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ANCIENT TIMES
"There is nothing but atoms and space,
everything else is only an opinion"
- Democritus from Abdera
To assure you the best
understanding and to let you have a closer look at the development
of atomic physics' thoughts and ideas we will start our scientific
journey from the achievements of ancient Greek philosophers
therefore going back in time for over two thousand years. The man
we are going to tell you now about were the first ones to research
the structure of the world. As it was so long ago no wonder that
researches they did were in considerable range (but fortunately not
always) limited to solely logical considerations which were not
supported by any experiments or more discerning observations of
nature. It is not hard to guess that the fact caused lots of
contradictions and often divergence between theory and
practice.
Anaximander from Miletus (611
- 547 B.C.), was Thales's disciple. He
perceived world in quite a simple way - as the composition of
contrasts: dry and wet, hot and cold. You might think that quite a
smart teacher had quite a silly disciple. Well... not exactly
because Anaximander said that one contrast element couldn't came
from the other and it would be a mistake to declare any one of them
as a basic element. "So what" you may say again. So what?! Think!
He found out that there is more than one basic substance. Nowadays
we call them chemical elements. Think again! - There was a man
living before Christ who knew that some things cannot change into
others just as we today know that for example copper cannot be
changed into gold and vice versa!
That is not all about him - he believed in the subsistence of
substance he called "apeiron". He thought it was
a great, infinite in time and space, undiverted and neutral
immensity. Strange features? Well, as for us apeiron resembles something well known nowadays - vacuum!
Of course Anaximander wasn't always that right: He said that
apeiron filled the whole world and was a creative
element of all the other substances which later disappeared in it.
According to Anaximander oppositions included in apeiron could
separate. What he also maintained is that matter was combined with
motion making a unit.
And what do you think about him now? |
| Anaximenes from Miletus (585 - 525 B.C.), was another
of Thales's disciples. Although the names
of both Thales's disciples sound very similar
try not to mismatch them because their thoughts were different.
Anaximenes maintained that basic substance was not water as his
teacher said neither apeiron like his college said but air. By
Anaximenes it was to be infinite in quantity. His observation of
nature confirmed that. He said all other things could be created in
the process of air thickening (while cooling it down), and the
process of air rarefying (during warming it up). For example, fire
was to be created by air rarefying but winds, clouds, water, earth
and other solid substances by air condensation. Such thermal
conversions he connected with everlasting movement in the universe.
He used mentioned above considerations to explain weather
conditions. Isn't it great that he knew so much about the nature of
gases?! So we hope you will never again say that you can't tell
Anaximander from Anaximenes. |
| Anaxagoras from Clazomenae (500 - 428 B.C.) also stated
that world's components were unchanging. Just like Empedocles he was of the opinion that particles
could combine with each other and disintegrate. But his all new
idea was that each and every substance had its own kind of
particle, called by him "nucleus". According to
Anaxagoras there was the infinite number of nucleuses and they
could be divided endlessly. For the first time we find here the
opinion that matter consistence is more complicated then
(combination of) four elements. Anaxagoras stipulated that each and
every particle contained all the other particles in different
proportions. His example was that eating particles of meat one ate
also the particles of muscles, bones and blood, building up his
organism in this way. |
Democritus from Abdera (460 - 370 B.C.) the greatest,
the most important Greek philosopher engaged with the problem of
world's structure. Indeed, it is from his times that the
development of atomic physics dates. "On the Little Order of the
World" is the title of his work where he described his theory.
"Nothing can change into something absolutely different" he said.
He saw nature as the ceaseless motion of small, material,
indivisible and eternal particles. So they could not be created not
annihilated and were unchanging. "Indivisible" in Greek is
"atomos", so Democritus called his particle atom.
Would you like to know what made us still use the same name today?
First of all Democritus called this way the particle he imagined to
be the basic brick of matter. Then - it had a shape and place in
the space. Before Democritus people believed that matter was built
of something so abstractive that it couldn't be sees because it had
no "look-like". But his point of view was different and he even
believed that atom had some mass. Seeing that things are so much
various, he came to the opinion that atoms couldn't be identical,
but of different shapes and sizes. These differences were
influencing features of materials. He imagined it this way: White
things were made of smooth atoms and black of rough ones. Sweet
things were made of spherical atoms and bitter of angular ones. He
also believed that life consisted of very small, round, smooth
atoms and soul was mode of the smallest particles
of air and heat. Later on Democritus ascertained that hard things
were made of many atoms without much space between them and soft
things were made of loose atoms. Then he said
that particles situated in empty space could move all the time with
similar atoms approaching and different repulsing; sometimes
colliding, bounding and gathering into groups. For him the universe
was an act of perpetual gathering and diffusing of atoms kept in
everlasting motion.
It is hard to believe that he could came to all this using only his
reason, having no laboratory neither any experimental
equipment. |
Titus Lucretius Carus (95 - 55 B.C.), who was a Roman,
continued Epicurus's philosophy. He wrote
a monumental poem "On the Constitution of the Nature" ("De
Rerum Natura"). There he enclosed his considerations. He explained
all occurrences on the basis of atomic physics theories. Thanks to
his work the opinions of Democritus and
Epicurus penetrated the Roman Empire and
consolidated there. And here are some interesting verses off his
work turned by us, and unfortunately it is not Latin into English
translation but Polish into English one. So it is not very artistic
but we hope still can give you a view on his ideas:
" ...And we see the stone
pavements of the highroads abraded
Blank by the feet of the crowd; standing in gates bronze
Statues also show, how their right hands grow thin
Touched over and over again by the many of greeting
passers-by.
We see than, that it all become lose of abrasion,
But the jealous Nature won't let you
See, what particles run away there all the time.
And also even the most sharp-eyed one can't see
Trying the hardest he can, the particles which Nature every
day
Secretly adds to the things, ordering them to slowly grow... " |
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Aristotle (384 - 322 B.C.) was especially respected
in Middle Ages with the bad event
for atomic physics must say. He was a resolved opponent of Democritus's atomic physics. He stated that world
couldn't consist of small, indivisible particles because if so they
should fell down like a thrown up rock did. Do you remember
Anaximander from Mileus? Well,
Aristotle stated something very similar to that: He was of the
opinion that there were four basic qualities determining the
constitution of substance. Those four were to be: dryness, wetness,
heat and cold. For example, fire consisted of heat and dryness;
water consisted of cold and wetness. The conversion of water into
steam he explained in that way: The heat of fire joins the wetness
of water creating air and earth (the last one can be found at the
bottom of the pot after vaporising the water). Those qualities were
abstract. The vision created by him buried Democritus's theories for many centuries and that
is why we have told you about the not very interesting ideas of
Aristotle. |
Greek philosophers
achieved very much in the world's construction understanding.
Although their thoughts were rather philosophical than natural
scientific, still great. Only uncommon people could dare to make an
attempt to understand and describe rationally the universe. The
achievements of the philosophers began the history of atomic
physics' development. The conception of atom was formulated.
Philosophers tried to describe it but without the possibility of
checking the presumptions experimentally. It led to many different,
contradient theories. One can say that every philosopher had a
different opinion on microstructure. Unfortunately, in Middle Ages people chose wrong theory (Aristotle's one). Nevertheless Democritus's works prevailed again in contemporary
times influencing scientists.
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