Tian Hong walked to the podium and began to carefully weigh every stone and branch, his expression was unusually focused, not stopping to think.

The physics teacher stood aside, looking coldly at the school's biggest problem teenager, he didn't interrupt him, he really wanted to see what tricks this problem teenager had, whether it was before or now, he hated this problem teenager, in his mind, Tian Hong was a garbage.

The process of thinking was long, and twenty minutes had passed, and Tian Hong weighed more than ten fast stones and miscellaneous wood.

Finally, Tian Hong began to arrange, and the branches and small stones fell one by one in his hands, forming an irregular oval.

"That's it!"

Tian Hong put the last slightly larger stone in the middle, and breathed a long sigh of relief, this rejection formation actually took forty minutes, that is to say, the time of this physics class was occupied by him alone.

This is also Tian Hong's way, although the requirements for materials are not very high, but it is not without requirements, simply put, the better the materials, the shorter the time for arrangement, like these stones and branches that have not been selected, to arrange a rejection array, it takes much more time than the selected materials.

In ancient times, the stones and timbers of the city gate were carefully selected, every stone was polished, and every piece of wood was trimmed.

"Tian Hong, this is your perpetual motion machine?" The physics teacher said with a mocking expression.

"Haha......"

"Haha......"

……

Hearing the physics teacher's words, a group of students immediately gloated and burst into laughter.

"Dear teacher, this is just a perpetual motion machine, and it is precisely because I don't understand the principle that I hope you can solve the doubts in my heart." Tian Hong said respectfully.

"Okay, is there anything special about this so-called perpetual motion machine?" Seeing Tian Hong's respectful demeanor, the physics teacher couldn't help but feel a little uncomfortable, and put away the mockery.

"Outside forces cannot enter this elliptical circle unless they are strong enough to destroy it, for example, if I take a book and fall from the top of the circle, the book will not fall at a vertical angle, but will slide back around the circle......"

Tian Hong picked up a book on the podium, held it high above the circle, and then let go......

"Peng!"

The book fell, and as it fell to the top of the circle, it slid sideways, as if resisted by an invisible force, first on the podium, and then on the ground.

There was an exclamation from under the podium, especially the young man who helped Tian Hong pick up the branches just now.

If everyone thought it was magic at the beginning, now the situation is very different, everyone knows that no matter how advanced a magician is, he needs props when performing, and cooperation needs to be coordinated, but just now Tian Hong really did an incredible thing with just a few stones and branches.

The physics teacher also looked at the rejection array on the table with a blank face, dumbfounded and speechless.

Everyone knows that gravity is one of the intrinsic essences of mass. Each object is necessarily attracted to the other. Although the nature of gravity has yet to be determined, its existence and role have long been recognized. Objects that are close to the Earth, without exception, are attracted towards the center of the Earth's mass. Because any object on the surface of the earth is really insignificant compared to the mass of the earth itself.

That is to say, any object that approaches the earth will attract to the earth, and in general, in the absence of external forces, objects of a certain mass will fall at a near-vertical angle, such as apples in an apple orchard.

Obviously, the angle at which this book falls without the influence of an external force is not a vertical angle, which has defied the common sense of physics.

"Teacher, you can try it too." Tian Hong reminded.

"Good!"

The physics teacher's expression became serious and solemn, and after thinking about it, he picked up a piece of chalk, compared to the shape of the book, although the chalk is small, it is less susceptible to external forces, after all, when the page is opened, it is easy to affect the vertical angle of the book falling.

Looking at the chalk in the physics teacher's hand, the atmosphere in the classroom became tense inexplicably, and everyone's eyes fell on the physics teacher's hand.

"Sand ......"

A slight frictional sound that was so slight that it was inaudible, the chalk fell from the physics teacher's hand, without any force, and was completely free falling.

Miracles struck again, and the chalk drew a very distinct semicircle in the air, as if there was a transparent glass cover in the air.

"Smack!" The chalk slipped onto the podium and then fell to the ground.

This time, the physics teacher was completely shocked, and a pair of eyes were fixed on the rejection array on the podium.

"Can I touch it?" The physics teacher felt that his voice was a little hoarse, and his throat was a little dry.

"Of course you can, but if you exert too much force, it will collapse, unless I find my own materials to arrange, but as long as I don't deliberately destroy it, it can last for a long, long time, as for how long, I don't know, maybe years, maybe decades, or hundreds, or even thousands of years, tens of thousands of years......"

The physics teacher carefully stretched out his hands and stroked them lightly on the oval circle, he felt as if his hand was touching a transparent barrier, it felt very soft, a little hard, but his hand could not enter at all.

Marvel!

Marvel!

The shock on the physics teacher's face turned to horror, and he tried to move the stones and branches with his hands, but the stones and branches stuck to the podium as if they had taken root.

"Teacher, as long as you don't destroy it, the stones and branches, and the podium, there will be a whole between the three, and you can shake the podium."

The physics teacher shook the podium with a cautious expression.

Sure enough, the stones and branches did not slip, as if they were fixed with glue.

"Is there any way you can access this force?" The physics teacher controlled the crazy beating heartbeat, looking at Tian Hong, the trace of ridicule at the beginning had long since disappeared, replaced by a kind of awe.

In this world, no matter who does Tian Hong, he can gain enough respect, which has broken the laws of nature and physics.

"It's simple."

Under dozens of pairs of eyes, Tian Hong bent a finger and slowly inserted it into the transparent barrier, and then, with a flick, a small stone flicked.

"Now, its energy is gone."

"Really?" With a look of disbelief, the physics teacher touched the imaginary barrier with his hand, and sure enough, the barrier disappeared, and his hand could drive straight into the stone.

There was an eerie silence in the classroom, and people were oblivious to the bell ringing at the end of class.

……

ps: Make up all the chapters you owe in front of you today!