Jag har idag haft ett konstruktivt och mycket trevligt samtal med Jessica Berglund och Lisa Söderlund på Kodcentrum om eventuellt samarbete vad gäller att sprida programmeringens evangelium till svenska elever och svensk skola.
Kodcentrum har hittills satsat på Scratch som introduktion till programmering och verkar ha behov av att kunna leverera vidareutbildning, och kanske Matematik-IT därvid kan vara ett alternativ. Vi får se om Kodcentrum vill utnyttja denna möjlighet under nästa läsår. Chansen finns...
Vad gäller programmeringsplattform har jag alltså använt Codea (programmering på iPad för iPad), men det finns många alternativ, tex Corona för PC/Mac som använder samma språk som Codea (Lua). Codea kostar några kronor, medan Corona är gratis.
Sen finns det ju många andra möjligheter som Xcode, Swift, Python, JavaScript, Perl....Till slut måste man välja något specifikt språk/plattform, om man vill säga/göra något konkret med någon mening... på samma sätt som med kärleken, som är ju evig och det bara är föremålen som växlar...
PS Det finns en inställning som verkar ha många företrädare, att möta Regeringens uppdrag till Skolverket att införa programmering i skolan, inte med att helt sonika följa uppdragets direktiv och göra så, utan istället ersätta konkret programmering med betydligt mindre konkreta slagord som "digital kompetens" och "datalogiskt tänkande". Tanken är alltså att gå runt den heta gröten och inte ta del av den och istället konsumera ev urvattnade derivat av den goda och stärkande gröten.
Inte att lära sig programmera (det behöver man inte eftersom det finns så många programmerare), utan istället lära sig att det finns något som kallas programmering. Inte att de facto få lära sig multiplikationstabellen och att använda den, utan istället få lära sig att det räcker att veta att den finns och att några kan den (den behövs ju egentligen inte eftersom det finns så många mini-räknare).
Tanken borde istället vara att om man äter programmeringsgröten och smälter den, så får man bättre förmåga att utveckla både "digital kompetens" och "datalogiskt tänkande", om det nu är huvudsaken, än om man bara går runt gröten.
Det är bättre att kunna multiplikationstabellen och kunna använda den, än att inte kunna den och inte veta att använda den, även om det finns miniräknare. Varför? Därför att människan är en tänkande varelse och tänkande bygger på förståelse.
tisdag 31 maj 2016
måndag 30 maj 2016
New Theory of Flight: Time Line
Potential flow around circular cylinder with zero drag and lift (left).
Real flow with non-stationary turbulent 3d rotational slip separation and non-zero drag (right).
The New Theory of Flight published in J Mathematical Fluid Mechanics, can put be into the following time line:
1750 formulation by Euler of the Euler equations describing incompressible flow with vanishing viscosity expressing Newton's 2nd law and incompressibility in Euler coordinates of a fixed Euclidean coordinate system.
1752 d'Alembert's Paradox as zero drag and lift of potential flow around a wing defined as stationary flow which is
- incompressible
- irrotational
- of vanishing viscosity
- satisfies slip boundary condition
1904 resolution of d'Alembert's paradox of zero drag by Prandtl stating that potential flow is unphysical, because 4. violates a requirement that real flow must satisfy
- no slip boundary condition.
1904 resolution of d'Alembert's paradox of zero lift by Kutta-Zhukovsky stating that potential flow is unphysical, because 2. violates that a sharp trailing edge in real flow creates
- rotational flow.
2008 resolution of d'Alembert's paradox of zero drag and lift by Hoffman-Johnson stating that potential flow is unphysical, because
- potential flow it is unstable at separation and develops into non-stationary turbulent 3d rotational slip separation as a viscosity solution of the Euler equations with substantial drag and lift.
Recall that d'Alembert's paradox had to be resolved, in one way or the other, to save theoretical fluid mechanics from complete collapse, when the Wright brothers managed to get their Flyer off ground into sustained flight in 1903 with a 10 hp engine.
Prandtl, named the Father of Modern Fluid Mechanics, discriminated the potential solution by an ad hoc postulate that 4. was unphysical (without touching 2.) and obtained drag without lift.
Kutta-Zhukovsky, named Fathers of Modern Aero Dynamics, discriminated the potential solution by an ad hoc postulate that 2. was unphysical (without touching 4.) and obtained lift without drag.
Hoffman-Johnson showed without ad hoc postulate that the potential solution is unstable at separation and develops into non-stationary turbulent 3d rotational slip separation causing drag and lift.
The length of the time-line 1750-1752-1904-2008 is remarkable from scientific point of view. Little happened between 1752 and 1904 and between 1904 and 2008, and what happened in 1904 was not in touch with reality. For detailed information, see The Secret of Flight.
1946 Nobel Laureate Hinshelwood made the following devastating analysis:
1946 Nobel Laureate Hinshelwood made the following devastating analysis:
- D’Alembert’s paradox separated fluid mechanics from its start into theoretical fluid mechanics explaining phenomena which cannot be observed and practical fluid mechanics or hydraulics observing phenomena which cannot be explained.
The only glimpse in the darkness was offered by the mathematician Garret Birkhoff in his 1950 book Hydrodynamics, by asking if any potential flow is stable, a glimpse of light that was directly blown out by a devastating critique of the book from fluid dynamics community, which made Birkhoff remove his question in the 2nd edition of the book and to never return to hydrodynamics.
The 2008 resolution of d'Alembert's Paradox leading into the New Theory of Flight by Hoffman-Johnson, has been met with complete silence/full oppression by the fluid mechanics community still operating under the paradigm of Hinshelwoods analysis.
The 2008 resolution of d'Alembert's Paradox leading into the New Theory of Flight by Hoffman-Johnson, has been met with complete silence/full oppression by the fluid mechanics community still operating under the paradigm of Hinshelwoods analysis.
Etiketter:
Kutta-Zhukovsky,
Prandtl,
theory of flight
söndag 29 maj 2016
Restart of Quantum Mechanics: From Observable/Measurable to Computable
Schrödinger and Heisenberg receiving the Nobel Prize in Physics in 1933/32..
If modern physics was to start today instead of as it did 100 years ago with the development of quantum mechanics as atomistic mechanics by Bohr-Heisenberg and Schrödinger, what would be the difference?
Bohr-Heisenberg were obsessed with the question:
But the Schrödinger equation is an ad hoc model with only weak formal unphysical rationale, including the basic ingredients of (i) linearity and (ii) multi-dimensionality.
Copenhagen quantum mechanics is thus based on a Schrödinger equation, which is an ad hoc model and which cannot be solved with any assessment of accuracy because of its multi-dimensionality and thus cannot really deliver predictions which can be tested vs observations, except in very simple cases.
The Copenhagen dogma is then that predictions of the standard Schrödinger equation always are in perfect agreement with observation, but a dogma which cannot be challenged because predictions cannot be computed ab initio.
In this situation it is natural to ask, in the spirit of Schrödinger, for a new Schrödinger equation which has a direct physical meaning and to which solutions can be computed ab initio, and this is what I have been exploring in many blog posts and in the book (draft) Many-Minds Quantum Mechanics.
The basic idea is to replace the linear multi-d standard Schrödinger equation with a computable non-linear system in 3d as a basis of a new form of physical quantum mechanics. I will return with more evidence of the functionality of this approach, which is very promising...
Note that a wonderful thing with computation is that it can be viewed as a form of non-destructive testing, where the evolution of a physical system can be followed in full minute detail without any form of interference from an observer, thus making Bohr's Law into a meaningless limitation of scientific thinking and work from a pre-computer era preventing progress today.
PS It is maybe wise to be a little skeptical to assessments of agreement between theory and experiments to an extremely high precision. It may be that things are arranged or rigged so as to give exact agreement, by changing computation/theory or experiment.
If modern physics was to start today instead of as it did 100 years ago with the development of quantum mechanics as atomistic mechanics by Bohr-Heisenberg and Schrödinger, what would be the difference?
Bohr-Heisenberg were obsessed with the question:
- What can be observed?
motivated by Bohr's Law:
- We are allowed to speak only about what can be observed.
Today, with the computer to the service of atom physics, a better question may be:
- What can be computed?
possibly based on an idea that
- It may be meaningful to speak about what can be computed.
Schrödinger as the inventor of the Schrödinger equation as the basic mathematical model of quantum mechanics, never accepted the Bohr-Heisenberg Copenhagen Interpretation of quantum mechanics with the Schrödinger wave function as solution of the Schrödinger equation interpreted as a probability of particle configuration, with collapse of the wave function into actual particle configuration under observation/measurement.
Schrödinger sought an interpretation of the wave function as a physical wave in a classical continuum mechanical meaning, but had to give in to Bohr-Heisenberg, because the multi-dimensionality of the Schrödinger equation did not allow a direct physical interpretation, only a probabilistic particle interpretation. Thus the Schrödinger equation to Schrödinger became a monster out of control, as expressed in the following famous quote:
- If we have to go on with these damned quantum jumps, then I'm sorry that I ever got involved.
But the Schrödinger equation is an ad hoc model with only weak formal unphysical rationale, including the basic ingredients of (i) linearity and (ii) multi-dimensionality.
Copenhagen quantum mechanics is thus based on a Schrödinger equation, which is an ad hoc model and which cannot be solved with any assessment of accuracy because of its multi-dimensionality and thus cannot really deliver predictions which can be tested vs observations, except in very simple cases.
The Copenhagen dogma is then that predictions of the standard Schrödinger equation always are in perfect agreement with observation, but a dogma which cannot be challenged because predictions cannot be computed ab initio.
In this situation it is natural to ask, in the spirit of Schrödinger, for a new Schrödinger equation which has a direct physical meaning and to which solutions can be computed ab initio, and this is what I have been exploring in many blog posts and in the book (draft) Many-Minds Quantum Mechanics.
The basic idea is to replace the linear multi-d standard Schrödinger equation with a computable non-linear system in 3d as a basis of a new form of physical quantum mechanics. I will return with more evidence of the functionality of this approach, which is very promising...
Note that a wonderful thing with computation is that it can be viewed as a form of non-destructive testing, where the evolution of a physical system can be followed in full minute detail without any form of interference from an observer, thus making Bohr's Law into a meaningless limitation of scientific thinking and work from a pre-computer era preventing progress today.
PS It is maybe wise to be a little skeptical to assessments of agreement between theory and experiments to an extremely high precision. It may be that things are arranged or rigged so as to give exact agreement, by changing computation/theory or experiment.
lördag 28 maj 2016
Aristotle's Logical Fallacy of Affirming the Consequent in Physics
One can find many examples in physics, both classical and modern, of Aristotle's logical fallacy of Affirming the Consequent (confirming an assumption by observing a consequence of the assumption):
- Assume the Earth rests on 4 turtles, which keeps the Earth from "falling down". Observe that the Earth does not "fall down". Conclude that the Earth rests on 4 turtles.
- Observe a photoelectric effect in accordance with a simple (in Einstein's terminology "heuristic") argument assuming light can be thought of as a stream of particles named "photons" . Conclude that light is a stream of particles named photons.
- Assume light is affected by gravitation according the general theory of relativity as described by Einstein's equations. Observe apparent slight bending of light as it passes near the Sun in accordance with an extremely simplified use of Einstein's equations. Conclude universal validity of Einstein's equations.
- Observe lift of a wing profile in accordance with a prediction from potential flow modified by large scale circulation around the wing. Conclude that there is large scale circulation around the wing.
- Assume that predictions from solving Schrödinger's equation always are in perfect agreement with observation. Observe good agreement in some special cases for which the Schrödinger equation happens to be solvable, like in the case of Hydrogen with one electron. Conclude universal validity of Schrödinger's equation, in particular for atoms with many electrons for which solutions cannot be computed with assessment of accuracy.
- Assume there was a Big Bang and observe a distribution of galaxy positions/velocities, which is very very roughly in accordance with the assumption of a Big Bang. Conclude that there was a Big Bang.
- Assume that doubled CO2 in the atmosphere from burning of fossil fuel will cause catastrophic global warming of 2.5 - 6 C. Observe global warming of 1 C since 1870. Conclude that doubled CO2 in the atmosphere from burning of fossil fuel will cause catastrophic global warming of 4 - 8 C.
- Assume that two massive black holes merged about 1.3 billion years ago and thereby sent a shudder through the universe as ripples in the fabric of space and time called gravitational waves and five months ago washed past Earth and stretched space making the entire Earth expand and contract by 1/100,000 of a nanometer, about the width of an atomic nucleus. Observe a wiggle of an atom in an instrument and conclude that two massive black holes merged about 1.3 billion years ago which sent a shudder through the universe as ripples in the fabric of space and time called gravitational waves...
- Observe experimental agreement of the anomalous magnetic dipole moment of the electron within 10 decimals to a prediction by Quantum Electro Dynamics (QED). Conclude that QED is universally valid for any number of electrons as the most accurate theory of physics. Note that the extremely high accuracy for the specific case of the anomalous magnetic dipole moment of the electron, compensates for the impossibility of testing in more general cases, because the equations of QED are even more impossible to solve with assessment of accuracy than Schrödinger's equation.
The logic fallacy is so widely practiced that for many it may be difficult to see the arguments as fallacies. Test yourself!
PS1. Observe that if a theoretical prediction agrees with observation to a very high precision, as is the case concerning the Equivalence Principle stating equality of inertial and gravitational (heavy) mass, then it is possible that what you are testing experimentally in fact is the validity of a definition, like testing experimentally if there are 100 centimeters on a meter (which would be absurd).
PS2 Books on quantum mechanics usually claim the there is no experiment showing any discrepancy whatsoever with solutions of the Schrödinger equation (in the proper setting), which is strong evidence that the Schrödinger equation gives an exact description of all of atom physics (in a proper setting). The credibility of this argument is weakened by the fact that solutions can be computed only in very simple cases.
PS1. Observe that if a theoretical prediction agrees with observation to a very high precision, as is the case concerning the Equivalence Principle stating equality of inertial and gravitational (heavy) mass, then it is possible that what you are testing experimentally in fact is the validity of a definition, like testing experimentally if there are 100 centimeters on a meter (which would be absurd).
PS2 Books on quantum mechanics usually claim the there is no experiment showing any discrepancy whatsoever with solutions of the Schrödinger equation (in the proper setting), which is strong evidence that the Schrödinger equation gives an exact description of all of atom physics (in a proper setting). The credibility of this argument is weakened by the fact that solutions can be computed only in very simple cases.
fredag 27 maj 2016
Emergence by Smart Integration of Physical Law as Differential Equation
Perfect Harmony of European Parliament: Level curves of political potential generated by an empty spot in the middle.
This is a continuation of previous posts on a new view of Newton's law of gravitation. We here connect to the Fundamental Theorem of Calculus of the previous post, allowing a bypass to compute an integral by tedious laborious summation, using a primitive function of the integrand:
The magic is here computing an integral $\int_0^t f(s)ds$ in a smart way, rather than computing a derivative $\frac{dF}{dt}$ in a standard way.
The need of computing integrals comes from the fact that physical laws are usually expressed in terms of derivatives, for example as an initial value problem: Given a function $f(t)$, determine a function $F(t)$ such that
The differential equation $\Delta\phi =\rho$ would thus be valid by an interplay "in perfect harmony" in the spirit of Leibniz, where on the one hand "gravitational potential tells matter where to be how to move" and "matter tells gravitational potential what to be".
This would be like a Perfect Parliamentary System where the "Parliament tells People where to be and what to do" and "People tells Parliament what to be".
PS There is a fundamental difference between (1) and (2): (1) is an initial value problem in time while (2) is a formally a static problem in space. It is natural to solve an initial value problem by time stepping which represents integration by summation. A static problem like (2) can be solved iteratively by some form of (pseudo) time stepping towards a stationary solution, which in physical terms could correspond to successive propagation of effects with finite speed of propagation.
This is a continuation of previous posts on a new view of Newton's law of gravitation. We here connect to the Fundamental Theorem of Calculus of the previous post, allowing a bypass to compute an integral by tedious laborious summation, using a primitive function of the integrand:
- $\int_0^t f(s)ds = F(t) - F(0)$ if $\frac{dF}{dt} = f$.
The magic is here computing an integral $\int_0^t f(s)ds$ in a smart way, rather than computing a derivative $\frac{dF}{dt}$ in a standard way.
The need of computing integrals comes from the fact that physical laws are usually expressed in terms of derivatives, for example as an initial value problem: Given a function $f(t)$, determine a function $F(t)$ such that
- $DF(t) = f(t)$ for $t\ge 0$ and $F(0) = 0$,
where $DF =\frac{dF}{dt}$ is the derivative of $F$. In other words, given a function $f(t)$, determine a primitive function $F(t)$ to $f(t)$ with $F(0)=0$, that is, determine/compute the integral
by the formula
by the formula
- $\int_0^t f(s)ds = F(t)$ for $t\ge 0$.
Using the Fundamental Theorem to compute the integral would then correspond to solving the initial value problem by simply picking a primitive function $F(t)$ satisfying $DF = f$ and $F(0)=0$ from a catalog of primitive functions, allowing to in one leap jump from $t=0$ to any later time $t$. Not very magical perhaps, but certainly smart!
The basic initial value problem of mechanics is expressed in Newton's 2nd Law $f=ma$ where $f$ is force, $m$ mass and $a(t)=\frac{dv}{dt}=\frac{d^2x}{dt^2}$ is acceleration, $v(t)=\frac{dx}{dt}$ velocity and $x(t)$ position, that is,
- $f(t) = m \frac{d^2x}{dt^2}$. (1)
Note that in the formulation of the 2nd Law, it is natural to view position $x(t)$ with acceleration $\frac{d^2x}{dt^2}$ as given, from which force $f(t)$ is derived by (1) . Why? Because position $x(t)$ and acceleration $\frac{d^2x}{dt^2}$ can be observed, from which the presence of force $f(t)$ can be inferred or derived or concluded, while direct observation of force may not really be possible. In this setting the 2nd Law acts simply to define force in terms of mass and acceleration, rather than to make a connection with some other definition of force.
Writing Newton's 2nd law in the form $f=ma$, thus defining force in terms of mass and acceleration, is the same as writing Newton's Law of Gravitation:
- $\rho = \Delta\phi$, (2)
thereby defining mass density $\rho (x)$ in terms of gravitational potential $\phi (x)$ by a differential equation.
With this view, Newton's both laws (1) and (2) would have the same form as differential equation, and the solutions $x(t)$ and $\phi (x)$ would result from solving differential equations by integration or summation as a form of emergence.
In particular, this reasoning gives support to an idea of viewing the physics of Newton's Law of Gravitation to express that mass density somehow is "produced from" gravitational potential by the differential equation $\rho =\Delta\phi$.
To solve the differential equation $\Delta\phi =\rho$ by direct integration or summation in the form
- $\phi (x) = \frac{1}{4\pi}\int\frac{\rho (y)}{\vert x-y\vert}dy$,
On the other hand, if there was a "smart" way of doing the integration by using some form of Fundamental Theorem of Calculus as above, for example by having a catalog of potentials from which to choose a potential satisfying $\Delta\phi =\rho$ for any given $\rho$, then maybe the requirement of instant action at distance could be avoided.
A smart way of solving $\Delta\phi =\rho$ would be to use the knowledge of the solution $\phi (x)$ in the case of a unit point mass at $x=0$ as
A smart way of solving $\Delta\phi =\rho$ would be to use the knowledge of the solution $\phi (x)$ in the case of a unit point mass at $x=0$ as
- $\phi (x)=\frac{1}{4\pi}\frac{1}{\vert x\vert}$
In any case, from the analogy with the 2nd Law we have gathered an argument supporting an idea to view the physics of gravitation as being expressed by the differential equation $\rho =\Delta\phi$ with mass density $\rho$ derived from gravitational potential $\phi$. Rather than the opposite standard view with the potential $\phi$ resulting from mass density $\rho$ by integration or summation corresponding to instant action at distance.
The differential equation $\Delta\phi =\rho$ would thus be valid by an interplay "in perfect harmony" in the spirit of Leibniz, where on the one hand "gravitational potential tells matter where to be how to move" and "matter tells gravitational potential what to be".
This would be like a Perfect Parliamentary System where the "Parliament tells People where to be and what to do" and "People tells Parliament what to be".
PS There is a fundamental difference between (1) and (2): (1) is an initial value problem in time while (2) is a formally a static problem in space. It is natural to solve an initial value problem by time stepping which represents integration by summation. A static problem like (2) can be solved iteratively by some form of (pseudo) time stepping towards a stationary solution, which in physical terms could correspond to successive propagation of effects with finite speed of propagation.
torsdag 26 maj 2016
Fatal Attraction of Fundamental Theorem of Calculus?
Calculus books proudly present the Fundamental Theorem of Calculus as the trick of computing an integral
where $F(x)$ is a primitive function to $f(x)$ satisfying $\frac{dF}{dx} = f$,
The trick is thus to compute an integral, which by construction is a sum of very many terms, not by doing the summation following the construction, but instead taking just one big leap using a primitive function.
On the other hand, to compute a derivative no trick is needed according to the book; you just compute the derivative using simple rules and a catalog of already computed derivatives.
In a world of analytical mathematics, computing integrals is thus valued higher than computing derivatives, and this is therefore what fills Calculus books.
In a world of computational mathematics, the roles are switched. To compute an integral as a sum can be viewed to be computationally trivial, while computing a derivative $\frac{dF}{dx}$ is a bit more tricky because it involves dividing increments $dF$ by small increments $dx$.
This connects to Poisson's equation $\Delta\phi =\rho$ of Newton's theory of gravitation discussed in recent posts. What is here to be viewed as given and what is derived? The standard view is that the mass density $\rho$ is given and the gravitational potential $\phi$ is derived from $\rho$ as an integral
- I=$\int_a^b f(x)dx$,
- $\sum_i f(x_i)h_i$
on a partition $\{x_i\}$ of the interval $(a,b)$ with step size $h_i = x_{i+1} - x_i$, but by the formula
- $I = F(b) - F(a)$,
The trick is thus to compute an integral, which by construction is a sum of very many terms, not by doing the summation following the construction, but instead taking just one big leap using a primitive function.
On the other hand, to compute a derivative no trick is needed according to the book; you just compute the derivative using simple rules and a catalog of already computed derivatives.
In a world of analytical mathematics, computing integrals is thus valued higher than computing derivatives, and this is therefore what fills Calculus books.
In a world of computational mathematics, the roles are switched. To compute an integral as a sum can be viewed to be computationally trivial, while computing a derivative $\frac{dF}{dx}$ is a bit more tricky because it involves dividing increments $dF$ by small increments $dx$.
This connects to Poisson's equation $\Delta\phi =\rho$ of Newton's theory of gravitation discussed in recent posts. What is here to be viewed as given and what is derived? The standard view is that the mass density $\rho$ is given and the gravitational potential $\phi$ is derived from $\rho$ as an integral
- $\phi (x) = \frac{1}{4\pi}\int\frac{\rho (y)}{\vert x-y\vert}dy$,
seemingly by instant action at distance.
In alternative Newtonian gravitation, as discussed in recent posts, we view instead $\phi$ as primordial and $\rho =\Delta\phi$ as being derived by differentiation, with the advantage of requiring only local action.
We thus have two opposing views:
- putting together = integration requiring (instant) action at distance with dull tool.
- splitting apart = differentiation involving local action with sharp tool.
It is not clear what to prefer?
Connection between Neo-Newtonian and Einsteinian Gravitational Theory
Hen laying eggs by local action.
If you are a strong supporter of Einstein's general theory of relativity, like almost all modern physicists, then maybe you would be open to see the following connection with the Neo-Newtonian
theory I have been exploring in recent posts, with the gravitational potential $\phi$ viewed as primordial and matter density $\rho =\Delta\phi$ as derived by local action in space of the Laplacian $\Delta$ and with the gravitational potential playing the same role as the "space-time curvature" of Einstein:
If you are a strong supporter of Einstein's general theory of relativity, like almost all modern physicists, then maybe you would be open to see the following connection with the Neo-Newtonian
theory I have been exploring in recent posts, with the gravitational potential $\phi$ viewed as primordial and matter density $\rho =\Delta\phi$ as derived by local action in space of the Laplacian $\Delta$ and with the gravitational potential playing the same role as the "space-time curvature" of Einstein:
- space-time curvature tells matter to move along geodesics
- gravitational potential tells matter to move according to Newton's 2nd Law
with
- space-time curvature connected to matter by Einstein's equation
- gravitational potential connected to matter by Poisson's/Newton's equation.
This connects to the iconic summary of general relativity by John Archibald Wheeler:
- Spacetime tells matter how to move; matter tells spacetime how to curve,
where the "telling" goes both ways.
But maybe it is enough that the "telling" only goes one way, maybe it suffices that the gravitational potential tells where matter will be and how it is to move. After all, it is only the equality $\rho =\Delta\phi$ that counts and thus has to be established is some way, and then possibly through one-way communication from $\phi$ to $\rho$ in some form of local action.
Maybe it is enough to understand/explain how a hen can lay an egg by local action in a poultry yard, and leave out the much more difficult problem of how a hen can come out of an egg by global action outside the poultry yard.
onsdag 25 maj 2016
Newton's Genius and New View on Gravitation
Newton computed the gravitational attraction of a planet as a spherically symmetric distribution of matter, to be equal to that of a point mass of the same total mass at the center of the planet, away from the planet.
This made it possible for Newton to model gravitational interaction of planets as gravitational interaction of point masses, as a much simpler problem from computational point of view.
Newton thus could simplify the computationally impossible problem of instant gravitational interaction at distance of all the individual atoms of one planet with all the individual atoms of another planet, to the interaction between two point masses of the same total mass. Genial and absolutely necessary to make the theory useful and thereby credible.
But let us reflect a bit about the physics of instant individual interaction at distance of each atom of one planet with each atom of another planet, which we agreed is computationally impossible. We now ask if it is physically possible?
Is it thinkable that each atom can instantly at distance exchange details about position and mass with all others atoms by using some form of world wide web? Think about it!
The answer can only be NO. Atoms cannot have access to such technology. It is unthinkable.
The result is that we have to view gravitation in a different way, not as individual instant attraction between small pieces of matter at distance, and then why not in the other way as suggested in recent posts:
What is primordial is then a gravitational potential $\phi$ with associated gravitational force $\nabla\phi$, to which matter density $\rho$ is connected by $\rho =\Delta\phi$ through the local operation in space of the Laplacian $\Delta$.
With this view there is no instant action at distance between atoms to explain, but instead local production of matter without demand of atomistic resolution into pieces, which at least is thinkable.
It would be interesting to listen to Newton's reaction to this idea.
PS Business Insider reports that:
PS Business Insider reports that:
- Earth's core is 2.5 years younger than its crust due to some eerie physics
the eerie physics being Einstein's general theory of relativity claiming that clocks slow down with increasing gravitation. Yes, maybe your feet are a bit younger than your head...
The Value of Compulsory (Climate) Science?
Sunset over fossil free state without CO2 polluting people and welfare.
Tim Ball asks for Compulsory Courses for Any Curriculum; The Science Dilemma:
Tim Ball asks for Compulsory Courses for Any Curriculum; The Science Dilemma:
- Science is pervasive directly and indirectly in every phase of modern life.
- This knowledge must be a fundamental part of any school curriculum.
Tim suggests that compulsory science could save people from a meaningless ban on fossil fuel:
- Climate skeptics struggle with getting the majority of people to understand the problems with the UN Intergovernmental Panel on Climate Change’s (IPCC) anthropogenic global warming (AGW) story. The problem is much wider because it relates to the lack of scientific abilities among a majority of the population.
Tim is not happy with the present situation:
- I was involved in many curricula fights, few of them ever resolved much.
- Ever subject area and discipline considered theirs essential to an education. They failed in achieving curricula useful to the student and society.
- This was because they were controlled by people ensuring what interested them or what ensured their job, rather than what the student needed to become an effective informed citizen.
- Students are not given the tools to avoid being exploited. Indeed, sometimes I think the system keeps them ignorant so it can exploit them as adults.
- Peoples of the Rainforest teach their children what they need to survive in the real and dangerous world in which they live.
- We don’t do this at any level. For most North American university or college students the experience is a socially acceptable and ridiculously expensive form of unemployment. Most of them learn more about life and themselves in part-time and summer jobs.
I agree with Tim about the incitaments behind curricula, but I am not sure compulsory science would be beneficial. The trouble with anthropogenic global warming is that it is massively backed by scientists and academic institutions, and compulsory science could just mean more backing of fake science.
The real Science Dilemma is maybe rather to distinguish real science from fake science.
PS Our new social democratic Minister of Climate and Vice Prime Minister Isabella Lövin today proudly announces that
PS Our new social democratic Minister of Climate and Vice Prime Minister Isabella Lövin today proudly announces that
- Sweden will be the first fossil free welfare state in the Milky Way Galaxy.
Isabella Lövin of course has no climate science education, but would that have changed anything?
tisdag 24 maj 2016
Wallström: Förmån (utan Tjänstesamband) Ingen Muta
Chefsåklagare Alf Johansson vid riksenheten mot korruption meddelar till TT:
- Det begicks inget mutbrott när utrikesminister Margot Wallström fick en lägenhet av Kommunal. Åklagaren lägger ner förundersökningen.
- Det är också uppenbart att Wallström har mottagit en förmån, anser Johansson, men det kan alltså inte bevisas att hon har fått den just i egenskap av minister.
- Sammanfattningsvis har jag inte kunnat finna att det föreligger ett så kallat tjänstesamband, det vill säga en förmån i form av ett hyreskontrakt som har lämnats med anledning av statsrådets uppdrag.
- Av kontraktet parterna emellan framgår att hyresförhållandet gäller så länge Margot Wallström har sin nuvarande anställning.
Chefåklagaren anser alltså att Wallström tagit emot förmån, men anser, i synbar strid med kontraktet, att denna förmån inte har haft samband med Wallströms anställning som minister.
Eller kanske har tjänsten haft visst samband, men jämfört med det rena vänskapssamband som Johansson vet måste ha funnits (ja, vad annat skulle det ha kunna vara?) mellan Wallström och Kommunal (dock utan att ha hört Wallström), måste väl tjänstesambandet anses som försumbart?
Så klart att Wallström säger "Jag älskar Kommunal" och så klart att kärleken är besvarad!
Så klart att Wallström säger "Jag älskar Kommunal" och så klart att kärleken är besvarad!
Under alla förhållanden är Sverige det land i världen som har minst korruption, om man inte räknar vänskapskorruption förstås, och det är ju inte detsamma som den riktiga rejäla korruption som florerar i alla andra länder...
Det rimliga är väl nu att Wallström åter flyttar in i Kommunals lägenhet, eftersom som Wallström säger "inget fel är begånget". Det är ju trots allt en ganska trevlig lägenhet, stor, möblerad, central, låg hyra...
Se också tidigare post.
Jämför också med SVT: Wallströms lägenhet direkt kopplade till hennes politiska uppdrag.
Det rimliga är väl nu att Wallström åter flyttar in i Kommunals lägenhet, eftersom som Wallström säger "inget fel är begånget". Det är ju trots allt en ganska trevlig lägenhet, stor, möblerad, central, låg hyra...
Se också tidigare post.
Jämför också med SVT: Wallströms lägenhet direkt kopplade till hennes politiska uppdrag.
The Stupid Demand of Absolute Simultaneity which Destroyed Rational Physics
Absolute simultaneity of Tea Time
The book Einstein, Relativity and Absolute Simultaneity edited by William Lane Craig and Quentin Smith, starts out
- 2005 marked the centenary of one of the most remarkable publications in the history of science, Albert Einstein’s ‘‘On the Electrodynamics of Moving Bodies,’’ in which he presented a theory that later came to be known as the Special Theory of Relativity (STR).
- This 1905 paper is widely regarded as having destroyed the classical conceptions of absolute time and space, along with absolute simultaneity and absolute length, which had reigned in physics from the times of Galileo and Newton to the dawn of the twentieth century.
Einstein is thus commonly viewed to have destroyed classical Newtonian physics, and to judge if this is to applaud or not, it is necessary to take a look at Einstein's reason for the destruction as presented in the 1905 article. And that is a perceived impossibility of synchronising clocks with different positions and velocities, a perceived impossibility of fulfilling an absolute need of absolute simultaneity which Einstein attributed to classical Newtonian mechanics.
But what says that the world as classical mechanics requires absolute simultaneity to go around? Yes, it is needed for navigation by the Sun or GPS by humans, but birds navigate without synchronised clocks. And wasn't the world going around pretty well before there were any Poincare or Einstein worrying about clock synchronisation and absolute simultaneity?
So is there no need of absolute simultaneity in classical Newtonian mechanics? Yes, the standard idea is that the gravitation from the Sun is pulling the Earth around by instant action at distance, and that seems to require (i) synchronisation of Sun time and Earth time and (ii) a mechanism for instant action at distance.
Since no progress has been made concerning (i) and (ii) over the centuries since Newton, I have in recent posts tested a way to circumvent these difficulties or impossibilities, and that is to view the gravitational potential $\phi$ as primordial from which matter density $\rho =\Delta\phi$ is derived by the local action in space of the Laplacian $\Delta$.
With this view, which is Newtonian mechanics with just a little twist on what comes first, matter or gravitational potential, there is no need for absolute simultaneity and thus no longer any need to destroy a most beautiful and functional Newtonian mechanics.
Einstein thus attributes an unreasonable requirement of absolute simultaneity to Newtonian mechanics, and then proceeds to kill Newton. Of course this can be seen as an example of the all too well known tactics of attributing some evil quality (true or false) to your enemy, and then killing him.
And the book also ventilates such criticism:
- Unfortunately for Einstein’s Special Theory, however, its epistemological and ontological assumptions are now seen to be questionable, unjustified, false, perhaps even illogical.
- The precise philosophical arguments for the illogicality, falsity, or unjustifiably of the epis- temological, semantic, and ontological presuppositions of the Special Theory remain, with a few exceptions, unknown among physicists.
Pretty tough words, but how to cope with lack of knowledge and ignorance?
Etiketter:
absolute simultaneity,
Einstein,
theory of relativity
måndag 23 maj 2016
Neo-Newtonian Cosmology: Progress!
We consider a Neo-Newtonian cosmological model in the form of Euler's equations for a compressible gas subject to Newtonian gravitation: Find $(\phi ,m, e,p)$ depending on a Euclidean space coordinate $x$ and time $t$, such that for all $(x,t)$:
- $\Delta\dot\phi + \nabla\cdot m =0$ (1)
- $\dot m +\nabla\cdot (mu) +\nabla p + \rho\nabla\phi =0$ (2)
- $\dot e +\nabla\cdot (eu) +p\nabla\cdot u +\rho\nabla\cdot m=0$, (3)
The primary variables in this model are the gravitational potential $\phi$ and the momentum $m$ connected through (2) expressing conservation of momentum or Newton's 2nd law. We view matter density $\rho =\Delta\phi$ as being derived by local action of the differential operator $\Delta$. The model is complemented by a constitutive equation for the pressure.
The essential components of this model are:
- Newton's law of gravitation $\rho =\Delta\phi$ connecting mass to gravitational potential
- $\nabla\phi$ as gravitational force
- Newton's 2nd law (2) connecting motion to force,
- (1) expressing conservation of mass and (3) conservation of energy,
with the following features:
- no action at distance with $\phi$ primordial and $\rho =\Delta\phi$ derived quantity
- global clock synchronisation not needed because all action is local
- equivalence of inertial and gravitational mass by (2)
- $\Delta\phi$ of variable sign opens to positive and negative matter
- no limit on matter speed
- no electro-magnetics or nuclear physics so far included in the model.
It may well by that a model of this form is sufficient to describe the mechanics of the universe we can observe, a universe resulting from an interplay of gravitational force and motion of matter. You can test the model in the app Dark Energy at App Store. Try it!
Some form of starting values are needed for simulations using the model, but like in weather prediction initial values at a given global time are not known, but have to be constructed from observations over time possibly involving synchronisation of nearby clocks.
Some form of starting values are needed for simulations using the model, but like in weather prediction initial values at a given global time are not known, but have to be constructed from observations over time possibly involving synchronisation of nearby clocks.
The primordial quantity in this Newtonian model is the gravitational potential and gravitational force. It is the opposite of Einstein's model, where gravitational force is eliminated and replaced by "space-time" curvature. It is no wonder that Einstein expressed "Forgive me Newton!!" when taking this big extreme step.
A fundamental problem with modern physics is the incompatibility of Einstein's theory of gravitation in "curved space-time" and quantum mechanics in Euclidean space. This big obstacle would disappear if Einstein's gravitation was given up, and Newton's gravitation was resurrected in suitable form.
What is the reason to not take this step and open for progress?
Recall that nobody understands what "curved space-time" is, while everybody can understand what a Euclidean coordinate system is and how to measure local time. If we follow Einstein's device of always seeking to "make things as simple as possible, but not simpler", then Newton would have to be preferred before Einstein, or what do you think?
The basic force of cosmology is gravitation, and thus it may appear from rationality point of view to be irrational to seek to eliminate gravitational force from the discussion altogether, which is what Einstein did and which maybe paradoxically gave him fame bigger than that of Newton.
PS1 What drove Einstein into his extremism? Well, the reception of the special theory of relativity Einstein presented in a short sketchy note in 1905, did not draw any attention the first years and when it did, the reaction was negative. The only thing left for Einstein before getting called and kicked out of academics, was to increase the bet by generalising the special theory, which did not cover gravitation, into a general theory of relativity including gravitation. The only thing Einstein had in his scientific toolbox was the Lorentz transformation between non-accelerating inertial systems and the only way to bring that in contact with gravitation was to introduce coordinate systems in free fall, which in the presence of gravitation required strange transformations of space and time coordinates.
Einstein's "happiest thought" was when he realised that sitting in a freely falling elevator cannot be distinguished from sitting in an elevator at rest assuming no gravitation... until the freely falling elevator hits ground....It was this idea of free fall seemingly without gravitation, which allowed him to keep the Lorentz transformation with all its wonderful effects of the special theory without gravitation, when generalising to include gravitation...but the price was high...and the free fall is going on...Compare with Einstein's Pathway to General Relativity.
PS2 Another fact not to suppress is that the special theory of relativity was focussed on propagation of light with the same speed in all inertial coordinate systems if connected by the Lorentz transformation, which gave strange effects for the mechanics of matter (without gravitation) including dilation in time and contraction in space. But the Lorentz transformation was shaped for light propagation and not for mechanics of matter and so it was no wonder that strange effects came out. Since the Lorentz transformation also underlies the general theory of relativity, it is even less wonder that strange effects come out when adding gravitation to the picture.
The lack of scientific logic is clear: If you apply a theory designed to describe a a certain phenomenon (light propagation) to a different type of phenomenon (mechanics of matter), then you must be prepared to get in trouble, even if your name is Einstein...
Recall that nobody understands what "curved space-time" is, while everybody can understand what a Euclidean coordinate system is and how to measure local time. If we follow Einstein's device of always seeking to "make things as simple as possible, but not simpler", then Newton would have to be preferred before Einstein, or what do you think?
The basic force of cosmology is gravitation, and thus it may appear from rationality point of view to be irrational to seek to eliminate gravitational force from the discussion altogether, which is what Einstein did and which maybe paradoxically gave him fame bigger than that of Newton.
PS1 What drove Einstein into his extremism? Well, the reception of the special theory of relativity Einstein presented in a short sketchy note in 1905, did not draw any attention the first years and when it did, the reaction was negative. The only thing left for Einstein before getting called and kicked out of academics, was to increase the bet by generalising the special theory, which did not cover gravitation, into a general theory of relativity including gravitation. The only thing Einstein had in his scientific toolbox was the Lorentz transformation between non-accelerating inertial systems and the only way to bring that in contact with gravitation was to introduce coordinate systems in free fall, which in the presence of gravitation required strange transformations of space and time coordinates.
Einstein's "happiest thought" was when he realised that sitting in a freely falling elevator cannot be distinguished from sitting in an elevator at rest assuming no gravitation... until the freely falling elevator hits ground....It was this idea of free fall seemingly without gravitation, which allowed him to keep the Lorentz transformation with all its wonderful effects of the special theory without gravitation, when generalising to include gravitation...but the price was high...and the free fall is going on...Compare with Einstein's Pathway to General Relativity.
PS2 Another fact not to suppress is that the special theory of relativity was focussed on propagation of light with the same speed in all inertial coordinate systems if connected by the Lorentz transformation, which gave strange effects for the mechanics of matter (without gravitation) including dilation in time and contraction in space. But the Lorentz transformation was shaped for light propagation and not for mechanics of matter and so it was no wonder that strange effects came out. Since the Lorentz transformation also underlies the general theory of relativity, it is even less wonder that strange effects come out when adding gravitation to the picture.
The lack of scientific logic is clear: If you apply a theory designed to describe a a certain phenomenon (light propagation) to a different type of phenomenon (mechanics of matter), then you must be prepared to get in trouble, even if your name is Einstein...
söndag 22 maj 2016
Equivalence Principle as Definition: Experiment
Here is little experiment you can do yourself on the kitchen table supporting the idea that intertial mass is made equal to gravitational mass by definition as a result of a definition of force in terms of gravitational force:
Take two identical pieces of material, put one of the pieces on a horisontal table with frictionless surface and connect the other by a weightless rope as indicated in the picture and let go from rest.
Record the acceleration of the system. Observe that it is half of the gravitational acceleration of one of the pieces in free fall. Conclude that inertial mass = gravitational mass and that force ultimately is defined in terms of gravitational force as expressed by the green arrows.
Understand that what you test with the experiment is if mass = force/acceleration is independent of orientation of Euclidean coordinate system.
Take two identical pieces of material, put one of the pieces on a horisontal table with frictionless surface and connect the other by a weightless rope as indicated in the picture and let go from rest.
Record the acceleration of the system. Observe that it is half of the gravitational acceleration of one of the pieces in free fall. Conclude that inertial mass = gravitational mass and that force ultimately is defined in terms of gravitational force as expressed by the green arrows.
Understand that what you test with the experiment is if mass = force/acceleration is independent of orientation of Euclidean coordinate system.
fredag 20 maj 2016
Gravitational Mass = Inertial Mass by Definition: Hard Thinking
Typical illustration of equivalence principle. Get the point?
In Newtonian mechanics as already observed and understood by Galieo, inertial and gravitational (heavy) mass are equal, because there is only one form of mass and that is inertial mass as a measure of acceleration vs force per unit of volume. Since Newtonian gravitation is a force per unit of volume, gravitational mass is equal to inertial mass, by definition, as expressed by the fact that the dimension of gravitation is $m/s^2$. See also Chap 18 of Many-Minds Relativity.
Let us compare this insight with what modern physics says as told by Nigel Calder in Magic Universe:
In Newtonian mechanics as already observed and understood by Galieo, inertial and gravitational (heavy) mass are equal, because there is only one form of mass and that is inertial mass as a measure of acceleration vs force per unit of volume. Since Newtonian gravitation is a force per unit of volume, gravitational mass is equal to inertial mass, by definition, as expressed by the fact that the dimension of gravitation is $m/s^2$. See also Chap 18 of Many-Minds Relativity.
Let us compare this insight with what modern physics says as told by Nigel Calder in Magic Universe:
- A succession of experiments to check the equivalence principle—the crucial proposition that everything falls at the same rate—began with Lorand Eötvös in Budapest in 1889. After a century of further effort, physicists had improved on his accuracy by a factor of 10,000. The advent of spaceflight held out the possibility of a further improvement by a factor of a million.
- If another theory of gravity is to replace Einstein’s, the equivalence principle cannot be exactly correct. Even though it’s casually implicit for every high-school student in Newton’s mathematics, Einstein himself thought the equivalence principle deeply mysterious. ‘Mass,’ he wrote, ‘is defined by the resistance that a body opposes to its acceleration (inert mass). It is also measured by the weight of the body (heavy mass). That these two radically different definitions lead to the same value for the mass of a body is, in itself, an astonishing fact.’
- Francis Everitt of Stanford put it more forcibly. ‘In truth, the equivalence principle is the weirdest apparent fact in all of physics,’ he said. ‘Have you noticed that when a physicist calls something a principle, he means something he believes with total conviction but doesn’t in the slightest degree understand.’
- Together with Paul Worden of Stanford and Tim Sumner of Imperial College London, Everitt spent decades prodding space agencies to do something about it. Eventually they got the go-ahead for a satellite called STEP to go into orbit around the Earth in 2007. As a joint US–European project, the Satellite Test of the Equivalence Principle (to unpack the acronym) creates, in effect, a tower of Pisa as big as the Earth. Supersensitive equipment will look for very slight differences in the behaviour of eight test masses made of different materials— niobium, platinum-iridium and beryllium—as they repeatedly fall from one side of the Earth to the other, aboard the satellite.
- ‘The intriguing thing,’ Everitt said, ‘is that this advance brings us into new theoretical territory where there are solid reasons for expecting a breakdown of equivalence. A violation would mean the discovery of a new force of Nature. Alternatively, if equivalence still holds at a part in a billion billion, the theorists who are trying to get beyond Einstein will have some more hard thinking to do.’
So Einstein thought to be deeply mysterious, what every high school student directly understands, and was able to imprint his idea into the brains of all modern physicists, who now have some hard thinking to do...
Einstein skillfully jumped between definition as a tautology true by construction and physical principle/law, which may be valid/true or not, thereby creating a total confusion. Another aspect is the constancy of the speed of light, which today is used as definition with the meter defined by distance traveled by light in certain time, yet physicists go around and believe that this works because the speed of light is constant. If you cannot distinguish between a definition without content and statement with content, then you may find yourself in trouble and mislead others...
PS This previous post may be consulted: The Principal Difference between Principles and Laws in Physics. Note in particular the distinction that a law is typically expressed as a formula, while a principle is expressed in words e.g. as equality of inertial and gravitational mass.
Einstein skillfully jumped between definition as a tautology true by construction and physical principle/law, which may be valid/true or not, thereby creating a total confusion. Another aspect is the constancy of the speed of light, which today is used as definition with the meter defined by distance traveled by light in certain time, yet physicists go around and believe that this works because the speed of light is constant. If you cannot distinguish between a definition without content and statement with content, then you may find yourself in trouble and mislead others...
PS This previous post may be consulted: The Principal Difference between Principles and Laws in Physics. Note in particular the distinction that a law is typically expressed as a formula, while a principle is expressed in words e.g. as equality of inertial and gravitational mass.
Etiketter:
Equivalence Principle,
mysticism of modern physics
New Theory of Flight Presented at KTH
The New Theory of Flight developed together with Johan Hoffmann and Johan Jansson will be presented at a KTHX seminar on May 26, see
- KTHX
- Flow Theory Beyond Prandtl: Change of Paradigm?
- The Secret of Flight (website)
- The Secret of Flight (book).
Note that the starting point is the incompressible Euler equation formulated by Euler around 1750 and presented as follows:
- Everything that the theory of fluids contains is embodied in the two equations I have formulated. It is not the laws of mechanics that we lack in order to pursue this research, only the analysis which has not been sufficiently developed for this purpose.
What we do is to compute turbulent solutions of the Euler equations after having realised for the first time the development Euler is asking for, and we then discover as predicted by Euler "everything that the theory of fluids contains" or at least lots of it.
Sometimes it takes a long time for a correct idea to bear fruit.
torsdag 19 maj 2016
Unsolvable Incompatible Equations of Modern Physics = Complete Success!
All books on modern physics start out with a praise to Schrödinger's equation of quantum mechanics and Einstein's equation of general relativity as the highest achievement of science. Here is what Stephen Hawking says in The Grand Design (while signaling that something is weird):
- The quantum model of nature encompasses principles that contradict not only our everyday experience but our intuitive concept of reality. Those who find those principles weird or difficult to believe are in good company, the company of great physicists such as Einstein and even Feynman, whose description of quantum theory we will soon present. In fact, Feynman once wrote, “I think I can safely say that nobody understands quantum mechanics.” But quantum physics agrees with observation. It has never failed a test, and it has been tested more than any other theory in science.
- Through years of research, physicists have experimentally confirmed with tremendous accuracy virtually every prediction made by these two theories when in their appropriate domains of applicability. In accordance with their findings, scientists also learned that GR and QFT, as they are currently formulated, are mutually incompatible – they cannot both be right.
- Some theoretical physicists currently believe that a quantum theory of general relativity may require frameworks other than field theory itself, such as string theory or loop quantum gravity. Some models in string theory that are promising by way of realizing our familiar standard model are the perturbative heterotic string models, 11-dimensional M-theory, Singular geometries (e.g. orbifold and orientifold), D-branes and other branes, flux compactification and warped geometry, and non-perturbative type IIB superstring solutions (F-theory).
Schrödinger's equation for an atom with $N$ electrons is formulated in terms of a wave function which depends on $3N$ space coordinates, which makes numerical solution impossible for N > 10
according to Nobel Laureate Walter Kuhn, and already the case N=2 of Helium is filled with difficulty not to speak about the case of Oxygen with N=8. And analytical solution is known only in the case of Hydrogen with N=1.
Einstein's equation is even more difficult to solve and only a few analytical solutions in extreme simplicity are known (e.g. vacuum solution of a spherically symmetric gravitational field for a static mass), and numerical solution is not really an issue because data such as initial and boundary values and forcing are completely up in the air and the choice of coordinate system is unclear. We quote from Baumgarte Numerical Relativity: Solving Einstein's equations on the Computer:
- Chapters 12 and 13 focus on the inspiral and coalescence of binary black holes, one of the most important applications of numerical relativity and a promising source of detectable gravitational radiation. These chapters treat the two-body problem in classical general relativity theory, and its solution represents one of the major triumphs of numerical relativity.
Of course you cannot know that. But this troublesome fact for modern physicists, is twisted into: Since solutions cannot be computed, it is impossible to find any discrepancy between predictions according to the equations and observations! There are no predictions from solving the equations and thus there is no discrepancy!
More precisely it works this way: Suppose you have computed a what you view as an approximate solution of Schrödinger's equation for some atom with many electrons, by an ingenious choice of "atomic orbitals" combined with some optimisation to choose a best combination of orbitals, and that the predicted energy is in perfect agreement with observation. Then you congratulate yourself and say that you have produced yet another piece of evidence that solutions of Schrödinger's equation always agree exactly with observations. On the other hand, if your approximate solution does not agree exactly with observation, then you blame the approximation and take that as evidence that without approximation the agreement certainly would be complete, and then you try some other orbitals...until complete agreement...possibly by twisting the observation under the firm conviction that solutions to Schrödinger's equation give an exact description of atomic physics.
The net result is that the unsolvable equations of modern physics, which unfortunately are incompatible, anyway both must be valid to an unprecedented precision, since there are no examples of slightest discrepancy between prediction based on solving the equations and observation.
In other words the equations serve like oracles who know exact answers to important questions, but are not willing to reveal the full truth. Not very helpful.
Do you buy this? Or is there something fishy about solutions to unsolvable mathematical equations, which always give results in perfect agreement with observations? Doesn't perfect agreement sound little bit too good?
Some quotes, among many similar:
- In fact, it is often stated that of all the theories proposed in this century, the silliest is quantum theory. Some say that the only thing that quantum theory has going for it, in fact, is that it is unquestionably correct. (Michio Kaku)
- When thinking about the new relativity and quantum theories I have felt a homesickness for the paths of physical science where there are ore or less discernible handrails to keep us from the worst morasses of foolishness. (Sir Arthur Stanley Eddington)
- Einstein, my upset stomach hates your theory [of General Relativity]—it almost hates you yourself! How am I to' provide for my students? What am I to answer to the philosophers?!!(Paul Ehrenfest)
- I count Maxwell and Einstein, Eddington and Dirac, among “real” mathematicians. The great modern achievements of applied mathematics have been in relativity and quantum mechanics, and these subjects are at present at any rate, almost as “useless” as the theory of numbers. (G. H. Hardy)
- Quantum field theory, which was born just fifty years ago from the marriage of quantum mechanics with relativity, is a beautiful but not very robust child. (Steven Weinberg)
- Niels Bohr brainwashed a whole generation of theorists into thinking that the job of interpreting quantum theory was done 50 years ago. (1969 Nobel Laureate Murray Gell-Mann)
- Let me say at the outset, that in this discourse, I am opposing not a few special statements of quantum physics held today (1950s), I am opposing as it were the whole of it, I am opposing its basic views that have been shaped 25 years ago, when Max Born put forward his probability interpretation, which was accepted by almost everybody. I don’t like it, and I’m sorry I ever had anything to do with it. (Erwin Schrodinger talking about Quantum Physics)
- One might very well be left with the impression that the theory (of general relativity) itself is rather hollow.: What are the postulates of the theory? What are the demonstrations that else follows from these postulates? Where is the theory proven? On what grounds, if any, should one believe the theory? ....One’s mental picture of the theory is this nebolous mass taken as a whole.....One makes no attempt to derive the rest of the theory from the postulates. (What, indeed, could it mean to “derive” somtheing about the physical world?). One makes no attempt to “prove” the theory, or any part of it. (Robert Geroch in General Relativity from A to B)
Etiketter:
Einstein,
mysticism of modern physics,
Schrödinger's equation
Spiral Galaxy Formation in Extended Newtonian Gravitation
1. Cosmological Model
This is a continuation of previous posts on dark matter and The Universe as Weakly Compressible Gas subject to Pressure and Gravitational Forces, which post we recall:We consider a cosmological model in the form of Euler's equations for a compressible gas subject to Newtonian gravitation: Find $(\rho ,m, e ,\phi ,p)$ depending on a Euclidean space coordinate $x$ and time $t$, such that for all $(x,t)$:
- $\dot\rho + \nabla\cdot (\rho u ) =0$ (or $\frac{D\rho}{Dt} = -\rho\nabla\cdot u$)
- $\dot m +\nabla\cdot (mu) +\nabla p + \rho\nabla\phi =0$
- $\dot e +\nabla\cdot (eu) +p\nabla\cdot u +\rho\nabla\cdot m=0$,
- $\frac{D\rho}{Dt}=\dot\rho +u\cdot\nabla\rho$
These equations express conservation of mass $\rho$, conservation of momentum $m$ with $\nabla p$ pressure force and $-\nabla\phi$ gravitational force, and conservation of internal energy $e$. These laws of conservation are complemented with constitutive laws connection $p$ and $\phi$ to density, of the following form:
A1: Weakly compressible gas ($\delta$ small positive constant):
- $\Delta p =\frac{\nabla\cdot u}{\delta}= - \frac{1}{\delta\rho}\frac{D\rho}{Dt}$
A2: Compressible perfect gas ($0 < \gamma < 1 $):
- $p=\gamma \rho T$.
- $\Delta\phi =\rho$ with $\phi =0$ at infinity.
We observe
- Similarity of $\nabla p$ and $\nabla\phi$ in momentum equation.
- Similarity between A1 and B connecting $\Delta p$ to $-\frac{D\rho}{Dt}$ (or $-\rho$) and $\Delta\phi$ to $\rho$.
- $p \ge 0$ and $\phi \le 0$.
Here 1. can be seen as the Equivalence Principle (equality of heavy and inertial mass) expressing that there is no difference between gravitational and other forces (pressure) in Newton's 2nd law expressing conservation of momentum.
Further, 2. expresses that the constitutive laws A1 and B both can be viewed as action at distance if $\rho$ is viewed as the cause, but represent local action of differentiation if $\rho$ is viewed as the effect.
For a weakly compressible gas described by A1, there is no need per se to identify a cause-effect relation between $p$ and $\rho$; it is enough to say that $p$ and $\rho$ are connected in a certain way expressing a form of "perfect harmony".
In the same way, there is no need per se to identify a cause-effect relation between $\phi$ and $\rho$; it is enough to say that $\phi$ and $\rho$ are connected in certain way expressing a form of "perfect harmony" in the spirit of Leibniz.
The relation $\Delta\phi =\rho$ is explored in Newtonian Matter and Antimatter with $\Delta\phi > 0$ identifying matter and $\Delta\phi < 0$ antimatter, with dark matter where $\Delta\phi$ is smooth and visible matter where $\Delta\phi$ is singular, typically as a sum of multiples of delta functions representing matter in point form. We refer to such a model as Extended Newtonian Gravitation.
The relation $\Delta\phi =\rho$ is explored in Newtonian Matter and Antimatter with $\Delta\phi > 0$ identifying matter and $\Delta\phi < 0$ antimatter, with dark matter where $\Delta\phi$ is smooth and visible matter where $\Delta\phi$ is singular, typically as a sum of multiples of delta functions representing matter in point form. We refer to such a model as Extended Newtonian Gravitation.
2. Galaxy Formation
We start from a spherical distribution of matter of low density of dark matter (a halo) with $\Delta\phi$ a smooth function, which we assume to be in static equilibrium with the the gravitational force balanced by a weak pressure force with $\nabla p = - \rho\nabla\phi$.
Starting from this halo of low density dark matter, we assume that some visible matter (stars) is formed by concentration of dark matter by gravitational attraction into point masses with $\rho$ becoming large locally with the result that the gravitational force $\rho\nabla\phi$ can no longer be balanced by a weak pressure force $-\nabla p$. This is an effect of the different action of pressure and gravitational force, with pressure scaling with surface and gravitational force with volume.
The combined effect of the presence of a halo of dark matter and gravitational collapse of visible matter as a system of point masses, may then create a spiral galaxy of visible matter surrounded by a halo of dark matter, which is the standard view of the nature of a spiral galaxy, with in particular a characteristic distribution of velocity of visible matter as roughly independent of the distance to the galaxy center as an effect of the dark matter halo.
It thus appears that an extended Newtonian model with $\Delta\phi$ of variable sign and concentration may be sufficient to explain essential aspects of galaxy formation, for which Einstein's equation equation is useless.
tisdag 17 maj 2016
Einsteins "Scientific Method": Magic Physics from Definition
Einstein "scientific method", which brought him immense fame as the greatest physicist of all times, consists of:
- Start from a definition, convention or stipulation/law without physical content, and then draw far-reaching consequences about the physics of the world.
It is not hard to understand that such a "method" cannot work: You cannot draw meaningful conclusions about the world simply from a definition empty of physics content. You cannot develop a meaningful scientific theory from a definition that there are 100 centimeters on a meter.
Einstein cleverly covered up by naming his definitions or conventions or stipulations/laws, "principles":
- Equivalence Principle: Gravitational mass is equal to inertial mass.
- Relativity Principle: Observations in inertial coordinate systems moving with constant velocity with respect to each other, are to be connected by the Lorentz transformation.
- Covariance Principle: Physical laws are to have the same form independent of the choice of coordinate system.
Here 1. is an empty definition, because there is only one mass, and that is inertial mass, which measures acceleration vs force and gravitational force is a force. Gravitational mass is equal to inertial mass by definition. Attempts to "prove/verify" this experimentally, which are constantly being made with ever increasing precision and always with the same result of equality, are as meaningful as experiments attempting to verify that there are 100 centimeters on a meter, which could very well be the next grand challenge for LHC, in the spirit of Einstein.
2. stipulates that different physical phenomena are to be viewed to be the same. This is because the Lorentz transformation is not invariant with respect to initial conditions, and thus Einstein stipulates that two waves satisfying the same form of wave equation, but having different initial conditions, shall be viewed to be the same. No wonder that with this play with identities, all sort of strange effects of time dilation and space contraction can be drawn out of a magicians hat.
It is clear that physical laws in general take different forms in different coordinate systems, and thus 3. is an absurd stipulation. Alternatively, it is trivial and just says that a physical law will have to transform when expressed in different coordinates so that the law has the same physical content. So 3. is either absurd or trivial, in both cases devoid of physics.
It is depressing that none of this can be understood by leading modern physicists. Nada. Even more depressing is that the discussion is closed since 100 years.
2. stipulates that different physical phenomena are to be viewed to be the same. This is because the Lorentz transformation is not invariant with respect to initial conditions, and thus Einstein stipulates that two waves satisfying the same form of wave equation, but having different initial conditions, shall be viewed to be the same. No wonder that with this play with identities, all sort of strange effects of time dilation and space contraction can be drawn out of a magicians hat.
It is clear that physical laws in general take different forms in different coordinate systems, and thus 3. is an absurd stipulation. Alternatively, it is trivial and just says that a physical law will have to transform when expressed in different coordinates so that the law has the same physical content. So 3. is either absurd or trivial, in both cases devoid of physics.
It is depressing that none of this can be understood by leading modern physicists. Nada. Even more depressing is that the discussion is closed since 100 years.
måndag 16 maj 2016
The Blind Space Traveler with Gravitational Potential Meter
Hawking inside a space ship without windows with a Gravitational Potential Meter
Imagine you are a space traveler locked into a space ship without windows, or traveling through a region of invisible dark matter. Imagine that in this difficult situation, you have access to an instrument capable of recording the gravitational potential around the space ship from near to far away, an instrument or sense which we may call a Gravitational Potential Meter. Below I discuss how such an instrument might be designed.
Would that allow you to create a normal picture of the distribution of celestial objects/matter around you including your own position, which would be the picture you could see if there were windows or dark matter somehow was made visible, a standard picture/map making it possible to navigate?
Yes, it would because the mass distribution $\rho (x)$ depending on a Euclidean space coordinate $x$ at any instant of time, is related to the gravitational potential $\phi (x)$ by Poisson's equation (in normalised form):
Imagine you are a space traveler locked into a space ship without windows, or traveling through a region of invisible dark matter. Imagine that in this difficult situation, you have access to an instrument capable of recording the gravitational potential around the space ship from near to far away, an instrument or sense which we may call a Gravitational Potential Meter. Below I discuss how such an instrument might be designed.
Would that allow you to create a normal picture of the distribution of celestial objects/matter around you including your own position, which would be the picture you could see if there were windows or dark matter somehow was made visible, a standard picture/map making it possible to navigate?
Yes, it would because the mass distribution $\rho (x)$ depending on a Euclidean space coordinate $x$ at any instant of time, is related to the gravitational potential $\phi (x)$ by Poisson's equation (in normalised form):
- $\rho = \Delta\phi$, (*)
where $\Delta$ is the Laplacian with respect to $x$. In this setting you would naturally view the gravitational potential $\phi (x)$ as primordial, because this is what you can record/sense, and you would view the mass distribution $\rho (x)$ as a derived quantity, because this is what you can compute knowing $\phi (x)$ by applying the Laplace operator, which is a differential operator acting locally in space.
In this new setting you would not, as in the classical setting of viewing $\rho (x)$ as primordial and $\phi = \Delta^{-1}\rho$ as derived by the inverse of the Laplacian as a non-local operator, have to explain instant action at distance, only the local action of (*), and you would thus have eliminated the question of the physics of instant action at distance, which does not seem to have an answer, and as such may be the wrong question.
We conclude that depending on what we can see through instruments or senses, we are led to questions, which may have answers or not. It is natural to think that questions, which may have answers, are better questions than questions which do not have answers.
As to the design of a Gravitational Potential Meter or Gravitational Force Meter, imagine a system of little satellites in free fall distributed over the space of interest and connected to a GPS system allowing tracing of the satellites, thus giving information about the Gravitational Force and from that the Gravitational Potential. It is not unthinkable that such a system could cover any space accessible for space travel and beyond.
As to the design of a Gravitational Potential Meter or Gravitational Force Meter, imagine a system of little satellites in free fall distributed over the space of interest and connected to a GPS system allowing tracing of the satellites, thus giving information about the Gravitational Force and from that the Gravitational Potential. It is not unthinkable that such a system could cover any space accessible for space travel and beyond.
Etiketter:
instant action at distance,
New View on gravitation
Simultaneity as Non-Physical Convention along with Special Relativity
The book Concepts of Simultaneity: From Antiquity to Einstein and Beyond is presented by:
- Max Jammer's Concepts of Simultaneity presents a comprehensive, accessible account of the historical development of an important and controversial concept—which played a critical role in initiating modern theoretical physics—from the days of Egyptian hieroglyphs through to Einstein's work in 1905, and beyond.
- Beginning with the use of the concept of simultaneity in ancient Egypt and in the Bible, the study discusses its role in Greek and medieval philosophy as well as its significance in Newtonian physics and in the ideas of Leibniz, Kant, and other classical philosophers.
- The central theme of Jammer's presentation is a critical analysis of the use of this concept by philosophers of science, like Poincaré, and its significant role in inaugurating modern theoretical physics in Einstein's special theory of relativity.
- Particular attention is paid to the philosophical problem of whether the notion of distant simultaneity presents a factual reality or only a hypothetical convention. The study concludes with an analysis of simultaneity's importance in general relativity and quantum mechanics.
In earlier post on I have argued that simultaneity in time at distant points in space is a man-made convention, which is useful to humanity in many ways including GPS, but as convention has no role in describing the physics of material bodies without GPS receivers. Jammer presents much evidence supporting this view without closing the door to simultaneity as some form of factual reality.
Einstein's special relativity came out from an a simple thought experiment showing that agreement on distant simultaneity defined by a certain conventional form of clock synchronization set up by Einstein, cannot be established for different observers moving with speeds comparable to the speed of light with respect to each other.
Einstein thus started from a certain ad hoc man-made convention and from the impossibility of making the convention work for moving observers Einstein jumped to the conclusion that our concepts of the physics of space and time will have to be fundamentally changed. And the world jumped along. But is it possible to change physics by man-made convention? Can we change physics by changing our man-made conventions to measure time and space, by changing from yard to meter? I think not.
Why believe that special relativity is real physics, when special relativity is based on an impossibility to make a certain man-made convention work?
I have stressed that the notion of distant simultaneity is present in the standard form of Newton's law of gravitation as Poisson's equation $\Delta\phi =\rho$, seemingly creating a gravitational potential $\phi (x)$ depending on a Euclidean space coordinate $x$ from instant action at distance by a primordial matter distribution $\rho (y)$ with $y$ different from $x$, represented as $\phi =\Delta^{-1}\rho$ with the inverse $\Delta^{-1}$ a non-local (integral) operator.
On the other hand, viewing the gravitational potential $\phi$ as primordial and $\rho =\Delta\phi$ as derived by local differentiation, there is no need to explain the physics of instant action at distance, which Newton left open under the criticism of Leibniz and which has resisted all attempts after Newton.
We conventionally view matter $\rho$ as primordial, since we can see matter at distance if it is sending out light, while we cannot see the gravitational potential $\phi$, only feel that it is there.
But with a different eyes we may be able to see the gravitational potential $\phi$, but not $\rho$, and we would then naturally view $\phi$ to be primordial. With such eyes we might be able to see a gravitational potential of dark matter and dark energy, which we now cannot see, only feel that it is there.
Etiketter:
Einstein,
many-minds relativity,
relativity,
simultaneity,
theory of relativity
söndag 15 maj 2016
The Quest for the Ultimate Theory of Time: Physical Stability or Empty Probability?
The question of the direction of time, or the arrow of time, is still haunting physicists with the physicist and cosmologist Sean Carrol expressing state of art in e.g. the book From Eternity to Here: The Quest for the Ultimate Theory of Time, which is basically to say following old Boltzmann: There is a quantity named entropy, which cannot decrease with time and when strictly increasing sets a direction of time motivated by Carroll as follows in an introduction:
- The reason why entropy wants to increase is deceptively simple:
- There are more ways to be disorderly than orderly, so an orderly arrangement will naturally tend toward increasing disorder.
But Carroll is not very happy with this his explanation:
- If everything in the universe evolves toward increasing disorder, it must have started out in an exquisitely ordered arrangeement...a state of very low entropy.
- Why were conditions in the early universe set up in a very particular way? That is the question this book sets out to address.
- Unfortunately, no one yet knows the right answer.
And then follows the rest of the book, without answer. The only attempt to give reason to the tendency of entropy to increase, is to argue following Boltzmann, that things naturally evolve from less probable/low entropy states to more probable/higher entropy states. But of course this is circular: To say that more probable is more probable than less probable is a tautology without actual content.
In the book The Clock and the Arrow: A Brief Theory of Time I argue that there is another way of explaining the arrow of time and that is with reference to the physics of stability instead of the non-physics of probability of Boltzmann. The key point is:
- A system cannot remain in an unstable state because the inevitable effect of small fluctuations will have a major effect and thus transform the system to either a more stable state of more or less rest or to another unstable state of non-rest.
- The transition from unstable to stable rest is irreversible since the reverse process from stable rest to unstable is impossible without major exterior forcing.
- The transition from unstable is sensitive to small perturbations along with the formally reversed process, and thus cannot be reversed under any form of finite precision physics.
- An arrow of time is given by physical stability properties of certain systems making them irreversible, without asking any specific order of an early universe.
- An arrow of time is motivated by an empty tautology stating that systems evolve from less probable to more probable states, asking for a highly improbable highly ordered early universe.
You may decide yourself between 1. and 2. Which is more probable?
Etiketter:
2nd law of thermodynamics,
arrow of time,
entropy,
turbulence
Instant Action at Distance and Simultaneity not Needed in New Theory of Gravitation including Dark Energy
Einstein won the game. But what was the game about? Simultaneity?
Einstein's theory of relativity grew out from a question of simultaneity in time of events at different locations in space, which Einstein could not answer in a non-ambiguous way and then jumped to the conclusion that a fundamental revision of our concepts of space and time was necessary. Einstein took so on the responsibility in the service of science and humanity to make the revision and thereby open the door to a modern physics of "curved space-time" with all its wondrous new effects of time dilation and space contraction, albeit too small to be detected.
It is clear that simultaneity plays an important role in our society, to set schedules and allow people to meet at the same place and for these purposes we all have clocks synchronized to a reference clock. And to decide which scientist first submitted an article reporting a certain new scientific break-through and to navigate...
But what role does simultaneity play in physics? In what sense do distant physical objects care about simultaneity? Do they all have synchronised clocks? Of course not. What they do is to react to local forces acting locally in time, and no simultaneity with the action of distant objects is involved.
Or is it? What about gravitation, isn't it supposed to act instantly over distance and thus require a form of exact simultaneity? Yes, it so seems because in Newtonian gravitation the Earth is instantly acted upon by a gravitational force from the Sun directed towards the present position of the Sun, and not towards the position where we see the Sun because of the 8 minute time delay of the light from the Sun.
The standard view on gravitation, is thus that the presence of matter instantly generates a gravitational potential/force (Newton) or "curvature of space" (Einstein) at distance. This view comes with the following questions:
Einstein's theory of relativity grew out from a question of simultaneity in time of events at different locations in space, which Einstein could not answer in a non-ambiguous way and then jumped to the conclusion that a fundamental revision of our concepts of space and time was necessary. Einstein took so on the responsibility in the service of science and humanity to make the revision and thereby open the door to a modern physics of "curved space-time" with all its wondrous new effects of time dilation and space contraction, albeit too small to be detected.
It is clear that simultaneity plays an important role in our society, to set schedules and allow people to meet at the same place and for these purposes we all have clocks synchronized to a reference clock. And to decide which scientist first submitted an article reporting a certain new scientific break-through and to navigate...
But what role does simultaneity play in physics? In what sense do distant physical objects care about simultaneity? Do they all have synchronised clocks? Of course not. What they do is to react to local forces acting locally in time, and no simultaneity with the action of distant objects is involved.
Or is it? What about gravitation, isn't it supposed to act instantly over distance and thus require a form of exact simultaneity? Yes, it so seems because in Newtonian gravitation the Earth is instantly acted upon by a gravitational force from the Sun directed towards the present position of the Sun, and not towards the position where we see the Sun because of the 8 minute time delay of the light from the Sun.
The standard view on gravitation, is thus that the presence of matter instantly generates a gravitational potential/force (Newton) or "curvature of space" (Einstein) at distance. This view comes with the following questions:
- What is the physics of the instant action at distance? Gravitons?
- What is the physics of the simultaneity associated with instant action?
- $\Delta\phi =\rho$. (*)
With this view there is no instant action at distance to explain and no associated simultaneity, since the action of Laplacian $\Delta$ as differential operator is local is space and time.
It may thus be that the questions 1. and 2. are not the right questions, and then also that Einstein's relativity originating from a question about simultaneity, is not the right answer to the right question.
More precisely, simultaneity does not appear to be a matter of the physics of the world, since atoms are not equipped with a man-made system of synchronised clocks, and so it is not reasonable to make a complete revision of Newtonian mechanics starting from an ad hoc idea of probably little significance.
More precisely, simultaneity does not appear to be a matter of the physics of the world, since atoms are not equipped with a man-made system of synchronised clocks, and so it is not reasonable to make a complete revision of Newtonian mechanics starting from an ad hoc idea of probably little significance.
The equation (*) further suggests that with $\phi$ primordial there is no reason to insist that $\rho$ as a derived quantity must be non-negative, thus (*) opens to the possible existence of matter density $\rho$ of both signs, that is to both positive and negative matter.
This idea is explored in the app Dark Energy on App Store with in particular a simulation of a universe resulting from a fluctuation of the gravitational potential with associated positive and negative matter, with the negative matter forcing a positive matter world into accelerating expansion, which may be the missing dark energy you are looking for. Try it!
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