Pioneer Effect

bonzelite · Feb 18, 2006

it does mean Newton's work is absolutely HIGHLY based on Kepler. if anything, there is little use for Newton in planetary motion computation. you can disregard entirely gravity/mass when computing plantary motion. Kepler's laws alone are enough. you don't need Newton for that. this is why your statement is basically true and 200% verifies what i am saying: you aren't reverse engineering newtons work to get kepler. You are using a coherent, general explaination of physical motion to derive planetary motion. These give you the same answers as keplers empirical work. Newton is not necessary in this context as his planetary motion computations already pre-existed him. this is historical fact.

Saiph · Feb 18, 2006

kmarinas is right, our primary disagreement is on the word "based". I'm taking it to be that when something is "based" upon something (say theory a is based on theory b) that theory a uses, as a primary assumption or foundation for all subsequent work, theory B. For example, current analysis of stellar composition is based upon the theory of spectral lines. Spectral lines are based upon various aspects of quantum mechanics. So, when you say newton's work is based on Kepler's, I see you saying that newtons work in gravity uses as a primary basis kepler's laws. If that's the case, derivation of keplers laws is purely cicurlar logic. However, it is not based on keplers laws. It is based on newtons laws of motion, and gravity, from which kepler's laws can be derived. <blockquote>In reply to:<hr />little use for Newton in planetary motion computation<hr /></blockquote> Not true. First, kepler's laws do nothing to explain why the bodies move that way. They also apply only to bodies orbiting the sun. They also apply only to two body interactions (you cannot compute fly-by maneuvers with kepler). If anything keplers work, while chronologically first, is a subset of newtonian mechanics. They are "special case" answers that can be derived from a more general system of mechanics. This is analogous to how Relativity can derive the simpler newtonian laws of motion. And kmar: Wiki isn't lying. Newton did derive kepler's laws in an effor to demonstrate the validity of his models. Why? Because kepler's laws worked very well. He was taking his theoretical model, and seeing if it matched observation (which is how kepler got his laws). <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Feb 18, 2006

If anything keplers work, while chronologically first, is a subset of newtonian mechanics. They are "special case" answers that can be derived from a more general system of mechanics. This is analogous to how Relativity can derive the simpler newtonian laws of motion. And kmar: Wiki isn't lying. Newton did derive kepler's laws in an effor to demonstrate the validity of his models. Why? Because kepler's laws worked very well. He was taking his theoretical model, and seeing if it matched observation (which is how kepler got his laws). you are invaliding what i say, then only to finish up your posts by validating it again. the above validates what i said. Kepler pre-dated Newton ----period. Newton derived his laws directly from Kepler's. this is fact. the only other thing really needed to calculate planetary motion as well as trajectory maneuvers, speed or fly-bys as you suggest, is Newton's Orbital Equation, again lifted from pre-existing knowledge of the time. the seed of Newton's principles is the "subset" you suggest that exists in the pillar of Kepler's laws. Newton did not create these ideas by himself. he built upon them, certainly. but that is all. you should say Newton's laws are derived from Kepler's.

kmarinas86 · Feb 18, 2006

Kepler did not invoke F=ma. Newton uses F=ma and the Gravitational Constant to explain planetary motion. Newton had to think about the mass of the earth, and the subsequent acceleration was derived from that. Kepler did not have to think about the mass of the earth. http://en.wikipedia.org/wiki/Kepler%27s_Laws_of_Planetary_Motion F=ma is not derived from Kepler's Laws. Netwon's intuitive knowledge, however, was inspired in part by Kepler's work. Historically, Kepler knew about planetary motion and described it before Newton did. Newton discovered F=ma before Kepler did. He made their own (sharable) discoveries.

Saiph · Feb 19, 2006

ack...my post didn't go through. " Kepler pre-dated Newton ----period." agreed. but that does not mean subsequent work was based on it, nor was derived from it. Those terms have very specific meanings in the realm of science. "Newton derived his laws directly from Kepler's. this is fact" N-O, NO! Newtons laws are independent from keplers, and cannot be derived from them. Newtons three laws of motion are universal, interia, force, and action-reaction pairs are not derived from Keplar. Keplar's laws also do not lead to gravity (heck, you're saying that!). Kepler's laws have, in and of themselves, no reason to be true, other than they are empirically derived to fit the data. This is like identifying a trend, saying it's a 1/r trend, but having no reason why it's 1/r, instead of 1/r^2. Kepler's laws state observations, but they do not provide an explaination. They are an "answer" but not a complete solution. Newton, starting from independent assumptions, can derive kepler's laws, thus proving that his model correctly predicts observations. Newton's derivation does not require, nor is based on, kepler's laws. Now, if your point is that Newton didn't work in a vacuum, fine, agreed. He was a very educated individual, and he had heard of kepler's laws and their accuracy. As for needing only kepler's laws to calculate orbits...show me. Calculate geosynchronous orbit for a satellite orbiting the moon using only kepler's laws. So p^2=a^3. units are traditionally years and A.U. also, show me where, in the newtonian derivation of kepler's laws, that kepler's laws appear anywhere, other than at the end. And/OR show me how newtons laws of motion and gravitation can be derived from kepler's laws. You say this is all true, time to show me. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

newtonian · Feb 19, 2006

Borman - you posted: "Pioneer force does not affect outer planets within errors of measurement." Or the inner planets either - correct? So this points to something perculiar to the Pioneer probes but not to planets. Have you considered my suggestion that the planets are bound while the pioneers are loosened? Notably gravitationally - but there may be other bonds involved. A clue is here: (Job 38:31-33) 31 Can you tie fast the bonds of the Ki´mah constellation, Or can you loosen the very cords of the Ke´sil constellation? 32 Can you bring forth the Maz´za·roth constellation in its appointed time? And as for the Ash constellation alongside its sons, can you conduct them? 33 Have you come to know the statutes of the heavens, Or could you put its authority in the earth? Note the bonds are plural - hence not just gravity. Does the specific bond, or lack thereof, causing the Pioneer effect, have authority on earth so as to be observed by scientists locally? Is there a force that specifically works against being 'loosened' from the vicinity of the earth? Another hint on this is the Biblical statement that evil extraterrestrial life forms are bound to the vicinity of the earth in some way. These are, btw, energy based not matter based - and perhaps involving forms of energy we do not yet scientifically understand - compare dark energy. Just some 'outside the box' thoughts.

bonzelite · Feb 19, 2006

Newtons laws are independent from keplers, they are conceptually based upon, if not highly influenced by, them. i see what you are saying about "direct derivation," and you are correct in this way. but you are not correct otherwise. direct derivation mathematically does not lead back to literally Kepler, but does lead to non-Newtonian equations that were commonly known during his time, ie, centripetal force and another "empirical" geometric-only based equation for orbit computation. Newton did introduce the addition of mass and gravity into the equations and made them "his." but gravity is NOT necessary in Keplerian geometry. nor are Newtons equations entirely of his own creation. Keplar's laws also do not lead to gravity (heck, you're saying that!). Kepler's laws have, in and of themselves, no reason to be true, i never postualted anything about Kepler leading to gravity. in a prior post, i even said that his laws could not invoke gravity, as they predate Newton. we do not need gravity for Kepler's laws to ring true. but Kepler's laws ARE true. and they predated Newton. Newton did not derive his gravitational laws from thin air, having no prior awareness of the science contemporary to his time; they were entirely based in concept upon Keplerian law and centripetal force that was commonly known at the time. Keplerian law does not need gravity to accurately calculate planetary motion. that is the thrust of my point. and this is absolutely true. the laws do not need to explain why, or invoke gravity, to stand as true. a lack of gravity in Keplerian geometry does not invalidate this geometry. your use of the word "empirical" does not help to invalidate my point or Kepler's work. his observations were every bit as scientific regardless. and they are pillars of modern astronomy.

mkofron · Feb 19, 2006

<blockquote>In reply to:<hr /> I'm sure, that there has been some controversy over whether or not Voyager 1 has actually passed the heliopause? <hr /></blockquote> Voyager 1 is in the heliosheath and has not yet crossed the heliopause. <blockquote>In reply to:<hr />This is because its instruments saw the expected data not once but several times. (Well, at least twice. I don't actually know how many times.) <hr /></blockquote> I think you are referring to the termination shock which scientists originally though Voyager 1 passed in August 2002, but instead passed in December 2004. Both suggestions were based on changes in magnetic readings taken by Voyager 1.

Saiph · Feb 20, 2006

by saying that newtons laws were based upon kepler, you imply that keplers laws lead to gravity (as that is one of newtons laws). You seem to be ranting that newton didn't work in a vacuum. that's fine, he was influenced, I'm sure, by lots of things. But I don't believe kepler's laws had any indication of a centripetal force in them (if there was, that would be gravity...which you say isn't required). IIRC, at the time of kepler it was still a common notion that inertia led to circular paths, not linear ones (one of the reasons newton put forth his objects in motion law). So the reason keplers objects moved in a circular fashion (even if not entirely circular anymore): simple, that's how inertia worked. <blockquote>In reply to:<hr />direct derivation mathematically does not lead back to literally Kepler, but does lead to non-Newtonian equations that were commonly known during his time, ie, centripetal force<hr /></blockquote> direct derivation does lead directly to kepler's laws. I provided a reference in a previous post. Centripetal force is a newtonian concept. see above about circular inertia. Newton applied the concept of a centripetal force (which may or may not be directly attributed to newton, not sure) to keplers work. Gravity is not implied in Kepler's work because kepler's work provides absolutely no reason why the planets move that way. This is the same way that Bode's Law predicts the positions of planets out to jupiter (or saturn...) but there is no reason given why. Heck, no reason has ever been found other than sheer coincidence (though people do still look). So kepler's laws are severly lacking precisely because they give no reason why they work. newton's derivations fixed that (though we still can ask...why/what is gravity?) by showing kepler's laws are merely a consequence of the laws of motion, conservation of momentum/energy and g <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Feb 24, 2006

pioneer effect violates conservation of energy and momentum.

Saiph · Feb 24, 2006

well...those are probably conserved. As we have never ever seen a violation before, it's just much more likely that we just don't have the complete picture, than the laws are vioalate, not impossible mind you, just incredibly unlikely. It does appear to be that they aren't, then again, we don't know the mechanism. Once we know what's causing it, we'll probably find something else is losing energy and momentum and transfering it to the pioneer spacecraft. It's just like saying systems with friction don't conserve energy. And they don't...unless you incorporate the frictional heating of the surfaces and air. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Feb 24, 2006

i hear what you are saying. and there is the possibility that they are not conserved. i'm not as bought into standard theory as you. i'm not a PhD.

Saiph · Feb 24, 2006

neither am I. But I see no compelling reason to think that the conservation laws are broken. especially since we don't know much about the situation (only that they are not "de"-cellerating as expected). <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Feb 24, 2006

the debate rages on, then... i see that it's slowing down is extremely compelling. and you remain leisurely disaffected.

Saiph · Feb 25, 2006

I see it as puzzling, and an indication that we're missing information. It isn't conclusive at all that energy isn't being conserved. It's a possibility, and one to keep in mind, but every other time we've been puzzled by energy conservation dilemas, it turns out we're just not considering the whole picture. I also don't think we're going to get the information as we've only got,IIRC, one way fo getting info from pioneer, the radio signal. We can't do spectroscopy or any of our other tools. We can/could run diagnostics, and measure doppler shift. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Feb 25, 2006

another problem is that we cannot send out a "chase vehicle," either.

CalliArcale · Feb 28, 2006

<blockquote>In reply to:<hr />another problem is that we cannot send out a "chase vehicle," either. <hr /></blockquote> Well, in a sense, there's one on its way: New Horizons. However, I don't believe New Horizons is spin-stabilized like the Pioneers were. Thus, like the Voyagers, the margin for error from using its RCS for attitude control will probably swamp any effect. Assuming, of course, that the Pioneer Effect is real. There is some doubt; if I'm not mistaken, the data comes entirely from Pioneer 10, and it was extremely difficult to receive its signal during the last few years of its mission. And the effect is very very small, low enough to be negligible for most trajectory calculation purposes within the solar system. So there is still the possibility of some kind of error in the data. A second spin-stablized probe could rule that out, however, especially as it could (in theory) be specifically designed to rule out alternate explanations for the observed effect. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

bonzelite · Mar 30, 2006

lets clarify. pioneer effect has craft accelerating back towards the sun, yes? comets coming into sun, ie, going back, arrive at faster speeds, yes? the two examples, comet and pioneer, both exhibit an accelertion towards the sun, yes? please clarify so that i know my thinking is in line with yours <img src="/images/icons/wink.gif" />

bonzelite · Mar 30, 2006

ok <img src="/images/icons/wink.gif" /> this opens up a controversial idea...

derekmcd · Mar 30, 2006

uh oh... <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <div> </div> <div>"If something's hard to do, then it's not worth doing." - Homer Simpson</div> </div>

bonzelite · Mar 30, 2006

A central force will accelerate both comets and Pioneers in the same direction. the central force is there, definitely. it is the acceleration of the solar system expanding out to meet the comet and pioneer. pioneer is not accelerating anymore constantly. it is free-floating and "coasting." in so doing, eventually, it will begin to lag behind the expansion rate of the solar system rushing out to meet the craft. this is why measurements have detected a "deceleration." when, really, relative to the craft, the solar system is accelerating out to meet the craft.

rocketman5000 · Mar 31, 2006

CalliArcle "* the heliopause is complex and has several layers to be traversed * the heliopause is moving in and out, and so the boundary itself passed across Voyager 1 " I would go with the first statement. Most think of the heliopause as a single shockwave. In the past I studied compressible fluid flow. It is not impossible for a sperical shock wave from an explosion (think real big bomb) to have secondary and even tertiary shockwaves expanding outward behind the initial shock wave. It might even be possible to have more waves but the techniques for viewing them don't have the fidelity for their visualization. If you would like to see some cool photos look up schlierin optical techniques.

CalliArcale · Mar 31, 2006

It is worth pointing out that the Pioneer effect is known from a sample of only one: Pioneer 10. It cannot be measured with the Voyagers, and Pioneer 11 failed before it started showing up in the Pioneer 10 data. Thus, it is quite possible that it is not a real effect but rather some previously unforseen skew in the data (experimental error, in other words). It's hard to completely rule that out without sending more probes able to detect any effect. The reason Voyager data cannot be used is because their positions are not as well known. The Pioneers used spin-stabilization, so they very rarely had to fire thrusters. The Voyagers are not spin-stabilized, and must use their thrusters to orient themselves. Although negligible on the short term, over a long period of time this tiny amount of thrust becomes significant and overwhelms any effect similar to what was observed in the Pioneer 10 data. Unfortunately, I think New Horizons has the same problem as the Voyagers, with respect to this sort of experiment. There's a good reason for it, though; not being spin-stabilized gives the probe a lot more options when it comes to acquisition of science data during the Pluto encounter and any KBO encounters. So we're not likely to get the easy answer to this question anytime soon. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

bonzelite · Mar 31, 2006

eventually, the Pioneers and the Voyagers will be seen to "return" to the vicinity of earth's orbit, as the solar system continues to expand and accelerate out to the trajectories of the probes. velocity/trajectory allowing, as well, the probes may go into orbit around the sun.

romulan_invader · Aug 5, 2006

What do you mean like a gravit wave? Is not seen but is what is there? You can see that happen?

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