I'm assuming that you're looking for an answer that digs a little deeper than "magic"?
[With one forefinger bent below his lower lip. There's genuinely no sass in his mind with that one - come, now, magic is a perfectly valid just-as-it-is answer, but in terms of purpose or engineering, well... the former's not exactly something it's his business to know and as for the latter, honestly, magic's never really been of interest on a scientific level to him in general, especially in the wake of having had a friend he could've fallen back on for input on that front, once upon a time.]
no subject
[With one forefinger bent below his lower lip. There's genuinely no sass in his mind with that one - come, now, magic is a perfectly valid just-as-it-is answer, but in terms of purpose or engineering, well... the former's not exactly something it's his business to know and as for the latter, honestly, magic's never really been of interest on a scientific level to him in general, especially in the wake of having had a friend he could've fallen back on for input on that front, once upon a time.]