Question

The inability of this theory’s ideal form to explain reconnection led to the creation of Sweet-Parker and Petschek models. For 10 points each:
[10m] Name this formalism whose ideal version ignores terms proportional to diffusivity, resulting in a simpler form of Ohm's Law and the induction equation.
ANSWER: magnetohydrodynamics [or MHD; accept ideal magnetohydrodynamics or ideal MHD]
[10h] By analogy to rubber bands, the stretching, twisting, and folding of these constructs creates a dynamo. Álfven's theorem constrains the size of these surfaces by implying that a certain quantity is conserved.
ANSWER: magnetic flux tubes
[10e] Ideal MHD is a good approximation when the magnetic analogue of this quantity is large. Fluids transition from laminar to turbulent flow when this value is around a few thousand.
ANSWER: Reynolds number [accept magnetic Reynolds number]
<Science - Physics>

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2024 ARGOS @ Brandeis03/22/2025Y310.0067%33%0%
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Data

I wish it were possible to freeze time so I would never have to watch you retireCLEVELAND, THIS IS FOR YOU!001010
Thompson et al.UBC001010
throw away your cards, rally in the streetsAw we're so sorry to hear that maman died today, she gets five big booms001010