Forming light and creating darkness
I form the light and create darkness. (Isaiah 45:7)
We are creatures of the light, we are made of particles that exchange quanta of electromagnetic field.
No electromagnetic "darkness" exists in our world, there are only better approximations thereof: even when there are no detectable photons (and the universe is permeated with radiation), there are plenty of virtual ones. However, electromagnetism alone is a bad deal. A hypothetical universe consisting of nothing but photons, electrons and positrons would be a boring place devoid of complex structure. It needs to be complemented with fields that involve dual carriers responding to electromagnetic fields, which is a tricky thing to do. Forming light is relatively easy. The creative part is making of the darkness in which this light can shine.
A good analogy would be phonons, the quanta of radiation emitted by atoms vibrating in a lattice. Producing such vibrations (forming light) is the trivial task compared to assembling of a crystal that would produce the desired pattern of radiation. Radiation itself is relatively simple; the source of radiation is much more complex than the radiation itself. This radiation are elementary particles and the crystal is the vacuum state.
Most of the light that we observe is from transitions of electrons orbiting atomic nuclei. The latter consist of quarks brought together by the strong force which is described by quantum chromodynamics, QCD. At short distances, the quarks interact weakly, so they are relatively easy to deal with using perturbation theory; at longer distances, the interaction becomes stronger, and one obtains states of which only crude models presently exist. There is no real hope that experiments will “explain” QCD vacuum. The common method of high-energy physics is smashing things at (what else) high energies; naturally, this method sheds little light on the ground state (this would be like smashing crystals in order to understand phonon spectra). No analytical methods for solving QCD equations exist, so numerical methods are used. What comes out of these computations is a lava lamp
http://www.physics.adelaide.edu.au/theory/staff/leinweber/VisualQCD/Nobel/
which looks impervious to analysis.
As far as I know, all efforts to find simplicity in this chaos (by representing the lava as a condensate of topological objects: vortices, monopoles, instantons) have failed, and the problem remains where it was at the inception of QCD. Numerical solutions were expected to provide guidance for developing better models of QCD vacuum. That did not happen. Now we need a theory to explain the results of these calculations.
The same problem exists in chemical physics of liquids. Molecular interactions are well understood, yet only crude models of liquid structure are available. Starting from the 1960s, people largely gave up on developing analytical models of liquids and glasses and crunched numbers doing brute-force molecular dynamics. First it was purely classical, now it is increasingly quantized. Despite great increase in the computational power and sophistication of these models, they remain incapable of quantitatively predicting the observed properties of water, even when the models are tweaked to "explain" a subset of the known properties. I do not believe that we will ever get "the theory of water". No one develops such a theory, although everyone would love to have it. People are developing numerical models that hopefully will account for more properties as they become more complex. This is re-creation of nature in silico rather than theorizing about it.
With QCD vacuum there still remains hope, presently tepid, that ingenious reformulation of the theory will make it more amenable to analytical treatment. However, when one asks who's working on this problem, it becomes clear that the best minds occupy themselves otherwise. Understanding of QCD vacua is patently hard, nearly hopeless, and promising of no rewards at the intermediate stages, whereas suggesting yet another “theory of everything” is a quick and easy kill.
The validity of QCD in the short-distance limit has been proved beyond any doubt; the structure of QCD vacuum is an important problem, but it is regarded as a second-tier one. Everyone wants to be a Newton; no one wants to spend one’s entire life proving that the equations do describe (or do not quite describe) the motion of Mercury. The equation more-or-less describes the motion of Mars and (if you are an optimist) also of the Moon; the rest is left for the lesser minds to figure out. Today, the lesser minds delegate this task to computers; they also want to be Newtons.
Which brings me to the meaning of creation.
Theoretical physics is based on the premise that there is a mathematical from that describes the world, perhaps as an equation. This equation may or may not have analytical solutions. Surely, an approximate solution can be found numerically, but then one's knowledge of this equation cannot be claimed to be exact and exhaustive. Hydrodynamic equations have been written centuries ago, and still no one knows how to solve them analytically. Many of approximations exist, and they are insightful, but when it comes to the design of a supersonic jet, people do not rely on such approximations, building wind tunnels and performing supercomputer computations instead. Starting from Newton, easy-to-write, impossible-to-solve equations have been the plague of science. Writing equations and knowing the world described by such equations turned out to be two different things, one being akin to light shining through the darkness, another being like the darkness illuminated by this light.
Ironically, the only way to "know" the solution may be making a world guided by the equations that implements them fully and in the exact way. As the equations have different boundary conditions, all of these need to be implemented. Only when this program is realized comprehensively, then one can claim full and accurate knowledge of the equations. Quite possibly, the only way to know QCD phase diagram is to create the world implementing QCD equations in such a way that it can chart this entire diagram. Recreation of the world in silico is the only acceptable answer to the problem whose real solution is the Creation rather than re-creation. As we cannot do this real thing, we are limited to the second best.
That is to say that creating darkness can be the intent while forming light can be a means of inquiring into the heart of darkness.
Blessed be the one who forms light and creates darkness.
בָּרוךְ אַתָּה יְיָ אֱלֹהֵנוּ מֶלֶךְ הָעוֹלָם, יוֹצֵר אוֹר וּבוֹרֵא חשֶׁךְ, עֹשֶֹה שָׁלוֹם וּבוֹרֵא אֶת הַכֹּל. בָּרוךְ אַתָּה, יְיָ, יוֹצֵר הַמְּאוֹרוֹת
We are creatures of the light, we are made of particles that exchange quanta of electromagnetic field.
No electromagnetic "darkness" exists in our world, there are only better approximations thereof: even when there are no detectable photons (and the universe is permeated with radiation), there are plenty of virtual ones. However, electromagnetism alone is a bad deal. A hypothetical universe consisting of nothing but photons, electrons and positrons would be a boring place devoid of complex structure. It needs to be complemented with fields that involve dual carriers responding to electromagnetic fields, which is a tricky thing to do. Forming light is relatively easy. The creative part is making of the darkness in which this light can shine.
A good analogy would be phonons, the quanta of radiation emitted by atoms vibrating in a lattice. Producing such vibrations (forming light) is the trivial task compared to assembling of a crystal that would produce the desired pattern of radiation. Radiation itself is relatively simple; the source of radiation is much more complex than the radiation itself. This radiation are elementary particles and the crystal is the vacuum state.
Most of the light that we observe is from transitions of electrons orbiting atomic nuclei. The latter consist of quarks brought together by the strong force which is described by quantum chromodynamics, QCD. At short distances, the quarks interact weakly, so they are relatively easy to deal with using perturbation theory; at longer distances, the interaction becomes stronger, and one obtains states of which only crude models presently exist. There is no real hope that experiments will “explain” QCD vacuum. The common method of high-energy physics is smashing things at (what else) high energies; naturally, this method sheds little light on the ground state (this would be like smashing crystals in order to understand phonon spectra). No analytical methods for solving QCD equations exist, so numerical methods are used. What comes out of these computations is a lava lamp
http://www.physics.adelaide.edu.au/theory/staff/leinweber/VisualQCD/Nobel/
which looks impervious to analysis.
As far as I know, all efforts to find simplicity in this chaos (by representing the lava as a condensate of topological objects: vortices, monopoles, instantons) have failed, and the problem remains where it was at the inception of QCD. Numerical solutions were expected to provide guidance for developing better models of QCD vacuum. That did not happen. Now we need a theory to explain the results of these calculations.
The same problem exists in chemical physics of liquids. Molecular interactions are well understood, yet only crude models of liquid structure are available. Starting from the 1960s, people largely gave up on developing analytical models of liquids and glasses and crunched numbers doing brute-force molecular dynamics. First it was purely classical, now it is increasingly quantized. Despite great increase in the computational power and sophistication of these models, they remain incapable of quantitatively predicting the observed properties of water, even when the models are tweaked to "explain" a subset of the known properties. I do not believe that we will ever get "the theory of water". No one develops such a theory, although everyone would love to have it. People are developing numerical models that hopefully will account for more properties as they become more complex. This is re-creation of nature in silico rather than theorizing about it.
With QCD vacuum there still remains hope, presently tepid, that ingenious reformulation of the theory will make it more amenable to analytical treatment. However, when one asks who's working on this problem, it becomes clear that the best minds occupy themselves otherwise. Understanding of QCD vacua is patently hard, nearly hopeless, and promising of no rewards at the intermediate stages, whereas suggesting yet another “theory of everything” is a quick and easy kill.
The validity of QCD in the short-distance limit has been proved beyond any doubt; the structure of QCD vacuum is an important problem, but it is regarded as a second-tier one. Everyone wants to be a Newton; no one wants to spend one’s entire life proving that the equations do describe (or do not quite describe) the motion of Mercury. The equation more-or-less describes the motion of Mars and (if you are an optimist) also of the Moon; the rest is left for the lesser minds to figure out. Today, the lesser minds delegate this task to computers; they also want to be Newtons.
Which brings me to the meaning of creation.
Theoretical physics is based on the premise that there is a mathematical from that describes the world, perhaps as an equation. This equation may or may not have analytical solutions. Surely, an approximate solution can be found numerically, but then one's knowledge of this equation cannot be claimed to be exact and exhaustive. Hydrodynamic equations have been written centuries ago, and still no one knows how to solve them analytically. Many of approximations exist, and they are insightful, but when it comes to the design of a supersonic jet, people do not rely on such approximations, building wind tunnels and performing supercomputer computations instead. Starting from Newton, easy-to-write, impossible-to-solve equations have been the plague of science. Writing equations and knowing the world described by such equations turned out to be two different things, one being akin to light shining through the darkness, another being like the darkness illuminated by this light.
Ironically, the only way to "know" the solution may be making a world guided by the equations that implements them fully and in the exact way. As the equations have different boundary conditions, all of these need to be implemented. Only when this program is realized comprehensively, then one can claim full and accurate knowledge of the equations. Quite possibly, the only way to know QCD phase diagram is to create the world implementing QCD equations in such a way that it can chart this entire diagram. Recreation of the world in silico is the only acceptable answer to the problem whose real solution is the Creation rather than re-creation. As we cannot do this real thing, we are limited to the second best.
That is to say that creating darkness can be the intent while forming light can be a means of inquiring into the heart of darkness.
Blessed be the one who forms light and creates darkness.
בָּרוךְ אַתָּה יְיָ אֱלֹהֵנוּ מֶלֶךְ הָעוֹלָם, יוֹצֵר אוֹר וּבוֹרֵא חשֶׁךְ, עֹשֶֹה שָׁלוֹם וּבוֹרֵא אֶת הַכֹּל. בָּרוךְ אַתָּה, יְיָ, יוֹצֵר הַמְּאוֹרוֹת