Last night I came across a headline in the WSJ about how this company, UBeam, just raised $10M to create wireless ultrasound phone charges, and it grabbed my attention because it illustrates the fundamental flaw in tech investing right now, namely the enormous disconnect between the investors and the physics behind the technology in which they invest. See, this junior undergrad at U Penn had this crazy idea to charge phones by beaming ultrasonic energy at them. It got picked up by Walt Mossberg and featured at AllThingsD (does the D now stand for Dumb? I didn’t realize…), at which point Marc Andreessen, Mark Cuban, and other tech movers and shakers dumped $10M on them.

Except, here’s the problem. IT’S AN IMPOSSIBLE IDEA. Having done my share of ultrasound physics AND wireless charging work in the past, the first thing that struck me about the idea was that, to transmit any appreciable amount of energy through sound waves, those waves would likely burn you, or at least deafen you, and any other small animals in the vicinity. This is why charging is currently done inside copper wires surrounded by plastic - so you don’t get hurt!

I’m no physicist - oh, wait, I am - but I did a little back-of-the-envelope (ok, front of the paper) calculation this morning trying to figure out how you might be able to do this safely and whether that would result in a useful product. I started with the current standard, Apple’s 5W iPhone charger, as the reference for a useful amount of charging power. Then I took the upper limit of how much ultrasonic energy one can safely transmit (~100 dB SPL). Note that 100 dB SPL is about the equivalent of standing three feet from an operating jack hammer. Now, I know what you’re thinking, it’s ultrasound, so we can’t hear it. But your cats and dogs can, especially around 20 kHz where ultrasound transmits efficiently through air (it drops way off the higher in frequency you go). In fact, at that level, the neighbors’ cats and dogs would probably hear it, too. Good luck getting them out from under the bed once you turn on your UBeam.

So given a 100 dB SPL transmitter (goodness knows how much electricity that will need… anyone want to install a three phase outlet by the bed?) and the loss numbers quoted in UBeam’s patent applications, I did the following calculation.

I used nice round numbers and assumed things like perfect focusing and a 1 square meter transmitter (seriously… 3 feet by 3 feet?? The cracks are showing…) and then calculated how much power you’d end up with at the phone, and it turns out to be about 100x less than the standard wall charger. That means it’ll take 100x longer to charge your phone with one of these, assuming you’re willing to deafen your dog and mount a 9 square foot speaker on the wall. Instead of a charge taking overnight, with UBeam it’ll take three months. Oh, and whatever you do, don’t ever stand in front of it or you might get killed!

So how does this illustrate a fundamental problem in technology investing - hell, in society - right now? The answer is obvious - crazy ideas that are physically impossible are raising huge sums and getting tons of traction on nothing but dishonest PR, while great ideas that have huge potential are sitting by the wayside trying to rise above the noise. Investment decisions are made for all these ancillary reasons, like what the founders look like on YouTube videos and how well they rattle off meaningless tech jargon. Meanwhile no one is doing the hour’s worth of basic math to see if their ideas have any legs. We’re seeing larger and larger hoaxes getting more and more support, whether it’s D-wave’s (not actually a) quantum computer or the the fact that vaccination rates among California’s children have dropped to historically low levels. These trends have serious consequences, from wasting investment resources to endangering the lives of children.

America’s always been a nation that gloms onto the latest fads without the slightest need for supporting evidence (Yogurt enemas, anyone?). But when $10M can get thrown into some idea without even the slightest sanity check, I’d say we have a bigger problem. I once had the opportunity to see Mike Lazaridis speak when I was in school, and the theme of his talk was physics-based design. Basically, you can dream up whatever you want, but no matter how much money you have, you’ll always be constrained by physics. That lesson stuck with me, and it’s one that seems to be missing from today’s technology investment world, where people think that because they have money, they can buy their way out of basic physics. Not so. Physics always wins in the end.