Physicist finds new laws of physics, patents toys

Question

Looking for a short story, 40 years old or older: A physicist finds some new law of physics and is told he can't patent it. So he first builds a toy airplane that actually flies without any visible engine, but based on the new law of physics he discovered (anti-gravity), and patents it and makes money. Nobody can explain why the airplane flies, but anyone can copy it following his patent which just says that it works based on some new law of physics.

He makes a second toy: A transparent plastic ball separated into two separate compartments, and inside a small ball which sometimes moves from one compartment to the other (teleportation). A third invention is a gambling machine, where most people lose money, but a small number of people (with hidden ESP talents) can actually predict the outcome and win. All this to convince the government that he should get a patent for his new law of physics.

Answer 1

The first paragraph sounds a lot like this short story, "Toy Shop", by Harry Harrison, which is also the one Broklynite is talking about.

"Sold, my boy!" the colonel said, slamming three bills down on the table. "I'll give that much for it no matter how it works. The boys in the shop will get a kick out of it," he tapped the winged rocket on his chest. "Now really—what holds it up?"

The demonstrator looked around carefully, then pointed. "Strings!" he said. "Or rather a black thread. It runs from the top of the model, through a tiny loop in the ceiling, and back down to my hand—tied to this ring on my finger. When I back up—the model rises. It's as simple as that."

... later

The thread broke again when Biff tried it, which got a good laugh that made his collar a little warm. Someone mentioned the poker game.

This was the only time that poker was mentioned or even remembered that night. Because very soon after this they found that the thread would lift the model only when the switch was on and two and a half volts flowing through the joke coils. With the current turned off the model was too heavy to lift. The thread broke every time.