Possible Explanation of Unpredictable Sun 17
Weedstock writes "According to this article on New Scientist, it would be caused by a magnetic field that affect the gas flow in the star. This magnetic field being created in the first place by the gas flow, it results in a loop which cause the star to act unpredictably."
"It?" (Score:2)
It isn't unpredictable. (Score:1)
We just haven't figured it out yet.
These things take complex mathematical models,
and lots of observational data, you know.
Re:It isn't unpredictable. (Score:1)
Re:It isn't unpredictable. (Score:1)
Within the sun there is a finite number of particles, which are made up of a finite number of subatomic particles... and the movement of each particle can be measured exactly if we take in account of all the number of forces acting upon it (which is... you guessed it... finite). Essentially, you would have to make a great deal of computations (...again, finite), but it is possible. The only problems you would get into would be continual motion... if there is such a thing...
That's pretty much the definition of a chaotic system-- tiny changes in initial conditions can have enormous effects on the behavior of the system.
Your two methods of estimation the number of effects coming from a single cause would indicate that there is a finite number of interactions within the star... thus allowing it to be computational. The word you would be looking for to fit the "unpredictable" scenario would be "randomness"
And yes, we will be able to achieve the state of mind which would allow us to compute these chaotic systems... that is if we don't get wiped out by plague, a meteor, or any other disaster, natural or man-made... and the leaders of the world aren't as doubting as you are. Just because our current thinking abilities are still at a very primitive state, doesn't mean we have to doubt our own future... Look how far the human mind has come...
Never underestimate the capability of the human mind...
It IS unpredictable. (Score:2, Interesting)
Within the sun there is a finite number of particles, which are made up of a finite number of subatomic particles... and the movement of each particle can be measured exactly if we take in account of all the number of forces acting upon it (which is... you guessed it... finite). Essentially, you would have to make a great deal of computations (...again, finite), but it is possible. The only problems you would get into would be continual motion... if there is such a thing...
Not unless our understanding of atomic and sub-atomic particles is completely wrong. You can NOT measure "the movement of each particle ... exactly", as explained by the Heisenberg Uncertainty Principle [unr.edu]. There is a limit to the precision to which you can measure the particle's 'movement'. If you somehow measured the velocity of the particle exactly, you would have a very uncertain idea of its exact location, which would also be a major factor in determining that particle's effects on its surrounding particles. Which is of course necessary if your goal is to be able to calculate the movements of every particle in the Sun.
It would not be possible, and not necessary or useful either, to build a complete model that calculates the exact movement of every part of the Sun. We will just keep creating slightly more accurate models over time, until we have one that is "good enough".
Re:It IS unpredictable. (Score:1)
Mapping the velocities and positions of each subatomic particle is almost necessary in fully calculating the motion within the sun. Sine there is a great ammount of fusion going on (well... thats pretty much all the sun is, a fusion reactor), then we have to calculate each particle... or we won't get the full effect...
1. The evolution of such a system is, even in principle, impossible to predict
2. We will just keep creating slightly more accurate models over time, until we have one that is "good enough"
Just a tiny bit of contradicting yourself there...
retraction (Score:1)
2. We will just keep creating slightly more accurate models over time, until we have one that is "good enough"
Just a tiny bit of contradicting yourself there...
didnt realise it was two different people... just thought it was the same one coming back at me... oops
Re:It IS unpredictable. (Score:1)
please learn sophomore physics! (Score:3, Interesting)
Newtonian mechanics has the concepts of "position" and "momentum," but in QM there is only the wave equation. That wave equation can be solved for position or momentum, or both with a bit of "smearing," but the equations themselves incorporate a minimum amount of uncertainty when you try to solve for both simultaneously.
No problem, the equations just describe behavior, not reality, right? Only problem is the "hidden variables" theory was disproved by some clever experiments back in the 30's (iirc).
It's possible that QM will someday be superceded by a new theory... but that new theory has to explain close to a century of experiments that have repeatedly demonstrated that the Uncertainty Principle, or something functionally equivalent to it, is real. In other words, any direct replacement for QM will still show Uncertainty.
Is all hope lost? Not quite - all of these experiments were conducted with tools that themselves incorporated a number of implicit assumptions. It's conceivable that some radically different technology could yield absolute knowledge. But the problem here is that we don't have this technology, we don't know where to start looking for it, and even if we found some instruments in a crashed UFO the concepts may be totally foreign. Perhaps these instruments can precisely measure the snerk and squutl... but there will again be inevitable uncertainty when we convert snerk and squutl to position and momentum.
Re:please learn sophomore physics! (Score:1)
Re:It isn't unpredictable. (Score:3, Interesting)
In addition, it's so difficult to measure the system, that even if one managed to do it, the energy and precision required to do so would ultimately result in a change of the system as you measure it; meaning that the model that you create would no longer be accurate when you were done.
Basically, in any positive-feedback system, precision on the atomic scale is necessary to predict long-term behaviour. Short-term behaviour can be predicted in a gross way, but the length of the prediction is volatile; the speed of the positive-feedback system (in this case, how long it takes a small magnetic domain to become a large magnetic domain) ultimately determines for how long your model will remain reasonably accurate. And measuring things on the atomic scale ALWAYS results in changes at the same scale; it's like taking a gymnasium full of tennis balls and bouncing basket balls around, trying to determine where the tennis balls are from the angles that the basket balls bounce at; you can get useful information that way, but the tennis balls will be bounced around in unpredictable ways while you do it.
Weather (Score:1)
Re:Weather (Score:1)
So perhaps predicting the weather on the sun is an (admittedly fairly non-intuitive) step towards predicting the weather closer to home.