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Pioneer Anomaly Solved
First time accepted submitter gstrickler writes "After years of work recovering and analyzing old mission data and vehicle schematics, a just published analysis(Pdf) provides strong evidence for anisotropic thermal radiation being the source of the slowing of the Pioneer 10 and 11 spacecraft. The theory isn't new, but the recovered data and new analysis provide solid evidence that at least 80% of the deceleration is accounted for by anisotropic thermal radiation. Members of The Planetary Society were instrumental in recovering the data and helping fund the analysis. The lesson is, in space, it matters what direction your heat radiating surfaces point."
Heat makes things go fast!
Acceleration can be positive or negative.
Is it just my observation, or are there way too many stupid people in the world?
Sorry to self-correct - acceleration is a vector, it has both magnitude and direction. By summing all of the acceleration vectors, you get a resultant which determines the rate of change of your velocity.
Is it just my observation, or are there way too many stupid people in the world?
its accelerating backwards... ie, it's effectively got its "engine" (ie the heat radiating surface) pointing in the direction its heading, and this is slowing it down. I guess its still got a lot of velocity, but this is being reduced by the lack of anything pushing it in the right direction.
In other words, in space, your hot arse is a form of propulsion!
Does this discovery have a relationship (however distant or inefficient) to Nuclear Lightbulb or Nuclear Photonic propulsion? https://en.wikipedia.org/wiki/Nuclear_lightbulb
The lesson is, in space, it matters what direction your heat radiating surfaces point.
It matters in bed too.
It must have been something you assimilated. . . .
A portuguese aeronautics engineering student from Instituto Superior Técnico already figured this out way back in 2009 in his masters thesis, available here.
Slashdot, fix your code or at least hire someone who is competent at it to do it for you.
Will this effect be powerful enough to ever cause it to stop, turn around and come home? And when it does so, how much strife will it cause to Spock and Kirk?
Or rather a confirmation of some preliminary work done years agor (2008) http://www.planetary.org/blog/article/00001400/
100% certainty exists only in a fictional version of science.
They showed that the residual 20% is not statistically significant. This is a showing that there is no additional anomaly to be accounted for. This is what is called "solving a problem" in real science.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Does it have mass?
In a sense yes. Radiation and all other forms of energy have relativistic mass, as in the m in E=mc^2, as in things that have more energy (moving objects, high-energy states of atoms and molecules, systems in general) have more mass as it applies to inertia and gravity.
Heat radiation as in (mostly infrared) photons don't have rest mass. That's the m0 in E = root(pc^2 + m0^2*c^4). So they don't have mass in the sense of matter as you usually think of it. But it turns out the way you usually think of mass is not equivalent to matter. Even though the usual way you think about it is that they are.
Hope that clears things up. :)
The enemies of Democracy are
If I understand ion thrusters correctly (that's a big if), a big tank of neutral atoms are bombarded by electrons to knock other electrons out of orbit around those atoms, creating positive particles, which are electrostatically accelerated out a big metal screen thing and the motion of them going the opposite way makes your spaceship go the correct way.
I believe thermal radiation in this article's context means heat being turned into infrared light, that means photons going the opposite direction can have a noticeable impact on an existing spaceship in a real world text over a relatively short distance in space. I would think a gigantic atom nucleus has thousands of times more mass than a photon so ion thrusters would be pretty effective over time. Now of course the opposite "kick back" reaction is proportionate to the amount of energy you're putting into the ions and their speed is ohhhhh just a hair slower than a photon (lol) but at least we can say the theory should work in real space based on this experience.
I thought that E=mc^2 meant that E could me converted to M not that all it was both energy and mass at the same time.
So did I! But it's not a conversion, it's an equivalence! Energy and mass -- relativistic mass, the quantity that informs our notions of gravity, weight, and inertia -- are really, always, the same thing just in different units. If there's more energy in a system, then it weighs more on a scale. Water weighs less than two hydrogen and one oxygen because it's at a lower energy state. This of course includes the energy that is in the form of rest mass.
Rest mass is a form of energy. It can be converted into other forms of energy at a rate equal to m0*c^2. Energy and relativistic mass are always related by the equation E=mc^2.
The enemies of Democracy are