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The day that the atom as particle died and Quantum Mechanics was born.
People had much greater confidence in their understanding of matter and energy back in the late 1800's and early 1900's than they do today.
At that time, all matter was considered to be made of "particles" and all energy was considered to be made of "waves".
Particles had the unique characteristic that they obeyed Newton's Laws of Motion, particularily the law of Conservation of Momentum. That is, if you knew the mass and speed of two particles, you could accurately predict how they would behave if they collided.
Energy was considered to be made of waves, and waves had the unique property that they would superimpose on one another when they collided. That is, two small waves would add together to momentarily produce one large wave when they passed through one another.
Light was considered an odd sort of wave that could propogate through a vaccuum. All other waves, like sound waves, waves on a string and even real life ocean waves needed a medium through which to propogate.
In the late 1800's, the biggest WTF? question facing science was the problem of "cavity radiation".
That is, if you took any hollow body and drilled a hole in it, when you heated that body, the spectrum of light being emitted from the body would depend on both it's temperature and the material the body was made of.
However, the spectrum of light emanating from the hole was dependant on only the temperature, and was the same regardless of what material the body was made of.
WTF?
No one could explain the phenomenon of cavity radiation. Since the light emanating from the hole originated at the interior surface of the body, and that was the same material as the exterior surface of the body, why should the interior surface behave any differently than the exterior surface when both were at the same temperature?
The first one to shed any real light on the problem of Cavity Radiation was Wilhelm Wein, a theoretical physicist in Munich, Germany. Using the theory of atoms as particles and light energy as waves, Wein was able to derive an equation which kinda sorta predicted the phenomenon of cavity radiation. His equation kinda sorta agreed with observational data only at high temperatures. At lower temperatures, it completely broke down and gave erroneous results. Nonetheless, about 20 years later Wilhelm Wein was awarded the 1911 Nobel Prize in Physics for his work.
(At that time it took years for theories to be tested and proven or disproven, and so the Nobel Committee wouldn't award a Nobel Prize in Physics unless and until the theoretical basis of the work was proven by experimentation, and that often took years. Nowadays, when a highly controversial idea comes out, universities around the world jump on it, and the theory gets proven or blown up fairly quickly. Member Pond and Fleishman with their cold fusion experiment that no one could duplicate? Member superconductivity of yttrium that within the space of one year every university physics professor and his dog were playing with frozen yttrium.)
Anyhow, back to the chase...
A professor of mathematics and physics working at the University of Berlin at the time, Dr. Max Planck found that a small modification to Wein's theoretical equation would result in an equation that accurately predicted experimental results over the entire temperature spectrum. Believing his emperical equation was also theoretically correct, Max Planck then used his equation as a starting point and worked backward through Wein's derivation to see if he could come up with a derivation of his own equation.
And, he found that he could do it. All he had to do was to make two radical and highly controversial assumptions about atoms and energy:
1. That the vibration of atoms consumed no energy at all, and
2. Atoms could not have any level of energy, but only specific energy levels.
Think of it this way: The coins and bills in your wallet can't have ANY value. They can only be worth specific values that are all multiples of the smallest amount of money; namely the penny. You can't for example have a bill in your wallet that's worth pi dollars, or roughly $3.1416. The same is true for energy. Planck was saying that there was a smallest amount of energy and so an atom couldn't have any amount of energy, it could only have multiples of that smallest amount of energy. It's the same as saying that you can't have ANY amount of money in your wallet. No matter what, the amount of money in your wallet will always be an integer multiple of 1 cent.
Also, he was saying that the vibration of atoms consumed no energy. Basically what he's saying is that atomic vibration was much like the propogation of a wave through a medium in that the movement of the atoms doesn't consume any energy. In the case of a water wave, no water actually moves forward. The water goes up and down, but the water molecules themselves don't actually move forward. So, a wave on the ocean behaves exactly like a people "wave" at a football stadium; the wave moves, but the people don't. The people just go up and down. This idea that atomic vibration didn't require any energy input was way out in left field to scientists at the time because it takes energy to move any object, so why should atoms, small as they are, get a free ride?
On December 14, 1900, Max Karl Ernst Ludwig Planck presented the derivation of his controversial equation to the German Physical Society. That presentation marked the birth of the branch of physics we now call "Quantum Mechanics".
17 years later, when experimental data proved his theory about the nature of atoms and energy correct, Max Planck was awarded the 1918 Nobel Prize in Physics for his discovery of the "Elemental Quanta".
People had much greater confidence in their understanding of matter and energy back in the late 1800's and early 1900's than they do today.
At that time, all matter was considered to be made of "particles" and all energy was considered to be made of "waves".
Particles had the unique characteristic that they obeyed Newton's Laws of Motion, particularily the law of Conservation of Momentum. That is, if you knew the mass and speed of two particles, you could accurately predict how they would behave if they collided.
Energy was considered to be made of waves, and waves had the unique property that they would superimpose on one another when they collided. That is, two small waves would add together to momentarily produce one large wave when they passed through one another.
Light was considered an odd sort of wave that could propogate through a vaccuum. All other waves, like sound waves, waves on a string and even real life ocean waves needed a medium through which to propogate.
In the late 1800's, the biggest WTF? question facing science was the problem of "cavity radiation".
That is, if you took any hollow body and drilled a hole in it, when you heated that body, the spectrum of light being emitted from the body would depend on both it's temperature and the material the body was made of.
However, the spectrum of light emanating from the hole was dependant on only the temperature, and was the same regardless of what material the body was made of.
WTF?
No one could explain the phenomenon of cavity radiation. Since the light emanating from the hole originated at the interior surface of the body, and that was the same material as the exterior surface of the body, why should the interior surface behave any differently than the exterior surface when both were at the same temperature?
The first one to shed any real light on the problem of Cavity Radiation was Wilhelm Wein, a theoretical physicist in Munich, Germany. Using the theory of atoms as particles and light energy as waves, Wein was able to derive an equation which kinda sorta predicted the phenomenon of cavity radiation. His equation kinda sorta agreed with observational data only at high temperatures. At lower temperatures, it completely broke down and gave erroneous results. Nonetheless, about 20 years later Wilhelm Wein was awarded the 1911 Nobel Prize in Physics for his work.
(At that time it took years for theories to be tested and proven or disproven, and so the Nobel Committee wouldn't award a Nobel Prize in Physics unless and until the theoretical basis of the work was proven by experimentation, and that often took years. Nowadays, when a highly controversial idea comes out, universities around the world jump on it, and the theory gets proven or blown up fairly quickly. Member Pond and Fleishman with their cold fusion experiment that no one could duplicate? Member superconductivity of yttrium that within the space of one year every university physics professor and his dog were playing with frozen yttrium.)
Anyhow, back to the chase...
A professor of mathematics and physics working at the University of Berlin at the time, Dr. Max Planck found that a small modification to Wein's theoretical equation would result in an equation that accurately predicted experimental results over the entire temperature spectrum. Believing his emperical equation was also theoretically correct, Max Planck then used his equation as a starting point and worked backward through Wein's derivation to see if he could come up with a derivation of his own equation.
And, he found that he could do it. All he had to do was to make two radical and highly controversial assumptions about atoms and energy:
1. That the vibration of atoms consumed no energy at all, and
2. Atoms could not have any level of energy, but only specific energy levels.
Think of it this way: The coins and bills in your wallet can't have ANY value. They can only be worth specific values that are all multiples of the smallest amount of money; namely the penny. You can't for example have a bill in your wallet that's worth pi dollars, or roughly $3.1416. The same is true for energy. Planck was saying that there was a smallest amount of energy and so an atom couldn't have any amount of energy, it could only have multiples of that smallest amount of energy. It's the same as saying that you can't have ANY amount of money in your wallet. No matter what, the amount of money in your wallet will always be an integer multiple of 1 cent.
Also, he was saying that the vibration of atoms consumed no energy. Basically what he's saying is that atomic vibration was much like the propogation of a wave through a medium in that the movement of the atoms doesn't consume any energy. In the case of a water wave, no water actually moves forward. The water goes up and down, but the water molecules themselves don't actually move forward. So, a wave on the ocean behaves exactly like a people "wave" at a football stadium; the wave moves, but the people don't. The people just go up and down. This idea that atomic vibration didn't require any energy input was way out in left field to scientists at the time because it takes energy to move any object, so why should atoms, small as they are, get a free ride?
On December 14, 1900, Max Karl Ernst Ludwig Planck presented the derivation of his controversial equation to the German Physical Society. That presentation marked the birth of the branch of physics we now call "Quantum Mechanics".
17 years later, when experimental data proved his theory about the nature of atoms and energy correct, Max Planck was awarded the 1918 Nobel Prize in Physics for his discovery of the "Elemental Quanta".
Little about a lot and a lot about a little.
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