Alpha Centauri Explorer II

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vidargander

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That's it. Gimme a "P"....errr "U" <br />Posted by MeteorWayne</DIV></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><span style="font-size:9pt;color:#404040;font-family:Verdana">That is as clear as the icon's message:</span></p><span style="font-size:9pt;color:#404040;font-family:Verdana"><font size="1">The rusted chains of prison moons<br />Are shattered by the sun.<br />I walk a road, horizons change<br />The tournament's begun.<br />The purple piper plays his tune,<br />The choir softly sing;<br />Three lullabies in an ancient tongue,<br />For the court of the crimson king.<br /><br />The keeper of the city keys<br />Put shutters on the dreams.<br />I wait outside the pilgrim's door<br />With insufficient schemes.<br />The black queen chants<br />the funeral march,<br />The cracked brass bells will ring;<br />To summon back the fire witch<br />To the court of the crimson king.<br /><br />The gardener plants an evergreen<br />Whilst trampling on a flower.<br />I chase the wind of a prism ship<br />To taste the sweet and sour.<br />The pattern juggler lifts his hand;<br />The orchestra begin.<br />As slowly turns the grinding wheel<br />In the court of the crimson king.<br /><br />On soft grey mornings widows cry,<br />The wise men share a joke;<br />I run to grasp divining signs<br />To satisfy the hoax.<br />The yellow jester does not play<br />But gently pulls the strings<br />And smiles as the puppets dance<br />In the court of the crimson king.</font></span> <p><br /><br />&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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duke_the_nuke

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Multiple laser beam continual acquisitions on such a small target at those distances is highly problematic, earth's axial rotation, orbital motion, weather...just to name a few issues, can't really see it happening. For example as the earth rotates you would need multiple laser sites to come on line and acquire as the previous one rotated out of sight, and how do you acquire such a pinpoint at say 1 lightyear out, and adjust so thet it hits the target where it will be 1 year from now, over and over again? Not possible imo. <div class="Discussion_UserSignature"> </div>
 
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mithridates

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>"Project Longshot? Got any links to that one. I don't think I've ever heard of it...how'd I miss that one?"It was a study by the U.S. Naval Academy that essentially built on the idea of Project Daedalus, but it was designed to orbit Alpha Centauri A after a 100 year journey.http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890007533_1989007533.pdfOn the topic of the Partial Ban Test Treaty, it bans nuclear explosions in space.&nbsp; I'm pretty sure there is another treaty that bans the stationing of nuclear weapons in space (such as an orbital nuclear platform).&nbsp; Nothing bans nuclear reactions such a would be used in "confined" nuclear propulsion systems (salt water, gas core, etc.).&nbsp; They'd have to go take care of the Sun if that were the case, and all the stars! :p&nbsp;"Anyway, it&rsquo;s as simple as hammering on the front of a vessel, - it will eventually move forward, - no matter what physical laws says."No, that would not work.&nbsp; Everytime you swung your arm back the ship would move back.&nbsp; Conservation of momentum is a well-proven law.&nbsp; I suggest you wiki "Reactionless propulsion" to find an explanation of why "hammering on the front of the vessel" wouldn't work.&nbsp; <br /> Posted by baulten</DIV></p><p>After looking at the pdf there I decided that it needed to be typed up so I redid it (took a week):</p><p>http://mithridates.blogspot.com/2008/06/project-longshot-unmanned-interstellar.html</p><p>http://www.scribd.com/doc/3502229/Project-Longshot</p><p>I was about to start a new thread on the subject but then I noticed that this thread hasn't dropped down yet.</p><p>BTW, it might have been mentioned in the thread already but Project Longshot was to go around Alpha Centauri B, not A, as they thought it would be more interesting considering A's similarity to the sun, a star we already know well.</p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>
 
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mithridates

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<p>Oh, and one more question about parallax that I just remembered. One part of the paper talked about the advancement of astrometry as one of the most exciting parts of the project, being able to more accurately measure the distance to distant stars. It talked about only being able to use the Earth's orbit as a comparison to judge the distance to stars but that after a 20 parsecs the accuracy goes way down:</p><p style="margin-bottom:0in" align="left">"Perhaps the greatest contribution that the mission will make to the scientific community will be in the field of astrometry. Sending a spacecraft to the Alpha Centauri system provides an opportunity to make parallax measurements with a baseline of 4.34 light years (see Fig 2.1a). This is over 63,000 times longer than the present method, which uses the semi-major axis of the Earth's orbit as a baseline (see Fig 2.1b). At this time, parallax measurements are only accurate to about 20 parsecs from the Sun. The longer baseline would allow accurate measurements of stellar distances of more than 1.2 million parsecs. If the probe lasts long enough, it has the potential to accurately determine the distance to hundreds of trillions of stars. Knowing the distance to a star is vital in determining its properties. Such an accomplishment would keep astronomers busy for quite some time."</p><p style="margin-bottom:0in" align="left">However, probes like Deep Space 1 (now EPOXI) also provide the same information, do they not?</p><p style="margin-bottom:0in" align="left">http://en.wikipedia.org/wiki/EPOXI </p><p style="margin-bottom:0in" align="left">How much more accurate information do we have now compared to 1988 and would getting a longer baseline for astrometry still be a valid argument to make for proposing the project? </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>
 
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MeteorWayne

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Knowing the distance to a star is vital in determining its properties. Such an accomplishment would keep astronomers busy for quite some time."However, probes like Deep Space 1 (now EPOXI) also provide the same information, do they not?http://en.wikipedia.org/wiki/EPOXI How much more accurate information do we have now compared to 1988 and would getting a longer baseline for astrometry still be a valid argument to make for proposing the project? <br />Posted by mithridates</DIV><br /><br />Not even close. Even&nbsp;the furthest spacecraft&nbsp;from earthc(Voyager 2) is only 100 AU away. That's about 0.0016 Light year. 4.4 light years is a bit longer of a baseline... <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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mithridates

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not even close. Even&nbsp;the furthest spacecraft&nbsp;from earthc(Voyager 2) is only 100 AU away. That's about 0.0016 Light year. 4.4 light years is a bit longer of a baseline... <br /> Posted by MeteorWayne</DIV></p><p>Yes, but we surely could get a somewhat longer baseline today, could we not? Voyager 2 is going one way, Voyager 1 another, other probes go in their own directions and the Earth meanwhile rotates around the sun, or is even all this put together still woefully inaccurate? Also is there no other way to improve parallax than simply obtaining a really long baseline? Aren't general improvements in accuracy in observation helpful as well without having to go to the next solar system?</p><p>The reason I'm wondering is because I can imagine someone in charge of actually funding the mission just kind of shrugging at using improved parallax as a reason to send a probe. A mission to Alpha Centauri, sure; improved astrometry, perhaps not so exciting to the average taxpayer. </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>
 
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vidargander

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not even close. Even&nbsp;the furthest spacecraft&nbsp;from earthc(Voyager 2) is only 100 AU away. That's about 0.0016 Light year. 4.4 light years is a bit longer of a baseline... <br /><font size="2">Posted by MeteorWayne</DIV></font></p><p style="margin:0cm0cm0pt" class="MsoNormal"><span><font face="Times New Roman"><font size="2">You know I hate to correct you MeteorWayne <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-wink.gif" border="0" alt="Wink" title="Wink" />&nbsp;</font></font></span></p><span><font face="Times New Roman"><font size="2">However, in time with some luck, it&rsquo;s possible to encounter Alpha Centaury C that happens to periodically be 0.21 ly (13000 AU) closer to us than the twins.</font></font></span><span><font face="Times New Roman" size="2">&nbsp;</font></span><span><font face="Times New Roman"><font size="2">Anyway, 100 AU distance for Voyager 2? That&rsquo;s pass the Kuiper belt! </font></font></span><p style="margin:0cm0cm0pt" class="MsoNormal"><span><font face="Times New Roman" size="2">How did it make it? Do we know something about its state and its surroundings on the path?</font></span></p> <div class="Discussion_UserSignature"> </div>
 
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vidargander

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The reason I'm wondering is because I can imagine someone in charge of actually funding the mission just kind of shrugging at using improved parallax as a reason to send a probe. A mission to Alpha Centauri, sure; improved astrometry, perhaps not so exciting to the average taxpayer. <br />Posted by mithridates</DIV><br /><br /><p style="margin:0cm0cm0pt" class="MsoNormal"><span><font size="3"><font face="Times New Roman">Who will pay? </font></font></span></p><span><font size="3"><font face="Times New Roman">That&rsquo;s a good question.</font></font></span> <div class="Discussion_UserSignature"> </div>
 
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MeteorWayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You know I hate to correct you MeteorWayne &nbsp;However, in time with some luck, it&rsquo;s possible to encounter Alpha Centaury C that happens to periodically be 0.21 ly (13000 AU) closer to us than the twins.&nbsp;Anyway, 100 AU distance for Voyager 2? That&rsquo;s pass the Kuiper belt! How did it make it? Do we know something about its state and its surroundings on the path? <br />Posted by vidargander</DIV><br /><br />I only posted general numbers, it's not significant at all looking at the big picture of $+ light years vs 100 AU.</p><p>The current distance is about 265,000 AU.</p><p>If you want to wait 27,000 years, the alpha Centauri AB system will be only 3.26 light years away, but I don't find that relevant to any current missions.</p><p>Suggest you do a search on Voyager 2. Have you ever heard of it?</p><p>Oh what the heck, I'll save you the time...</p><p>http://voyager.jpl.nasa.gov/mission/mission.html</p><p>http://en.wikipedia.org/wiki/Voyager_program</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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MeteorWayne

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Yes, but we surely could get a somewhat longer baseline today, could we not? Voyager 2 is going one way, Voyager 1 another, other probes go in their own directions and the Earth meanwhile rotates around the sun, or is even all this put together still woefully inaccurate? Also is there no other way to improve parallax than simply obtaining a really long baseline? Aren't general improvements in accuracy in observation helpful as well without having to go to the next solar system?The reason I'm wondering is because I can imagine someone in charge of actually funding the mission just kind of shrugging at using improved parallax as a reason to send a probe. A mission to Alpha Centauri, sure; improved astrometry, perhaps not so exciting to the average taxpayer. <br />Posted by mithridates</DIV><br /><br />Yes but both Voyagers are over 30 years old, and have enough power to run a transmitter, and enough to run one or two instruments intermittently, so they are no use for astrometry. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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mithridates

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Yes but both Voyagers are over 30 years old, and have enough power to run a transmitter, and enough to run one or two instruments intermittently, so they are no use for astrometry. <br /> Posted by MeteorWayne</DIV></p><p>I just meant as an example when debating over the possible benefits of a mission to Alpha Centauri, since precise distances to stars beyond 20 parsecs isn't really an attention-grabber, and by using current and upcoming missions somewhat deeper in the solar system it should be easy enough to get accurate parallax measurements of stars nearby us, the only ones that most people would be interested in. </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>
 
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vidargander

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I only posted general numbers, it's not significant at all looking at the big picture of $+ light years vs 100 AU.The current distance is about 265,000 AU.If you want to wait 27,000 years, the alpha Centauri AB system will be only 3.26 light years away, but I don't find that relevant to any current missions.Suggest you do a search on Voyager 2. Have you ever heard of it?Oh what the heck, I'll save you the time...http://voyager.jpl.nasa.gov/mission/mission.htmlhttp://en.wikipedia.org/wiki/Voyager_program <br />Posted by MeteorWayne</DIV><br /><br /><span style="font-size:12.5pt;line-height:115%;font-family:'Verdana','sans-serif'"><font size="2">Yes MeteorWayne, I would like to wait 27,000 years. But I can&rsquo;t figure out how, when I have lost my faith in that rather special relativity <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-smile.gif" border="0" alt="Smile" title="Smile" />.</font></span></p><p><span style="font-size:12.5pt;line-height:115%;font-family:'Verdana','sans-serif'"><font size="2">I first got interested in V&rsquo;ger after seeing the first Startrek movie. It&rsquo;s a good story that should be remade. I kind of had a &lsquo;lost-in-space&rsquo; impression about those probes. I did look into their status via Wikipedia. I think it&rsquo;s very fascinating that such a 30 years old probe still is functional and can be remotely controlled (What a frack-up with that heater though.)</font></span></p><p><span style="font-size:12.5pt;line-height:115%;font-family:'Verdana','sans-serif'"><font size="2">What I was thinking of when asking about the probes status and experience, is of cause due to the interest in finding some interstellar paths. Getting past the Kuiper is certainly overcoming a major barrier. </font></span></p><p><span style="font-size:12.5pt;line-height:115%;font-family:'Verdana','sans-serif'"><font size="2">I can&rsquo;t imagine that the Pioneers or Voyagers were meant for interstellar voyages (unless there was an unrealistic target to encounter Alpha Centauri C in 27 ky or so). They must have been made to explore our own solar system. When thinking about it, what was the plan for them and what have they discovered when passing the Kuiper belt.</font></span></p><p><span style="font-size:12.5pt;line-height:115%;font-family:'Verdana','sans-serif'"><font size="2">Getting back to the theme of the discussion, I can&rsquo;t figure out what is the best path from here to Alpha Centauri. Is it through the Kuiper belt, or is the direct path free of that risk?</font></span></p> <div class="Discussion_UserSignature"> </div>
 
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MeteorWayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I just meant as an example when debating over the possible benefits of a mission to Alpha Centauri, since precise distances to stars beyond 20 parsecs isn't really an attention-grabber, and by using current and upcoming missions somewhat deeper in the solar system it should be easy enough to get accurate parallax measurements of stars nearby us, the only ones that most people would be interested in. <br />Posted by mithridates</DIV><br /><br />OK, see what you were aiming at.</p><p>I still thing an alpha CEntauri mission is a looong way off.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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dryson

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<p>I will have to give Vid my support on this matter, Einstein although seemingly intelligent to all but himself has done nothing but take what has already been said and fancied it up with a drress and put flowers in it's mouth. </p><p>The laws of Earth Physics and the Laws of Space Physics are two totally different sciences. The real way to advance is to take your imagination and put it to work. If the your idea fails, try again until it works. I think it was Edison that said after failing 2000 times inveting the the lightbuld that he didn't fail 2000 times he only found 2000 ways to make the lightbuld not work.</p><p>&nbsp;If Einstein was right about everything and everything is relative then water would flow like a stream in space. But it doesn't water or any liquid globs in space. Explain that with E=M/C 2.</p><p>&nbsp;</p>
 
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scottb50

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The laws of Earth Physics and the Laws of Space Physics are two totally different sciences.... </p><p>No, Physics is Universal. The same properties are observed throughout the Universe, star formation and destruction have been observed and nothing suggests the same principles don't exist in every instance.&nbsp; </p><p> If Einstein was right about everything and everything is relative then water would flow like a stream in space. But it doesn't water or any liquid globs in space. Explain that with E=M/C 2.&nbsp; <br /> Posted by dryson</DIV></p><p>That has nothing to do with E+M/C2, it has to do with gravity and flow dynamics. In zero G pressure on water will make it flow just like it does here. You could easily have a faucet that would spew water just like it does in your bathroom. The problem is when no Gravity is there to hold the molecules of water together in the sink it would randomly float about once released. Similarly hydraulics work the same way in Space as they do on the ground, a pump produces pressure and moves the fluid.</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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vidargander

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I will have to give Vid my support on this matter, Einstein although seemingly intelligent to all but himself has done nothing but take what has already been said and fancied it up with a drress and put flowers in it's mouth. The laws of Earth Physics and the Laws of Space Physics are two totally different sciences. The real way to advance is to take your imagination and put it to work. If the your idea fails, try again until it works. I think it was Edison that said after failing 2000 times inveting the the lightbuld that he didn't fail 2000 times he only found 2000 ways to make the lightbuld not work.&nbsp;If Einstein was right about everything and everything is relative then water would flow like a stream in space. But it doesn't water or any liquid globs in space. Explain that with E=M/C 2.&nbsp; <br />Posted by dryson</DIV><br /><br /><span><font face="Times New Roman" size="2">There was a scientist Gottfried Wilhelm Leibniz during 1676-1689 that first introduced a form of kinetic energy, called vis viva, E=mv^2. Max velocity would give max Energy, namely E=mc^2. </font><font face="Times New Roman" size="2" color="#800080">http://en.wikipedia.org/wiki/Vis_viva</font></span><span><font face="Times New Roman" size="2">&nbsp;</font></span></p><p><span><font face="Times New Roman"><font size="2">In the early 20<sup>th</sup> century there was a race about&nbsp;figuring out what the factor could be, - if not Newton&rsquo;s: 0.5 or Leibniz&rsquo;s: 1.0. Proposed factors were: </font></font></span></p><ul><li><div class="MsoNormal" style="margin-top:0cm;margin-left:0cm;margin-right:0cm"><span><font face="Times New Roman"><font size="2">1900 Henri Poincar&eacute;:1.0 </font></font></span></div></li><li><div class="MsoNormal" style="margin-top:0cm;margin-left:0cm;margin-right:0cm"><span><font face="Times New Roman"><font size="2">1904 Friedrich Hasen&ouml;hrl: 3/8 </font></font></span></div></li><li><div class="MsoNormal" style="margin-top:0cm;margin-left:0cm;margin-right:0cm"><span><font face="Times New Roman"><font size="2">1904 Max Abraham: 3/4 </font></font></span></div></li><li><div class="MsoNormal" style="margin-top:0cm;margin-left:0cm;margin-right:0cm"><span><font face="Times New Roman"><font size="2">1905 Albert Einstein: 1.0 </font></font></span></div></li></ul><p><span><font face="Times New Roman" size="2">http://en.wikipedia.org/wiki/E%3Dmc#Electromagnetic_rest_mass</font></span><span><font face="Times New Roman" size="2">&nbsp;</font></span></p><p><span><font face="Times New Roman"><font size="2">I, at any rate, am convinced that mass&rsquo; total energy is not that simple.</font></font></span></p> <div class="Discussion_UserSignature"> </div>
 
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vidargander

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'><span style="font-size:7.5pt;font-family:Verdana">The reason I'm wondering is because I can imagine someone in charge of actually funding the mission just kind of shrugging at using improved parallax as a reason to send a probe. A mission to Alpha Centauri, sure; improved astrometry, perhaps not so exciting to the average taxpayer. <br /></span><span style="font-size:7.5pt;font-family:Verdana">Posted by mithridates</span></DIV></p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Who will pay? That&rsquo;s a good question. <br />Posted by vidargander</DIV></p><span><font face="Times New Roman"><font size="2">Quite interesting that nuclear pulse propulsion and chemical jet propulsion has the same payload cost - and that it&rsquo;s possible to build such nuclear pulse rocket with today&rsquo;s technology.&nbsp; </font></font></span><p style="margin:0cm0cm0pt" class="MsoNormal"><font face="Times New Roman" size="2">http://en.wikipedia.org/wiki/Interstellar_travel#Nuclear_pulse_propulsion</font></p><font face="Times New Roman" size="2">&nbsp;</font><span><font face="Times New Roman"><font size="2">Why not use nukes on the next rocket then? </font></font></span><span><font face="Times New Roman"><font size="2">It could were well explore our own solar system much more effectively.</font></font></span> <p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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MeteorWayne

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Quite interesting that nuclear pulse propulsion and chemical jet propulsion has the same payload cost - and that it&rsquo;s possible to build such nuclear pulse rocket with today&rsquo;s technology.&nbsp; http://en.wikipedia.org/wiki/Interstellar_travel#Nuclear_pulse_propulsionWhy not use nukes on the next rocket then? It could were well explore our own solar system much more effectively. &nbsp; <br />Posted by vidargander</DIV><br /><br />Pragmatically, even if funding magically appeared from somewhere, a nuclear pulse mission would be many decades away as there is no development going on, and no plans for such development. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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DrRocket

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>There was a scientist Gottfried Wilhelm Leibniz during 1676-1689 that first introduced a form of kinetic energy, called vis viva, E=mv^2. Max velocity would give max Energy, namely E=mc^2. http://en.wikipedia.org/wiki/Vis_vivaIn the early 20th century there was a race about&nbsp;figuring out what the factor could be, - if not Newton&rsquo;s: 0.5 or Leibniz&rsquo;s: 1.0. Proposed factors were: 1900 Henri Poincar&eacute;:1.0 1904 Friedrich Hasen&ouml;hrl: 3/8 1904 Max Abraham: 3/4 1905 Albert Einstein: 1.0 http://en.wikipedia.org/wiki/E%3Dmc#Electromagnetic_rest_massI, at any rate, am convinced that mass&rsquo; total energy is not that simple. <br />Posted by vidargander</DIV></p><p>I think you are a bit confused.&nbsp; The link that you supplied discusses these factors in terms of an electromagnetic mass.&nbsp; There has been an effort to try to explain the mass of the electron, for instance, in terms of the electromagnetic force. An accelerating charge radiates energy, which is supplied by the force causing the acceleration.&nbsp; The resisting force can, in part be explained, as a self interaction between the charged particle (the electron) and the electcric field that is created by the charge on that same electron.&nbsp; One can compute the effectcive inertia from that effect, and it is real.&nbsp; It does not explain the total mass of the electron however.&nbsp; There are a few other problems with this approach, and at this point, there is no good explanation of the origin of mass, other than the hypothesis that it is connected with the Higgs field and the Higgs boson.</p><p>There is no disagreement that E=mc^2 is valid or that the expression&nbsp;1/2*m*v^2 represents kinetic energy in classical mechanics, which is a very good approximation to the precise expression from general relativity when velocities are small compared with the speed of light.<br /></p> <div class="Discussion_UserSignature"> </div>
 
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vidargander

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think you are a bit confused.&nbsp;&nbsp;....................&nbsp; One can compute the effectcive inertia from that effect, and it is real.&nbsp; It does not explain the total mass of the electron however.&nbsp; There are a few other problems with this approach, and at this point, there is no good explanation of the origin of mass, other than the hypothesis that it is connected with the Higgs field and the Higgs boson. There is no disagreement that E=mc^2 is valid or that the expression&nbsp;1/2*m*v^2 represents kinetic energy in classical mechanics, which is a very good approximation to the precise expression from general relativity when velocities are small compared with the speed of light. <br />Posted by DrRocket</DIV></p><p><span><font face="Times New Roman"><font size="2">The formula E=mc^2 simply states the mass&rsquo; energy can be calculated merely by speed. </font></font></span><span><font face="Times New Roman"><font size="2">It&rsquo;s neither more nor less. I don&rsquo;t find that confusing at all.</font></font></span><span><font face="Times New Roman" size="2">&nbsp;</font></span></p><p><span><font face="Times New Roman"><font size="2">However, it is confusing, all that unfounded beliefs in that iconized formula.</font></font></span></p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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MeteorWayne

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The formula E=mc^2 simply states the mass&rsquo; energy can be calculated merely by speed. It&rsquo;s neither more nor less. I don&rsquo;t find that confusing at all.&nbsp;However, it is confusing, all that unfounded beliefs in that iconized formula.&nbsp; <br />Posted by vidargander</DIV><br /><br />That's not what it says at all. In the formula "c^2" is a contant that allows you to determine how much energy is contained in a given mass. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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holmec

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> If ACE is accelerated with 10 G, it will reach the speed of light in a month. The whole journey will last 5 years according to classic physic (v=at).</DIV></p><p>&nbsp;Well first of all there is nothing that can provide 10 Gs of thrust for a month.&nbsp; I would think a chemical rocket would be too big to get into earth orbit for that.&nbsp; And to harness nuclear pulse or fusion pulse is a long ways off even if there were no political propblems and you started today where the old Orion project stopped.&nbsp;&nbsp;</p><p>&nbsp;</p><p>The best we could possibly do today is to do what we did with voyager to escape the solar system and add some ion drives to try to shorten the trip.&nbsp; Of course I imagine the trip would take 70 to 100 years, but that's just a guess.&nbsp; The good news is that if you do send one at such a slow speed, you might be able to navigate it into solar orbit by ussing planets and maybe a solar sail. </p><p>&nbsp;Of course such a craft would have to be highly autonomous, being able to degociate orbit inserstion maneuvers and select targets to take pictures and record data of the star(s) and planets...etc. </p> <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
 
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qso1

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<p><font color="#800080">I can&rsquo;t imagine that the Pioneers or Voyagers were meant for interstellar voyages (unless there was an unrealistic target to encounter Alpha Centauri C in 27 ky or so). They must have been made to explore our own solar system. When thinking about it, what was the plan for them and what have they discovered when passing the Kuiper belt.Getting back to the theme of the discussion, I can&rsquo;t figure out what is the best path from here to Alpha Centauri. Is it through the Kuiper belt, or is the direct path free of that risk? Posted by vidargander</font></p><p>You are correct, the pioneers and voyagers were not meant for interstellar travel. Pioneer 10 was a Jupiter flyby, Pioneer 11 flew past Jupiter but used gravity assist during the flyby to do a flyby of Saturn. Voyager 1 repeated the Pioneer 11 mission and Voyager 2 did as well but Voyager 2 also flew by Uranus and Neptune. Voyager 2 was the closest thing we actually had to what was originally called the "Grand tour of the planets" mission concieved in the late 1960s.</p><p>The craft were not designed or intended for interstellar targets and IIRC, the Kuiper belt was not discovered till long after the last Voyager past Neptune in 1989. The only reason these probes have become the first human objects to go interstellar so to speak is that as flyby missions, they were bound to.</p>As for the best path to A.C. nobody can probably really say for sure at this point as far as avoiding KBOs of other possible objects. But at the distances of KBOs etc...the chances of collision are remote in the extreme. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>
 
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vidargander

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;Well first of all there is nothing that can provide 10 Gs of thrust for a month.&nbsp; I would think a chemical rocket would be too big to get into earth orbit for that.&nbsp; And to harness nuclear pulse or fusion pulse is a long ways off even if there were no political propblems and you started today where the old Orion project stopped.&nbsp;&nbsp;&nbsp;The best we could possibly do today is to do what we did with voyager to escape the solar system and add some ion drives to try to shorten the trip.&nbsp; Of course I imagine the trip would take 70 to 100 years, but that's just a guess.&nbsp; The good news is that if you do send one at such a slow speed, you might be able to navigate it into solar orbit by ussing planets and maybe a solar sail. &nbsp;Of course such a craft would have to be highly autonomous, being able to degociate orbit inserstion maneuvers and select targets to take pictures and record data of the star(s) and planets...etc. <br />Posted by holmec</DIV><br /><span><font face="Times New Roman" size="2">&nbsp;</font></span><span><font face="Times New Roman"><font size="2">Yes it&rsquo;s highly hypothetical and there&rsquo;s no real solution to that yet. If the total Energy of matter is limited to mc^2, a antimatter propulsion wont even be sufficient to reach c.</font></font></span><span><font face="Times New Roman" size="2">&nbsp;</font></span></p><p><span><font face="Times New Roman"><font size="2">&frac12; c in 10 years with antimatter propulsion seems to be the least impossible mission.</font></font></span></p> <div class="Discussion_UserSignature"> </div>
 
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vidargander

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You are correct, the pioneers and voyagers were not meant for interstellar travel. Pioneer 10 was a Jupiter flyby, Pioneer 11 flew past Jupiter but used gravity assist during the flyby to do a flyby of Saturn. Voyager 1 repeated the Pioneer 11 mission and Voyager 2 did as well but Voyager 2 also flew by Uranus and Neptune. Voyager 2 was the closest thing we actually had to what was originally called the "Grand tour of the planets" mission concieved in the late 1960s.The craft were not designed or intended for interstellar targets and IIRC, the Kuiper belt was not discovered till long after the last Voyager past Neptune in 1989. The only reason these probes have become the first human objects to go interstellar so to speak is that as flyby missions, they were bound to.As for the best path to A.C. nobody can probably really say for sure at this point as far as avoiding KBOs of other possible objects. But at the distances of KBOs etc...the chances of collision are remote in the extreme. <br />Posted by qso1</DIV><br /></p><span><font face="Times New Roman" size="2">What I was wondering about, but didn&rsquo;t get into the posting, is; if the Voyagers were not meant for interstellar voyage, what is the point in the &lsquo;golden record&rsquo;? </font><font face="Times New Roman" size="2" color="#800080">http://en.wikipedia.org/wiki/Voyager_Golden_Record</font><font face="Times New Roman"><font size="2"> </font></font></span><span><font face="Times New Roman"><font size="2">Do astronomers still consider Extra Terrestrial life in our own solar system as possible?</font></font></span><span><font face="Times New Roman" size="2">&nbsp;</font></span> <p style="margin:0cm0cm0pt" class="MsoNormal"><span><font face="Times New Roman" size="2">I don&rsquo;t really know the 3D direction from Sol to Alpha Centauri. Is it through the Kuiper Belt&rsquo;s plane, or is the direct path another angle, free from plutoids' hazard?</font></span></p> <div class="Discussion_UserSignature"> </div>
 
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