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## Main Question or Discussion Point

Hi!

I can't wrap my head around the formula [tex]\textbf{D} = \epsilon \textbf{E} + \textbf{P}[/tex].

The electric field, [tex]\textbf{E}[/tex], goes through the dielectric. It polarizes the atoms/molecules, which creates a field going the opposite way, which cancels out at least part of [tex]\textbf{E}[/tex] (right?). Now, for some reason textbooks say that this polarization field [tex]\textbf{P}[/tex] is defined as pointing from negative to positive, thus going the

If [tex]\textbf{D}[/tex] is supposed to be the resulting field in the dielectric, why are they added and not subtracted? Or am I misinterpreting the point of [tex]\textbf{D}[/tex], and it really stands for the original field

Thanks!

Seb

I can't wrap my head around the formula [tex]\textbf{D} = \epsilon \textbf{E} + \textbf{P}[/tex].

The electric field, [tex]\textbf{E}[/tex], goes through the dielectric. It polarizes the atoms/molecules, which creates a field going the opposite way, which cancels out at least part of [tex]\textbf{E}[/tex] (right?). Now, for some reason textbooks say that this polarization field [tex]\textbf{P}[/tex] is defined as pointing from negative to positive, thus going the

*same*way (with, not against) the original field.If [tex]\textbf{D}[/tex] is supposed to be the resulting field in the dielectric, why are they added and not subtracted? Or am I misinterpreting the point of [tex]\textbf{D}[/tex], and it really stands for the original field

*plus*whatever the polarization reduces?Thanks!

Seb