Posts Tagged ‘Curvature’

Flat Universe Flattens Twisted Logic

April 11, 2015

The observed universe is flat. I will explain what it means in practice, before going into a bit of theory. Including a sickle move through the lamentable precedent of the heliocentric system.

Basically, when we look at a galaxy which is very very very far away, it appears to have the same size as it should have considering its distance. Ah, yes, because we can determine the distance of a very very remote galaxy, or so we think, by looking at its red shift (how much redder it looks than what it would be if it were next door).

This apparently innocuous set-up creates lots of problems for the ruling cosmological theory, the Big Noise Bang. The barnacles attached to the Big Noise, thousands of professional cosmologists, would not be happy to see their ship sink, so they insist it’s doing all right. Yet I am dancing all around with the facts, and, should they read me carefully, they would be less sanguine about the respect they will enjoy, in the fullness of time.

Gravitational Lensing. Lensing Without Gravitation Would Signal Curvature. So Would Apparent Size Variations. Neither Is Observed, However far We Look.

Gravitational Lensing. Lensing Without Gravitation Would Signal Curvature. So Would Apparent Size Variations. Neither Is Observed, However far We Look.

The Big Noise cosmologists may well be wrong, because they suppose plenty of things for their model. All too many things, some of them, pretty weird. I get to the same observations, while being much more parsimonious with my hypotheses.

We have seen it all before, this conflict between common sense , and complicated absurdities by great priests, themselves at the service of higher authorities. Remember the Ptolemaic system? That claimed the Sun rotated around Earth. That absurdity ruled for around 15 centuries


Cosmology is serious business:

The Ptolemaic System Was An Obese Lie, Thus Contradicting It, A Capital Crime:

The bigger the lie, the greater the authority. So great authority loves big lies: it is a training ground for the feeble minds which make authority so great.

The greatest philosopher of the Fourteenth Century, and the greatest physicist of the Middle Ages, the Parisian Johannes Buridanus, sent the Ptolemaic system to the bottom of the sea (1320s CE).

However Jean Buridan, adviser to 4 kings, and head of the University of Paris, did not want to be burned alive. So Buridan presented all his new physics and cosmology as something “supporters” of the point of view that “authority does not demonstrate” were talking about (he named no names).

Buridan believed that the Earth turned on itself each day, and around the sun in a year, that the arrow would fall at the same point, because of his own theory of impetus. Etc. It’s all very clear, and some of it can even be read. (In this extract Buridan supports geocentrism; in later extracts, he concludes he cannot be distinguished from heliocentrism observationally; a full study of Buridan is not extant. Some of the later arguments of Buridan are found in Oresme.)

Even the ship example used by Galileo, 300 years later, to demonstrate the undetectability of uniform motion is Buridan’s invention, for the same purpose (Buridan’s student, bishop Oresme wrote about it too).

The Catholic Church, supported by King Plutocrat Louis XI, made reading Buridan a capital crime in 1473 CE. Buridan’s cosmology was posthumously re-amplified by his student and (self) publicist, the dying Abbot Copernicus.

That fancy, the heliocentric system, was, on the face of it, quite ridiculous: Buridan said the Earth was “tiny” so it was only understandable that the tiny thing would rotate on itself, while enormous thing would stay put.


Authorities Love Systems Which Lie And Make No Sense:

Why the heliocentric system, was entertained so long explains much of the enthusiasm for the Big Bang. The psychology is similar: an obscure set of ideas was made more hermetic by computations nobody understands. Actually, it’s Plato who launched the Big Ptolemaic Noise, six centuries prior to Ptolemy’s efforts.

Believing in the heliocentric system was good training for submitting to stupid authority, and learning to become non-critical.

But let’s go back to flatness.

Basic Math Of Flatness:

Our universe of stars, clouds, and galaxies, is three dimensional (as I often talk of high dimensions, see note: the “3” maybe an average of the “many”).

Geometries can be flat (a plane) or spherical (aka “elliptic”; as on a round planet), or “hyperbolic” (a saddle).

A mighty theorem (Perelman-Thurston; see technical note on mathematical background) implies that astronomically plausible non-flat geometries contain flat, spherical or hyperbolic elements.

I will simplify further.

Geometries are determined by their geodesics (the shortest paths). At least locally.

A non-flat universe means that that some perspective can be found so that two neighboring geodesics will either converge or diverge.

For a proof, just look at a sphere, or a saddle; the geodesics can be determined by pulling a string between two points, making the shortest paths. They are the greatest circles in the case of a sphere. Notice that the distances between two nearby strings, once pulled to make geodesics, vary. The big math proof, with equations, does not say anything more.

No Empty Space Lensing, No Curvature:

In space, geodesics are paths followed by light. If the universe is not flat, light will either diverge, or converge, as if space itself was a lens. This means that a galaxy, or a galactic cluster, will appear bigger, or smaller, than it should.

Some may object that lensing in space is well known, and is even used to look at the furthest galaxies. However that lensing is due to gravity slowing down, and bending light, as happens with light grazing the sun. That’s called gravitational lensing. Entire galactic clusters are known to operate as giant lenses.

If one saw lensing, with nothing in between, the lensing would not be gravitational and the universe would not be flat.

But so far, this has not been observed.

A perfectly flat universe means global curvature zero. However the basic idea of the Einstein Field Equation (EFE) is:


Actually, this equation is the basic idea, thus the ultimate simplification. As it is, it cannot work without further complications, because the object on the left has much higher dimension than the 10 dimensional tensor on the right; so one has to simplify the curvature first). The real equation is more like:

Function of Curvature = Mass-Energy-Momentum

There are a lot of mathematical details to figure out, to make that basic idea fit in. It took many stupendous mathematicians and physicists many years working together frantically to figure them out. In particular, Einstein and Hilbert cooperated intensely, helped by many collaborators… And the initial idea comes from the mathematician/physicist/philosopher Riemann (1866). So it took 60 years to make the idea work, and one should not expect casual readers to get the ideas in 60 lines, let alone 60 seconds.

An obvious (sort of) prediction was that, as the Mass-Energy of the universe is not zero (it’s full of galaxies, which have mass, and energy), then the curvature could not be zero. But then, if curvature (of the space-time of the universe) is not zero, then the universe has got to be moving.

Revolted by a moving universe, Einstein then added another curvature term, Lg. Lg counterbalanced Mass-Energy-Momentum, and gave a static (but unstable) universe.

Thus Einstein did not predict what the astronomers were starting to observe, namely the expansion of the universe. Einstein abandoned L (“Lambda”), calling it the “biggest blunder [he] ever made”.

(According to me, he made a much graver error in 1905.)


Dark Energy Flattens Cosmological Logic:

Ninety years later, the most basic supernovas were studied. They arise in binary systems: a star transfers part of itself to its companion, a super hot white dwarf. It is a bit like transferring gasoline on an amber: when enough mass has been transferred to Dwarf, the pressure and heat in the depth is just right for thermonuclear fusion to re-ignite explosively. It happens in exactly the same way always (although some argue about this). So these Type 1a supernovae are viewed as candles always of the same luminosity.

Large surveys (rejecting some explosion viewed as outliers) concluded that far-away Type 1a explosions were weaker than the Hubble law of expansion predicted. And the further one looked, the more the 1a explosions faded.

The conclusion was drawn that the universe expanded faster than the old model of Hubble and Einstein’s Gravitation theory predicted.

Greater expansion meant greater energy, and its source was not clear, so it was named DARK ENERGY.

Ironically to describe the simplest way to describe it was just to re-introduce the Lg term Einstein had introduced and then rejected, while he blundered about clumsily.


Your Humble Servant Flattens All:

It remains that the original theory of Einstein requires a very fine tuning of parameters to make our universe explode into its present very flat state in a bit less than 14 billion years. It also requires a supplementary explosion, called “Cosmological Inflation”.

I don’t have this problem.

I just wipe Einstein and his cohorts clean. I am master of my own soul. They have two Cosmological Inflations. I have just one, the one that is observed.

And my version of the universe can be 100 billion years old, or more.

I don’t confuse gravitation and revolution, inflation and what not. The Einstein Field Equations are correct, I just don’t apply them to the universe.

Simple does it.

Making something complicated simply because it allows to “shut and calculate” (the philosophical doctrine of contemporary physics) has been seen before. This was the trap into which Ancient Greek astronomy fell, making ever more sophisticated versions of the Ptolemaic system.

We should avoid duplicating our forebears’ mistakes.

Patrice Ayme’

Mathematical Note:

That I consider the universe three dimensional may sound as a strange admission, as I always advocate all sorts of dimensions, from the brain to fundamental physics. But not so: just view the three dimensional aspect as an… average.

(Here I am going to talk as a common physicist or mathematician, and elide the tweaking of fundamental axioms of topology and logic that I am wont to engage in, because I want to present the simplest picture.)

More precisely, this is what happens in two dimensions. In one dimension, the line or circle, there is just one geometry.

The USA mathematician Thurston launched a theorem, proven by the Russian Perelman, which showed there were just eight fundamental geometries in three dimensions.

(Disgusted by the dog eat dog attitude of famous mathematicians, some of whom I personally know, Perelman refused prizes, and abandoned math; I do share Perelman’s indignation, and then, more. Austerity, as imposed by plutocrats, has made even mathematicians like rats, prone to devour the innocent. The problem is not just in physics.)


August 8, 2013

Abstract: simple considerations of a philosophical, non computational, nature, on Space, Time and the Quantum show that the former two are not basic (and that some apparently most baffling traits of the Quantum are intuitive!). Progress in knowledge of the interdependence of things should not be hampered by traditional prejudices. (Not an easy essay: readers are encouraged to jump around it like kangaroos!)


What is time? Today’s physics does not answer that question, it just computes with the notion as if it were obvious. To find out what time could be, a little bout of metaphysics different from the tentative one in today’s understanding of nature, is needed.

Einstein amplified the notion that the universe is about spacetime (x,t) in a reference frame F. He, and his friends Hilbert and Besso used the mathematical, and physical ideas, created by Riemann (and his Italian successors: Ricci, Levi-Civita, etc.)

"Solitary and Uncomprehended Genius"

Riemann: “Solitary and Uncomprehended Genius” (Poincaré said)

Lorentz discovered one had to assume that (x’,t’) in a moving frame F’ cruising by at a steady speed v is related to (x,t) in frame F according to the Lorentz transformations.

Lorentz got the Nobel Prize, for finding these (thanks to the recommendation of the towering Henri Poincaré); I am not pointing this out to compare the relative merits of celebrities, but to establish the hierarchy of the discoveries they made, and thus the logic therein. (Poincaré’s 1904“Principe de Relativite’” was firmly established before Einstein showed up on the scene, and the latter’s contributions, although enlightening, have been vastly overestimated.)

Not that the initial logic of a discovery always perdures, but sometimes it’s important. The Einstein cult has been obscuring reality; Einstein would have been the first one to decry it (Einstein basically ran away with the idea of Poincaré that the constancy of the speed of light, c, being always observed, was thus a fundamental law of physics, and made it the foundation of what Poincare’ called “Relativite'”).

Only by using the Lorentz transformations are the equations of electrodynamics preserved. In other words: only thus is the speed of light measured to be c in both F, using (x,t) and F’, using (x’,t’).

So what is time t?

According to the scheme in Relativity, it’s simple: given the sanctity of the speed of light, c, and space x, time can be measured by having a photon of light going between two perfect mirrors, and counting the impacts (that’s what is called a light clock; it’s very useful to derive most equations of Relativity).

Indeed space is measured by the time it takes light to go back and forth. This sounds like a circular logic: time is needed to measure space and space is needed, to measure time.

Does that mean one of the two, say, time, is derivative?

I used to think so (propped by the lack of time in Quantum Theory, see below). But, actually, no.

Indeed, time can be localized down to the proton scale.

One can measure time at that scale with how long it takes some elementary particle to decay. Or because to any particle is associated its De Broglie wave, hence a frequency (and that particle can be confined in as small a space as a proton).

Basically time can be measured at a point.

However, space, by definition is… non local (space is always an extent, all the more if time is used to measure it, thanks to c; technically my idea is that space depends upon the holonomy group, time does not; thus Minkowsky’s “spacetime” belongs to the dustbin!).

Thus the conceptual universe in which bask electromagnetism makes it look as if, somehow, time was more fundamental.

The situation is the exact opposite in Quantum Theory. Quantum Theory is full of entangled situations. Measure such a situation somewhere, and it changes all over. “Measure such a situation somewhere, and it changes all over” means that a Quantum Process is all over it. Whatever “it” is. Einstein called that “spooky interaction at a distance”. I call it the QUANTUM INTERACTION.

Einstein tried to escape the spookiness. Instead, I claim it should be embraced. After all, Quantum spookiness makes life possible.

We indeed know now that this spooky Quantum interaction is fundamental to life. It allows life to be more efficient than any understanding from classical mechanics could have it. Vision and the chlorophyll molecule use Quantum spookiness at a distance. This recent discovery did not surprise me at all. I fully expected it, just as I fully expect that consciousness will be revealed to be a Quantum effect (an easy prediction, at this point, in this Quantum universe!)

A computer using the Quantum Theory would be more efficient, for the same reason: the Quantum computer computes all over, in a non local way. (The computers we have now are just sleek electron-using versions of the classical computers the ancient Greeks had, with their little teethed wheels; the Quantum computer is founded on a completely different process.)

This “spooky” non locality has alarmed many a thinker. But notice this simple fact: space itself, even the classical space used in electromagnetism, is non local (as one uses light travel, plus time, to determine space).

So it’s only natural that space in Quantum Theory be non local too.

The “spookiness” is easily understood thus: spacetime physics a la Einstein and company singles out a particular interaction, electromagnetism, and the sanctity of c, to measure the universe with. Why this one, and not another of the fundamental interactions we know?

Quantum Theory (QT) gets out of this would-be choice by choosing none of the traditional forces to measure space with!

As QT has it, as it stands, QT does not need to measure the universe. (I believe it does, using the Quantum Interaction, and I can support that with impossible simultaneous measurements at great distances, but that’s another, more advanced set of considerations.)

Those who think thinking is reduced to computing will object that it is not the same type of non locality (the one I claim to see in classical space and the “spooky” one of Quantum space). Whatever: the non locality in quantum Theory does not depend upon light speed. That’s the important point.

There, the lesson cannot be emphasized enough: on the face of it, the basic set-up of Quantum Theory tells us that light, and, in particular light speed, is NOT fundamental.

This few observations above should they prove to be as deep and correct as I believe they are, show the power of the philosophical method, even in today’s physics. Some will scoff, but not consider carefully all the philosophy behind spacetime a la Einstein.

A warning for those who scoff about the importance of meta-physics: the founding paper of differential geometry in mathematics, and physics, was a lecture by Bernhard Riemann. It’s full of metaphysics and metamathematics, for the best.

The paper had just one equation (and it is a definition!)

That lecture was entitled “Über die Hypothesen welche der Geometrie zu Grunde liegen (“On The Hypotheses Which Underlie Geometry“). (Call these “hypotheses” meta-geometrical, metamathematical, or metaphysical.)

The lecture was published in 1868, two years after his author’s death (and 14 years after he gave it). Riemann’s main idea was to define manifolds and curvature. (Riemannian) manifolds were defined by a metric. Curvature ought to be a tensor, Riemann said, not just a simple number (scalar; as Gaussian curvature).

From top to bottom: positive, negative and no curvature.

From top to bottom: positive, negative and no curvature.

Riemann generalized the notion of curvature to any dimension, thanks to the Riemann Curvature Tensor (the simplified Ricci form of which appears in Einstein’s gravitational field equation).

Here is for some meta-physics; Riemann: “It is quite conceivable that the geometry of space in the very small does not satisfy the axioms of [Euclidean] geometry… The properties which distinguish space from other conceivable triply-extended magnitudes are only to be deduced from experience.

Gauss, Riemann’s teacher, knew this so well that he had tried to measure the curvature of space, if any, using a triangle of tall peaks. Gauss found no curvature, but now we know that gravitation is best described as curved spacetime.

(This lack of Gaussian curvature shows that it’s not because situation is not found under some conditions that it is not there under other conditions; in biology the proof by Medawar that Lamarckism was false, using mice, for which he got the Nobel (being British, ;-)) comes to mind: no Lamarckism in Medawar experiments did not prove that there would be no Lamarckism in other experiments; now four Lamarckist mechanisms are known!)

Twentieth Century physics, in particular the theory of gravitation, exploits the following fact, understood by Riemann as he laid, dying from tuberculosis in Italy. Force is a tautology for geodesics coming closer (or not). Thus curvature is force.

Einstein remarkably said: “Only the genius of Riemann, solitary and uncomprehended, had already won its way by the middle of the last century to a new conception of space, in which space was deprived of its rigidity, and in which its power to take part in physical events was recognized as possible.”

(I find this statement all the more remarkable and prophetic in that it is not in Einstein’s physics, and could not be, but rather in the one I would like to have, where fundamental dynamic processes literally create space…)

The fact that a tautology is at the heart of Einstein’s Theory of Relativity means that it explains nothing much! (Relativity fanatics are going to hate that statement!…although it describes very well what happens to objects evolving in spacetime, especially GPS, let it be said in passing.)

“Only to be deduced from experience”, said mathematician Riemann. What’s the ultimate experience we have? Quantum Theory. And what did we find QT said? You can’t measure with space, you can’t measure with time (although clearly the Quantum depends upon the differential topology of the situation, see the Bohm-Aharanov effect! where, by the way, the space metric is made fun of once again!)

Last splendid idea from Riemann (1854-1866):

“Researches starting from general notions, like the investigation we have just made, can only be useful in preventing this work from being hampered by too narrow views, and progress in knowledge of the interdependence of things from being checked by traditional prejudices.”



Patrice Ayme