Monday, October 13, 2014

Scent Of Beauty...

This is obviously a joke.

From the previously post "Magnetic Field In General, HuYaa",

\(\cfrac { \partial B }{ \partial \, t } =-i\cfrac { \partial \, E }{ \partial x^{ ' } } \)

\(\cfrac { \partial B }{ \partial \, x } \cfrac { \partial x }{ \partial t } =-i\cfrac { \partial \, E }{ \partial x^{ ' } } \)

Since,  \(-i.i=1\),

\(\cfrac { \partial B }{ \partial \, x } \cfrac { \partial x }{ \partial t } =-i\cfrac{1}{(-i.i)}\cfrac { \partial \, E }{ \partial t } \cfrac { \partial t }{ \partial x^{ ' } } \)

\(\cfrac { \partial B }{ \partial \, x } \cfrac { \partial x }{ \partial t } =\cfrac { \partial \, E }{ \partial t } \cfrac { 1 }{ i } \cfrac { \partial t }{ \partial x^{ ' } } \)

and  \(i\) rotates  \(x^{'}\)  to  \(r\),  the radial distance,

\( \cfrac { \partial B }{ \partial \, x } \cfrac { \partial x }{ \partial t } =\cfrac { \partial \, E }{ \partial t } \cfrac { \partial t }{ \partial r } =\cfrac { \partial \, E }{ \partial t } \cfrac { \partial x }{ \partial r } \cfrac { \partial t }{ \partial x } \)

\( \cfrac { \partial B }{ \partial \, x } (\cfrac { \partial x }{ \partial t } )^{ 2 }=\cfrac { \partial \, E }{ \partial t } \cfrac { \partial x }{ \partial r } \)

Integrating by \(x\)  and by  \(r\),

\( \iint { \cfrac { \partial B }{ \partial \, x } (\cfrac { \partial x }{ \partial t } )^{ 2 }d x\,d r=\iint { \cfrac { \partial \, E }{ \partial t } \cfrac { \partial x }{ \partial r }d x\,d r }  } \)

Since, for an electromagnetic wave,

\( (\cfrac { \partial x }{ \partial t } )^{ 2 }=c^ 2=(\cfrac { 1 }{ \sqrt { \varepsilon _{ o }\mu _{ o } }  } )^{ 2 }=\cfrac { 1 }{ \varepsilon _{ o }\mu _{ o } } \)

\( \iint { d B } \,d r=\varepsilon _{ o }\mu _{ o }\iint { \cfrac { \partial \, E }{ \partial t } d x\,d x } \)

\( \int { B } \,dr=\varepsilon _{ o }\mu _{ o }\cfrac { \partial  }{ \partial t } \left\{\iint {E }\,(dx)^2 \right\} \)

If  \(\int{B}\,dr\)  is around a square loop with length  \(dx\) and height also  \(dx\),  bear in mind that \(r\) is perpendicular to  \(x\),  then,

\( \oint { B } \,dr=\varepsilon _{ o }\mu _{ o }\cfrac { \partial \,  }{ \partial t } \left\{ \oint { E } \,dA \right\} \)

Which is Maxwell's  displacement current.  This is the last of Maxwell's Equations not considering current density,  \(j_e\).

The maths is not rigorous but it seems to indicate that dynamically all that is needed is,

\(\cfrac { \partial B }{ \partial \, t } =-i\cfrac { \partial \, E }{ \partial x^{ ' } } \)

to define the  \(B\)  field established by moving charges.  I have to think about this one.