YouTube Meredith Perry, founder of uBeam.

Last week, a startup called uBeam, working on way to let you charge your iPhone without plugging anything into a power outlet received a $10 million investment from Upfront Ventures.

It had already recieved about $1.7 million from a bunch of famous angels.

uBeam is the latest moonshot startup darling in the Valley, founded by 25-year-old Meredith Perry . Angel investors include Yahoo’s Marissa Mayer and Zappos co-founder Tony Hsieh.

Perry is working on something unprecedented. She is creating a device that will convert electricity into ultrasound, meaning sound waves not audible to the human ear, beam them into a charging device that will convert them back into electricity to power your mobile devices.

The device will require a charger (which can be attached to a wall) and a receiver put on each device you want to charge. You are free to roam about the room with your device, even as it charges.

But a physicist, named "Danny" has posted a blog called " How putting $10M into UBeam illustrates everything that is wrong with tech investing today." He argues that the physics of uBeam at best won't work and at worst, will be unsafe for your family, especially your pets:

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!

Other folks in the tech industry, also physicists, are already disputing Danny's post.

"There's almost nothing right about his physics. It's mind-boggling," one of them tweeted.

The whole thing has sparked a big discussion on Hacker News, Tumblr and elsewhere on if venture capitalists really have the technical chops to recognize true scientific breakthroughs from ideas that are fundamentally flawed.

When VC Mark Suster wrote about the $10 million investment on Medium, he called it "the most ambitious project I’ve seen since I became a VC." (He joined the firm in 2007 after selling the startup he co-founded, Koral, to Salesforce.com.)

uBeam was the "largest A-round check" Suster ever wrote, he said. So he lined up experts to help him investigate the company and its tech before investing. He wrote:

Did the physics actually work? Check
Was it safe? Well … for starters it is just an inaudible soundwave being transferred – as in the kind also used for women during pregnancy. It also happens to be how your car likely tells the distance to objects when you park or if you have a side assist whether you can change lanes safely. Check