Reverse Polarity: Difference between revisions

* The Earth literally reverses the polarity of its magnetic field every couple of hundred thousand years. Scientists are not entirely sure what happens to life when it happens, but you can bet it will be the solution to ''somebody's'' problem.http://en.wikipedia.org/wiki/Capillary_electrophoresis

** Similary, the magnetic field of the sun itself rearranges itself so that at any point, in eleven years it'll be the exact same pattern, only backwards (and when it goes another eleven to twenty-two years, it gets back to where it started).

* Thermal optics can also reverse polarity. Doing so switches between White Hot and Black Hot (Meaning that heat shows up as white or black, respectively.)

* In an MRI, the spinning dipoles slowly come out of sync with each other over time, which makes it difficult to observe them. The solution is to use a burst of radiation to reverse the polarity of the spin, which means that all the dipoles will sync up again after the same amount of time between the initial burst and the polarity reversal. This process can be repeated until other sources of error eventually overwhelm the signal.