Spyman

Ok, I have read through this thread a couple of times now and it seems as you do accept what observations tells us, that very distant galaxies recede from us but close galaxies don't and you want to understand how they can resist the expansion. Is that correct, or do you want to deny current interpretation of observations or contest the metric expansion of space?

Like this?

Does it come with a special forum title and nice looking staff stripe with stars?

I am sorry, but I am unable to understand your drawing, could you be so kind and provide an explanation for it?

Your numbers and calculations doesn't match with estimates published on Wikipedia: Galaxy rotation curve for the Milky Way. Vertical axis is speed of rotation about the Galactic Center. Horizontal axis is distance from the Galactic Center in kpcs. The Sun is marked with a yellow ball. The observed curve of speed of rotation is blue. The predicted curve based upon stellar mass and gas in the Milky Way is red. Scatter in observations roughly indicated by gray bars. The difference is due to dark matter. http://en.wikipedia.org/wiki/Milky_Way#Galactic_rotation

Some of the facts you might need can be found here: Solar System

If the Earth is hollow and the whole Universe is on the inside then how can we take pictures like this? "The Blue Marble" photograph of Earth, taken from Apollo 17 http://en.wikipedia.org/wiki/Earth

I would not recommend removing the wires to the elements unless you are well versed in electricity and its hazards! Those wires more than likely carry lethal voltage and it is possible that one or more of them are hot even when the on/off switch in the off position, which is not even marked on the panel and the indication lamp can be broken. A safe disconnection includes: 1) Identification and removal of all fuses powering the device, 2) Measuring or by other safe means secure that all wires to be disconnected and every other close connection point are free from harmful electrical potential and 3) Isolating the ends of the disconnected wires such that they can't do any harm in the future, either by someone touching them and getting a direct electric shock or by causing a short leading to a fire. A professional would find the fuse box and only remove the fuses, because it would make a future reconnection much easier. (Depending on type of fuses even that can be dangerous for a non experienced.) It is very likely that the fuses have been removed already to prevent unnecessary electrical costs if someone should accidentally switch it on or to remove the risk of fire. I think it could be a good idea to find the fuse box and check if they have been removed, if the equipment still have power then it continues to pose a fire threat, especially if it is broken or wrongly disconnected. Sometimes fuse boxes have a detailed list of what the fuses deliver power to and that could leave us a tip on what the room have been used for.

It could be a Sauna, which is often a small room, (for heat efficiency), where you can relax in a high temperature environment. Picture of a modern Finnish sauna with light sources in the corners and an electric stove in center. A sauna is a small room or house designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these and auxiliary facilities. A sauna session can be a social affair in which the participants disrobe and sit or recline in temperatures typically between 70 °C (158 °F) and 100 °C (212 °F). This induces relaxation and promotes sweating. http://en.wikipedia.org/wiki/Sauna

I am sorry Michel, but your unchangeable conviction that mainstream science regard the cosmological principle to be contradicting the Big Bang theory, is so far from any normal interpretation that I can't help you further. However, facts will remain as facts, even if you disagree about them or when you are unable to understand them.

Everyone with a reasonable reading comprehension who have read my post #26 can see that I have presented factual consensus of mainstream science where the cosmological principle and the Big Bang theory are consistent with each others. I suggest you stop repeating yourself, remove your fingers out of your ears, open up your eyes and go back to read it again.

Supernovas do have physical relative velocities to us that affects their measured redshift, but 1) random supernovas in random directions from us have random physical velocities relative us, that is caused by the local to them environment and is therefore not increasing with the relative distance to us and 2) this physical relative velocity is normally not so high and is also limited to be below the speed of light while the expansion of space can cause receding velocities much greater than lightspeed for very distant objects, so when distances increase the rate between physical velocity and receding velocity changes such that physical velocity have lesser and lesser influence on the expected rate between redshift and distance. In physical cosmology, the term peculiar velocity (or peculiar motion) refers to the components of a receding galaxy's velocity that cannot be explained by Hubble's law. According to Hubble, and as verified by many astronomers, a galaxy is receding from us at a speed proportional to its distance. The relationship between speed and distance would be exact in the absence of other effects. Galaxies are not distributed evenly throughout observable space, but typically found in groups or clusters, ranging in size from fewer than a dozen to several thousands. All these nearby galaxies have a gravitational effect, to the extent that the original galaxy can have a velocity of over 1,000 km/s in an apparently random direction. This velocity will therefore add, or subtract, from the radial velocity that one would expect from Hubble's law. The main consequence is that, in determining the distance of a single galaxy, a possible error must be assumed. This error becomes smaller, relative to the total speed, as the distance increases. A more accurate estimate can be made by taking the average velocity of a group of galaxies: the peculiar velocities, assumed to be essentially random, will cancel each other, leaving a much more accurate measurement. http://en.wikipedia.org/wiki/Peculiar_velocity#Cosmology General relativity describes spacetime by a metric, which determines the distances that separate nearby points. The points, which can be galaxies, stars, or other objects, themselves are specified using a coordinate chart or "grid" that is laid down over all spacetime. The cosmological principle implies that the metric should be homogeneous and isotropic on large scales, which uniquely singles out the Friedmann-Lemaître-Robertson-Walker metric (FLRW metric). This metric contains a scale factor, which describes how the size of the Universe changes with time. This enables a convenient choice of a coordinate system to be made, called comoving coordinates. In this coordinate system the grid expands along with the Universe, and objects that are moving only due to the expansion of the Universe remain at fixed points on the grid. While their coordinate distance (comoving distance) remains constant, the physical distance between two such comoving points expands proportionally with the scale factor of the Universe. The Big Bang is not an explosion of matter moving outward to fill an empty universe. Instead, space itself expands with time everywhere and increases the physical distance between two comoving points. Because the FLRW metric assumes a uniform distribution of mass and energy, it applies to our Universe only on large scales - local concentrations of matter such as our galaxy are gravitationally bound and as such do not experience the large-scale expansion of space. http://en.wikipedia.org/wiki/Big_Bang#FLRW_metric

Well Michel, this is clearly your own personal opinion and not the conventional interpretation made by mainstream scientists. Furthermore you are muddling the truth with false claims to make your argument sound better than what it actually is: * The Big Bang theory does NOT state that we are living in a special epoch. It says that we are living in a different epoch than how it was in the past and that the future will bring new times. There is no claims on anything special about our current epoch. * The Big Bang theory does NOT state that observers far from us observe different thing than we do. It says that all observers, including us right here, would have observed different things in the past. There is no claims that far from us observers are in the past. * The Big Bang theory does NOT state that the place of the observer in space determines what he will observe. It says that the Universe has evolved from a hot and dense state to this cold expanding state it currently is in. Observers in different ages will see different stages of this development, but there is no claims on special locations with special views. * It is NOT only some few scientists that think the future will look different. This is the mainstream scientific consensus, which means that most professional scientists in the field of cosmology together have made a collective judgement of this. A well versed and experienced member like you should know that when you want to propose that the ordinary cosmological principle should be changed to a more specialized variant, argue that the currently accepted Big Bang theory is wrong or speculate about obsolete Steady State theories, then this is best done by creating a new thread in the Speculations section and not by hijacking a thread in the Astronomy section where people expects answers in concordance with mainstream scientific consensus.

If you truly agree then why do you quibble about what other people have said in the past? Individuals on public forums don't get to decide what is mainstream science or not, if we would make judgements depending on whats considered in various threads then clearly Big Bang is wrong, Relativity is false and the Moon landing was a fraud... My post on the other hand included a quote from a reputed and famous scientist that was considered a top expert on the subject in his time, with a link so everyone can verify and check the source or read the context around his statement. All our observations and measurements are made by our metersticks and equipments that are locally together with us, so clearly since our metersticks and equipment don't change and remain in their size relative us, we normally consider the Universe to be expanding relative us and not the other way around. But obviously that also means that we are shrinking relative the Universe. I don't know why AJB and swansont said what they did, as I already have said in my previously post, if you want clarifications about their statements then you really should ask them and not me, I am not a mindreader.

Both humans and hypothetical aliens in the past viewed the Universe in a different age than what we do today. The cosmological principle is NOT in conflict with the Big Bang theory, you are misinterpreting it. Did you even read what your Wikipedia link about the cosmological principle said under Implications? The universe is now described as having a history, starting with the Big Bang and proceeding through distinct epochs of stellar and galaxy formation. Because this history is currently described (after the first fraction of a second after the origin) almost entirely in terms of known physical processes and particle physics, the cosmological principle is extended to assert the homogeneity of cosmological evolution across the anisotropy of time: ... all points in space ought to experience the same physical development, correlated in time in such a way that all points at a certain distance from an observer appear to be at the same stage of development. In that sense, all spatial conditions in the Universe must appear to be homogeneous and isotropic to an observer at all times in the future and in the past. That is, earlier times are identical to the "distance from the observer" in spacetime, which is assessed as the redshift of the light arriving from the observed celestial object: the cosmological principle is preserved because the same sequence of evolution is observed in all directions from earth, and is inferred to be identical to the sequence that would be observed from any other location in the universe. /../ Cosmologists agree that in accordance with observations of distant galaxies, a universe must be non-static if it follows the cosmological principle. In 1923, Alexander Friedmann set out a variant of Einstein's equations of general relativity that describe the dynamics of a homogeneous isotropic universe. Independently, Georges Lemaître derived in 1927 the equations of an expanding universe from the General Relativity equations. Thus, a non-static universe is also implied, independent of observations of distant galaxies, as the result of applying the cosmological principle to general relativity. http://en.wikipedia.org/wiki/Cosmological_principle

Are you saying that Sir Arthur Eddington which was famous for his work and interpretations on Relativity is not creditable or that there has been major changes in the basics of the theory of Relativity that makes my quoted passage from Eddington's book obsolete? Sir Arthur Eddington In the early years after Einstein's theory was published, Sir Arthur Eddington lent his considerable prestige in the British scientific establishment in an effort to champion the work of this German scientist. Because the theory was so complex and abstruse (even today it is popularly considered the pinnacle of scientific thinking; in the early years it was even more so), it was rumored that only three people in the world understood it. There was an illuminating, though probably apocryphal, anecdote about this. As related by Ludwik Silberstein, during one of Eddington's lectures he asked "Professor Eddington, you must be one of three persons in the world who understands general relativity." Eddington paused, unable to answer. Silberstein continued "Don't be modest, Eddington!" Finally, Eddington replied "On the contrary, I'm trying to think who the third person is." http://en.wikipedia.org/wiki/History_of_general_relativity#Sir_Arthur_Eddington Relativity aside and since you are an architect, I would expect you to realize that if an building is ten times larger than an replica then the replica is also ten times smaller than the building, so if the building gets eleven times larger than the replica then the replica also gets eleven times smaller than the building. If someone tells you differently, I think you should ask them for clarification and not me. The volume and contents inside of the building can be considered to be the inside and contents of the observable universe. Depending on your definition of "demonstrable way", I would say that there is substantial observational evidence that space is expanding relative our definition of the metric length. The relation between "occupants sizes" and "space between them" is changing such that the occupants measure an increase in the distances, more meterstick length are needed to fill up the increasing distance. When all our applied measures is shrinking relative large distances, we can determine that relative sizes are changing. The relative sizes between us and the building is changing whether or not it is the building that is expanding or we who are shrinking. We can't distinguish an external "absolute" related to sizes, such an absolute would need a foundation outside of the Universe to relate against, what we can say is that: relative us the Universe is expanding or relative the Universe we are shrinking.

No, I am saying that they would see a similar thing in the sky as we do which is in concordance with the cosmological principle. Why do you think the bolded part of what I said is contradicting the cosmological principle? Yes, the Universe was very very different around 13 billion years ago when the CMBR we see today was emitted. Modern cosmology features a changing universe that develops and ages, a backwards time traveller would see a younger Universe.

Try to imagine that you are inside a huge building without any windows or other possibilities to look out outside. For every day that passes you seem to shrink compared to the size of the building and when you use your meterstick to measure distances for several days, you can confirm that the building is getting larger compared to your meterstick. When space is expanding the Universe is not thought to be growing into some empty surroundings, according to the theory of Relativity it is the scale of our local meterstick that is changing. It doesn't make any difference if the Universe outside of the building is finite or infinite since it is the relation that is changing and not the walls that are moving apart. When we assert that the universe expands, what is our standard of constancy? There is no particular subtlety about the answer; the expansion is relative to the standards that we ordinarily employ. It is relative to the standard metre bar, for example, or to the wave-length of cadmium light which is often suggested as a more ideal standard, or to any of the linear dimensions associated with atoms, electrons, etc. which are regarded as "natural constants" in atomic physics. But if the universe is expanding relatively to these standards, all these standards are shrinking relatively to the universe. The theory of the expanding universe is also the theory of the shrinking atom. Sir Arthur Eddington, New Pathways In Science (1935), page 223

I am missing that I am unable to see any voting score on posts when I am lurking and browsing the forum without logging in. I think it would be good if people without accounts coming here to read and learn also could be able to see the voting score. Is it possible to change the rights for Guests to also see the voting score on each post?

According to our standard model of space expansion, intelligent aliens that are around 46 billion light years away today would see our part of the Universe as it was in the past around 13 billion years ago. That is a long time before our Sun and Earth was formed and very close to when the Universe itself started, they would only see the Cosmic Microwave Background Radiation that was released from our area of the Universe during the Recombination epoch.

A diagram depicting the expansion of the universe and the appearance of galaxies moving away from a single galaxy. The phenomenon is relative to the observer. Object t1 is a smaller expansion than t2. Each section represents the movement of the red galaxies over the white galaxies for comparison. The blue and green galaxies are markers to show which galaxy is the same one (fixed center point) in the subsequent box. t = time. http://en.wikipedia.org/wiki/Metric_expansion_of_space In physical cosmology, the Copernican principle, named after Nicolaus Copernicus, states that the Earth is not in a central, specially favored position. More recently, the principle has been generalized to the relativistic concept that humans are not privileged observers of the universe. /../ Measurements of the effects of the cosmic microwave background radiation in the dynamics of distant astrophysical systems in 2000 proved the Copernican principle on a cosmological scale. The radiation that pervades the universe was demonstrably warmer at earlier times. Uniform cooling of the cosmic microwave background over billions of years is explainable only if the universe is experiencing a metric expansion. http://en.wikipedia.org/wiki/Copernican_Principle

I consider the situation symmetric, maybe I didn't express myself clearly, what I meant to say is that an alien in the distant galaxy looking in our direction will see a similar CMBR that we see, they would see our part of the Universe as it was back then around 13 billion years ago, just like we see their part of the Universe as it was around 13 billion years ago. The alien can not view the Earth or me waving my hand and we can not see him waving his tentacle because it takes time for light to travel the distance between us and if space continues to expand with an accelerating rate then we will never be able to see each others. Also you seem to be confusing distance with time, with an expanding Universe they are not equal. The distant galaxy with the alien is now 46 billion lightyears distant but the light we see today from that part of the Universe was emitted from a distance of only 0.04 billion lightyears around 13 billion years ago.

The reputation system we have is not perfect, it has flaws and drawbacks, but while there is still room for improvement it also has advantages and most importanly it is a system already in place, it has a function and despite smaller problems it actually does work: I have yet to find a member with 20 or more negative points that I don't think deserved most of them and members with 20 or more positive points are also likely decent and polite persons worthy of them. Sure, a lot of people make mistakes, I even manage to click on the wrong button from time to time, but the main argument with a community's total votes is that even if people vote wrong, by mistake or on evil purposes, the end score made by the average of votes smoothes out personal biases. The vast majority may consist of not total perfect beings with personal bias but the community as a whole is greater than its parts, where we all can contribute to its consensus. I agree with you that it is better to post a reply to acknowledge agreement, thank for a great answer or to explain why one think something is wrong, but sometimes such posts can derail the thread. Another big issue is for me is that I come here to participate in discussions I enjoy and arguing with people who behaves badly is not fun and can take a lot of my limited time that could be better spent elsewhere. In those cases I can instead use the reputation system and choose to place my only negative vote this day, to show others my anonymous opinion as part of the community that I think the post is bad. As already said above, someone who has managed to accumulate 20 or more negative points is either on a very good way to be permanently banned and/or have repeatedly spouted nonsense and should not be considered a trusted member. Making a long and comprehensive explanation for such a person will not likely be meet with any gratitude and are probably a complete waste of time. As such the community's judge of members bad behaviour serves as a warning for both the offender and readers, but is also as a rough measurement of our credibility. I guess what I am trying to say is that my time is limited and valuable for me and I don't consider it lazy when I down vote what I think is a bad post, instead of spending lots of time in a futile argument, banging my head against a brick wall replying to a troll, a deceiving crackpot or some other type of misfit. So while it is a drawback for the person gaining negative reputation to not get any explanation for it, it is still a slight advantage to at least get an indication that there was something wrong with the approach in the post, but it is a big advantage for me to not have to spend valuable time when I don't want to and it is also an advantage for people coming here searching for knowledge to get an heads up that someone think that there is something wrong with that post. Without the reputation system I and others would not be able to show our opinion with a fast mouse click and we would still hesitate to write a long reply, which would make more bad posts uncontested, increase the burden on the experts and in the long run lower the good credibility the site has achieved.

Was not are, but otherwise yes, if some intelligent aliens in a very distant galaxy at around 46 billion lightyears distant are looking in our direction, then they see our part of their observable CMBR receding away from them at 56 times lightspeed.

If we know the distance then the constancy of lightspeed tells us how long time light has travelled to reach us. There was no stars at time zero and before the Recombination epoch space was not transparent for light. (Recombination occurred around 377 000 years after the Big Bang.)