It can be - did a graduate paper on the topic some years ago, looking at it through the Dirac sea - and appears others are taking an interest in the topic too -

It can be - did a graduate paper on the topic some years ago, looking at it through the Dirac sea - and appears others are taking an interest in the topic too - here's a nice paper which gives a good overview: http://iopscience.iop.org/1742-6596/306/1/012047/pdf/1742-6596_306_1_012047.pdf http://iopscience.iop.org/1742-6596/306/1/012047/pdf/1742-65...