|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
pioneer 10 acceleration
In message , alistair
writes In message , alistair writes Dark energy could be causing the anomalous acceleration of pioneer 10. The solar system is surrounded by the spherical Oort cloud.If dark energy consists of particles that flow into the galaxy, the Oort cloud would shield the solar system from those particles.However a gap in the Oort cloud would allow some dark energy particles to flow into the solar system. ANDRE?MICHAUD wrote: There are a few problems with this idea :-) The paper by Anderson et al. which everyone cites is available online at http://xxx.lanl.gov/abs/http://www....gr-qc/0104064. It has figures for the mass of the Pioneers (223 kg dry mass) and their surface area (or at least that of the dish antenna, which accounts for nearly all of it. It's a 2.74 meter dish giving an area of 5.9 square meters. Also, the two Pioneers are going in nearly opposite directions. ALISTAIR writes: The mass and surface area you quote for Pioneer 10 would give an acceleration for Pioneer 10 that is roughly only one third smaller than the figure I calculated of 10^ -12 m/s^2.The correct figure NASA gives is 10^-10 m /s^2. However, if dark energy consists of particles with rest mass and these particles in our part of the Milky Way move at 99.9999 per cent the speed of light then there would be a relativistic mass increase by a factor of 10000 compared to the average expectation for dark energy mass which would have to be moving at a speed of around 1/3 that of light.Whether or not dark energy actually has a different mass density in galaxies compared to intergalactic space,I couldn't say.There is also the possibility that dark energy coming through a gap in the Oort cloud could pick up speed and mass if it has fluid like properties ( though I think such a Bernouilli flow is unlikely given how large the mass increase would be).Both these factors could give the acceleration NASA quotes.The fact that the Pioneers are moving in opposite directions is irrelevant because the Oort cloud could have other gaps in it which allow dark energy particles into the solar sytem. I hope you can sort out your attributions :-) That's my reply you're quoting. And I have an even bigger problem with the nature of the particles making up your "dark energy". What sort of particle density are you assuming - how many per m^3, for instance? It looks to me as though you're proposing some sort of relativistic particle, a new sort of cosmic ray, and I'm sure they would have been detected in other ways. I don't see how they could be blocked by anything in the outer solar system to produce the sort of localised flux you need, or how they could deliver momentum to the Pioneers. It gets worse! I've already mentioned Galileo, and the "Pioneer effect" has also been reported for Ulysses. That's four probes in different parts of the solar system. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
pioneer 10 acceleration | Nodem Info. Sys. | Research | 19 | June 4th 04 10:15 AM |
pioneer 10 acceleration | Jonathan Silverlight | Research | 0 | June 2nd 04 07:03 PM |
Probably Dumb Questions | John | Research | 49 | May 6th 04 09:01 AM |
"Pioneer anomalous acceleration" and Cassini | Jonathan Silverlight | Astronomy Misc | 49 | November 18th 03 07:37 PM |