I think it's important to note this was from last October (2014). And here is somewhat of a response blog post from Suster (investor) around that time:
This article by Suster is awful. The take down discussed physics, Suster discusses "doubters". The take down did not suggest it wasn't possible to transmit energy through sound waves, simply that it seemed very impractical to be able to charge a phone without pretty drastic side effects.
Another point though, the CTO of Ubeam had a MS in nuclear engineering from MIT and was a deputy director of innovation at Raytheon -- I expect he knows a bit of physics too. Their VP of Engineering has a PhD in acoustics and they employ other specialist PhD electrical engineers..
I appreciate a good 'take-down' as much as the next person but I don't think it's as clear cut as the napkin-math suggests.
You are likely right, it probably isn't clear cut. But if there is a response to his discussion of physics, it should be around physics, not the fact that he is a "doubter". The world would be in an awful place without any "doubters".
http://www.bothsidesofthetable.com/2014/11/05/the-case-for-o...