Dark matter article on BBC website

Chipper Q
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RE: Also the language used

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Also the language used to program the hardware aboard these long missions may be a problem, since there is nobody who knows it after 30 years. All programmers who wrote it may be out of reach. I read of a similar problem with the hw used by the Federal Aviation Administratiom, and written in Jovial. Did you ever hear of it?
Tullio


I know a lot of work was done with it prior to the late eighties, and that FORTRAN was used for some newer (international) systems in the nineties. You're right about the importance of keeping records (and multiple copies of backups, in different places).

With regard to not being able to figure something out that was engineered by others, take a quick look at this E@H Cruncher's Corner thread to read about a marvelous improvement in processing time using a 'hand-optimized version of the albert code', by a bright young Hungarian lad, E@H participant "akosf". If I understand correctly, processing times for albert WUs are about halved, and the optimized version uses only 386 code!

Odysseus
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RE: Here's a link to the

Message 24813 in response to message 24810

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Here's a link to the Pioneer Mission Status page. I think the reason the missions are over is because the craft stopped responding/communicating. The power supply on the Voyager craft should keep working until about 2020, and hopefully the craft will have journeyed out of the heliosphere and into actual interstellar space by then, providing data the whole way. Not sure about any data on concentrations of dark matter, though...

From what I've heard Voyager's position isn't known precisely enough to tell whether or not it's also affected by the "Pioneer anomaly", something to do with its having made more manoeuvres over the course of its journey, or less precisely controlled ones at least, than did the Pioneers. The discrepancy is very tiny: even differences in the amount of heat radiating from the craft in various directions have to be taken into account in determining the true velocity as compared to the 'expected'.

tullio
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RE: With regard to not

Message 24814 in response to message 24812

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With regard to not being able to figure something out that was engineered by others, take a quick look at this E@H Cruncher's Corner thread to read about a marvelous improvement in processing time using a 'hand-optimized version of the albert code', by a bright young Hungarian lad, E@H participant "akosf". If I understand correctly, processing times for albert WUs are about halved, and the optimized version uses only 386 code!


From what I read the Akosf code is a Windows code,while I am running Linux on an old Pentium II. Little wonder Hungarians are good programmers, they had Von Neumann as a teacher! But get a look at the NYTimes science section, it looks like the Microwave Anisotropy Probe has confirmed the inflationary model of Big Bang. Next step should consist in the detection of GW fromn the early universe. The article mentions a Planck satellite from ESA to be launched next year, but I never heard of it.
Tullio

Chipper Q
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Fascinating... universe's 1st

Fascinating... universe's 1st trillionth of a second. Here's a smaller image showing the early polarizations (white bars):

If the Wilkinson probe were at any other location (even across the universe), would the polarization appear the same? Or is the circumferential pattern indicative of a preferred direction?

Odysseus
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RE: Fascinating...

Message 24816 in response to message 24815

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Fascinating... universe's 1st trillionth of a second. Here's a smaller image showing the early polarizations (white bars):

If the Wilkinson probe were at any other location (even across the universe), would the polarization appear the same? Or is the circumferential pattern indicative of a preferred direction?

It looks to me like an artefact of the map projection: that's the complete celestial sphere we're looking at, so the edges are distorted.

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RE: RE: Here's a link to

Message 24817 in response to message 24813

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Quote:
Here's a link to the Pioneer Mission Status page. I think the reason the missions are over is because the craft stopped responding/communicating. The power supply on the Voyager craft should keep working until about 2020, and hopefully the craft will have journeyed out of the heliosphere and into actual interstellar space by then, providing data the whole way. Not sure about any data on concentrations of dark matter, though...

From what I've heard Voyager's position isn't known precisely enough to tell whether or not it's also affected by the "Pioneer anomaly", something to do with its having made more manoeuvres over the course of its journey, or less precisely controlled ones at least, than did the Pioneers. The discrepancy is very tiny: even differences in the amount of heat radiating from the craft in various directions have to be taken into account in determining the true velocity as compared to the 'expected'.

The Voyager probes' positions are known quite well. What isn't know well enough to test for the Pioneer anomoly is exactly where they should be, assuming that the physics we know is correct.

Odysseus
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RE: The Voyager probes'

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The Voyager probes' positions are known quite well. What isn't know well enough to test for the Pioneer anomoly is exactly where they should be, assuming that the physics we know is correct.

Thanks for the clarification: that's what I meant, but I guess I didn't express it very well.

Steve
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RE: Tullio, I think the

Message 24819 in response to message 24808

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Tullio, I think the Pioneer craft are reported to be slowing down (or accelerating towards the center of the solar system). Here's a link to a Jan. '06 update from the Planetary Society: Update From the Pioneer Anomaly Team

I wonder if they take the mass from this link into consideration?[url= http://cfa-www.harvard.edu/iau/lists/InnerPlot.html] Individually these may not amount to a hill of beans, but collectivly I would think it adds up. I imagine most of this was discovered after pioneer launch.

Chipper Q
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Interesting article from

Interesting article from SPACE.com updating the shape of the helioshpere. Data from both Voyager craft indicate that the shape is asymmetrical, thinner in the southern hemisphere and thicker in the north. (I know what you're thinking, Mike, about the taxes :o) Possibly a weak interstellar magnetic field; see "Voyager 2 Detects Odd Shape of Solar System's Edge"

Erik
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Out of curiosity, why was

Out of curiosity, why was Voyager 2 launched before 1?

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