pioneer puzzle

[miriam_e]

Anybody see this before? I found out about it through the new Australian science magazine Cosmos. Space.com has a good article on the problem at http://www.space.com/scienceastronomy/mystery_monday_041018.html

The two old Pioneer spacecraft 10 and 11 have been heading out of our solar system for the last 34 years in opposite directions, but it turns out that they are not where they "should" be. The calculations are just a tiny bit out -- by about 400,000km, which sounds like a lot to us here on Earth, but out there it is a miniscule compared to the distance they've traveled.

Something is slowing their travel more than expected. What could it be? After posing many possibilities, all but 3 have been investigated and dismissed. Those 3 are:

    • dark matter
    • some other unknown force
    • our understanding of gravity is incomplete

Edit: the list of undiscounted possibilities is greater than those 3 above. See the article at http://en.wikipedia.org/wiki/Pioneer_anomaly for lots more info. Thanks to keithlard.

Comments

Re: All three?

[miriam-e.livejournal.com]

It occurred to me that it would be very funny if it was none of the above... what if it was aether. Heheheheh. :)

Perhaps the Michelson-Morley experiment has another explanation. :)

I'm mostly kidding... but...

If the aether exists throughout space, but is affected by gravity then it might retard slightly the spacecraft but have negligible effect on more massive objects (like planets). Being drawn in by the sun it would have a constant retarding effect on both sides of the sun because such an aether might have little relative motion within the solar system. It would be interesting to see what results an interferometer would produce if put on a distant spacecraft. Hmmm... I wonder if any current spacecraft use interferometers that can be rotated toward and away from the Sun...

Re: All three?

[(Anonymous)]

Heh... luminiferous aether rocks.

Just the thought makes me want to read John Carter of Mars, and play some Space: 1889 and otherwise feed my Victorian-era sci-fi bug. :)

Re: All three?

[miriam-e.livejournal.com]

:) I've been wanting to read more John Carter of Mars for a while. Loved those stories when I was a kid. I read one again a few years back and enjoyed it again, so looks like chauvinism and lack of science won't ruin it totally. Did you know that all the John Carter of Mars books are available for free download from Gutenberg Project? And that includes the Carson of Venus books, most of the Tarzan books, and various others like Pellucidar, The Lost Continent, At the Earth's Core, The Land that Time Forgot, etc.

Something not many people know is that the John Carter of Mars story idea was... ummm... lifted from Edwin Arnold's Gulliver of Mars (originally titled Lieut. Gulliver Jones), which was written back in the late 1800s? It is available from Gutenberg too. I read it in paper form decades ago, so have forgotten the bulk of it. I must read that again one day too.

Borrowing ideas, back in those days, seems to have been quite normal. These days people have become quite anally retentive about "their" ideas, and all this "Intellectual Property" (IP) law has suddenly proliferated. Needless to say, I'm a strong opponent of IP. I see it as needlessly restricting our future options, being constantly forced to re-invent the wheel or pay through the nose forever for existing ones. Copyright and patent systems have been turned around to work in exactly the opposite fashion to their original purpose.

Copyright was originally intended to ensure works made it quickly into the public domain for the benefit of all society.

Patent was to protect little people against the big and rich, allowing them a small time where they could profit from their invention before the giant vultures moved in.

Both have been altered to benefit only the giant corporations now. Copyright keeps being extended beyond its original 7 years after first publication, to now I think it is 90 years after the author's death in USA (75 years after death in Australia) which is obscene.

Patents cost so much (thousands of $$) that only people who are well off or have the backing of a corporation can afford them, and regardless of whether you are "protected" by one or not a corporation can afford to tie you up endlessly in court till you are sent broke if you want to defend your patent against them.