The topic about cannonballs - Why did they shoot with stone, if cast iron was easier to do - - got a very unexpected continuation.
There is such an effect. Usherenko effect
In 1974, the director of the Institute of Impulse Processes of the Minsk Concern "Powder Metallurgy", discovered that when bombarded with the help of an explosion with metal sand, individual particles of sand penetrate very deeply into the metal! Particles per 100-10,000 calibers. (with the usual it is 6) This releases a huge amount of energy. There is a lot of things there, and the X-ray film is exposed and new elements and plasma jets and so on are formed. The main point is that a colossal amount of energy is released, much more than the kinetic energy of grains of sand.
A lot of scientists are fighting over this effect. Many theses have been defended and models have been created and experiments have been carried out. There is an effect. And he violates the classical idea …
To understand that this is not pseudoscience and other my favorite conspiracy theories - here is a link to the article "A NEW LOOK AT THE EFFECT OF USHERENKO LN Rainkina, Ph. D., Associate Professor of the Russian State University of Oil and Gas. IM Gubkina"
Promotional video:
How can this be related to the stone cannonballs?
So. There is a cast iron cannon - a healthy fool made of cast iron with reinforcement belts in the right places - calculated on an ancient calculator (I wrote about it here). And the cores for it are stone? Why not cast from the same cast iron?