To say the universe is all there is, is awfully arrogant and presumptuous. If virtual particles bounce back in and out of existence, it is more than plausible it is going somewhere. Space is not empty with random particles but a mesh of physical laws and whether something appears to be expanding or appears to not have an edge has nothing to do with the fact we don't know what else is out there period.
looking at the start of the universe
- Thread starter Captain Kremmen
- Start date
Dear Wilgory, thank you for the recommendations in strand #11. I've started reading the UCLA one and it looks very good. It is answering some questions that I hadn't even thought of! In Strand #18 you said that these websites will clear up FAQs concerning centre,age, size and shape. Expansion seems to be an important factor. My model is simple, but can't see how extra factors such as expansion of the universe really affect the argument as presented in strand #3. If the energy which we are observing and the planet we are observing it from both originated at the same place at the same time, the energy should have outpaced the matter not vice versa. I can't see how any factor would not affect both the matter and the energy. I would like a few people to go through my question as stated in strand #3, where I have broken it into three stages, and comment on it stage by stage. Then let battle commence again. I'm really pleased with the number of replies this is getting. I joined sciforums just to ask this question.
Chris:
Go back and read my previous posts.
In answer to your "strand #3", here goes. It's a good question based on a common misperception regarding the BB.
The matter that emitted the "blackbody background radiation" [2.7 degree K radiation that we see in microwave frequencies] left our vicinity of the universe [our Milky Way region] roughly 14 billion years ago, travelling at very high speed [roughly 0.9999991 c]. It is NOT the same matter that formed our Milky Way, but entirely separate and distinct matter, just as the other galaxies are entirely separate and distinct chunks of matter, separate and distinct from our Milky Way.
The light that it emitted is just now arriving on Earth, highly red-shifted. We did not 'beat it here', because our Milky Way matter has always been located here, and our galaxy is the small, finite portion of the BB explosion that remained in this vicinity, with all of the rest of the matter exploding away from us [in our rest frame]. Because of the finite speed of light, we in essence see that region of the universe "the way it was" and not the way it is now. We presume that that matter has likewise continued to cool and expand into space, eventually forming stars and galaxies similar to the ones we see near to home. However, because of the finite speed of light, we cannot see what has become of that matter, and won't be able to for quite some time. It almost certainly [to a very high degree of certainty] has cooled, gravitationally collapsed, and formed into matter that produce quasars, exploding giant stars, etc. [like what we see at about 2/3rds that distance away]. We just can't see that yet, because it is so far away, and light takes a finite amount of time to get here.
Imagine the BB explosion blowing all of the matter of the universe away from us here at the Milky Way region, and we are now surrounded by a spherical shell of very hot plasma gas moving away from us at very high speed, with us in the center [which is the view in our rest-frame]. In between there and here, the gas has cooled and contracted to form numerous galaxies [as seen in our reference frame]. Likewise, we can presume that that sphere of hot plasma has also, within its own reference frame, cooled and contracted to form galaxies - - we just can't see that yet because it's so far away, and with the finite speed of light, we can only see it the way it used to be, not the way it is now.
Regards,
Walter
---------
Go back and read my previous posts.
In answer to your "strand #3", here goes. It's a good question based on a common misperception regarding the BB.
The matter that emitted the "blackbody background radiation" [2.7 degree K radiation that we see in microwave frequencies] left our vicinity of the universe [our Milky Way region] roughly 14 billion years ago, travelling at very high speed [roughly 0.9999991 c]. It is NOT the same matter that formed our Milky Way, but entirely separate and distinct matter, just as the other galaxies are entirely separate and distinct chunks of matter, separate and distinct from our Milky Way.
The light that it emitted is just now arriving on Earth, highly red-shifted. We did not 'beat it here', because our Milky Way matter has always been located here, and our galaxy is the small, finite portion of the BB explosion that remained in this vicinity, with all of the rest of the matter exploding away from us [in our rest frame]. Because of the finite speed of light, we in essence see that region of the universe "the way it was" and not the way it is now. We presume that that matter has likewise continued to cool and expand into space, eventually forming stars and galaxies similar to the ones we see near to home. However, because of the finite speed of light, we cannot see what has become of that matter, and won't be able to for quite some time. It almost certainly [to a very high degree of certainty] has cooled, gravitationally collapsed, and formed into matter that produce quasars, exploding giant stars, etc. [like what we see at about 2/3rds that distance away]. We just can't see that yet, because it is so far away, and light takes a finite amount of time to get here.
Imagine the BB explosion blowing all of the matter of the universe away from us here at the Milky Way region, and we are now surrounded by a spherical shell of very hot plasma gas moving away from us at very high speed, with us in the center [which is the view in our rest-frame]. In between there and here, the gas has cooled and contracted to form numerous galaxies [as seen in our reference frame]. Likewise, we can presume that that sphere of hot plasma has also, within its own reference frame, cooled and contracted to form galaxies - - we just can't see that yet because it's so far away, and with the finite speed of light, we can only see it the way it used to be, not the way it is now.
Regards,
Walter
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Thanks Walter. It's beginning to make sense.
Chris
Chris
Walter,
When you said:
Only one of those "models" can be correct. A more in depth analysis yields the result that it is the infinite universe model that would be correct, though I will not attempt to present that indepth analysis here.
You implied I used more than one model. This misses my point completely. What I was trying to say is that the data we have to work with is not precise. That the(single) LCDM model gives a range of possible solutions, and due to the inaccuracy of the data, we can't determine if the universe is infinite or not. If you have information that validates an infinite universe please post a link or give a reference so I can further my understanding of what is "known" about the universe.
Also, you seem to accept the ideas that the universe is infinite with no edge, and that observers far from one another both see the universe as expanding from their position. These ideas, I believe, are contradictory to the expansion being like that of an explosion. If the expansion is like an explosion there would be a center that the explosion radiates from. This can't be if all observers see the universe expanding from their particular location. The cosmic background radiation being uniform in all directions also disproves the idea of a center to an expansion.
I agree the raisinbread analogy is not a very good one when it tries to model the universe. I like the way it shows a 3-dimensional expansion unlike the one of an explosion. That is why I used it. Do you know of an analogy other than the balloon that better fits the universe?
Chris,
I agree with Walter on the point that the Milky Way formed in the general area it is in now(allowing for its motion and the expansion of space) and did not travel through the same space as the radiation that we receive from distant galaxies.
I would add, some galaxies are close enough to us that their light has been passing through our region since the Milky Way formed. Some are not that far away but formed recently and the light hasn't had time to reach us. Some are very far away but they formed long before and the light has had the time to reach us. The cosmic background radiation formed so long ago that it pervades the entire universe and has spread out uniformly throughout.
I would also add. There are many theories about the universe. Some based on GR and some not. GR has passed virtually all tests and while it has it's problems, it seems to be the best one we have for now. There are many people working on quantum theories of gravity and string theories, however there has been no test (experimental or observational) to validate or falsify these. The Gravity Probe B experiment may help weed some of these out however there have been some delays and the results will not be finalized until near the end of this year. Here is a link to the Stanford site for the GPB test of GR.
http://einstein.stanford.edu/
I don't have a link but if you search for "alternative theories tested by Gravity Probe B" you can find a forum discussion concerning this.
Wilgory
When you said:
Only one of those "models" can be correct. A more in depth analysis yields the result that it is the infinite universe model that would be correct, though I will not attempt to present that indepth analysis here.
You implied I used more than one model. This misses my point completely. What I was trying to say is that the data we have to work with is not precise. That the(single) LCDM model gives a range of possible solutions, and due to the inaccuracy of the data, we can't determine if the universe is infinite or not. If you have information that validates an infinite universe please post a link or give a reference so I can further my understanding of what is "known" about the universe.
Also, you seem to accept the ideas that the universe is infinite with no edge, and that observers far from one another both see the universe as expanding from their position. These ideas, I believe, are contradictory to the expansion being like that of an explosion. If the expansion is like an explosion there would be a center that the explosion radiates from. This can't be if all observers see the universe expanding from their particular location. The cosmic background radiation being uniform in all directions also disproves the idea of a center to an expansion.
I agree the raisinbread analogy is not a very good one when it tries to model the universe. I like the way it shows a 3-dimensional expansion unlike the one of an explosion. That is why I used it. Do you know of an analogy other than the balloon that better fits the universe?
Chris,
I agree with Walter on the point that the Milky Way formed in the general area it is in now(allowing for its motion and the expansion of space) and did not travel through the same space as the radiation that we receive from distant galaxies.
I would add, some galaxies are close enough to us that their light has been passing through our region since the Milky Way formed. Some are not that far away but formed recently and the light hasn't had time to reach us. Some are very far away but they formed long before and the light has had the time to reach us. The cosmic background radiation formed so long ago that it pervades the entire universe and has spread out uniformly throughout.
I would also add. There are many theories about the universe. Some based on GR and some not. GR has passed virtually all tests and while it has it's problems, it seems to be the best one we have for now. There are many people working on quantum theories of gravity and string theories, however there has been no test (experimental or observational) to validate or falsify these. The Gravity Probe B experiment may help weed some of these out however there have been some delays and the results will not be finalized until near the end of this year. Here is a link to the Stanford site for the GPB test of GR.
http://einstein.stanford.edu/
I don't have a link but if you search for "alternative theories tested by Gravity Probe B" you can find a forum discussion concerning this.
Wilgory
I can't imagine how you are understanding it, Walter is giving you false information. Any number of reputable sources will confirm that.
Wilgory:
One would see galaxies moving away from one's location [except for a local group that might be gravitationally bound to one's own galaxy, as we have here in our Milky Way], wherever one might be in the universe. They would all have the same general description as we have here in our Milky Way; that is, the farther away they are, the faster they are receding from the viewpoint. There is no "center" to the explosion. In our reference frame, it 'appears' that we are at a center. That is simply because it is our reference frame.
Q:
Either put up or shut up. What exactly is it you believe that is "false information" that I have provided? There is nothing that I have described that does not fit with observation and GR. Certainly Spidergoat recognizes that.
You are likely one of those confused physicists who believe [and state] that the matter [mostly Hydrogen, some Helium] that emitted the 'blackbody' microwave background radiation is the same matter that formed our Milky Way. That is what ultimately confuses people like Chris; physicists who have only a limited understanding of GR and its BB implications, but spout off as if they were knowledgeable. That's why Chris had a hard time understanding how our Milky Way 'beat us to this location', 'ahead of the microwave background' - because that's how some ignorant physicists have described the BB to him, which was a false description Are you one of those?
That microwave-background-emitting matter was once in our vicinity, a long time ago [in our reference frame]. It exploded away from our Milky Way region at nearly the speed of light, and eventually cooled [in its reference frame] to where the electrons and protons could couple and emit light that we see. We see that matter at a great distance away, its light having travelled nearly 14,000,000,000 light years to get to us from where it was emitted. Because the matter that is emitting that light is receding from us so fast [about 0.9999991 c], it is highly red-shifted [red-shift of about 1,000], and we see it as microwave frequency photons, rather than visible-light frequency photons. That matter [Hydrogen, etc.] at that great distance is not, and never has been, the same matter that our Milky Way is composed of [also Hydrogen, etc.], just as the matter of the other galaxies that we see is not, and never has been, the same matter that our Milky Way is composed of. It is separate and distinct. What don't you understand about that? The only time that it was in direct 'communication' with our Milky Way was at the point origin of our universe. That is the purpose of our collider experiments - to further understand those earliest of times.
You're probably still confused about how come there is some 100,000 metric tons of Uranium that we spread onto bathroom tiles in the US in the 1920s to 1930s [and likely an equal amount in Europe], too, though it's not too much of a radiologic concern. That's another thread, though, as you well know.
Regards,
Walter
--------------
One would see galaxies moving away from one's location [except for a local group that might be gravitationally bound to one's own galaxy, as we have here in our Milky Way], wherever one might be in the universe. They would all have the same general description as we have here in our Milky Way; that is, the farther away they are, the faster they are receding from the viewpoint. There is no "center" to the explosion. In our reference frame, it 'appears' that we are at a center. That is simply because it is our reference frame.
Q:
Either put up or shut up. What exactly is it you believe that is "false information" that I have provided? There is nothing that I have described that does not fit with observation and GR. Certainly Spidergoat recognizes that.
You are likely one of those confused physicists who believe [and state] that the matter [mostly Hydrogen, some Helium] that emitted the 'blackbody' microwave background radiation is the same matter that formed our Milky Way. That is what ultimately confuses people like Chris; physicists who have only a limited understanding of GR and its BB implications, but spout off as if they were knowledgeable. That's why Chris had a hard time understanding how our Milky Way 'beat us to this location', 'ahead of the microwave background' - because that's how some ignorant physicists have described the BB to him, which was a false description Are you one of those?
That microwave-background-emitting matter was once in our vicinity, a long time ago [in our reference frame]. It exploded away from our Milky Way region at nearly the speed of light, and eventually cooled [in its reference frame] to where the electrons and protons could couple and emit light that we see. We see that matter at a great distance away, its light having travelled nearly 14,000,000,000 light years to get to us from where it was emitted. Because the matter that is emitting that light is receding from us so fast [about 0.9999991 c], it is highly red-shifted [red-shift of about 1,000], and we see it as microwave frequency photons, rather than visible-light frequency photons. That matter [Hydrogen, etc.] at that great distance is not, and never has been, the same matter that our Milky Way is composed of [also Hydrogen, etc.], just as the matter of the other galaxies that we see is not, and never has been, the same matter that our Milky Way is composed of. It is separate and distinct. What don't you understand about that? The only time that it was in direct 'communication' with our Milky Way was at the point origin of our universe. That is the purpose of our collider experiments - to further understand those earliest of times.
You're probably still confused about how come there is some 100,000 metric tons of Uranium that we spread onto bathroom tiles in the US in the 1920s to 1930s [and likely an equal amount in Europe], too, though it's not too much of a radiologic concern. That's another thread, though, as you well know.
Regards,
Walter
--------------
Q. I couldn't understand why the most eminent minds in cosmology would believe in something which throws up such a flaring contradiction. The answer that the size of the universe increases by expansion of space rather than movement through space does seem to clear up at least the point which I initially raised.
Whether it is true or not is another matter, but at least it seems self consistent.
Walter, I will have to side with (Q) somewhat. I can't speak for (Q), but here are some problems I see with some of your posts. Some of your quotes:
Walter Wagner,
(2) I think you are combining cosmological redshift and Doppler shift as one parameter. They are separate measurements. Cosmological redshift is the so-called 'stretching' of light's wavelength due to the expansion of the space the light is travelling through, not Doppler shift due to velocity. You are familiar with the 'Hubble sphere' aren't you? Anything beyond the Hubble sphere is moving away from us at a speed greater than the speed of light. We can still receive the light because space itself is expanding between us and the object that emitted the light, the evidence for the cosmological redshift.
I am not trying to argue with you, but it does seem to me that your posts were a little different than current consensus. I am not, however, stating I agree that current consensus is correct.
Walter Wagner,
The proponents of the Big Bang theory do not describe the Big Bang as an 'explosion'. The mass is not physically moving 'through' space and distant mass has no greater kinetic energy in its own region of space than similar mass does at our location in the universe. (1) Remember those virtual particles you spoke of that pop in and out of existence? Do you believe that distant galaxies are moving 'through' those local virtual particles at 0.9999991 c? Or is 'space' itself moving relative to us, both the newly formed particles from pair production and the galaxies themselves?
(2) I think you are combining cosmological redshift and Doppler shift as one parameter. They are separate measurements. Cosmological redshift is the so-called 'stretching' of light's wavelength due to the expansion of the space the light is travelling through, not Doppler shift due to velocity. You are familiar with the 'Hubble sphere' aren't you? Anything beyond the Hubble sphere is moving away from us at a speed greater than the speed of light. We can still receive the light because space itself is expanding between us and the object that emitted the light, the evidence for the cosmological redshift.
Do you not see the problem with this statement? If we assume the universe occupied a very small region 14 billion years ago, that the galaxies were close together at that epoch, why did it take 14 billion years for light from some galaxies to reach us? Are you proposing that light from those galaxies and the CMB is moving at a slow rate of speed relative to us because of the high recessional velocities? I'm not trying to put words in your mouth, but I believe the inflationary period that preceeded the formation of galaxies is an intregral part of modern Big Bang theory. According to inflation theory, those early galaxies were already a great distance from us when they first formed, correct?
I am not trying to argue with you, but it does seem to me that your posts were a little different than current consensus. I am not, however, stating I agree that current consensus is correct.
I've already pointed out your errors in my posts. Read them and learn.
Inflationary theory states that space CAN expand faster than the speed of light, there is no problem with as it does not violate any laws. Everything in the universe was carried along with that expansion, hence the light from the early universe is still traveling to our location.
Walters explanation violates a few laws, and would make it impossible to observe cosmological redshift as it is currently observed and understood.
In fact, 2inquisitive has a better grasp than Walter.
2 Inquisitive:
What you are saying, in essence, is that the nearby galaxies that we "see receding from us" are not actually receding from us, but rather that "space is expanding" between us and those nearby galaxies. That' also what Q is in essence saying. I disagree. Those galaxies are physically moving away from us THROUGH space [mostly emptiness, with perhaps some stray Hydrogen atoms]. Because they are physically receding from us, the light that they emit is slightly red-shifted.
The red-shift is exactly a doppler shift, caused by the emitter physically receding from the observer. To describe it as an "expansion of space" is a pure mathematical construct that causes confusion as to the nature of the "expansion".
All early proponents of the BB describe it as physical movement through space [emptiness], and the red-shift as a doppler shift caused by physical movement.
As to such distant objects encountering "resistance" in their movement due to the "virtual particles", such would not occur. First, they are "virtual particles", not real particles unless energy is applied to separate them, and they cannot interact. Second, they certainly cause no problems for our planets moving through space, or the Space Shuttle moving through space. Rather, the only "resistance" are the cosmic ray particles, micrometeorites, and the like, which exist in some abundance in our cluttered solar neighborhood, but which are in very low abundance overall.
And certainly, what I have explained shows that the universe is relatively isotropic. If one examines a spherical shell surrounding our Milky Way of 1 billion light years radius, and thickness of 1 million light years, one would find a large number of galaxies of total mass X. If one examined a spherical shell surrounding our Milky Way of 2 billion light years radius, and thickness of 1 million light years, one would find a much larger number of galaxies of total mass 4X. There is a lot more mass the farther away one looks, simply because it contains a larger volume. What's so hard to figure out about that? It is still relatively isotropic. [Please note, I have ignored a slight relativistic effect, because at that distance, the recessional velocities are still relatively low.] Quite naturally, when we look out at a distance of some 14,000,000 light years, we see a HUGE amount of mass, in which we also cannot neglect the relativisitic effect.
More later.
What you are saying, in essence, is that the nearby galaxies that we "see receding from us" are not actually receding from us, but rather that "space is expanding" between us and those nearby galaxies. That' also what Q is in essence saying. I disagree. Those galaxies are physically moving away from us THROUGH space [mostly emptiness, with perhaps some stray Hydrogen atoms]. Because they are physically receding from us, the light that they emit is slightly red-shifted.
The red-shift is exactly a doppler shift, caused by the emitter physically receding from the observer. To describe it as an "expansion of space" is a pure mathematical construct that causes confusion as to the nature of the "expansion".
All early proponents of the BB describe it as physical movement through space [emptiness], and the red-shift as a doppler shift caused by physical movement.
As to such distant objects encountering "resistance" in their movement due to the "virtual particles", such would not occur. First, they are "virtual particles", not real particles unless energy is applied to separate them, and they cannot interact. Second, they certainly cause no problems for our planets moving through space, or the Space Shuttle moving through space. Rather, the only "resistance" are the cosmic ray particles, micrometeorites, and the like, which exist in some abundance in our cluttered solar neighborhood, but which are in very low abundance overall.
And certainly, what I have explained shows that the universe is relatively isotropic. If one examines a spherical shell surrounding our Milky Way of 1 billion light years radius, and thickness of 1 million light years, one would find a large number of galaxies of total mass X. If one examined a spherical shell surrounding our Milky Way of 2 billion light years radius, and thickness of 1 million light years, one would find a much larger number of galaxies of total mass 4X. There is a lot more mass the farther away one looks, simply because it contains a larger volume. What's so hard to figure out about that? It is still relatively isotropic. [Please note, I have ignored a slight relativistic effect, because at that distance, the recessional velocities are still relatively low.] Quite naturally, when we look out at a distance of some 14,000,000 light years, we see a HUGE amount of mass, in which we also cannot neglect the relativisitic effect.
More later.
Walter L. Wagner,
You have also not addressed comments regarding the time of flight of photons if the galaxies were very close together in the early universe. Why did it take light almost 14 billion years to reach us if the other galaxy were nearby when the light was emitted?
By the way, I think the vacuum is not 'empty', but is filled with a dynamical aether that causes the expansion, gives rise to 'virtual particles', gives a value to the permittivity and permeability of the vacuum, and gives a reason as to why massive particles become harder to 'push' through the local vacuum when they approach 'c'. This last paragraph is JMHO, of course.
No, what I am saying is that, according to inflationary theory, the distant galaxies are receeding from us because the vacuum is expanding between us and them. The distant galaxies are carried along with the expanding space. The nearby galaxies are gravitationally bound to our galaxy and are collapsing toward the Virgo cluster because of the gravitational attraction. (A slight side note here that is not connected to the topic of the thread, but interesting non-the less. Have you read of the latest hypothesis that states that the sun and our solar system may not be a part of the Milky Way galaxy? It may be possible our solar system is originally a part of the Sagittarius Dwarf galaxy that the Milky Way is merging with. The remnants of the Sagittarius Dwarf is currently passing through the Milky Way at exactly our location. We are positioned above the equatorial plane of the Milky Way, but in the middle of the Sagittarius remnants passing through the Milky Way.)
I don't know why you placed the word "resistance" in quotation marks when addressing my post. I never used the word and do not think virtual particles would cause any "resistance" to motion. What I do think, is that if galaxies were 'moving through space', space would have a detectable direction from the prospective of those galaxies. If the galaxies were moving, but the surrounding space were relatively stationary, the virtual particles would all be moving in the same direction at '0.9999991 c' during their short lifetimes. The particles that excaped annilation would also be moving at 0.9999991 c relative to the galaxies. We have not detected such a direction to space through our observations.
You have also not addressed comments regarding the time of flight of photons if the galaxies were very close together in the early universe. Why did it take light almost 14 billion years to reach us if the other galaxy were nearby when the light was emitted?
By the way, I think the vacuum is not 'empty', but is filled with a dynamical aether that causes the expansion, gives rise to 'virtual particles', gives a value to the permittivity and permeability of the vacuum, and gives a reason as to why massive particles become harder to 'push' through the local vacuum when they approach 'c'. This last paragraph is JMHO, of course.
Sorry Walter, but all the tea in china won't make what your saying right. You are the one causing the confusion, regardless that you disagree.
Objects are being carried away with the expansion, that's why we observe cosmological redshift. The light reaching us has been stretched by the expansion of space.
Ever hear of a guy named, "Hubble?"
It's rubbish.
More rubbish.
2Inquisitive:
When I spoke of the nearby galaxies, I did not mean the ones gravitationally bound to our local cluster, but rather those that are receding from us, with a red-shift. More about that further below.
Yes, I am aware that our galaxy, as most galaxies, is composed of many smaller galaxies that have collided. Indeed, there's a lady in Hilo who searches for colliding galaxies [at the Subaru] by their strong bluish emissions where they intersect [due to extensive new star formation in that region when gas clouds collide]. She told me she's found well over 100 with her technique in such searches. They are quite interesting photos that she showed me, most being of two spiral galaxies colliding [with their collisional plane 'lit-up' in the bluish frequencies due to numerous young stars that were formed by the collisions of gas clouds in each separate galaxy]. Most of the spiral galaxies, in turn, are now believed to have formed from collisons of many [several score?] smaller cluster galaxies. Computer models show such collisions result in a spiral form for the "super galaxy" that results. It makes sense that our sun is a recent addition to the Milky Way by the collision of a smaller dwarf galaxy; but I'm not certain if the sun was formed by the collision which occured [which would then have been circa 5-6 billion years ago, followed not long thereafter by formation of our sun] or was already one of the stars of the dwarf galaxy [with a more recent date for the collision]. The speeds of gas clouds moving about in our own Milky Way are typically measure in Mach units. Any insight on when our Solar System [or its precursor] joined the Milky Way?
The nearby galaxies that are receding [as determined by their red-shift] are "moving through space" away from us. To state that "space is expanding" between us is actually a mathematical construct that results in a similar result, with a "doppler" shift, etc. However, it is proper to also refer to it for what it is, motion away from us into space [nothingness, or a vacuum], i.e. motion through space, with an actual doppler red-shift caused by the motion of the galaxy away from us.
Thus, nearby galaxies at, say, 1 billion light-years distance are moving away from us in our reference frame [and away from each other in their own reference frames]. Farther away there are even more galaxies, all of which have even greater red-shifts, because they are moving away from us at even faster speeds. Of course, you and others are propounding that it is the "space" that is expanding between these "island universes" [galaxies], with the rate of expansion greater the farther away we look. I contend that that is a pure mathematical construct that perhaps models reality, but is not the easiest model to explain. After all, how can nothingness "expand"? It certainly can have 'properties', which exist everywhere in the nothingness, so that an electron and a positron can suddenly "materialize" [as PAM Dirac theorized to predict the existence of positrons], and if there is an energy source nearby, they can remain as real particles [instead of disappearing again as virtual particles] by converting that energy into the mass of those two particles [and they can re-convert back into energy via annihilation, as my colleagues and I routinely do in nuclear medicine every day with our PET isotopes].
Due to GR effects, anyone in that reference frame of some distant galaxy would also see a general recession of all galaxies [save for those locally gravitationally bound due to proximity] moving away from them in whatever galaxy "they" might reside in [and I am not propounding the existence of ET intelligence - this is purely a thought analysis]. However, they would not see all of the galaxies that we see, and we cannot see all of the galaxies that they could see from their perspective. The closer they are to us, the greater would be the overlap of the finite portion of the Universe that we could both see, and conversely, the farther away, the less of an overlap. Galaxies that exist in the region of the Universe that we call the CMB-emitter [which we see in nearly its earliest stage of existence, rather than cooled down and contracted into galaxies], in looking towards the Milky Way, would see us as we once were - - a hot plasma of electrons and protons coupling to form Hydrogen [and Helium], and not as we are now. They would have the same general description of the Universe, too, of a CMB [in which lies embedded our Milky Way galaxy, in their reference frame] at great distance, and galaxies receding from them at ever greater speed the farther away they are.
Q:
Ever hear of Penzias and Wilson? I suppose what they wrote was "rubbish" too.
When I spoke of the nearby galaxies, I did not mean the ones gravitationally bound to our local cluster, but rather those that are receding from us, with a red-shift. More about that further below.
Yes, I am aware that our galaxy, as most galaxies, is composed of many smaller galaxies that have collided. Indeed, there's a lady in Hilo who searches for colliding galaxies [at the Subaru] by their strong bluish emissions where they intersect [due to extensive new star formation in that region when gas clouds collide]. She told me she's found well over 100 with her technique in such searches. They are quite interesting photos that she showed me, most being of two spiral galaxies colliding [with their collisional plane 'lit-up' in the bluish frequencies due to numerous young stars that were formed by the collisions of gas clouds in each separate galaxy]. Most of the spiral galaxies, in turn, are now believed to have formed from collisons of many [several score?] smaller cluster galaxies. Computer models show such collisions result in a spiral form for the "super galaxy" that results. It makes sense that our sun is a recent addition to the Milky Way by the collision of a smaller dwarf galaxy; but I'm not certain if the sun was formed by the collision which occured [which would then have been circa 5-6 billion years ago, followed not long thereafter by formation of our sun] or was already one of the stars of the dwarf galaxy [with a more recent date for the collision]. The speeds of gas clouds moving about in our own Milky Way are typically measure in Mach units. Any insight on when our Solar System [or its precursor] joined the Milky Way?
The nearby galaxies that are receding [as determined by their red-shift] are "moving through space" away from us. To state that "space is expanding" between us is actually a mathematical construct that results in a similar result, with a "doppler" shift, etc. However, it is proper to also refer to it for what it is, motion away from us into space [nothingness, or a vacuum], i.e. motion through space, with an actual doppler red-shift caused by the motion of the galaxy away from us.
Thus, nearby galaxies at, say, 1 billion light-years distance are moving away from us in our reference frame [and away from each other in their own reference frames]. Farther away there are even more galaxies, all of which have even greater red-shifts, because they are moving away from us at even faster speeds. Of course, you and others are propounding that it is the "space" that is expanding between these "island universes" [galaxies], with the rate of expansion greater the farther away we look. I contend that that is a pure mathematical construct that perhaps models reality, but is not the easiest model to explain. After all, how can nothingness "expand"? It certainly can have 'properties', which exist everywhere in the nothingness, so that an electron and a positron can suddenly "materialize" [as PAM Dirac theorized to predict the existence of positrons], and if there is an energy source nearby, they can remain as real particles [instead of disappearing again as virtual particles] by converting that energy into the mass of those two particles [and they can re-convert back into energy via annihilation, as my colleagues and I routinely do in nuclear medicine every day with our PET isotopes].
Due to GR effects, anyone in that reference frame of some distant galaxy would also see a general recession of all galaxies [save for those locally gravitationally bound due to proximity] moving away from them in whatever galaxy "they" might reside in [and I am not propounding the existence of ET intelligence - this is purely a thought analysis]. However, they would not see all of the galaxies that we see, and we cannot see all of the galaxies that they could see from their perspective. The closer they are to us, the greater would be the overlap of the finite portion of the Universe that we could both see, and conversely, the farther away, the less of an overlap. Galaxies that exist in the region of the Universe that we call the CMB-emitter [which we see in nearly its earliest stage of existence, rather than cooled down and contracted into galaxies], in looking towards the Milky Way, would see us as we once were - - a hot plasma of electrons and protons coupling to form Hydrogen [and Helium], and not as we are now. They would have the same general description of the Universe, too, of a CMB [in which lies embedded our Milky Way galaxy, in their reference frame] at great distance, and galaxies receding from them at ever greater speed the farther away they are.
Q:
Ever hear of Penzias and Wilson? I suppose what they wrote was "rubbish" too.
Walter L. Wagner,
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Our sun is represented by the yellow dot, of course, which is above the equatorial plane of the Milky Way. The Sagittarius Dwarf was imaged by the 2MASS project. Here is a link to a description of the project and the images:
http://astsun.astro.virginia.edu/~mfs4n/sgr/
The hypothesis that our solar system may be an original part of the Sagittatius Dwarf is, as far as I know, a speculation at this website:
http://curezone.com/blogs/m.asp?f=1207&i=2
I know the author goes much farther in his speculation, but the part about our solar system being originally a member of the Dwarf galaxy does seem to fit at consideration. I just came across this yesterday and have not had time to look for possible flaws in the hypothesis. But it is interesting to me!
Here is a representation of the merger I was speaking about.
Our sun is represented by the yellow dot, of course, which is above the equatorial plane of the Milky Way. The Sagittarius Dwarf was imaged by the 2MASS project. Here is a link to a description of the project and the images:
http://astsun.astro.virginia.edu/~mfs4n/sgr/
The hypothesis that our solar system may be an original part of the Sagittatius Dwarf is, as far as I know, a speculation at this website:
http://curezone.com/blogs/m.asp?f=1207&i=2
I know the author goes much farther in his speculation, but the part about our solar system being originally a member of the Dwarf galaxy does seem to fit at consideration. I just came across this yesterday and have not had time to look for possible flaws in the hypothesis. But it is interesting to me!
By the way, can everyone see the image? I haven't tried posting images before and am not sure if I did it correctly.
Walter,
You asked, "How can nothingness expand". The only answer I can offer, is that it expands the same way nothingness(space-time) is curved by mass and causes gravity. Nobody yet knows the answer to "what is space made of?" Perhaps its a sea of gravitons that, in the absence of mass, becomes repulsive. Like I said, nobody knows. What is known, as you have said, is that the farther away a galaxy is, the faster it recedes. In fact there are some with redshifts that show they are receding faster than light. Now you will say that is impossible. It is only impossible if the galaxies are moving through space. If it is the expansion of space causing the high redshifts then there is no violation of the speed of light.
I believe this is the most widely accepted view. If you can provide some links or references that refute this, please do.
Wilgory
You asked, "How can nothingness expand". The only answer I can offer, is that it expands the same way nothingness(space-time) is curved by mass and causes gravity. Nobody yet knows the answer to "what is space made of?" Perhaps its a sea of gravitons that, in the absence of mass, becomes repulsive. Like I said, nobody knows. What is known, as you have said, is that the farther away a galaxy is, the faster it recedes. In fact there are some with redshifts that show they are receding faster than light. Now you will say that is impossible. It is only impossible if the galaxies are moving through space. If it is the expansion of space causing the high redshifts then there is no violation of the speed of light.
I believe this is the most widely accepted view. If you can provide some links or references that refute this, please do.
Wilgory
Yes, I have, they worked at Bell labs and discovered a background 'noise' while testing microwave radiation. That has nothing to do with the fact that you're wrong.
You're wild notions about galaxies flying off away from us with HUGE kinetic energies and masses is complete nonsense.
2Inquisitive:
Thanks for the excellent links, and representation of the merger of a dwarf galaxy with the Milky Way.
That image looks remarkably similar to the photos I saw of galaxy mergers, though of course the ones she [at the Subaru] took were of two galaxies combining of more equal mass [rather than the 9,999 to 1 ratio of the Milky Way to the dwarf in the study you cited]. I too will have to review the work more to see if it presents conclusive evidence that our solar system was part of that dwarf galaxy originally, but it does seem to be the case!
As I mentioned, the current knowledge is that galaxy formation is a long, ongoing process, starting almost from the time of the BB, right up to the present. Early on, there were lots of dwarf globular galaxies, which merged/cannibalized forming mostly spiral disk galaxies [like the Milky Way], which continue to cannibalize/merge with other galaxies [like in your links]. We also know that there are other galaxies in our immediate vicinity 'headed our way' and will likely begin merging in a few hundred million years.
Of course, these mergers rarely result in stars colliding - what collide are the large clouds of cold Hydrogen gas extant within the galaxies, which triggers star formation in a "stellar nursery", as we've seen locally in the "Pillars" photos, and as we believe occurred to form the solar system, which earlier on had many nearby young OB stars [as like we see in the stellar nurseries] that have since drifted much farther away. The interplay of gravity, distance, time and mass certainly makes for intriguing computer modeling!
Now, I wonder how much kinetic energy is represented by the merger?
And, is it not simple Newtonian physics to calculate the kinetic energy of a nearby, receding galaxy [one with relatively low red-shift so we don't need to do GR calculations of energy]. Isn't it just a function of the mass, and the square of the velocity? Seems to me that they'd have a tremendous kinetic energy, relative to us, since they are travelling so fast. Of course, we could get in a near-speed-of-light rocket ship and catch up to them, if we had the technology [which we don't]. And, the farther away they are, the more kinetic energy they'd have due to a larger recessional velocity.
By the time one started calculating the kinetic energy of the matter we see at the CMB-emitter region of the universe, receding at very high velocity, you'd of course need to do a relativistic calculation, and the kinetic energy [relative to us] becomes very huge. Of course, Q doesn't want to know about that.
Anyway, gotta go and rescue some steelhead in the Carmel river. More later.
Thanks for the excellent links, and representation of the merger of a dwarf galaxy with the Milky Way.
That image looks remarkably similar to the photos I saw of galaxy mergers, though of course the ones she [at the Subaru] took were of two galaxies combining of more equal mass [rather than the 9,999 to 1 ratio of the Milky Way to the dwarf in the study you cited]. I too will have to review the work more to see if it presents conclusive evidence that our solar system was part of that dwarf galaxy originally, but it does seem to be the case!
As I mentioned, the current knowledge is that galaxy formation is a long, ongoing process, starting almost from the time of the BB, right up to the present. Early on, there were lots of dwarf globular galaxies, which merged/cannibalized forming mostly spiral disk galaxies [like the Milky Way], which continue to cannibalize/merge with other galaxies [like in your links]. We also know that there are other galaxies in our immediate vicinity 'headed our way' and will likely begin merging in a few hundred million years.
Of course, these mergers rarely result in stars colliding - what collide are the large clouds of cold Hydrogen gas extant within the galaxies, which triggers star formation in a "stellar nursery", as we've seen locally in the "Pillars" photos, and as we believe occurred to form the solar system, which earlier on had many nearby young OB stars [as like we see in the stellar nurseries] that have since drifted much farther away. The interplay of gravity, distance, time and mass certainly makes for intriguing computer modeling!
Now, I wonder how much kinetic energy is represented by the merger?
And, is it not simple Newtonian physics to calculate the kinetic energy of a nearby, receding galaxy [one with relatively low red-shift so we don't need to do GR calculations of energy]. Isn't it just a function of the mass, and the square of the velocity? Seems to me that they'd have a tremendous kinetic energy, relative to us, since they are travelling so fast. Of course, we could get in a near-speed-of-light rocket ship and catch up to them, if we had the technology [which we don't]. And, the farther away they are, the more kinetic energy they'd have due to a larger recessional velocity.
By the time one started calculating the kinetic energy of the matter we see at the CMB-emitter region of the universe, receding at very high velocity, you'd of course need to do a relativistic calculation, and the kinetic energy [relative to us] becomes very huge. Of course, Q doesn't want to know about that.
Anyway, gotta go and rescue some steelhead in the Carmel river. More later.