- #1
rtharbaugh1
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Lord High Astronomer Somebody Rees was pontificating on NPR yesterday about the manned trip to Mars, and he said he thought someone would go, in about thirty years from now, but they shouldn't expect to be able to come back. I was confused by this. Why would anyone go to Mars if they could not reasonably expect to come back? I doubt if I will get a satisfactory answer, since by the time thirty years has gone, Lord Rees and I will both likely be mouldering.
I suppose Lord Rees was thinking of the dangers of the trip, since the logistics are not impossible. Six months there and six months back. It doesn't seem unreasonable. And I suppose someone would be willing to take it as a one way trip. I, for one, would probably volunteer for a manned flight to Jupitor, just for the chance to contemplate the great red eye up close, even if the right of return were not gauranteed.
But, our intrepid captain of the infinity drive has a different question. If I get on a ship and accellerate to infinity and beyond (shades of Buzz Lightyear!) can I ever expect to return? It seems from my understanding that the captain of such a voyage would be privaleged to watch Earth recede to the Planck limit and the end of time. His view of the shape of the space he was entering and leaving is the point of my question. Presumably, he might be able to accellerate to light speed relitive to Earth, but what would he see of Earth just before crossing the limit? And, looking in the other direction, what would he see of the Quasar?
I suppose I should break my long standing habit of innumeracy and try to do a calculation. Let's see, if I accellerate at one G, how long will it take me to reach c? Oh. Yeah. And if I have been accellerating at one G for, let's say four and a half billion years or so, how fast am I going now? Oh my.
Now if my measuring stick is any good at all, where, exactly, is that quasar? Let's say that quasar is a large hot object in some fixed direction but at some unknown (large) distance. I accellerate to Earth-light speed and beyond, abandon all hope of return, and continue on until I reach the vicinity where mission command said I should find a large hot object. Do I indeed find a large hot object there?
But my speed has changed a lot since I left earth. My stick (do I understand Lorenz contraction correctly?) has changed. Not that I would notice it shrinking in my hand, but what if I use it to try to measure the large hot object, which by now I should be close to? Is it still large? Or, with my shrinking stick, has it now grown much, much larger? And is it still hot? Or has my tiny stick shrunk so far that even heat is stretched out and cooled down?
I wonder if I am correct in thinking that when I get to the vicinity of the quasar, I will find that it has already grown up into a galaxy of its own? Perhaps if I pick the furthest quasar, by the time I get there, even if it only takes six months ship time, it will be the size of an entire universe.
I sense that this is a sort of extension of the HUP to cosmological scales. If I know how energetic an object like a quasar is, I can then not say with any clarity of meaning how far away it is. Let's say we estimate that it is ten billion light years. I accellerate to the speed of light. Ten billion years passes on Earth. But I am going so fast that I do not age at all. I get to the vicinity of the quasar in some reasonable time, maybe six months, since that is a figure with some currency. Of course that is six months ships time, ten billion years and some Earth time. How much older is the quasar than it was before I left? Ummmm. Now I turn around and accellerate back to where my positioning calculator says Earth should be. Is Earth there any more? Perhaps twenty billion years have passed for earth. I have aged a year and some. Oh dear. Everyone I knew has passed back into stardust.
Now I am going into bannishment theory development, here. But see, if the infinite drive has taken me to the furthest quasar in six months ship time, how much longer would it take to get me clear to the end of the universe? Hemm. Haww. Harumph. Well. It appears if i go to the end of the universe, there just isn't any there, there. (I know I have heard that quote recently but can't place who said it?)
Now this is really getting into strange fictions. But given an infinite number of tries, does not any possible combination have to occur? If I go far enough, long enough, does not every possible combination have to occur not once, but an infinite number of times? Might I not find another chance Earth in such an infinity of possibilities? And if I do find such a place, how will I know if it is just a copy, or if it is the original? Does the question even have any meaning? If I could find an Earth which was just like the day before I left, could I arrive there in time to tell myself not to go? Shades of Douglas Adams! Remember the infinite probability drive? well, why not? But then, if why not, why has it not already happened?
Ok, ok, I'm ready for the white coats now. I'll go peacefully. A nice long rest in a wet sheet in a rubber room is probably exactly what I need.
Cheers to you, and thanks for being here.
Richard
I suppose Lord Rees was thinking of the dangers of the trip, since the logistics are not impossible. Six months there and six months back. It doesn't seem unreasonable. And I suppose someone would be willing to take it as a one way trip. I, for one, would probably volunteer for a manned flight to Jupitor, just for the chance to contemplate the great red eye up close, even if the right of return were not gauranteed.
But, our intrepid captain of the infinity drive has a different question. If I get on a ship and accellerate to infinity and beyond (shades of Buzz Lightyear!) can I ever expect to return? It seems from my understanding that the captain of such a voyage would be privaleged to watch Earth recede to the Planck limit and the end of time. His view of the shape of the space he was entering and leaving is the point of my question. Presumably, he might be able to accellerate to light speed relitive to Earth, but what would he see of Earth just before crossing the limit? And, looking in the other direction, what would he see of the Quasar?
I suppose I should break my long standing habit of innumeracy and try to do a calculation. Let's see, if I accellerate at one G, how long will it take me to reach c? Oh. Yeah. And if I have been accellerating at one G for, let's say four and a half billion years or so, how fast am I going now? Oh my.
Now if my measuring stick is any good at all, where, exactly, is that quasar? Let's say that quasar is a large hot object in some fixed direction but at some unknown (large) distance. I accellerate to Earth-light speed and beyond, abandon all hope of return, and continue on until I reach the vicinity where mission command said I should find a large hot object. Do I indeed find a large hot object there?
But my speed has changed a lot since I left earth. My stick (do I understand Lorenz contraction correctly?) has changed. Not that I would notice it shrinking in my hand, but what if I use it to try to measure the large hot object, which by now I should be close to? Is it still large? Or, with my shrinking stick, has it now grown much, much larger? And is it still hot? Or has my tiny stick shrunk so far that even heat is stretched out and cooled down?
I wonder if I am correct in thinking that when I get to the vicinity of the quasar, I will find that it has already grown up into a galaxy of its own? Perhaps if I pick the furthest quasar, by the time I get there, even if it only takes six months ship time, it will be the size of an entire universe.
I sense that this is a sort of extension of the HUP to cosmological scales. If I know how energetic an object like a quasar is, I can then not say with any clarity of meaning how far away it is. Let's say we estimate that it is ten billion light years. I accellerate to the speed of light. Ten billion years passes on Earth. But I am going so fast that I do not age at all. I get to the vicinity of the quasar in some reasonable time, maybe six months, since that is a figure with some currency. Of course that is six months ships time, ten billion years and some Earth time. How much older is the quasar than it was before I left? Ummmm. Now I turn around and accellerate back to where my positioning calculator says Earth should be. Is Earth there any more? Perhaps twenty billion years have passed for earth. I have aged a year and some. Oh dear. Everyone I knew has passed back into stardust.
Now I am going into bannishment theory development, here. But see, if the infinite drive has taken me to the furthest quasar in six months ship time, how much longer would it take to get me clear to the end of the universe? Hemm. Haww. Harumph. Well. It appears if i go to the end of the universe, there just isn't any there, there. (I know I have heard that quote recently but can't place who said it?)
Now this is really getting into strange fictions. But given an infinite number of tries, does not any possible combination have to occur? If I go far enough, long enough, does not every possible combination have to occur not once, but an infinite number of times? Might I not find another chance Earth in such an infinity of possibilities? And if I do find such a place, how will I know if it is just a copy, or if it is the original? Does the question even have any meaning? If I could find an Earth which was just like the day before I left, could I arrive there in time to tell myself not to go? Shades of Douglas Adams! Remember the infinite probability drive? well, why not? But then, if why not, why has it not already happened?
Ok, ok, I'm ready for the white coats now. I'll go peacefully. A nice long rest in a wet sheet in a rubber room is probably exactly what I need.
Cheers to you, and thanks for being here.
Richard