Existing proposals use a plumb bob mechanism or directed light traversing the ergosphere in analogy with sound amplification via linear or in this case rotation

Existing proposals use a plumb bob mechanism or directed light traversing the ergosphere in analogy with sound amplification via linear or in this case rotational energy transfer rather than relying on the feasibility of a complete sphere to absorb any randomly directed radiation from the interior or accretion disk: https://news.ycombinator.com/item?id=30402679 https://news.ycombinator.com/item?id=30402679