my brain hurts Posted December 31, 2005 Report Share Posted December 31, 2005 What is the maximum distance between any two points in the universe. Would it be twice the age of the universe in light years, or otherwise? Please give your answer and a brief explaination as to why, and I will present an interesting point. Thanks. Quote Link to comment Share on other sites More sharing options...
virtualmeet Posted December 31, 2005 Report Share Posted December 31, 2005 Hi,What do you mean with "the maximum distance" ? we can only compute the "minimum" distance between two points...there is no defined "maximum" distance between two points...-----Ok..I got it. if you consider our universe as a sphere (linear propagation of matter in all direction), then the distance might be easy to compute...if you know were is the center of this sphere...I have to think about it more in deph Quote Link to comment Share on other sites More sharing options...
Turtle Posted December 31, 2005 Report Share Posted December 31, 2005 What is the maximum distance between any two points in the universe. Would it be twice the age of the universe in light years, or otherwise? Please give your answer and a brief explaination as to why, and I will present an interesting point. Thanks. ___The Universe is Fractal, that is, the Universe has a fractional dimension, therefore there is no maximum distance any more than a maximum distance on a Fractal Shoreline or a Koch Snowflake. The smaller the measure one takes, the longer the path grows. ___ Relativity is Fractal; it's all in how you hold your mouth.:xparty: Quote Link to comment Share on other sites More sharing options...
Tormod Posted December 31, 2005 Report Share Posted December 31, 2005 What is the maximum distance between any two points in the universe. Would it be twice the age of the universe in light years, or otherwise? If there is a maximum distance between any point in the universe I would argue that they would be separated in time and not in space: from the birth to the death of the universe. Otherwise I think there cannot be a maximum spatial distance as I don't know whether the universe has a finite expanse or not. Quote Link to comment Share on other sites More sharing options...
TheBigDog Posted January 1, 2006 Report Share Posted January 1, 2006 1 My unit of measure is Universe. The maximum distance across (edge to edge) is one. Bill Quote Link to comment Share on other sites More sharing options...
geokker Posted January 1, 2006 Report Share Posted January 1, 2006 I thought currently it is believed to be in the 28 billion light year area. Quote Link to comment Share on other sites More sharing options...
C1ay Posted January 1, 2006 Report Share Posted January 1, 2006 What is the maximum distance between any two points in the universe. Would it be twice the age of the universe in light years, or otherwise?Infinity. Between any two points we can enumerate infinitely many points..... Quote Link to comment Share on other sites More sharing options...
Boerseun Posted January 2, 2006 Report Share Posted January 2, 2006 I'd reckon infinity. Everyone lives in a slightly different universe, because we're not all occupying the same space. My personal universe is a few thousands of a light-second bigger in one direction than yours, whilst yours is a few thousands of a light-second bigger in the other direction than mine - and simply because you're on the other side of the world. Now if we were to construct a tube with the Earth as a starting point, and we eventually get to Sirius, would we be 8 light years closer to the edge of the universe? Nope. The edge will still be exactly where it was. If we build this tube for ten billion light-years, the edge will still be exactly the same distance off - although by now we're so far from Earth that we can well and truly say we are in a different universe than Earth - although our universe overlap for a bit with Earth's universe, what we can see on the far side is not accessable to Earth at all (yet). So, as you keep on building, you will never reach the end of your personal universe. You can built it to infinity. But for an observer on Earth, the tube can only be as big (the farthest point) as the section that intersects Earth's personal universe. So I suppose the question is rather what's the dimension of every personal universe? From an observational viewpoint, I guess 28 to 30 billion light-years side-to-side is about it.From my personal point of view, and keeping my interaction with the universe in mind, my personal universe is also about 28-30 billion light-years big, slightly off-set from yours. But as far as the universe is concerned, I'm living in a bubble with a radius of about 30 light years. Beyond that, the universe is simply not aware of my existence. This bubble is expanding, though - with one light-year added every year. Boy in a bubble, Boerseun Jay-qu 1 Quote Link to comment Share on other sites More sharing options...
TheBigDog Posted January 2, 2006 Report Share Posted January 2, 2006 Boerseun, if I had enough hair I would grow it into a mullet in honor of that answer. That is why I love this site. Bill Quote Link to comment Share on other sites More sharing options...
virtualmeet Posted January 2, 2006 Report Share Posted January 2, 2006 If there is a maximum distance between any point in the universe I would argue that they would be separated in time and not in space.It's also my conclusion...this distance depend on time. Trying to define a maximum "Distance" is like to define a maximum "Time " From my personal point of view, and keeping my interaction with the universe in mind, my personal universe is also about 28-30 billion light-years big, slightly off-set from yours. But as far as the universe is concerned, I'm living in a bubble with a radius of about 30 light years. Beyond that, the universe is simply not aware of my existence. This bubble is expanding, though - with one light-year added every year.Beautiful picture here :xparty: ...but...how about the power of humain thinking? is it also limited to this buble ? I think that "thinking" has something common with "Time" and the fourth dimension : It's the only way to get through our personal "buble" and thus, our only way to explore the entire universe. Quote Link to comment Share on other sites More sharing options...
kamil Posted January 3, 2006 Report Share Posted January 3, 2006 If you assume the Universe to have expanded in all directions from a single point ever since the big bang, then the maximum distance between two points would be expansion of universe per time*age of universe*2=maximum distance But what if you could and were to move at the speed of light, wouldnt you see one end of the Universe right next to the other:eek_big: ?? Quote Link to comment Share on other sites More sharing options...
Tormod Posted January 3, 2006 Report Share Posted January 3, 2006 If you assume the Universe to have expanded in all directions from a single point ever since the big bang, then the maximum distance between two points would be expansion of universe per time*age of universe*2=maximum distance Your equation assumes an equal expansion over time, and also equal expansion in all directions. We have no evidence (AFAIK) for this. Also keep in mind that according to the Big Bang model there were nothing present at the moment of the Big Bang. So when do we start figuring that there are objects or anything from which to measure distance? But what if you could and were to move at the speed of light, wouldnt you see one end of the Universe right next to the other:eek_big: ?? I don't understand this reasoning. Still, this question assumes that the universe has physical ends. I don't think we have any reason to think that it has, either. Quote Link to comment Share on other sites More sharing options...
lindagarrette Posted January 3, 2006 Report Share Posted January 3, 2006 For descriptive purposes, does it help to imagine the universe as the outside perimeter of a porous balloon? Maybe a flawed balloon made up of material that's not uniformly elastic. It will keep stretching out until there is nothing left to hold it together. Turtle 1 Quote Link to comment Share on other sites More sharing options...
virtualmeet Posted January 3, 2006 Report Share Posted January 3, 2006 For descriptive purposes, does it help to imagine the universe as the outside perimeter of a porous balloon? Maybe a flawed balloon made up of material that's not uniformly elastic. It will keep stretching out until there is nothing left to hold it together.The problem is that the porosity of this ballon may contain something that we call "vacuum space" but outside this ballon, and in accordance with the BigBang theory, there is "nothing" wich is really different compared to the "vacuum space"... Quote Link to comment Share on other sites More sharing options...
my brain hurts Posted January 4, 2006 Author Report Share Posted January 4, 2006 Let me rephrase this. I'm not looking for a philosophic answer, rather some simple math. It doesn't matter if the universe is infinite, or fractal, or whatever. In terms of simple three-dimensional space (note I didn't say spacetime), what would be the maximum distance between any two particles? If the universe (more correctly, space) sprang into being one minute ago, with particles receeding from each other at the speed of light, would the maximum physical distance between any two of those particles (the ones diametrically opposed to each other) be two light minutes? It should not matter where the center point is. What I'm questioning is whether we have any agreement on a few things-The shape of the universe. Is it shperical?Has the speed of light always been constant, or has there been a time of inflation? Now space may well be infinite, but how could any particles get "out there" beyond twice the age of the universe in light years without violating relativity? If particle "a" goes one direction for 15 billion years at the speed of light, and particle "b" goes in the opposite direction for the same period, would not the maximum distance betwen those points be 30 billion light years? Please chime in. Quote Link to comment Share on other sites More sharing options...
kamil Posted January 4, 2006 Report Share Posted January 4, 2006 Your equation assumes an equal expansion over time, and also equal expansion in all directions. We have no evidence (AFAIK) for this. Thats why I said 'If you assume'. Quote:But what if you could and were to move at the speed of light, wouldnt you see one end of the Universe right next to the other ?? I don't understand this reasoning. Still, this question assumes that the universe has physical ends. I don't think we have any reason to think that it has, either. Length Conrtaction. So the dimension that you are moving across will have length zero, therefore one end of the Universe next to the other. (If you assume the Universe is finite in space) Quote Link to comment Share on other sites More sharing options...
my brain hurts Posted January 4, 2006 Author Report Share Posted January 4, 2006 Hmmm. I haven't exactly received the sort of response I thought I would get here, so here goes. If the universe sprang into being from a singularity, with particles (whatever they may be) hurtling away from each other at no greater than the speed of light, after one year the furthest a particle could be from the point of origin would be one light year. Okay so far? The farthest particle from this location would be one that travelled from the origin one light year in a diametrically opposed direction, and the resulting distance between them would be two light years. Feel free to pick these points apart at any time. In the aforementioned scenario, with the universe one year old, no two things should be more than two light years apart without violating relativity (with that nasty restriction of the speed of light being a constant). Let's fast forward to today. For the sake of argument (NB- literally means don't argue, for, as we'll see, the exact numbers don't matter), let's assume that the universe is 15 billion years old. Nothing could have travelled more than 15 billion light years from the origin, and no two things could be separated by a distance greater than 30 billion light years. At this point we must diverge into two groups- those who agree up to this point, and those who do not. If you don't agree, please explain why it is otherwise. If, however, you agree, please consider the following. None of my physics professors has ever been able to explain this to me. An astronomer claims to have detected a galaxy two billion light years away. Two billion years ago, the universe was 13 billion (15-2) years old. The maximum distance between any two things would have been 26 billion light years, so no problem. Another astronomer detects a galaxy six billion light years distant. Again, no problem- six billion years ago the universe was nine billion (15-6) years old, and things could have been 18 billion light years apart. See where this is going? A third astronomer claims to have found a quasar that is 12 billion light years away. This I have a problem with. The light from this object would have started to head our way 12 billion years ago. At that time the universe was only three billion years old. If the preceeding logic holds, no two things could have been more than six billion light years apart at that time. How did this object manage to be so far from us at so early a period of the universe's life? If no two things were more that six billion light years apart (when the universe was a mere three billion years old), why has it taken the light from that object twelve billion years to reach us? Generally speaking, and without the need to lift a pencil, it should be clear that this problem would apply to any object claimed to be at a distance greater than 2/3's of the universe's age in light years. If the universe is 18 billion years old, how can one "see back" more than twelve billion years?(If the universe is 18 billion years old, 12 billion years ago it was a strapping lad of six billion years, and nothing could have been more than twelve billion light years apart. If it is 30 billion years old, 20 billion years ago it was a mere 10 billion years old, and nothing could be more than twenty billion light years apart.) If the universe is 15 billion years old, how can we see objects more that 10 billion light years away? No matter how I play with the numbers, I can't seem to get past this two-thirds limit. Fire away. Please! Quote Link to comment Share on other sites More sharing options...
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