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Martin, Thank you for the information. It throws a couple of wrenches into my model. I had not considered that the Hubble "constant" changes. Raises some questions though about how various figures and measurements were arrived upon and made. For instance, if we don't know what we are looking at, and we make assumptions about it's age and distance and structure, based on previous assumptions (made when we also didn't know what we were looking at,) it seems we could be multiplying our errors and omisssions. Have to go to work. Regards, TAR Merged post follows: Consecutive posts mergedMartin, Thought about your post off and on all day, driving, lunch, breaks and when I got home, after working on the lawn mower, I reread your post about 6 times, reading Wikipedia posts on time horizons and cosmic background radiation, the size of the universe, how many galaxies there are, how old and how far, etc. etc. And suddenly something started making sense. By the measurements you gave me, the current universe (locations a b and c) are 45 billion lys apart. 13-some billon years ago, they were 41 million lys apart. At that time, the cosmic time at all three locations was 330-360 million years ABB (after Big Bang.) Images of the time of last scattering would reach our location (b or the location that would become the Milky Way) coming from a in a little over 41 million years, let's say 45-90 million years. The time at b, when we see the last of the last scattering at a, is now 450 million years ABB. Meanwhile, c (also at 450 ABB) is looking toward b and sees b's first photons at the time of last scattering, emerging from the wall that appears to c to be receding at the speed of light. Little does c know that to b, the entire universe is crystal clear with photons streaming in from all directions. (Can't tell you what c sees when she turns around though, her being at the end of the universe and all.) Fast forward another 60 to 100 million years to 550 ABB and check the situation again. We (b) take a look over at a and see a region of space that looks about 60-100 million years older, development wise, and is a bit more red shifted and a bit farther then the 41 million lys it was last time. Meanwhile (still 550 ABB) at c, she looks at us and we (b) look to her, pretty much like a looks to us. But when she © looks at the region of a, she sees the last of the last scattering disappearing from the universe forever, and emerging from that last wisp of scattering, is region a, crisp and clear, looking a bit more red shifted than b, but not a day older than 330-360 million years and what, about 100 million lys away. Fast forward to the present. We (b), along with a and c are now 13.7 billion years old. We each are 45 billion lys away from each other. We (b) had watched a and c age along with us. When we were just 41 million years old we first saw them emerge from the cloud, we watched them develop along with us but each million years they were looking a little more red shifted, farther away, and seemed to be aging slower and slower. Then they red shifted into infrared, and we couldn't quite make them out anymore. When we look in their direction now we see they have red shifted into the microwave range. What do you think? Regards, TAR Merged post follows: Consecutive posts mergedWow, I just reread my post, and it doesn't express the thoughts I was having. I had a lot of insights last night, and formed a model in my head that made a lot of sense to me, answered a lot of questions, opened the door for a lot of predictions, and ruled out some ideas which, to me, no longer fit with reality. For instance, the idea that since the farther away an object is, the older it is, we should be able to, if we can look far enough, see the beginning of the universe. I concluded last night, that this is a false hope. I thought I was proving it, along with a dozen other insights, with my post last night. In rereading my post tonight I see that everything going on in my head was not relayed to the computer screen. And it does not read anything like the "ahah" moments it grew out of. Regards, TAR Merged post follows: Consecutive posts mergedBascule, "Isn't the answer to the question "what exists outside of the visible universe" unknowable? If something exists outside the visible universe, isn't it impossible for it to be causally linked to us?" My hypothesis could be wrong. But if it is correct, which it seems to me to be, so far, then you start with the premise that everything in the universe has to be causally linked, and figure out afterward what the link is, and how each item in the universe should look to us. So for instance, let's say we figure the universe to be 13.7 billion years old, and let's say it could be 600 billion lys wide. At first blush, it would seem that that location of space is locked away from us by time and distance, because if we sent a message to it, the message would take at least 600 billion years to get there, and the reply would take another 600billion years to return, and that is only if the universe would average the same size that it is now for the next trillion years. So it seems unlikey the two point could be causally linked. But that is just the way it seems. The time and distance that is our enemy in considering any two way communication with a distant object are are friends when considering if there ever was one way linkage. For if the universe expanded to 1000 times it size in the last 13.5 bys then it was 1000 times smaller 13.5 billion years ago. A 600million ly wide universe, although still expansive, might have two way communication possibilities. A message could be sent from one end to the other in 600 million years, if the universe would stay the same size. But it didn't. I am not so good with caluclus, so just sticking with ratios and making rough estimates, let's say that from the moment the message was sent,the universe would double in size every 1 billion years. So the message travels for a billion years, and finds itself 1 billion light years away from the sender, in a universe that is 1.2 billion years wide. 200 million ly short of its target. So like any good photon does, it keeps going for another 200 million years, traversing 200 million lys. But in that time, that 200 million ly stretch of space stretched 20 percent so its still conceivable that it is 40 million lys from its target. Its on the downhill stretch now and that 40 million can be covered while the expansion only adds another 5 percent or about 2 million miles which it should be able to cover in 2 and a bit million years. But it made the trip. Took 1.242 billion years. But it made it. From one side of the universe, to the other. Now the return message might or might not make it. My figures are too vague and my figuring to feable but at this point in the excercise, we are in a universe 1.5 billion lys across that will be 3 billion light years across after the return message covers its first billion miles, 6 billion light year across after 2 billion ly of travel, 12 billion across after 3, 24 billion after 4...seems to be fighting a losing battle. So although it appears there was a time, early on in the universe, when one way communication was possible. There also seems to be a time at which a photon leaving one end of the universe would not make it to the other end, ever. (unless the universe at some point in the future, slows its expansion drastically, stops or shrinks.) But we still have the guess that that first, one way message, could have been sent, from one side of the universe to the other. And if this is true, then the entire 13.7 billion year old universe is populated by locations in space that can see every other location in space. Because each location sent out a continuous stream of photons (starting around 13.4 billion years ago) and if the first photon could reach every location in space, some portion of the following ones could do the same. And the visible universe, is the entire universe. Its just a matter of figuring, when we see a location in space, which portion of that 13.4 billion year history of photon emissions we are seeing. Regards, TAR Merged post follows: Consecutive posts mergedP.S. Bearing in mind that by "visable" I mean a photon strikes us. It does not have to be in the visible spectrum. It could be stretched out to infrared, microwave, or radio waves. Merged post follows: Consecutive posts mergedcorrection: I used 330-360 million years after big bang as the time of recombination, or last scattering, and Martin, you gave me a time of 380,000 years for that era. Off by a factor of 1000. Pretty bad. But its even a better number for my argument. Light could make a 41-82(plus expansion) million light year trek well before the universe's 550 million year birthday. Probably closer to it's 200 million year birthday. Merged post follows: Consecutive posts mergedEarly on in the universe, right after the last scattering, each location in space saw the wall of fog, of the last scattering receed from their location at the speed of light, until each location could see the entire universe edge to edge. The clumps of matter at the farthest edge (to each observing location) were the last to emerge from the fog and looked to be 380,000 year old clumps, while each observing location was 200 million years old and probably a massive population III star in some stage of its development. As the universe aged, this type of effect continued to exist. Each location would see its stage of development spread out to the edge of the universe at the speed of light, and at all times, could see to the very edge of the universe. But the edge of the universe kept getting farther away and locations at the edge though still developing were appearing to develop at a slower and slower rate, and they were red shifting more and more. All the billions and billions of stars that Olber was looking for ARE lighting up the night sky, lighting it up in the microwave frequency. And they are probably the population III stars we've been looking for, to boot. Regards, TAR

Martin, Read half the article and skimmed the rest. I think the solution of the riddle is to be found in a little bit of each of many of the solutions, but mostly in reframing the question. All the solutions seem to have a major flaw in that the question has an anthropic bias, and an earthly bias, in that we are wondering why we haven't been able to zoom our telescopes in to an extraterrestrial Cape Kennedy, or intercept a radio show on the Alpha Centauri interplanetary football finals. Combine the fact that the signs we are looking for, may not be the traces left by other civilizations, with the fact that we may already have already seen signs which we have ignored, misinterpreted or dismissed, and the paradox sort of dwindles away. Our ideas of what life, intelligence and conciousness are, are very anthropically biased. Do you think the sun is alive? Do you think a tree is intelligent? Do you think an ant colony is conscious? Why do we not have SETI type programs aimed at comminicating with these types of entities? So my answer to the riddle is "no, we are not alone", and "yes, we have seen signs", and "probably" we will eventually be contacted by, or notice, or visit, extraterrestrials, but most likely they will not be what we expected. Our evolution from the first mitochondria to our present form, was dictated by the special characteristics of Earth. The temperature, the pressure, the elements in the air, water, rock and soil. Dictated by the other life forms that evolved beside us. Our evolution as a civilization was dictated by finding ways to utilize our surroundings to ensure survival and reproduction. Each technological advance and social progress was built on the body of knowledge and philosophy that previous members of our species laid down. Our civilization would be different had it not been for Plato, Hitler, Newton, Pasteur, Mohammed, Einstein, Confucius, etc. etc.. That WE would be different, given a few small changes in our past, and given that WE do not recognize the life, intelligence and conciousness in the entities we HAVE run into in the universe already, I would say there is little chance we will run into US, anywhere else, but here. Regards, TAR Merged post follows: Consecutive posts mergedBy the way, I do think I saw some alien crafts when I was 18, out on a farm in PA. It was during a party in the early 1970s, so all the observers were either intoxicated like I was, or stoned, but at least a dozen people, witnessed the same thing. 5 or 6 lights were hovering over a powerline that we knew ran through the woods behind the farm. Maybe about 1 or 2 miles away. Several of us stood together talking about the lights and what they could be for 5 or 10 minutes. We heard no sound, and figured we were close enough that we would have heard them if they were heliocopters, so we figured they were probably aliens, and were considering what we should do, others came from the house and mostly we decided it would be best just to put out positive "vibes" and not be scared or involve the authorities (we did have illegal substances about), or be aggressive in anyway or find our way over there. After several more minutes, they left, one by one, starting out, and then zipping out of sight in a manner not familar to us or any technology we were aware of. We figured they just fueled up, off of the magnetic flux surrounding the high voltage AC lines, and went off about their business.

ydoaPs, Nice drawing. More entertaining, but not as useful as, the university version. Regards, TAR

http://www.astro.princeton.edu/universe/all200.gif If you get a little strip of dots down the left side of the page, put your cursor down near the bottom of the strip and you should get a little "expand to regular size" icon. Click on that, and see a fantastic compilation of all the observations made and work done to date. (I would particularly like to talk about the lines at z=0.76 and z=1.69.) Regards, TAR

Martin, Thanks so much for your reply. This Lepton felt pretty good to read it. I am still perplexed by much of the math required to properly model the universe and figure out how things can and can't fit together. And I am completely lost with the 10 dimensional stuff. Even your mention of a hypersphere sent me scampering to Wikipedia, and left my head spinning with the symbols, transformations, jargon, and references to named equations that I am just not learned enough nor bright enough to fully comprehend, much less delve into, in terms of their subtleties and implications. So I, like most people who are outclassed, figure that all this dark matter, dark energy stuff was just made up to make the equations work. And I think in terms of Euclidean geometry, analogies to common experience and common sense. Not much of a scientist, really, although, when I understand it, I am fully appreciative of the great body of knowledge that a large number of great minds have gleaned from the study of, and the mathematical investigation of, our universe. And I rely on others to answer the questions I have, pertaining to my hypothesis. The first question is, how big was the universe, when it became transparent to photons? The second question is, how long would it take a photon to traverse that distance, if that distance was increasing at the Hubble constant? Thanks again for entertaining my thoughts. Regards, TAR Merged post follows: Consecutive posts mergedajb, "Inflation?" Was this the answer to what I couldn't put my finger on? If so, then I wasn't clear. I was trying to imagine what effects, on the appearance of b, my scenario should have. For instance should it appear younger or lengthened, faded, move in slow motion, or dissolve into radio waves or something. I have not thought it through. Gives me a thought though. I wonder if it would yield anything, to focus on a small patch of microwave "background radiation" and put it through a computer simulation that would "up the frequency" by the right multiple to put it into the visible spectrum, and "see" if it looked like anything? Regards, TAR

Please help me test my hypothesis against known observations and proven science. My guess is, that at the time the universe became transparent to photons the universe was small enough that a photon emitted at one end, would have been able to reach the other end, even counting for the expansion of space, within 13.7billion years. If this is true, then once two locations in space are thusly causally linked, they will not, indeed cannot, become unlinked, due to the fact that C is the speed limit of the universe, and no location or object can outrun an already arrived photon. Thus as object b receeds from a, a continues to receive b photons at lower and lower frequencies, gamma rays becoming x-rays, x-rays becoming ultraviolet ... visible ... infrared ... microwave ... radio waves of longer and longer wavelengths. When a and b's recession from each other exceeds the speed of light, the flow of photons will not stop. Photons just about to arrive at a from b will still arrive. Only something about the relative age or the apparent age of b will change. Something I have not put my finger on yet. Regards, TAR

AirBrush, So far I like your answer (to Swaha) the best. Regards, TAR

Klaynos, So still, I have a few questions. One is, when I read a finding, like "the universe is 158 billion light years wide", is that statement assuming a universal "now", and imagining the universe when all objects and locations in space are 13.7 billion years old? Regards, TAR

Klaynos, I am just trying to get a good picture of what did and is happening in the universe (generally speaking.) We will not see what is happening "now" anywhere in the universe until the light of the events get to us. We will have to wait 4.3 years to see what is happening "now" on Alpha Centauri. (But we can see now, exactly what was going on on Alpha Centauri 4.3 years ago.) We can only surmise that the rest of the universe is most likely pretty much like it seems to be around here, with strings of galaxies, clusters of galaxies, and voids. The objects we see 13 billion light years away, most likely tell us what things around here were like those billions of years ago. Those objects are no longer what occupies that location in space, that population III star, or whatever we see(in infrared) has long since become whatever population III stars became, and that location of space is probably inhabited by the children objects, or grandchildren objects of that population III star. "Now" meaning what that location of space is like, 13.7 billion years after the Big Bang. I have wondered several times, in my readings in the last couple days, what people mean, time wise, when they say "the universe consists...". Are they talking about what is around here and figuring that is what the rest of the universe consists of as well, or are they making their measurements and calculations based on what they observe far away (and hence long ago.) If it is the latter, then they should be saying what the universe consisted of. Regards, TAR

Klaynos, Thanks for the response. I think I have not, before, but do now, understand the role of expansion in imagining what is and has gone on in the universe. It has to be happening at a really rapid pace, though, to explain everything. Let me do some reading on expansion. Regards, TAR Merged post follows: Consecutive posts mergedDid a little reading. At 13km/s/Mpc, I suppose those far away objects that we are finding are receeding at what my rudimentary math, would put at about 1/2 the speed of light. But what sticks in my craw still is the fact that long ago, those objects were much closer to our location in space. Logic would suggest that object a can not be seen by object c because the expanse of space, now, is wider than light can travel in the time it has had to travel anywhere since the beginning of the universe. But, if we are talking about the objects a and c, that we are measuring, now, 13 billion years after the start of the universe, at 10 billion light years distance from us respectively, we are really talking about the image of a and c, when they were 3 billion years old. Now, if it took the light from 3 billion year old c, 10 billion years to arrive at our (b) location, it is going to take more that 10 million years more, to cover the distance from b to a across an already daunting and expanding distance. So I have no problem accepting that the light from 3 billion year old c, will never reach a's location in expanding space. However, this does not suggest that the light from location a never has, and never will, reach location c. The light from a 1 billion year old "location a" left "location a" when a-b-c where much closer together, and has had 12 billion years to make the trek to location c. Although I have not done the calculus, my intuition suggests that the light from 1 billion year old location a has already had the time to reach location c. How old location c was, is or will be, when the light from 1 billion year old location a reaches it, even if it is in the form of "background radiation", rather than an identifiable object, is not as important as DOES it. If it does, then I would guess that every location in space has a view of every other location in space, even if the view is of the location at a very very young age. Regards, TAR

Just can't make sense of it. If we can look in one direction, and see an object 10 billion light years away, and look in the opposite direction and see an object 10 billion light years away, that would suggest a universe that was at the very least, 20 billion light years wide, 10 billion years ago. The universe has continued to expand in the mean time, and those two objects are even more distant from each other now. Merged post follows: Consecutive posts mergedNeglected to type the implied question. If the universe is 15 billion years old, the two objects only had 5 billion years to get separated by 20 billion lightyear's distance, which means they were separated at a rate much greater than the speed of light. (twice the speed?). Isn't this impossible? And if we would discover an object 11billion lightyears away, and look in the opposite direction with the same technology and discover a similar object 11billion light years away, that would put those two objects, each at an age of 4 billion years, with a separation of 22 billion lightyears. Hypothetical 12 billion lightyear distant objects, 3 billion years old separated by 24 billion lightyears, 2billion year olds by 26 billion lightyears, 1byearolds by 28bly, and so on, till we find the earliest things we can see, at the GREATEST distance of separation. Doesn't this imply that the universe was BIGGER when it was younger? Where am I going wrong?