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"Phyloe" wrote in message
... Read the article on Gravity in the October 2003 Discover magazine. The author talks about how the force of gravity may be much different than we think. He mentions that Pioneer 10, launched in 1972 is actually slowing down the further it gets from the sun. this article may have some interesting information for your story and how you will define the "edge". Phyloe Of course, we expect Pioneer 10 to slow down the further it gets from the Sun. This is standard gravity theory. The thing about Pioneer is that it exhibits an anomalous acceleration; it is slowing down very, very, very slightly quicker than we would expect. Did I mention that it was *very* slightly? :-) The jury is still out as to the underlying reason for the anomaly. Efforts to modify the nature of the gravitational force (MOND theories) in order to explain such things as the non-Keplerian velocity profiles of galactic rotation curves run into problems such as not every galaxy exhibits such a profile. |
#12
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In message , Greg Neill
writes "Dario Vittori" wrote in message u... If I took off from earth and was traveling at the speed of light, how long would it take to get to the edge of the sun's gravity well or gravitational influence? It's just a hypothetical question, it's for a short story and I want to get it right. Thanks. The Sun's "sphere of influence" can be defined as the region in which its gravity dominates over other stars. The nearest neighbouring star (Proxima Centauri)is about 4.2 light years away, so figure (very) roughly half that distance. The other definition of the edge of the solar system is the heliopause, where the solar wind gives way to the interstellar medium. The Voyager probes haven't reached it yet, so it's at least twice as far as Pluto. -- "Forty millions of miles it was from us, more than forty millions of miles of void" |
#13
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In message , Greg Neill
writes "Dario Vittori" wrote in message u... If I took off from earth and was traveling at the speed of light, how long would it take to get to the edge of the sun's gravity well or gravitational influence? It's just a hypothetical question, it's for a short story and I want to get it right. Thanks. The Sun's "sphere of influence" can be defined as the region in which its gravity dominates over other stars. The nearest neighbouring star (Proxima Centauri)is about 4.2 light years away, so figure (very) roughly half that distance. The other definition of the edge of the solar system is the heliopause, where the solar wind gives way to the interstellar medium. The Voyager probes haven't reached it yet, so it's at least twice as far as Pluto. -- "Forty millions of miles it was from us, more than forty millions of miles of void" |
#14
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Thanks Guys, you all been helpful.
Dario. Greg Neill wrote: "Phyloe" wrote in message ... Read the article on Gravity in the October 2003 Discover magazine. The author talks about how the force of gravity may be much different than we think. He mentions that Pioneer 10, launched in 1972 is actually slowing down the further it gets from the sun. this article may have some interesting information for your story and how you will define the "edge". Phyloe Of course, we expect Pioneer 10 to slow down the further it gets from the Sun. This is standard gravity theory. The thing about Pioneer is that it exhibits an anomalous acceleration; it is slowing down very, very, very slightly quicker than we would expect. Did I mention that it was *very* slightly? :-) The jury is still out as to the underlying reason for the anomaly. Efforts to modify the nature of the gravitational force (MOND theories) in order to explain such things as the non-Keplerian velocity profiles of galactic rotation curves run into problems such as not every galaxy exhibits such a profile. |
#15
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Thanks Guys, you all been helpful.
Dario. Greg Neill wrote: "Phyloe" wrote in message ... Read the article on Gravity in the October 2003 Discover magazine. The author talks about how the force of gravity may be much different than we think. He mentions that Pioneer 10, launched in 1972 is actually slowing down the further it gets from the sun. this article may have some interesting information for your story and how you will define the "edge". Phyloe Of course, we expect Pioneer 10 to slow down the further it gets from the Sun. This is standard gravity theory. The thing about Pioneer is that it exhibits an anomalous acceleration; it is slowing down very, very, very slightly quicker than we would expect. Did I mention that it was *very* slightly? :-) The jury is still out as to the underlying reason for the anomaly. Efforts to modify the nature of the gravitational force (MOND theories) in order to explain such things as the non-Keplerian velocity profiles of galactic rotation curves run into problems such as not every galaxy exhibits such a profile. |
#16
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"Roger Hamlett" wrote in
: "Dario Vittori" wrote in message ... If I took off from earth and was traveling at the speed of light, how long would it take to get to the edge of the sun's gravity well or gravitational influence? It's just a hypothetical question, it's for a short story and I want to get it right. In one sense, if your detector is sensitive enough, never... How far away, you can detect gravitational influence, depends on how accurately you can measure. Realistically (unless it is essential), why not use the heliopause as the 'edge'?. This is the 'point', where the solar wind gets turned 'back' by gravity. No. The solar wind is not turned back by gravity at all - it's speed is much greater that the solar system escape velocity. The heliopause is the point where the solar wind becomes too rarified to have any noticeable effect on the interstellar medium. Llanzlan The exact distance is unknown, but the predicted distance, is in the order of 100AU beyond the major planets. So if you took a timescale of about 1000 minutes (starting at the Sun), you would not be far off. Best Wishes |
#17
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"Roger Hamlett" wrote in
: "Dario Vittori" wrote in message ... If I took off from earth and was traveling at the speed of light, how long would it take to get to the edge of the sun's gravity well or gravitational influence? It's just a hypothetical question, it's for a short story and I want to get it right. In one sense, if your detector is sensitive enough, never... How far away, you can detect gravitational influence, depends on how accurately you can measure. Realistically (unless it is essential), why not use the heliopause as the 'edge'?. This is the 'point', where the solar wind gets turned 'back' by gravity. No. The solar wind is not turned back by gravity at all - it's speed is much greater that the solar system escape velocity. The heliopause is the point where the solar wind becomes too rarified to have any noticeable effect on the interstellar medium. Llanzlan The exact distance is unknown, but the predicted distance, is in the order of 100AU beyond the major planets. So if you took a timescale of about 1000 minutes (starting at the Sun), you would not be far off. Best Wishes |
#18
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"Greg Neill" wrote in message ... "Phyloe" wrote in message ... Read the article on Gravity in the October 2003 Discover magazine. The author talks about how the force of gravity may be much different than we think. He mentions that Pioneer 10, launched in 1972 is actually slowing down the further it gets from the sun. this article may have some interesting information for your story and how you will define the "edge". Phyloe Of course, we expect Pioneer 10 to slow down the further it gets from the Sun. This is standard gravity theory. The thing about Pioneer is that it exhibits an anomalous acceleration; it is slowing down very, very, very slightly quicker than we would expect. Did I mention that it was *very* slightly? :-) The jury is still out as to the underlying reason for the anomaly. I think it is a tractorbeam, captain. |
#19
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"Greg Neill" wrote in message ... "Phyloe" wrote in message ... Read the article on Gravity in the October 2003 Discover magazine. The author talks about how the force of gravity may be much different than we think. He mentions that Pioneer 10, launched in 1972 is actually slowing down the further it gets from the sun. this article may have some interesting information for your story and how you will define the "edge". Phyloe Of course, we expect Pioneer 10 to slow down the further it gets from the Sun. This is standard gravity theory. The thing about Pioneer is that it exhibits an anomalous acceleration; it is slowing down very, very, very slightly quicker than we would expect. Did I mention that it was *very* slightly? :-) The jury is still out as to the underlying reason for the anomaly. I think it is a tractorbeam, captain. |
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