Downing once invented LegoPress, which can quickly assemble three-dimensional PPTs, but this is the first time he has used three-dimensional means to display things, and it is not a building block. Everyone looked at it, and it was actually a huge cloth.

The giant cloth was 5 x 5 meters in size, with six horns, each with a fulcrum, tightly rolling into a membrane. Everyone was puzzled, and they didn't know what this film had to do with simulating the solar system and galaxies.

Under the lens of the camera, Downing's every move on the large cloth film can be transmitted to the audience's eyes through the guò screen, and can also be transmitted to Internet terminals around the world. The whole world has been whetted by Downing, if you understand the question he asked, a question that Newton, the discoverer of gravity, was also puzzled by: Why can gravity extend far and wide into the universe?

When the large cloth film was deployed, Downing finally spoke, saying: "I have placed a soft magnet on this cloth, so give a disc magnet running on it a muzzle velocity, and it will be able to do an approximate uniform linear motion, like Newton's description." ”

He took out a small disc magnet and pushed it gently, and sure enough, the small round magnet flew to the other end of the cloth film at a uniform speed. This kind of thing is not unusual, under the auspices of Tang Ning, magic shoes and everything have been popularized, and everyone is no longer surprised by this physical phenomenon.

He continued: "Just now we simulated what an object would look like without gravity, and now, gravity is coming! ”

At this moment, he took out a large disc from the bucket next to the cloth film, the size of a hat and the height of a hat, which looked very heavy, and its weight could press a large hole in the middle of the cloth film. It is conceivable that such a large pit must be the deepest in the middle, and the farther away from the large disc it becomes, the shallower it becomes.

At this time, he put down a small disc on the edge of the shallow cloth film, and the small disc slid along the edge of the shallow pit to the large disc, as if attracted by gravity, and everyone finally understood how to simulate gravity.

Downing: "See? The closer you get to the big disk, the greater the gravitational pull on the small disk, isn't it just like the gravitational pull of our earth or the sun? ”

At the edge of the cloth film, the acceleration of the small disc is very slow, and when it is led to the deep pit, the acceleration is obviously much larger, which intuitively shows the properties of gravity, and Tang Ning puts the small round magnetic block again and again so that everyone can see clearly.

It turns out that "the bigger the pit" means the greater the gravitational force, and this "metaphor" is really coincidental. At this time, physicists thought it was just a metaphor.

Just now Downing just put the small magnetic block on the edge of the cloth film, and now the simulation is going to go further, he gives the small magnetic block a muzzle velocity tangent to the direction of the "pit gravity", and as a result, the small magnetic block has an angular momentum, and no longer falls into the big pit, but rotates around the big pit, which is just like the earth revolving around the sun.

It's getting more and more interesting, physicists seem to have captured something, as if this simulation system doesn't seem to be funny.

Of course, now Downing stepped up his efforts and released smaller magnetic blocks. The small magnetic block just now is renamed the medium magnetic block.

The medium magnetic block revolves around the large magnetic block, and the medium magnetic block itself also creates a pit on the magnetic cloth film, which is enough to form a pit gravitational force on the small magnetic block, and the result is that everyone sees a magical phenomenon, the small magnetic block revolves around the medium magnetic block, and the medium magnetic block revolves around the large magnetic block, which is almost perfectly similar to the surface of the sun, the earth and the moon.

Downing's real yàn cleverly uses magnetic force to suspend the "celestial bodies" in the air, so that their rotation will not be stopped for a long time without losing energy due to the friction with the cloth film, giving the audience a strong impression that this is simply a miniature version of the small solar system and the real solar system.

Tang Ning didn't think that such a simulation was real enough, so he grabbed a large handful of medium magnetic blocks and sprinkled them, and the mini solar system suddenly had more than a dozen mini planets. At this time, he said: "Now to show you why the rotation of the planets in our solar system is mostly the same." ”

Then, he grabbed a large handful of the middle magnetic blocks, this time giving the opposite angular momentum to represent the planets with opposite rotations. A large number of celestial collisions were immediately set off in the cloth, and the original opposite revolution was very easy to cause planetary collisions, and then lost angular momentum and fell into a deep pit.

After a short period of time, almost all the directions of revolution were unified! This time the demonstration was more profound, and physics enthusiasts were amazed.

The next step for Downing to demonstrate is the series related to the original problem, where he takes a small sun and puts it in the film, and the result is, of course, a large crater, and the nearby planets fall into it, at which point he says: "Looking at the replay of the high-speed camera, you can watch the formation of a new crater and imagine how the gravitational field is formed." ”

During the high-speed camera playback, it is natural to see that with the appearance of the small sun, the pit on the cloth film is getting bigger and bigger. The gravitational force of the crater appears very quickly, but there are also numbers, can't the high-speed camera see it? However, as long as the crater appears, the gravitational attraction on all the "celestial bodies" on the membrane will be instantaneous, and no matter where the celestial bodies are on the membrane, they will immediately fall into the crater.

Downing: "If you think about it, is this like a gravitational force with a speed of 'instantaneous'?" We can guess that the appearance of celestial bodies in space is like flattening space, and the speed of this flattening can be measured by the speed of light, but once space is flattened by celestial bodies, the propagation of gravity is no longer limited by the speed of propagation, and the entire universe is affected by it, instantaneously. ”

At this time, physicists already had some signs of understanding, but this conjecture was too absurd, and no matter how witty the scientist was, he could not grasp the mystery for a while, so he could only say it word by word by Tang Ning: "Actually, this is not a similar problem, this is the only solution."

Yes, our space is a membrane that can be flattened by anything that has mass, and the greater the mass, the more space is flattened, and then this pit space has a gravitational pull on everything in the universe, no matter how far away it is. However, the film is three-dimensional, and we are in it and cannot see it visually. ”

This is an earth-shattering new theory of physics, involving the most basic thing in physics, gravity, and all scientifically literate people should be shocked by this, in fact, from the venue to all nodes of the global Internet, those who understand this passage are shocked.

If you still have the energy to pay attention to the expressions of others, you will find that even Master Tang's two senior apprentices, Maxwell and Miss Faraday, are extremely surprised by the new theory of this three-dimensional membrane space. Master Tang actually hid this mystery and told it to others for the first time.

Also, if there are no radio astronomical telescopes that show the world a magnificent picture of the universe of billions of light-years, how can it appear that the membrane theory is great and glorious and correct? Without a pit-like space, how can gravity be transmitted to seemingly ridiculous distances millions of light-years away?

A typical non-native cluster of galaxies, with a diameter of 8 million light-years, up to 80 times the diameter of the Milky Way, is able to coalesce into a cluster because of the ubiquitous gravitational pull.

Only a membrane space that can be flattened by mass can explain such a wide range of celestial bodies. On the surface, the gravitational pull of the supercluster can span 8 million light-years in an instant, and it does not always attract objects on the edge, otherwise the huge angular momentum of the celestial bodies would have caused the objects to escape from the supercluster.

The power of this cloth is so great that it has convinced a large number of physicists to believe in the incredible retractable space, but few scientists believe the Duchess Ron's paper explaining the retractable space deduced from the constant speed of light.

Downing didn't stop there, he said: "I believe that some people have bought into the idea that gravity is indeed caused by the collapse of space, then the question arises - why is there only gravity in the world, but not the repulsion of everything?"

We all know that there is both attraction and repulsion in the electromagnetic field, and the same is true for the weak force between molecules, why is there no corresponding repulsive force in gravitational force?

The so-called correspondence, we can still see it in this cloth film! See! ”

Tang Ning stuffed a pillar that had been prepared to the bottom of the cloth film, and this time created a small cloth peak, which corresponded to the cloth pit. In the eyes of all the people, Tang Ning, as everyone predicted, put the small magnetic block on the mountainside of the cloth peak, and it is conceivable that the small magnetic block slid down quickly, and from the two points on the cloth, it was like a repulsive force.

Downing: "It's very much like universal repulsion, isn't it?" However, we can see the gravitational force when we look up at the sky and look down at the earth, why don't we see the repulsive force? Is there any?

I think: Yes. Now that I've shown you how big the universe can be, let's look a little further and see what happens millions of light-years away. At such a long distance, we have to introduce a new ranging method. A way to transcend Cepheid variables, because we can no longer see specific stars, only the light emitted by the galaxy as a whole.

Can you measure distance just by seeing the whole light? Yes. Let's take a look at these two spectrograms and carefully study whether they are a little subtle. ”

He showed on the big screen two spectral maps of distant galaxies like a rainbow, red, orange, yellow, green, blue, purple, and 99% of ordinary people could not see the difference between them. After everyone had gathered enough energy to work hard to find the difference between the spectral diagram for a long time, Tang Ning came out with the key points.

He marked the key values of equal colors in the picture, and everyone could see the difference at once, and the seven color values in the second picture were moved to the red end as a whole.

Downing: "The wavelength of the light wave has changed, what's going on?" In 1842, the Austrian scientist Doppler discovered a phenomenon in which he noticed that the whistle of a train speeding towards us would become shrill, while the whistle of a train moving away from us would instead become low and soothing.

In physical terms, the sound waves of the whistle are changed by moving closer and farther away. Let's think, what is the wavelength? We can imagine the distance between the crests of the waves or between the troughs, that is the wavelength, and this distance is shortened when the train is speeding by.

It means that the wavelength becomes shorter, and the energy of the sound wave is also shorter, and the higher the frequency of the vibration, the greater the energy, and the more intense it is when it hits our eardrums, so there will be a frequency conversion phenomenon. Only when the speed reaches a certain distance will the frequency conversion of the sound wave be experienced.

This is called the Doppler phenomenon. This phenomenon can also occur on light waves. The premise is that it's fast enough. Only the interplay of celestial bodies can give our optical spectrum analyzers a noticeable frequency conversion. If the spectrum collectively shifts towards the red end, it means that the wavelength is getting longer, indicating that the celestial body is moving away from us, and if the spectrum shifts towards the blue end, it means that the wavelength is shorter, indicating that the celestial body is moving closer to us.

We analyzed the spectroscopy of hundreds of thousands of distant galaxies and found that after a certain range of distances, galaxies began to show large-scale redshifts at a distance of tens of millions of light-years. The tighter the redshift, the faster the celestial body is receding.

If these astronomical phenomena correspond to the gravitational force, it will appear such a phenomenon - the farther away the galaxy will recede, the faster it recedes, because the universal repulsive force is to hold up the membrane space, and no matter how far and fast it is, it can also exert the repulsive force instantaneously, and this repulsive force is endless, so the speed of the galaxy in the distance is faster.

In fact, most of the hundreds of thousands of galaxies we track conform to this law, and we can say with some certainty that they are driven by forces that are opposite to gravity, and we can infer from the simulations that the two forces are essentially the same. The difference is simply whether our membrane space is collapsed by mass or protruded by energy.

If we think of mass as the source of space collapse, we see energy as the source of space bulge, and since this energy is not the energy we see in ordinary people, I call it 'dark energy'. ”

When Downing showed the hundreds of thousands of numbers tracking galaxies, some astrophysicists who understood involuntarily stood up from their seats and stared at the screen, as if trying to see the numbers more clearly.

Tang Dashen actually discovered the power of universal repulsion? This is a great discovery comparable to Newton. It is natural to speculate that only a membrane-like space can perfectly explain the ultra-long-range gravitational pull, and that the collapse of the membrane indicates a membrane bulge