A debate that lasted two thousand years, did the atom really exist?

Author: Ji Yang

Atom: fantasy or real?

Nuclear energy is also called atomic energy, which starts with people's exploration of atomic and atomic nuclear energy. But until nearly 100 years ago, many scientists did not believe in the existence of atoms.

In fact, as early as 2000 years ago, the ancient Greek scholar Democylt believed that all substances were composed of inseparable small particles called atoms [1].

However, the atoms that Democyte believes is endless, there are many shapes, concave, convex, like glasses, like hooks, which are very different from the atoms we are talking about today, but His view has become an important root of ancient Greek atomic theory [2].

(Of course, another saying that the earliest theory of atomicism was Democyt's teacher, but there was no clear record, so it is generally speaking of more Democylt).

However, things like atoms are too small, and no one has seen atoms and molecules. Therefore, for a long time, atomic theory is the same as other material origin, just hypothesis and guessing.

Until more than 2000, John Dalton once again pushed the atomic theory to the front desk. Dalton also believes that all substances are composed of atoms, and atoms cannot be divided and cannot be destroyed.

Unlike Democylit, Dalton did not put forward this view out of thin air. By studying distilled water, he found that each water particle was the same as every water particle, and the hydrogen particles and hydrogen particles were the same.

In addition, he also determined the quality of the elements of 6 elements through experiments and made atomic models. Even so, the doubts on the top of the atomic head are still there. These are inferences. No one has seen atoms. How can it prove that they are real things?

But at the time, I could only find another way to see them directly. And this method appeared in an inadvertent botanical observation.

Ghost hidden in the water

The earliest discovery of atomic whereabouts was a Scottish botanist named Robert Brown.

In 1827, Brown observed the pollen of Clarkia Pulchella under the microscope. He found that when there was no external force, the small particles in the pollen were shaking. This phenomenon was later called Brown.

It should be explained here that in many popular science content, Brown saw that pollen was trembling. But in fact, the particle size of the pollen is too large, and the Brown movement cannot occur. Brown's original text is "Tiny Particles from the Pollen Grains of Flowers". [3] Therefore, the smaller granules in pollen occurred.

At the beginning, it was believed that this phenomenon should be a certain life activity, and the things in the pollen are beginning to change when water encounters water. But the problem is that the pollen observed by Brown was collected 20 years ago and should have been dead, but they will still exercise like fresh pollen.

Brown speculated that this movement should have nothing to do with life activities. It is also easy to verify this. Brown has also found a variety of inorganic objects, from glass debris to the powder of the lion body.

Put these things into the water, and as a result, these things also shake. This shows that those who drive these small particles can never be related to creatures. But Brown didn't know what the real driving force behind it was at the time, but just recorded the results in the observation record.

It is this record that makes it difficult for the atom to escape the fate of being discovered.

Because for those who believe in atoms and molecules, the Brown movement is a great discovery. They believe that this movement is the result of the collision between particles and water molecules.

In the 1870s, some people had begun to explain the Brown movement with a random movement of molecularities. But at that time, people couldn't solve a problem: the particle size of the particles was much larger than the aquatic molecule. This was like a small table tennis that could not promote a big ball as a stadium.

Finally, 78 years after Brown discovered the Brown movement, the answer came.

Einstein's miracle

It is Einstein who solves this problem. And the year of solving this problem is also the "1905, Einstein Miracle Year" of Einstein.

In this year, Einstein published four papers, one of which was "Movement of Suspension particles in the Static Lights required by the theory of thermal molecular motion". This paper solves the problem of Brown Movement.

The focus of Einstein is that although a collision cannot be promoted at a time, billions of random collisions per second, the role of random collision is large enough, and the result can be seen under the microscope.

More importantly, Einstein uses the theoretical knowledge and experimental data of stickiness and diffusion rate to predict the Brown Movement. Put a particle with a diameter of 1/1000 mm in a pure water at 17 ° C. One minute for one minute Within, its average displacement is 6 microns.

In addition, in the paper, Einstein also gave a clear method of measurement atomic particle size. This is an extremely specific prediction that can be verified.

Soon, just three years later, French scientist Jean Battiste Pralan confirmed the guess of Einstein and confirmed that the atoms existed really. This study also allowed Pelan to win the Nobel Prize in Physics in 1926.

At this point, the problem of whether the atom exists is finally solved.But whether it is Democylit or Dalton, they guess something wrong, and the atoms can be divided.Moreover, as scientists split their atoms step by step, they will find the power of destroying the earth.references:

[1] Kenny, Anthony (2004).Ancient philosophy.New history of Western philosophy.roll.1. Oxford: Oxford University Press.Page 26-28.International Standard Number 0-19-875273-3.

[2] Bernard Purman (1998).Atoms in the history of human thought.Oxford: Oxford University Press.Page 31-33.International Standard Number 978-0-19-515040-7.

"In: Philosophical Magazine. Band 4, 1905, S. 161–173.

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