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#11
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In message , Lou
writes CeeBee wrote: "Grunt" wrote in alt.astronomy: Not much, The current constellations would be unrecognizable. It doesn't take millions of years for constellations to change. Some tens of thousands of years will distort the constellation due to the movement of the individual stars. None of the current constellations was present in its current form 7 million years ago. but you could see them better. No doubt. The night sky was very similar to the sky of today. And the constellations were the same. The only change was with the procession of the earth's axis. The wobble on it's axis. Real astronomers have figured this and have created programs that can show the sky at any given date. Past or future. Lou Utter nonsense. As I've already said, the proper motion of the other stars, not to mention our own sun, will distort the constellations beyond recognition. Real astronomers are well aware of this, and most predictions aren't valid for more than a few thousand years past and future. 7,000,000 million years is about 1/30 of a galactic year, the time our sun takes to go round the galaxy. In fact I wonder if precession (note spelling) will be the same as it is now. There are other cycles in the Earth's motion. Top posting corrected. -- Rabbit arithmetic - 1 plus 1 equals 10 Remove spam and invalid from address to reply. |
#12
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I'm not a real astronomer. Nor am I even an amateur. I came to this
group to find some help in setting up an observatory and purchasing a high quality scope. Never thinking that the egos of people would be strong enough to override the natural desire help others out. A little knowledge of engineering (which does make people dangerous) and and some common sense led me to the conclusion that the writing that I have seen on the subject might be correct. The precession of the earth's axis is a fact, I know this from the my engineering background and because I am a pilot and must take into consideration the changes in magnetic declination. The big bang theory if correct means that all things are separating at the same rate (so they wouldn't change but maybe grow over time.). Now the tricky part is where the bang took place, this could slew the separation slightly. And possibly the galaxy might have a spin to it that I don't understand as being equal to all stars. What did I miss? If there are other factors, let me know. No digs are necessary. Lou |
#14
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Lou wrote in alt.astronomy:
I'm not a real astronomer. Nor am I even an amateur. I came to this group to find some help in setting up an observatory and purchasing a high quality scope. Never thinking that the egos of people would be strong enough to override the natural desire help others out. Relax. That's not the case. Maybe you should just refrain from statements that "real astronomers have". It a. indicates that you have inside knowledge, which you now claim not to have, and b. people who just gave other answers here are dopeys, as opposed to "real astronomers". A little knowledge of engineering (which does make people dangerous) and and some common sense led me to the conclusion that the writing that I have seen on the subject might be correct. No big deal, it might be correct, but it isn't. The precession of the earth's axis is a fact, I know this from the my engineering background and because I am a pilot and must take into consideration the changes in magnetic declination. The precession of the Earth has nothing to do with the constellations. Constellations are imaginary 2D images against the imaginary background of the night sky. That background shifts as a whole due to precession, not in detail. The proper motion of the stars is not related to precession of the Earth axis. The big bang theory if correct means that all things are separating at the same rate (so they wouldn't change but maybe grow over time.). No, this is not correct. The Big Bang Theory theorizes that the universe as a whole is expanding, but this tells nothing about gravitational bound systems on the scale of groups of galaxies. Now the tricky part is where the bang took place, The Big Bang didn't "took place" somewhere inside the universe. The Big Bang contained the whole universe from moment 0 - or better: the Big Bang is an expansion of the space/time, the universe itself. There is no point where it happened. this could slew the separation slightly. And possibly the galaxy might have a spin to it that I don't understand as being equal to all stars. What did I miss? If there are other factors, let me know. No digs are necessary. As indicated by others, the proper motion of stars itself relative to our Sun, responsible for changing the constellations. All stars you see and are part of constellations are stars relatively close to our own Sun. As said above: in tightly gravitational bound systems like groups of galaxies, let alone groups of nearby stars, objects don't run from each other due to expansion of space itself. -- CeeBee "I am not a crook" |
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"Ugo" wrote in alt.astronomy:
So you say. Prove it. :-))) Ah - but you accuse, while I deny.. -- CeeBee "I am not a crook" |
#16
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On Mon, 05 Jan 2004 23:22:57 GMT, Lou wrote:
The night sky was very similar to the sky of today. And the constellations were the same. The only change was with the procession of the earth's axis. The wobble on it's axis. Real astronomers have figured this and have created programs that can show the sky at any given date. Past or future. Cool, which public available program would you reccomend I buy? CeeBee wrote: "Grunt" wrote in alt.astronomy: Not much, The current constellations would be unrecognizable. It doesn't take millions of years for constellations to change. Some tens of thousands of years will distort the constellation due to the movement of the individual stars. None of the current constellations was present in its current form 7 million years ago. but you could see them better. No doubt. |
#17
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Too many votes for a drastic change in star patterns. I stand humbly
corrected. One thing I still do not understand is the movement of stars. I was under the impression that the only movement of the stars were the separation due to the big bang. Are they traveling at different speeds? What's causing the movement? Lou Christopher wrote: On Mon, 05 Jan 2004 23:22:57 GMT, Lou wrote: The night sky was very similar to the sky of today. And the constellations were the same. The only change was with the procession of the earth's axis. The wobble on it's axis. Real astronomers have figured this and have created programs that can show the sky at any given date. Past or future. Cool, which public available program would you reccomend I buy? CeeBee wrote: "Grunt" wrote in alt.astronomy: Not much, The current constellations would be unrecognizable. It doesn't take millions of years for constellations to change. Some tens of thousands of years will distort the constellation due to the movement of the individual stars. None of the current constellations was present in its current form 7 million years ago. but you could see them better. No doubt. |
#18
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Lou wrote:
Too many votes for a drastic change in star patterns. I stand humbly corrected. One thing I still do not understand is the movement of stars. I was under the impression that the only movement of the stars were the separation due to the big bang. Are they traveling at different speeds? What's causing the movement? Lou The stars we see with our naked eye are those in our galaxy. Just like the planets orbit the Sun, the stars orbit around the galactic center, each star has its own direction and velocity. They are not static at all. If they were, they would have all fallen to the galactic center a long time ago. -- The butler did it. |
#19
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In message , Lou
writes Too many votes for a drastic change in star patterns. I stand humbly corrected. One thing I still do not understand is the movement of stars. I was under the impression that the only movement of the stars were the separation due to the big bang. Are they traveling at different speeds? What's causing the movement? Just random motions within our galaxy, mostly. There's also the fact that most stars probably start in clusters which then break up, so you get stars which start in roughly circular orbits and then start travelling across the galaxy. Add to that, slingshot effects (like Voyager's grand tour) in multiple star systems and the fact that all the stars are going around the galactic centre. The only speed I can quote easily is for our sun, which is moving at 12 miles per second in the approximate direction of Vega ("the apex of the Sun's way") Coincidentally, Andrew Yee has just posted an article in sci.astro "Young Star Caught Speeding" about the star PVCeph, which is now 30 light years from the cluster NGC7023. http://cfa-www.harvard.edu/~agoodman/Presentations/aas04PVCeph/ -- Rabbit arithmetic - 1 plus 1 equals 10 Remove spam and invalid from address to reply. |
#20
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On Wed, 7 Jan 2004 01:14:48 +0100, "Ugo"
wrote: Lou wrote: Too many votes for a drastic change in star patterns. I stand humbly corrected. One thing I still do not understand is the movement of stars. I was under the impression that the only movement of the stars were the separation due to the big bang. Are they traveling at different speeds? What's causing the movement? Lou The stars we see with our naked eye are those in our galaxy. Just like the planets orbit the Sun, the stars orbit around the galactic center, each star has its own direction and velocity. They are not static at all. If they were, they would have all fallen to the galactic center a long time ago. Take our sun for instance. It not only orbits the core, but moves up and down through the galactic plane. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
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