alt cosmology paper reinvents the big crunch
Extending my previous note on the state of many papers submitted to arXiv today, the view hungry editors at the Technology Review blog decided to do a very, very generous write-up for a paper that predicts a universe with no Big Bang and while explaining a few odd observations related to certain supernovae, forgets to make any provision for major cosmological events which serve as the evidence for the very Big Bang it’s trying pretty hard to avoid. And you know it’s going to be a review made of five parts hype to one part science when you see sensationalistic and disingenuous sentences like this in the opening paragraph:
And while there is scientific consensus that it is the best explanation for the origin of the Universe, the debate is far from closed. However, it’s hard to find alternative models of the Universe without a beginning that are genuinely compelling.
Debate about what exactly? We’re pretty confident that the universe began with a single event and the problem is figuring out exactly what this event was and what role it plays in the grand scheme of things. Yes, it’s a really big problem but there are very few scientists out there debating whether the Big Bang is or isn’t real. And if the quest for an alternative theory for the origin of our universe is so lackluster, shouldn’t it say something about a problem with arguments against the Big Bang model and indicate that there really isn’t much debate? I mean what could we debate if we have no real alternatives? This is why the post quickly moves on to an introduction of the paper it’s going to advertise as potentially compelling, manufacturing its importance in the intro.
Shu’s idea is that time and space aren’t independent entities but can be converted back and forth between each other. In his formulation of the geometry of spacetime, the speed of light is simply the conversion factor between the two. Similarly, both mass and length are interchangeable in a relationship in which the conversion factor depends on both the gravitational constant G and the speed of light, neither of which need be constant.
Ah, so once again, if we convert mass to height, divide it by width, crisscross it with the weak nuclear force by the factor of Newton’s law of fudge, then take this through left clavicle, past the left ventricle, and to grandma’s house, we’ll have a brand new universe. While there’s a well known relationship between space and time via the speed of light, an idea that Technology Review mistakenly attributes to Shu rather than Einstein who really may have gotten the idea from Poincare, the exchange between mass and length via G and the speed of light seems very clunky and comes from a complex blizzard of math rather than cited experimental data. And while his newly created mathematical redefinition of the universe can explain why the universe is expanding, neatly doing away with singularities of any type in the process, it does have a major weak spot…
That’s not to say Shu’s theory is perfect…. One of the biggest problems he faces is explaining the existence and structure of the cosmic microwave background, something many astrophysicists believe to be the the strongest evidence that the Big Bang really did happen. The CMB, they say, is the echo of the Big bang. How it might arise in Shu’s cosmology isn’t yet clear but I imagine he’s working on it.
Wait a second. We have an alternative cosmology that doesn’t explain CMBR? That’s kind of like a new theory of particle physics that doesn’t explain electrons and quarks. Sure, through some numerology, Shu makes his model of the universe expand and contract like a vibrating coil, but he can’t explain why it’s contracting without any trigger, simply resorting to an eternal universe that constantly oscillates like a Big Crunch that never gets to actually crunch itself. In fact, the Big Crunch does a much better job in explaining the same thing as Shu, as well as accounting for the CMBR. Unfortunately, the universe seems to be expanding too fast to later slow and fall in on itself, starting another cycle via a Big Bang. For all the mathematical huffing and puffing, and attention his work received on the web, Shu hasn’t done anything new other than figured out another way to reformat the abandoned theory of the Big Crunch and the editor who wrote up the ad for his paper was painfully unaware of this fact while gushing with praise about its implications.
This is why it’s a bad idea to write about “groundbreaking” and “revolutionary” and papers based on what just caught your eye in the arXiv repository, rather than something accepted by a serious peer reviewed journal, or being taken seriously by the cosmological community. I know what you’re thinking, all new ideas have to come from somewhere, right? Yes, but keep in mind that anybody can post anything to arXiv because it’s not a peer reviewed site and the papers aren’t vetted by experts. It’s just a place to put up something and get a little press for your efforts. Until actual experts have a chance to look at it and there’s real evidence for its conclusions that can be seen in colliders or in astronomical snapshots, getting too excited over what it means to the universe and the scientific community is premature at best and irritating at worst.
See: Wun-Yi Shu (2010). Cosmological Models with No Big Bang, arXiv: 1007.1750v1
But don’t you agree that maintenance of BB has also become rather convoluted? E.g. inflation that lacks a cause?
I admit that my expertise in cosmology is extremely limited, but objectively it isn’t the nice neat theory that many laymen assume.
Everytime inconsistent evidence is found there is a rush to find some new theory to explain it and maintain BB. So now in cosmology we have dark matter of which no one knows the nature and which has never been (directly) detected although it persumed to be pervasive and more common the ordinary matter. We have dark energy just discovered and we have some new mysterious force that caused the very brief hyper-expansion. That’s a lot of mysteries needed to support BB (or at least more generally contemporary cosmology).
Moreover there is lately increasing evidence that the very distent universe, theoretically young and unformed, looks much like the local universe.
But don’t you agree that maintenance of BB has also become rather convoluted? E.g. inflation that lacks a cause?
The cause of the inflation would be in the artifacts of the Big Bang. You’re appealing to the gaps in cosmological frameworks as an excuse to throw the baby out with the bathwater, something akin to demolishing your entire house if you can’t fix the leaky pipes and sagging doorways. Right now there is no better explanation for what we see in the universe and other explanations fall short because they leave huge gaps in the framework we’ve already settled with extensive observations.
there is lately increasing evidence that the very distant universe, theoretically young and unformed, looks much like the local universe.
To what evidence are you referring? There’s a marked difference between galaxies millions of years away from us and billions of years away from us. If your suggested scenario was right, there should be no evidence of the cosmic dark age, and yet we do see evidence of it with our telescopes. If you have links to the contrary, please go ahead, post it, and I’ll review it. But please don’t make claims without a reference.
I think what you are saying is that BB explains many observations and that without a better theory to explain those as well as the non-conforming observations one should stick with it.
However it has also run into some serious unresolved problems. A concocted theory of inflation is not a particularly satisfactory explaination of the large structure problem simply because it was constructed to explain it and has no other physical basis (that I’ve heard of).
Here is a recent reference discussing the problem of the appearance of the distant universe.
I have seen other articles like this in the past couple of years but I don’t have links. Don’t you agree that these observations are at least interesting and possible problematic for BB?
Can you site references about the marked difference between nearby galaxies and those billions of light years distant? I have seen that stated, but I have never seen an article that directly addresses it.
Also could you site some (not too technical) references that provide independent evidence of the youth of the universe?
One should not throw out the baby with the bathwater, but one should be wary that it may not be the baby. The danger I see is that a belief in BB might limit the ability to percieve or even pursue an alternative.
Can you site references about the marked difference between nearby galaxies and those billions of light years distant?
Um… They were right there in your article which says that a number of galaxies found about 15 billion light years away look very modern. If this was a common occurrence, why would this be even news? Again, you’re dismissing inflation based on finding an anomaly and using a single incident covered in popualr science articles to refute the theory you find problematic because it’s not neat or tidy.
Unfortunately, nature is not tidy. You will always have anomalies, you will always have questions, you will always have theories that don’t fit quite right. That’s not a basis for pot shots against a theory without being able to explain why it doesn’t work.
Also could you site some (not too technical) references that provide independent evidence of the youth of the universe?
They’re in the links of the previous post where you’re commenting. Again, slow down for a moment and note that you’re asking for something not too technical and not too complex in terms of evidence and citations. Why would people need to get a PhD in physics to study cosmology if we could make a dent in these questions with a couple of pop sci articles?
But if even one galaxy so far away is ancient, we have a problem, no?
“A team of astronomers … has discovered the most distant cluster of galaxies ever found” makes it rather unique and impossible to talk about statistically. The reason it’s news is not so much the rarity, but the fact (if indeed their interpretation is correct) that it exits at all.
I didn’t see that the article offered any specific statistical information. However, in your defense it does say this: “CLG J02182-05102′s large red galaxies are unexpected because most galaxies at that time were still rapidly forming stars, and, as a result, appear smaller and their emitted light bluer” which carries the apparent implication that most galaxies discovered at that distance are known to be young.
“Again, you’re dismissing inflation based on finding an anomaly.” No I’m not. I doing something much worse; I’m questioning BB. What I said in reference to inflation was that it was invented to explain some things needed to uphold BB, but as yet we have no physical explanation for inflation. In my mind, that rather limits the stature of the theory (of inflation).
So are you saying the answer to the age evidence is so complex it cannot be comprehended by a layman? I’m not trying to be cute here, I am actually looking for more information. I’m just saying I’m not prepared to read a technical paper loaded with math. Perhaps you are right that the information is so esoteric that it cannot be explained in layman’s terms.
Anomolies are the source of new understanding and are to be taken very seriously (if well verified of course). One might well say that the Michelson-Morely experient was an anomoly because it denied any effect of relative motion on the propigation of light through the either. Thus it killed the either theory and founded special relativity.
But if even one galaxy so far away is ancient, we have a problem, no?
I don’t think you understood what the astronomers were saying about the galaxies in question. They said that these galaxies appeared to have matured very quickly, living very fast lives. There’s no evidence that they’re older than they should be, just that the overall behavior and layout of these galaxies makes them look more mature.
… as yet we have no physical explanation for inflation.
But we see evidence it has happened. You’re questioning Big Bang because you’re unable to explain the exact mechanics of inflation and despite the evidence that it did indeed occur? I’m really not seeing the logic in that. And note that you’re not offering a viable alternative, you’re trying to use anomalies to poke at the theory. Do you have a better explanation, or do you just want to do away with the Big Bang theory?
are you saying the answer to the age evidence can’t be comprehended by a layman?
No, I’m saying that if the links already provided for you seemed too technical, it’s very unlikely that you’ll find something even more layman friendly. If you really want to get into every nook and cranny of how we date the universe, I suggest taking a course in astrophysics and cosmology.
I don’t have to offer a viable alternative to point out weaknesses. I don’t have to have a better theory. I think you better brush up on the scientific method. As I already mentioned, Michelson-Morely blew away the either theory, but they offered no alternative. That came later and I might add with a spectacular upset of existing physical theory.
You persist in misunderstanding my statements about inflation. Yes if BB is true then there are some observations that must be explained. Yes inflation offers an explanation but it is a weak one because it postulates something else (also profound) that needs an explanation. In any case it is entirely false to contend that inflation theory is evidence in favor of BB. It is nothing of a kind. It is a conjecture that presupposes some as yet unexplained force that together with some experimentally verfied physical laws was put forth to explain observations inconsistent with the earlier formulations of BB theory. There is no evidence that inflation did occur aside from 1) the belief that BB is correct and 2) that it explains observations in conflict with older formulations. I might (nearly) as well explain these observations by saying “and then a miracle occurred.” I admit inflation is much more cleaver than that, but is it really all that different?
My understanding is that there are in fact other theories of cosmology but that they have been pretty much dismissed by the present generation of cosmologists. Whether justifiably so, I cannot say. However, some do originate from people with similar qualifications. In fact, plasma theories seem to originate from people with areas of expertise uncommon in the astronomical community. Recently I saw an article (sorry but I cannot give a citation) declaring that the influence of magnetic and electrical forces on the structure of the cosmos may have been seriously underestimated. Not too suprising since these forces are many orders of magnitude stronger than gravity.
If you want to argue by popularity I certainly admit nearly all cosmologists with funding are on the BB bandwagon. I’ll bet that few astronomers would dare to have the termerity to seriously cast doubt on BB as it is so well established by theories like inflation (bit of sarcasm there, my apologies).
“They said that these galaxies appeared to have matured very quickly, living very fast lives.”
Perhaps that interpretation is based on their belief that they could not be so old rather than on any direct observational evidence of “living fast”. Do you really think that the existence of this extensive cluster with large red eliptical galaxies poses no issue at all?
Last I heard eliptical galaxies are thought to be highly evolved structures formed by the merger of many galaxies and thus presumably old. Last I heard large stars that burn fast are likely to become supernovas. So if this is happening, perhaps we should expect to see some special fireworks in this cluster? Perhaps at least one of those theories needs revision? One needs to explain how they could form and evolve so quickly and “[live] very fast” to preserve BB. I’m certainly not ruling out such an explanation, but obviously one is needed. Perhaps time ran faster then and slower now? (Not very appetizing.)
Or alternatively are you ready to just write this observation off as an anomoly? An unimportant deviation from the norm that will probably be explained somehow or other but poses no threat to BB?
Certainly taking a course in astromony and cosmology is good advice, but it is also a brush-off with regard to this discussion. I haven’t yet examined those links to determine whether they are too technical for my comprehension. Generally speaking original technical papers are addressed to people well versed in the theories, the math and the jargon. That does not put the concepts out of the range of those who are not, but it does make the papers difficult to comprehend. In addition, access to original papers is not so easy for those outside the field. On the web they have high prices and you have little idea of what you will get for your money. When I have the time, I’ll visit a university library.
What I was looking for in particular was a layman’s summary of the evidence for the evolution of stellar structures correlated with red shift. I’ll keep looking, I want to believe too.
The history of science is littered with theories once widely accepted and later disproved. Spontaneous generation (to go way back), epicycles, Newtonian mechanics, classical physics of electromagnetism. Sometime you should read about how wrong the Curie’s must have been to think that so much energy could be generated by radium. Impossible!
You should not get too smug about what has been established as the truth. That I think is my main point, not that you are right or wrong.
Cheers
I don’t have to offer a viable alternative to point out weaknesses.
Not necessarily, but you should be at least aware of whether you’re pointing out the right weaknesses. So far, what you’re doing is focusing on anomalies and insisting that if you can’t get a neat, airtight explanation for the inflationary theory, that theory is weak. Ok, fair enough, now what? Without an alternative theory, what all you’ve done is pointed out what other areas need more research and left things as they were.
Nobody is going to give up on the Big Bang until we see some very strong evidence that there’s another perfectly workable and better theory out there. If you’re telling me to brush up on the scientific method, I would suggest you take your own advice and realize that I’m not “misunderstanding you” but trying to pull out something more out of your comments, something with which I can actually work rather than correct.
Or alternatively are you ready to just write this observation off as an anomaly?
Anomalies are not written off. They’re investigated. However, when we cast them as an anomaly, what it means is that they’re a deviation from the norm for some reason or another, and that we need to try and find a plausible explanation within an existing framework. If we can’t do that, then we need to start branching out. But rushing to go and find a brand new cosmology every time we see something odd isn’t reasonable.
By the way, until recently, astronomers were scratching their heads about a swath of galaxies seemingly inexplicably missing from the sky, but predicted to be there by all the math done within the Big Bang framework. They couldn’t explain why the galaxies weren’t there for over a decade. And then, one day, they turned their telescopes down a notch and what do you know, the galaxies were there. All they needed to do was to look at a different wavelength of light. Again, anomalies are not proof that cosmology is wrong from top to bottom.
You should not get too smug about what has been established as the truth.
Me? Smug? In trying to correct problems with your statements or factual errors? You seem to have an interesting definition of smug going on there.
Carl says, I think you better brush up on the scientific method.
I think you better brush up on your reading comprehension. You’re doing a remarkable job of coming off as an arrogant prat.
Perhaps that interpretation is based on their belief that they could not be so old rather than on any direct observational evidence of “living fast”. Do you really think that the existence of this extensive cluster with large red eliptical [sic] galaxies poses no issue at all?
Well, you’re not going to get any “direct observation” of living fast. Even a short lived star lasts just a wee bit longer (like millions of years) than the few days spent observing the cluster.
You think this is an issue that refutes inflation? Were you the least aware of how many issues inflation actually addresses? The very distinct evidence that the universe is pretty evenly distributed and heated is something that hurts the steady expansion model, and is far from being the only thing that supports it. Wikipedia is your friend (actually, from your behavior here I suspect you don’t hold that opinion, but whatever..)
And you’re thinking that a large, old galaxy cluster turns this all upside-down? Unless, of course, they can form faster than we thought (as implied by the article.) Then, whoops, no issues at all, is there? You want to make a case that no one considered an alternative, without ever realizing that the alternative raises hundreds of times as many questions, all of which you have to consider when proposing it, than the idea of a short-lived cluster does.
Have you demonstrated in any way that the cluster cannot be short-lived? No? Then why are you giving it more weight?
The history of science is littered with theories once widely accepted and later disproved.
Uh huh. But to even see them, you have to sweep away the number of “theories” that were proposed without any evidence to back them up and were trashed quickly, which outnumber the accepted-then-rejected ones by about 10^60 to 1. How come these are never brought up by brave souls like you?
Certainly taking a course in astromony [sic] and cosmology is good advice, but it is also a brush-off with regard to this discussion. I haven’t yet examined those links to determine whether they are too technical for my comprehension.
Let me translate this for you: “I can’t be bothered to actually learn something about cosmology, or even to follow up on details about the very thing I’m espousing as evidence, but I’m more than happy to assert that everyone in the entire field is dumber than I am.”
I mean, fuck, dude, is perspective even in your vocabulary? In the time you’ve spent typing up your vague bullshit tactic of asking questions without really wanting to hear an honest answer, you could have actually learned some real science regarding your idea. But I understand, really – that’s to be avoided at all costs, because you might just find out that cosmology isn’t going to be stood on its ear by you. Some people don’t fare well with reality.
@Carl
Read Kavassalis’s remarks (specifically the section “No Big Bang”) on why it isn’t the anti-big bang nature of the paper that is upsetting people, it is the fact that it is illogical.
Al there is no need to resort to name-calling. I made an incorrect assumption that Greg was an astronomer and thought I was having a discussion with one. The remark about the scientific method could have been put in nicer terms. I was getting a bit frustrated trying to convey something about the character of inflation theory. I was told that I had suggested that GR was invented to explain BB, when I never even mentioned GR. (This was in another thread. but same subject.)
“Well, you’re not going to get any “direct observation” of living fast”
If by “fast” it is meant stars that burn fast (short life cycle), then I did suggest a plausible observation. I’m not sure it’s practical (due to the distance), but if supernovas can be detected in that cluster, one could compare that occurrence rate with the estimated mass of the cluster. It’s true that there are few direct observations of large scale change, but there are probably lots of ways that it can be inferred. If we have galaxies rotating at high rates or moving very fast relative to one another, those things can potentially be measured (as I’m sure they eventually will be) and they could play a part in fast evolution.
“You think this is an issue that refutes inflation?”
I never said that I was even trying to “refute” inflation. I did say it was concocted and I used that word because inflation presupposes some additional new unknown physical effect (to explain some problems in the BB theory). I cannot prove that inflation didn’t occur any more than you can prove that it did. Since no one knows anything about the physics of the “inflation field”, the theory can pick the start, the end and the rate of inflation to fit the observations. I’m not saying there is anything wrong with doing that either. It just makes the theory not so strong.
“And you’re thinking that a large, old galaxy cluster turns this all upside-down?”
It does if it can be established that it is older than the BB universe. At least 13.7 would need an adjustment, wouldn’t it?
“Have you demonstrated in any way that the cluster cannot be short-lived?”
Of course I haven’t. It’s just something that would not be expected considering the presumed size of the structure and what is currently believed about formation times. It’s not so much “short-lived” as “quickly-evolved” that makes it very interesting. I certainly have to admit the whole thing could turn out to be an incorrect observation. Or it could turn out that galaxy clusters with huge elliptical galaxies can form in a couple of billion years; that seems unlikely though. Maybe traversing billions of light-years of dark matter can alter red-shift readings? After all we don’t know what the stuff is or how it interacts except that it gravitates.
“…without ever realizing that the alternative raises hundreds of times as many questions…”
Is there something wrong with raising questions? It doesn’t really hurt anything; it just makes us think, perhaps in other directions.
I think you missed my point too. I’m not proposing any theory. It only takes one thing seriously wrong to require a change in a theory or even discarding it altogether. I’m not claiming to kill the theory either. BB has been changed from time to time and survived. But inflation is a pretty big patch. New observations cannot be ignored either and have to be explained in order for a theory to remain viable. I’m sure we agree on that.
““I can’t be bothered to actually learn something about cosmology, or even to follow up on details about the very thing I’m espousing as evidence, but I’m more than happy to assert that everyone in the entire field is dumber than I am.””
Now you are really stretching things to fit your misinterpretation of the entire dialogue. I tried to get more info and you and gfish have not been all that much help. I did check out those links in the article that I cited and I never said I was smarter than anyone. Any evidence I got was from reading astronomy articles.
Here is a quote from another of those links:
“It is very exciting to have discovered such a large sample of these rare objects,” Wilson said. “Although we are catching these clusters at early times, we can tell by their red colors that many of the galaxies we are seeing are already quite old. We will be following up this new sample for years to come, to better understand how clusters and their galaxies form and evolve in the early universe.”
What is “early”? The article refers to 4.8 billion post bang. What is “quite old”? Wilson doesn’t say here. The sun is at least 4.5 billion years old, but we don’t know if that is “quite old”.
I think if you were to reread carefully everything I wrote (in this and the other thread), you won’t find that I made most of the claims you have inferred. I simply pointed out things that may cast doubt on the BB theory. I’m certainly not the first (Hubble may have been). I thought there might be some interesting debate about it with more information presented.
If you want to talk about what supports inflation, why don’t you point something out instead of surmising that I don’t know how to use Wikipedia or could not be bothered?
(PhyGuy. I’ll read that article, but what we have above is not a complaint against anything illogical. What we have is a lot of anger.)
Now I’ll admit that creationist arguments piss me off because they deny the very existence of evidence in plain site, e.g. ancient whales with tiny little feet. (I’m trying to put myself in your shoes here.) Did I deny the existence of evidence for BB? If you want to declare that it is illogical to even suggest that BB could be wrong, well that’s a bit of a stretch. To declare that inflation is practically a fact would be a very big stretch.
There is a great deal that we do not know about cosmology. We don’t even know how galaxies form (to any degree of certainty). But because they are so large, so massive and move so slowly we assume it took a long time.
It’s just a couple of years since the apparent increase in the rate of expansion was discovered. That is an unexpected discovery for which BB provides no explanation. Wow, we thought it must be slowing down! Things are far from tied up in a nice neat package. If the expansion can speed up maybe just about anything is possible. Maybe other interpretations of observations are possible.
Al & gfish you had a choice here. You could be informative or reactive. It’s actually one of the reason’s I took up the debate. I had read others complain that cosmologists were overreacting to any suggestions that they could be wrong. But then are you cosmologists? Is it tradition in the field to end discussions with “I mean fuck, dude.”
Greg,
I got caught up in replying to the above tantrum. No time to reply to you today.
I’ll just say that I don’t disagree with much of anything in your reply. It just seemed in your first response that you were rather dimissive of interesting new evidence. If we didn’t have BB theory and we found that cluster we might think, just another old cluster like our own, but 2.8 BY from the begining is pretty interesting.
I made an incorrect assumption that Greg was an astronomer…
But hopefully you looked on the about page and saw that my field is really computer science, right? Though I do understand enough physics to explain the basics of the relevant theories and where to send you for more information if you’re not satisfied.
I was told that I had suggested that GR was invented to explain BB…
No. My comment on the other thread was trying to explain that you didn’t account for the role of general relativity in inflation. If the Big Bang carved out an expanding cavity of space and time and fueled the expansion of space, we could show how it allowed the fabric of space to expand faster than light without violating special relativity. With no grasp of general relativity, you couldn’t have the inflationary theory.
I got caught up in replying to the above tantrum. No time to reply to you today.
Well, I appreciate you taking your time to tell me that you’re too pressed to reply.
Some of these notions are pretty slippery, or perhaps just impossible to express in ordinary terms.
What’s your take on this: “space itself is expanding”. I’ve seen explanations of BB that put great emphasis on this. I suppose that has some rigorous definition mathematically but it’s very hard to understand just from those words.
I could define space as the distance between two objects or alternatively as the time required for light to travel between the objects (in the rest frame of the objects). So what does it mean to say that space itself is expanding (everywhere)? Naively you would think it would either be undetectable (by the first measure) or the equivalent to a deceleration of the speed of light (choosing the second measure).
But neither fits BB or observation. Why if space is expanding, isn’t the earth expanding? If it’s because gravity prevents the earth from expanding with space, then the expansion must be a force and energy must be continually added (apparently from out of nothing) to support it. I.e. from this analysis, the expansion is already dark energy even if slowing.
I just stopped for a moment and read a couple of explanations. One in particular refers to the “metric expansion of space” which the author defines as the average increase in distance between objects over time.
“The metric expansion of space is the averaged increase of metric (i.e. measured) distance between distant objects in the universe with time.”
He goes on to say that the current expansion has two components. One is the inertial component resulting from the pressure exerted when the universe was extremely dense. That pressure is pretty much gone now. The other component is the cosmological constant or dark energy recently discovered. This again acts like a pressure or negative gravity generated by the vacuum itself rather than anything in it.
Now, having read that explanation of expansion, I would say that insisting that “space itself” is expanding is rather misleading as it can certainly be taken the wrong way. He doesn’t really seem to mean that literally, but wait.
Now we get to an SR issue. The same author says:
“While special relativity constrains objects in the universe from moving faster than the speed of light with respect to each other, there is no such theoretical constraint when space itself is expanding. It is thus possible for two very distant objects to be moving away from each other at a speed greater than the speed of light (meaning that one cannot be observed from the other). The size of the observable universe could thus be smaller than the entire universe.”
Now that really sounds paradoxical, doesn’t it? First he says that SR limits objects from moving faster than light relative to one another. And then he says no it doesn’t, because “space itself” is expanding two objects can move relative to one another faster than light. But he already seems to have defined space as the distance between objects so how does this work? If indeed “space itself’ is expanding, then shouldn’t we all be expanding? It is certainly not a satisfactory explanation because we are back to wondering what is the definition of “space expanding”. How would I know that “space is expanding” as opposed to “things are getting farther apart”? What exactly is the distinction? Clearly there must be one is SR is upheld.
Can you shed some light on this?
If indeed “space itself’ is expanding, then shouldn’t we all be expanding?
Carl, are you seriously asking that? I mean, are you really equating the motion of the fabric of space and the motion of objects that exist in this space? Certainly you want to seem critical and insightful, but you’re asking questions that have been answered in just about every popular science source on the web and trying to chip the Big Bang model based on a very profound misunderstanding of how the cosmos works.
We live in space, not embedded into the fabric of space. When space itself expands, the objects in it are drawn further apart. When you see a floating leaf being pulled by currents, the leaf doesn’t expand. The same applies to space and the objects which exist in it. Momentum and inertia keeps planets orbiting around stars, stars around their galactic cores, smaller galaxies around larger ones, etc. But as space expands and separates the distance between them, the entire systems just get further apart, caught in the current. Googling “redshift” should’ve netted you plenty of explanations on how this concept works.
Again, please take the time to study the topic instead of expecting all the answers to be handed to you on a silver platter. I’m more than willing to answer questions, but I do have my limits, especially when it comes to questions that seek to dismantle an extremely well-established and supported theory by simply mangling what it says or setting up hypothetical strawmen.
Your brief expanation sounds like lots of pop-articles about BB.
I asked you a very specific question which you simply evaded.
How would I know that “space is expanding” as opposed to “things are getting farther apart”?
I’m guessing that you don’t know the answer either.
How would I know that space is expanding as opposed to things are getting farther apart?
You would see uniform redshift from every corner of the universe, or at least enough of the sky to tell that everything around us is moving away. If things were just moving and getting farther apart, we should be seeing objects going in many directions on a macro scale rather than generally heading out and away.
Oh and guess what? Even Wikipedia has a detailed primer on this concept which you could’ve found in less than a minute. Or do you seriously keep expecting to be spoon fed all of modern cosmology in this thread?