxies are receding [as was noted by Hubble], and that the interpretation thereof showed that in the distant past, they were all on top of us [some 14 billion years ago; though Hubble didn't have the age right back then]. There are many additional experiments since the 1970s that confirm this [as noted above]. Being "stuck" on Newtonian and Einsteinian physics, by the way, is a good thing, until it is disproven. Since it fits with experimental evidence, over and over, we rely extensively on Einstein and Newton, et al., even though much of that work was either centuries ago [Newton's laws], or a century ago [Einstein's earliest work]. Even work from the 1950s remains valid. Apparently, you don't quite understand it yet.

And Wilgory, the expansion is exactly like a 4-d explosion, NOT a 3-d explosion. In a 3-d explosion, there is a center, and an exterior edge, and an observer can see the explosion in 3-d from far away.

In a 4-d explosion, everywhere is the center. We are on the inside of the explosion. Nevertheless, it is an explosion, and we see the remnants of that receding from us in all directions.

It used to be really hot around here, but everything blew away from us in the explosion, and has continued to cool and expand over time, leaving it relatively cool around here after 14 billion years. We can see remnants of the explosion 14 billion light years away, as the CMB emitter. We can see closer remnants that have cooled and coalesced into galaxies. We cannot yet see the hotter portions of the explosion that are beyond the CMB-emitter [on the other side of the brehmstrahlung opacity wall]. As time passes, we will continue to see further and further away. One billion years from now, we will see a CMB-emitter that is 15 billion light-years away, matter which we can't yet see because it's beyond the CMB-emitter, in our reference frame. In its own reference frame, it too has cooled extensively and formed galaxies - we just can't see it yet due to the finite speed of light.

 

And, it has nothing to do with anything regarding cosmological redshift, you are creating a strawman argument.

Attempting to get support for your pet theory?

Or, in your case, how it is misinterpreted. Sorry Walter, your pet theories aren't flying.