Using transducers, uBeam’s device, which is not yet on the market, converts electrical energy into ultrasound waves and then back into electrical energy. (Perry gives a more detailed explanation here.) Back in October 2014, a physicist named Danny Rogers wrote a Tumblr post in which he questioned the technology. “Putting $10M into uBeam illustrates everything that is wrong with tech investing today,” he wrote. The company has since raised even more money, bringing its total funding to $24 million.

Lately, more skeptics have piled on. Last month, Los Angeles Business Journal ran a story with the headline, “Skeptics zap wireless charging.” The engineering magazine IEEE Spectrum declared, “Experts still think uBeam’s through-the-air charging tech is unlikely.”

The questioning of uBeam has focused on two issues: the argument that the technology violates laws of physics and isn’t actually possible, and the fear that the technology is unsafe and could cause health risks for people.

On Wednesday, Meredith Perry addressed these criticisms directly in an on-stage interview at Fortune‘s Most Powerful Women Next Gen conference in San Francisco.

“When we think about sound we don’t get scared,” she said, “but when we think about sound as wireless power, people get scared… Suddenly, people are talking about, ‘What’s it going to do to me? Am I going to get cancer? Am I going to become infertile?'” The answer, she says, is emphatically no. But she acknowledges that people get concerned easily because, “Wireless power is this mystical, scary thing that we’re unfamiliar with.”

Another reason people have become so heated about uBeam is that the product the company has promised has never been seen. If it’s real, Mark Cuban believes it is “a zillion-dollar idea.” Yes, there are wireless charging mats, but they require you to lay your phone on a surface. What Perry has said uBeam will do is “true” wireless charging, where your phone’s battery can charge from across a room, sans wires. The charging will not work through walls, but Perry told Fortune in an earlier interview, “Even working in one room, think about where that can be applied. Not only within homes and rooms, but think about airports, conference halls, concerts. And you can charge an arbitrary number of devices at any time.”

She’s right: If it really works, and safely, the product will be a game-changer. No one with a smartphone would want to go without.

At the Fortune conference, Perry continued: “Does this break the laws of physics? Is it unsafe? The answer is no, the technology does not break the laws of physics… if it broke the laws of physics, that’s something you can find out pretty early with basic principles and math. Those who thought this breaks the laws of physics didn’t have understanding of how the [uBeam] system worked, or what the basic specs are.”

Speaking of tech specs, earlier this month uBeam released some of its specs for the first time, in a TechCrunch article. The company had never done so before, because, as Perry said, “We’re a private company, and so, why would we? Would Apple or Samsung come out a year in advance and say, ‘Hi, next year we’re coming out with the iPhone 7 and it’s going to look like this and here are the dimensions.’ No, you just don’t do that. And no one is asking them how their technology works.”

So, why now? “There’s been a lot of excitement about the technology recently in the press, we’ve raised some money from some pretty high-profile people… And then the light shines on you,” said Perry. In other words: With negative press mounting, uBeam apparently decided to release some information about its science to prove its legitimacy.

Perry was asked if she feels that she and the company have been unfairly scrutinized. “Well, since I am a scientist, I can’t say yes or no, because I have no proof to back it up,” she said. “I’ve got a gut feeling that the answer might be yes, but I also know I’d probably be under attack for saying that.”

Despite the scrutiny, there are also some posts from the science community that refute the cynics. After the Danny Rogers post last year, Miriam Boer, a scientist who has collaborated with Rogers, wrote her own lengthy Tumblr post in response. At one point, Boer wrote, “Let’s settle this once and for all: is it physically possible to charge a phone with sound waves? Yes.” As for health risks, she pointed out that because uBeam had not yet said exactly what its power measurement would be, the rest is still merely speculation. “Without a current measurement, there is no way to understand how much power is being transmitted.”

Perry, in her Fortune panel, alluded to the same basic premise: Any theories supporting or questioning uBeam’s science are only theories until there’s an actual concrete product. “In the end,” she said, “it’s binary. You come out with the product and it’s either in your hand or it’s not.”