Moving at light speed

[Buffy]

Well that's not an--ahem--very scientific way to put it: It is true that we can only observe from where we are to the Hubble limit distance away from us, but the Cosmological Principle says that a galaxy that far away from us would have to see the universe just like we see it, but they'd be able to see all sorts of galaxies that we can't see. An important thing to understand is that ONLY because of Inflation, is there anything beyond the Hubble limit at all. In addition, the cosmic background radiation gives us increasingly accurate ages of the Universe, and from what we can deduce from it about inflation, we can even put limits on how "big" the Universe is beyond the Hubble limit, although its still subject to much debate.

 

To answer your question: What's beyond the Hubble Limit has to be the same as what we see here, or everything we know is wrong. That could be true, but since there's no evidence that there is anything different, and more importantly no theories about how it *could* be different which aren't *provably wrong* based on what we *can* test, its not really worth debating.

 

Here's one of my favorite books on the subject that I'd recommend you read: "The Inflationary Universe" by Alan Guth. Tremendously readable and it talks about most of the issues we've covered in this thread in much more detail.

 

Cheers,

Buffy

[Tormod]

I see. So all we KNOW of the universe is what we experience within in the hubble limit. So your model of the universe is purely speculation and there is no way to prove or disprove it.

 

Is this right?

 

It is a very arrogant way of putting it, if nothing else.

 

"Our" model of the universe is not speculation, but based on many years of scientific work where the data fits the predicted values in most cases. Like I have said many times now, read up on comsology.

 

Buffy's book recommendation is good - I'd also suggest The Five Ages of the Universe by Gred Adams and Fred Hoyle.

[Damo2600]

I understand the hubble limit and I know about the radiation suggesting there is an echo we can measure from the big bang. I understand there is expansion. However your model appears (to me anyway) to be that if you were living in a universe with a sun and earth and nothing else your whole life your assumption would be that the universe consists of a sun and the earth and nothing else. However someone outside the hubble limit would experience something different. So this specific point of view, I have just described, would be an incorrect one.

 

I did pose the question as to whether my supposition was correct. This suggests that my POV was not certain. So in fact it was scientific unless questioning theories is unscientific. I'm guessing you don't like this question because it goes against popular opinion.

 

Thanks Damien

[Buffy]

However your model appears (to me anyway) to be that if you were living in a universe with a sun and earth and nothing else your whole life your assumption would be that the universe consists of a sun and the earth and nothing else. However someone outside the hubble limit would experience something different. So this specific point of view, I have just described, would be an incorrect one.

The scientific method would require you to provide an alternate theory of what the person beyond *our* Hubble Limit would experience. We know we could move a few million light years from where we are, and we'd see stuff there that we don't see here, but if we don't see the same thing there that we see here, lots of physics theory which has been tested and proven locally would have to magically be different there, and we can even see physical evidence that these laws hold remotely. Its also important to realize that some of the conclusions you've drawn would only be consistent with what we observe about the structure of the universe and relativistic effects if and only if *we* were at the center of the universe, otherwise, we would see evidence of non-isomorphism and non-homogeneity in the astronomical observations we make.

I did pose the question as to whether my supposition was correct. This suggests that my POV was not certain. So in fact it was scientific unless questioning theories is unscientific. I'm guessing you don't like this question because it goes against popular opinion.

To continue my example, if you don't have an explanation why physical laws would be different a few million light years from here where the Hubble Limit describes an over lapping but different volume of space that goes beyond *our* visible universe, you have not provided any reason to question the existing theories. Questioning theories is what the scientific method is all about, but if you don't propose an alternate theory and simply say "it just doesn't make sense" you're not doing science. If you notice a strain of testiness in some of the responses here, its because you're not making the effort to do the research yourself before tossing back questions, and in fact you're trying to make your unwillingness to do the research our fault. Sorry!

 

Cheers,

Buffy

[Damo2600]

Hi Buffy

 

Well not exactly. Research takes time (does it not?) so my own research is happening at a very slow pace. Your comment makes the assumption that I am not conducting any research and that I have unlimited time in which to do so. How would you know this? Furthermore by questioning yourself, and Tormod on this forum, has educational value does it not? Enquiery is the basis of scientific knowledge, is it not? This assumption is similar to the example you have given. It is based on the fact that our limited observable space has certain uniform qualities. The model is then extrapolated to suggest that everything in all directions would have to experience the universe exactly the same as we do. But basically, your assumption is, if we experience something isomorphically then there is no absolute plausible reason for there to be something outside the box so to speak. There is nothing wrong with your assumption but to expect me to accept that your assumption is absolute because you say so. It is propaganda. You are saying we can't think outside the box we are limited by so there is nothing else.

 

Isomorphism within our local region does not mean that there is nothing outside. A person born in a bomb shelter travelling through space would experience the room to be isomorphic. If his parents did not explain that there is something ouside the bomb shelter then how would he know that the walls and ceilings were not the end of the universe? This does not mean that everything outside the bomb shelter does not exist. Your statement that if something were to exist outside the universe it would have to 'magically' exist is a further assumption. Don't you see? It adds to the propaganda by suggesting that anyone who accepts this as a possibility believes in 'magic'. Therefore perhaps I should be considered a looney by your propaganda. That's right hey guys? (very nice). (:Alien: < this is me ranting crazily).

 

I made the statement that we can not prove that the experiences we scientifically observe within this universe are absolutely the same in any direction you travel. You replied by requesting from me an anwser as what maybe outside the universe. If I don't know what is outside the universe as we know it, it does NOT however make my statement unscientific, because, I am making an observable statement.( and I made the comment that I couldn't prove any assumption that *I* make as well - Do you see how that works?)

 

We can't see what's outside the hubble limit - so we cannot prove absolutely that the universe is the same in all directions. Infinitely. Period. That is my scientific principle which is absolutely true at the present time within scientific history.

 

Damien

[Buffy]

Well not exactly. Research takes time (does it not?) so my own research is happening at a very slow pace. Your comment makes the assumption that I am not conducting any research and that I have unlimited time in which to do so.

That's great! But your research would go much faster if you spent some time learning the basics from the numerous sources out there which explain this in much more detail. Using us as your only source of getting answers to questions (and I'm afraid the nature of your questions make that a bit obvious), is just making it harder for you. You really need to walk before you can run, and you need to read the basics. I'd be the last one to say you might not be the next Einstein and we'd all like to encourage you, but you can't do original research without understanding that even the Issac Newton's of history say "I stand on the shoulders of giants."

 

...It is based on the fact that our limited observable space has certain uniform qualities. The model is then extrapolated to suggest that everything in all directions would have to experience the universe exactly the same as we do. But basically, your assumption is, if we experience something isomorphically then there is no absolute plausible reason for there to be something outside the box so to speak....Isomorphism within our local region does not mean that there is nothing outside. ... I made the statement that we can not prove that the experiences we scientifically observe within this universe are absolutely the same in any direction you travel.

This is unfortunately a good example of how you have not done any learning on the basics: The notion that "we can only *know* what we can observe" is completely fallacious. Cosmology makes predictions on how galaxies stars and other remote objects behave, and we can observe those remotely. Those remote objects would behave differently if the physical laws of the universe were different there. We can see that they *don't* behave differently, therefore we can conclude that the universe is the same there even if the volume described by the Hubble Limit is different from ours. Moreover as I said earlier, if the Universe is *not* isomorphic, we would HAVE TO BE AT THE EXACT "CENTER" OF THE UNIVERSE for our local observations to come out the way they do, which would be an unbelievable coincidence. Even if we were at that exact center, our observations of remote systems would show anomalies in physical laws so we could *still* prove or disprove isomorphism. You need to understand this basic method, which is not just used in cosmology, but virtually *every* scientific endevor, or you're not going to get terribly far in science.

 

Cheers,

Buffy

[Damo2600]

Dear Buffy,

 

Thank you for your diplomatic response. I expected a rather different response than the one you had given me due to the allegations that I made. There is no intention for me to become the next einstien. I just feel it's my universe aswell and scientifically I have an equal say in whether the observations are correct or not. I am learning the basics and the cosmology of the universe is a bit beyond me which is why I wished to pull out of the universe.

 

Now the point I was trying to get at is to ask is there any specific hard evidence to suggest that the universal model you have is correct. I see that if the universe were expanding in an isometrically manner, that would mean, there may be a geometric shpere surrounding us. There may be a geometric centre. The echo radiation from the big bang would still be able to measure the size and age of the universe. The end result is that if the sphere outside the universe as we know it was expanding in a way that seemed inflatory then all the galaxies would infact be expanding isometrically. Like I said with the elastic example I explained: You draw equal lines on a peice of elastic and hold one end representing the centre of the universe and the other end representing the edge of the universe. If you pull on the elastic you do find the lines all seperate in a uniform fashion. Now if you keep the elastic representing the geometric centre and have many elastics spread out from this point (this is not earth by the way. I'm not implying that) in a uniform fashion, by pulling on all the elastics evenly, you will notice that every line within the sphere will experience isomorphic expansion. You would not know in which direction the centre is nor the edge.

 

Now I have just shown that my model of the universe works exactly the same as yours does only in my example I have an edge to the universe. I have asked you many times to provide evidence as why there cannot be an edge and why my model is obsolete and you have fail to do so.

 

Further to the point I have described your universe to various people and they have all described it as completely absurd. Yet my model they feel makes more intuitive sense. Nobody has ever experienced moving along a geometric, one dimensional line and found themselves back at the point at which they started. This does not happen in nature. So how you can assume this to happen at a cosmological level is completely beyond me. Orbsycli stated when you explained your model that:

 

"blows my mind now that i finally understand that."

 

I would not like to state that I know what he meant by this, but it seems that he accepted your model without question. I do not accept information given to me on face value and care even less as to how many letters are attached to the name of the person who is telling me. It is not that I don't respect those letters. I just don't equate that to mean the person telling me is absolutely correct in everything they say. I'm obviously not the only one in that boat either.

 

So now would you like to provide me with any evidence you have? It would be much appreciated at this point and if it is sound reasoning I will accept it and the conversation will be over.

 

Yours faithfully

Damien

[Damo2600]

Correction: in the last sentence of the first paragraph that should be 'conversation' not 'universe'. That would be rather funny wouldn't it.

 

Damien :Alien:

[Buffy]

I'm not sure I understand why I should take the effort. You are asking me to provide you with evidence that requires you to understand things that you don't understand yet. There are numerous examples above that I have already given that provide proof. You do not accept these because you don't understand any of the principles they are based on. Your last post asks the question again, and it is clear that the only way to explain it is to take you through all of the fundamentals of cosmology and relativity which would be a major undertaking, yet at the same time, you apparently refuse to even take a mouse click or two, let alone try looking up the books that several of us here have suggested that would get you closer to this understanding. Its clear you see nothing wrong with this approach. Indeed you appear to think that I am some how obligated to give you a simple answer, or you've proven--as you've stated multiple times--that we don't know what we're talking about and you are more intelligent than we are. That is unfortunate.

 

Cheers,

Buffy

[Damo2600]

Fair enough. If you are suggesting that you've already provided this information I have been asking for, I will go back through the posts and attempt to find it. I have checked out the links you have provided so I will go through them again. I did not seem to find this proof however, if you are assuring me it's there, I am expecting it's there. I will reply as to my outcome.

 

Thanks Damien

[Damo2600]

O.k. Buffy,

 

I have gone through all the posts and read each one very carefully. I searched for the proof you state is contained within them. Many of the posts describe your model, which I understand don't get me wrong, but these cannot be considered proof as they are merely explanations. There are some posts which are speculations about the big bang and black holes (which you yourselves state to be speculation - so I can't be blamed for saying that). The closest I came to evidence of your model is the following post (which is stated a couple of times in your's and Tormod's posts in different ways):

 

""It is true that we can only observe from where we are to the Hubble limit distance away from us, but the Cosmological Principle says that a galaxy that far away from us would have to see the universe just like we see it, but they'd be able to see all sorts of galaxies that we can't see. An important thing to understand is that ONLY because of Inflation, is there anything beyond the Hubble limit at all. In addition, the cosmic background radiation gives us increasingly accurate ages of the Universe, and from what we can deduce from it about inflation, we can even put limits on how "big" the Universe is beyond the Hubble limit, although its still subject to much debate.

 

To answer your question: What's beyond the Hubble Limit has to be the same as what we see here, or everything we know is wrong. That could be true, but since there's no evidence that there is anything different, and more importantly no theories about how it *could* be different which aren't *provably wrong* based on what we *can* test, its not really worth debating.""

 

You explain this further in the manner of if there were something outside the universe it would need to exist based on different laws of physics than we experience. I don't particularly belive this because I can see that the physical laws, of anything, that may exist outside our universe maybe related to our physical laws although somewhat different.

 

Let us see how my universe model fits into the above statements (my universe model is explained in post #38 and again in #109)

 

In the first paragraph my model is: true

In the second paragraph my model is: false

In the third paragraph my model is: false

 

Now the two paragraphs where my model is false you are basing this on the fact that the isomorphism we experience within our part of the universe suggests that our experience must be the same for all observers outside the hubble limit (which is fair enough). However since we have found there is a finite size to the universe you have added one plus one with the previous point to suggest nothing outside the universe can exist (which is speculation). You have then formed a further mathematical opinion that since there is nothing outside the universe, we can't just hit a brick wall when we reach the end of the universe, so when you reach the end of the universe you must, of course, come back in the other side.

 

I'm sorry but that is not proof in my mind. Perhaps I will go as far as to suggest that it is evidence that your theory may be true. Now if I have missed some proof in your posts I would like to hear it (i.e. if you are willing to take time out to do this) or if you have further proof you would like to share I am willing to hear it. However I questioned your POV I did not attack your intelligence at any stage. I think however my intelligence has been attacked. Remember I wished to end this conversation more than once however you encouraged me to continue each time. "It'll be fun" Is a direct quote I recall.

 

So if you do not wish to respond that is fine by me.

 

I will now look through the links you so graciously provided and search there for any proof.

 

Thank you

Damien

[Buffy]

There are some key gaps in your understanding of cosmology that are preventing you from understanding the explanations given so far. You should be aware that many of the actual proofs require an understanding of the mathematics that is shown in some of the books referenced by us or in the books in their bibliographies: it is far beyond what we can do here to provide *proof* that these things are true. Here are some key things that are important to understanding how this stuff works:

You explain this further in the manner of if there were something outside the universe it would need to exist based on different laws of physics than we experience. I don't particularly belive this because I can see that the physical laws, of anything, that may exist outside our universe maybe related to our physical laws although somewhat different.

This is a misinterpretation: under the current models of the universe there is no "outside." There are multiple unverse theories and the multi-verse theory, but these have much more bizarre explanations of how they exist: they're not "outside" the universe in the conventional sense either. They also could all have the same physical laws, or they could not. In any case, this area of "other" universes is conjecture and outside of the scope of what we're talking about here. More on the "outside" below.

Now the two paragraphs where my model is false you are basing this on the fact that the isomorphism we experience within our part of the universe suggests that our experience must be the same for all observers outside the hubble limit (which is fair enough). However since we have found there is a finite size to the universe you have added one plus one with the previous point to suggest nothing outside the universe can exist (which is speculation). You have then formed a further mathematical opinion that since there is nothing outside the universe, we can't just hit a brick wall when we reach the end of the universe, so when you reach the end of the universe you must, of course, come back in the other side.

This is incorrect. The closed nature of the universe is based on very exact mathematical models which are used to define the geometry of the universe and work through problems such as is the universe's geometry "open" "flat" or "closed" (the latest research based on putting observational values into these equations indicates that it is probably "flat", but that's beyond what we are talking about here), under any of these there is curvature of space: in a closed universe, you can go in what you perceive to be a straight line, and you *will* end up at the same spot because of this curvature. Where you are missing this is that you are still trying to conceive of the universe as a sphere which it is not. This is obviously not intuitive and it is in fact very difficult to understand without resorting to simplifications like the balloon analogy. The main difference between that and your "elastic sheet" analogy is that the sheet *doesn't* curve and there *is* an edge. If you stop trying to think about it as a sheet and start looking at a balloon you'll start to get the idea. What I am trying to describe is not that you "go off the edge and magically end up on the other side of the universe" its that literally there is no edge because its one continuous thing like travelling around on the surface of a balloon. It is very difficult to extrapolate this from the two-dimensional surface of a balloon into our 3d world, but it does work that way. Now as a result, this is not "intuitive" at all, and that's why Orb, who's read the books and done the research still says it "blows his mind": it is mind blowing for all of us. Unfortunately for you, there's no simple answer on proof: there's a lot of very complex math and physics that goes on behind this and it takes a lot of it to get to *proof* that this is true, but I've referenced several points having to do with what we observe and what we can see is true at remote locations that indicate this. As I mentioned in my previous post, unless we are in the *exact* center of your sphere, we would indeed be able to percieve the edges in spite of the hubble limit: the microwave background radiation which is the echo of the big bang is *perfectly* distributed around us. If we were a little bit off from the "center of the sphere" it would be hotter on one side of us than it is on the other, and its not according to every measurement ever taken. Again as I said before, even if we were at the very center of the sphere, objects within the hubble limit would show different structures and have different motions if the universe were not isomorphic from their location (which they could not be since we are the only thing at the center which is the only location that could observe "same in all directions"). Your sheet may show that "everything is moving away from everything else" but it does not handle the effects that are easily observable from being closer to an edge, thus the sheet does not model what we observe at all.

 

This unbelievably brief explanation does not rise to the level of proof, and you may question the math and the sources of data behind it, but the math, physics and data is there if you want to investigate it in the books we've recommended. I will warn you that it is not just a matter of browsing a couple of pages of text, and you are likely to be dissatisfied with what you find, but if you do require proof you will have to make the investment. People spend years studying this stuff, and its hard to understand, but there's no free lunch. Sorry!

 

Cheers,

Buffy

[Damo2600]

Thanks for the heads up Buffy.

 

I'll go and study. This thread has been most illuminating for me and appreciate the time you have put into it. The issue is not closed for me so I'll pack my own lunch. LOL

 

Thanks Damien

[Damo2600]

Hi Buffy,

 

First I'd like to point out that you didn't read my model correctly and I did not describe a plastic sheet. I described it, if you care to look back at my model, as being an elastic sphere. This is merely based on the expansion and does not represent spacetime in any way.

 

Secondly I would like to point out a discrepancy in the statement you have made with regard to the Cosmic Background Radiation. Now the following website has the available information if you would care to check if my information is correct:

 

http://csep10.phys.utk.edu/astr162/lect/cosmology/cbr.html

 

Your statement was that the cosmic radiation was '*perfectly* distributed aroud us'. Alas I have found information that says it is not true. Further to this that Earth has been found to moving at a speed of 600km/s with respect to the CBR. So in fact on one side of the planet we see that the radiation is redshifted and on the opposite side the radiation is blueshifted.

 

The CBR is described as a faint echo of the big bang and the radiation is mere 3 degrees C above absolute zero.

 

[The earth's atmosphere blocks out most of the background radiation and it can only be detected from space and using sensors (I'm not sure which kind) in the ground. I'll have to find the site I found this on that provided me with this information.]

 

Another point to do with electromagnetic waves:

 

Get a bowl of water and using a round rod (so as to not produce too many small irregular waves, bob it up and down in the very centre until you get a good wave train going. Now the waves will reflect from the bowl and interfere on the way in with the waves going out. Vary the frequency until you can see no radial motion at all. What you have now is a "standing wave". Standing waves can be very important in physics, and in practice. The ringing of a bell is a standing wave. The sound inside a flute or organ pipe is a standing

wave, and there are many other examples.

 

As regards to the sphere:

 

You can model the electron in a hydrogen atom this way. Well - the lowest energy level anyway because its region of permitted occupation is spherical. The higher ones are more complex, but these too involve standing waves.

 

So you see my model of the universe as being a sphere also would have the same isotropic Cosmic Background Radiation. Except mine would explain why we are moving against the background radiation.

 

Damien

 

Got to hit the books again....

[Raelian1]

There are particles that move faster than light. I predict that eventually, we can create spacecraft that can go 7 times the speed of light.

[Damo2600]

Hi Buffy,

 

Oops I let that one slip.

 

I have to come clean and state my true model for the universe. As you may have figured out from my last post that if there were isotropic background radiation and the universe were not closed then the radiation would need to be bouncing off something right. My explanation wouldn't work either because if the sphere were expanding then you wouldn't actually have blueshift radiation bouncing off the edge of the universe would you? It would still have to be red shifted.

 

Now when I started learning about physics (little more than a month ago) I came up with a theory that suggested that we may be surrounded by an event horizon. Much like the event horizon you would find at the edge of a black hole (I know wild huh?). So anyway my theory was not well accepted however I had not given up on it.

 

Now if this were to be true and the fact that we are moving against this background radiation (the background radiation would not 'bounce' off the external event horizon now would it. The external EH would sending out it's own electromagnetic waves as the gravitation of the black holes, planets and stars have been found to do). The external EH would need to be stationary as would the EH at the centre of the universe. Now here we have movement against the radiation. The universe would no longer be expanding as such but moving away from the centre. Even if the galaxies furthest away from the universe were travelling at the speed of light this would not violate SR. It does not violate SR due to the fact that the energy needed to cause the big bang, I'm assuming, would have needed to be infinite. The galaxies themselves would not, as I have already stated, be experiencing the effects of such movement because space would be moving with it (not against it). The galaxy itself would appear to be not moving at all due to everything moving with it. Remember SR if you are moving at the speed of light then all other bodies moving relative to you will appear to be stationary.

 

I was upset when we began this discussion because I felt that what you were saying didn't conclusively proved me wrong. I however feel that my universe model could exist with all the necessary observations that your universe does (relative to each observer). Another point is I'm not really male, I chose the name Damien because I have found that people take you more seriously when they think you are male. Well there you go. I will understand if you think my credibilty is totally shot and would not like to discuss this further. My theory is as wild as yours although I do feel it has credible features to suggest that it fits the mold.

 

Thank you

Josephine

[Buffy]

First I'd like to point out that you didn't read my model correctly and I did not describe a plastic sheet. I described it, if you care to look back at my model, as being an elastic sphere. This is merely based on the expansion and does not represent spacetime in any way.

And that's exactly the problem: this is known popularly as the "raisin cake" analogy and its weakness is that it *only* describes expansion within a confined portion of the universe, *not* the universe as a whole. Its main benefit is that you can imagine it in three dimensions, but it loses the understanding of the geometry of the universe as a whole in that there's general agreement that the universe is not a sphere. The problem is that you are still drawing conclusions by extrapolating the sphere to the structure of the universe, which it does not and it sounds like you recognize.

Secondly I would like to point out a discrepancy in the statement you have made with regard to the Cosmic Background Radiation. Now the following website has the available information if you would care to check if my information is correct:

 

http://csep10.phys.utk.edu/astr162/lect/cosmology/cbr.html

 

Your statement was that the cosmic radiation was '*perfectly* distributed aroud us'. Alas I have found information that says it is not true. Further to this that Earth has been found to moving at a speed of 600km/s with respect to the CBR. So in fact on one side of the planet we see that the radiation is redshifted and on the opposite side the radiation is blueshifted.

The line on the web page you reference is incorrect. The anisotropy shown is due to the motion of the earth *within* the local group. This is *exactly* what you would expect from Special Relativity since it shows we are in motion and the CMB is stationary! See the other thread! Here's a better page with much more information that has the correct explanation:

 

http://www.astro.ucla.edu/~wright/cosmo_04.htm

 

Get a bowl of water and using a round rod (so as to not produce too many small irregular waves, bob it up and down in the very centre until you get a good wave train going. Now the waves will reflect from the bowl and interfere on the way in with the waves going out. Vary the frequency until you can see no radial motion at all. What you have now is a "standing wave". Standing waves can be very important in physics, and in practice. The ringing of a bell is a standing wave. The sound inside a flute or organ pipe is a standing wave, and there are many other examples.

That would certainly require a brick wall at the end of the universe, huh? One that expands. and you'd need a big 4 dimensional vibrating rod in the center of the universe to maintain it over time. You got any theories or evidence that any of these exist?

 

Glad to see you're working on it!

 

Cheers,

Buffy