Archive for the ‘Dark matter’ Category

“Fuzzy” Dark Matter & Sub Quantum Physical Reality (SQPR)

October 17, 2019

Abstract: An early Quantum universe would have appeared “fuzzy”, and striated, from Quantum self interference… If one adopts one basic consequence of my own SQPR theory: Dark Matter is made of ultra-light, ultra-low momentum particles. A team of physicists at prestigious institutions by adopting this conclusion of SQPR, one gets a drastically different looking model explaining the filament nature of galaxy distributions. (This completely new approach is indirectly rather supportive of SQPR… and very different from the usual LCDM; it should be testable soon, with new telescopes under construction…)

***

According to official, ruling Big Bang theory, Dark Matter was the starting ingredient for coagulating the very first galaxies in the universe. According to that “LCDM” model, shortly after the Big Bang, particles of Dark Matter clumped together in gravitational “halos,” pulling surrounding gas into their cores, which over time cooled and condensed into the first galaxies. [1]

Thus a curious situation: Dark Matter is considered the backbone to the structure of the universe, while physicists know very little about its nature, because the DM “particles” have so far evaded detection.

Now scientists at MIT, Princeton University, and Cambridge University have admitted the obvious, namely that the early universe, and the very first galaxies, would have looked very different depending upon the exact nature of Dark Matter.  They simulated what early galaxy formation would have looked like if Dark Matter were “fuzzy,” rather than cold or warm. “Fuzzy” here has a precise definition: it means very low momentum DM “particles”. Such “fuzzy” particles are what my own theory, SQPR is full of, as a consequence of my hypothesis that Quantum Mechanics is LOCAL.

Left is the conventional distribution of galaxies prediction of the conventional Big Bang (“LCDM”). Center is that with “warm” dark Matter. Right is the Quantum “fuzzy” DM model (compatible with SQPR).

Light Mechanics, electromagnetism, is local: this is also called Relativity (Poincaré named it thus). QM being a generalization of Light Mechanics, it is natural that it would be local too: this is the fundamental axiom of SQPR

In that most widely accepted scenario, the so-called LCDM (Lambda Cold Dark Matter) model of the early universe Dark Matter is Cold: it is made up of slow-moving particles that, aside from gravitational effects, have no interaction with ordinary matter (SQPR readily explains why DM doesn’t interact but gravitationally).

In LCDM, Warm Dark Matter is thought to be a slightly lighter and faster version of Cold Dark Matter (it has been heated by galaxies).

Fuzzy Dark Matter, is, for official physics, a new concept, something entirely different, consisting of ultralight particles, each about 1 octillionth 10^(-27) the mass of an electron (the Cold Dark Matter particle of LCDM are far heavier — about 100 times more massive than an electron). Repeat: the proposed mass for Dark Matter particles in this new simulation is the mass of an electron divided by 1,000,000,000,000,000,000,000,000,000

Now we are talking. This is the sort of numbers my own theory, SQPR considers.

The Millennium Simulation (below) is an example of an over 10 billion particle simulation that tries to reproduce the cosmic web of dark matter upon which exist galaxy clusters, filaments, and voids we see today. The LCDM (Lambda Cold Dark Matter) model of the universe assumes a flat universe now dominated by a cosmological constant $Lambda$, Einstein’s Cosmological Constant (Dark Energy?). As I said, the cosmological large structure formation is dominated by cold (non-relativistic) dark matter.

A view of the distribution of dark matter in our universe, based on the Millennium Simulation. The simulation is based on our current ideas about the universe’s origin and evolution. It included ten billion particles, and consumed 343,000 cpu-hours (Image: Virgo Consortium)Researchers found that if Dark Matter is cold, then galaxies in the early universe would have formed in nearly spherical halos, with ten times too much mass there. But if the nature of Dark Matter is fuzzy or warm, the early universe would have looked very different, with galaxies forming first in extended, tail-like filaments. In a fuzzy universe, these filaments would have appeared striated, like star-lit strings on a harp… As observed.

As new telescopes come online, with the ability to see further back into the early universe, scientists may be able to deduce, from the pattern of galaxy formation, whether the nature of dark matter, which today makes up nearly 85 percent of the matter in the universe, is fuzzy as opposed to cold or warm.

“The first galaxies in the early universe may illuminate what type of dark matter we have today,” says Mark Vogelsberger, associate professor of physics in MIT’s Kavli Institute for Astrophysics and Space Research. “Either we see this filament pattern, and fuzzy dark matter is plausible, or we don’t, and we can rule that model out. We now have a blueprint for how to do this.” [2]

Fuzzy Quantum Waves:

While dark matter has yet to be directly detected, the hypothesis that describes dark matter as cold has proven successful at describing the large-scale structure of the observable universe. As a result, models of galaxy formation are based on the assumption that dark matter is cold.

“The problem is, there are some discrepancies between observations and predictions of cold dark matter,” Vogelsberger points out. “For example, if you look at very small galaxies, the inferred distribution of dark matter within these galaxies doesn’t perfectly agree with what theoretical models predict. So there is tension there.” This is a euphemism: According to LCDM, the heavy DM particles should sink towards the core of galaxies, and this is exactly what is not observed.

Enter, then, alternative theories for dark matter, including warm, and fuzzy, which researchers have proposed in recent years.

“The nature of dark matter is still a mystery,” Fialkov says. “Fuzzy dark matter is motivated by fundamental physics, for instance, string theory, and thus is an interesting dark matter candidate. Cosmic structures hold the key to validating or ruling out such dark matter models.”

Fuzzy dark matter is made up of particles that are so light that they act in a quantum, wave-like fashion, rather than as individual particles. This quantum, fuzzy nature, Mocz says, could have produced early galaxies that look entirely different from what standard models predict for cold dark matter.

“Even though in the late universe these different dark matter scenarios may predict similar shapes for galaxies, the first galaxies would be strikingly different, which will give us a clue about what dark matter is,” Mocz says.

To see how different a cold early universe could be, relative to a fuzzy early universe, the researchers simulated a small, cubic space of the early universe, measuring about 3 million light years across, and ran it forward in time to see how galaxies would form given one of the three dark matter scenarios: cold, warm, and fuzzy.

The team began each simulation by assuming a certain distribution of dark matter, which scientists have some idea of, based on measurements of the cosmic microwave background — “relic radiation” that was emitted by, and was detected just 400,000 years after the alleged Big Bang. Dark matter doesn’t have a constant density, even at these early times. There are tiny perturbations on top of a constant density field. Those perturbations would gather more Dark Matter, nonlinearly.

The researchers were able to use existing algorithms to simulate galaxy formation under scenarios of cold and warm dark matter. But to simulate fuzzy dark matter, with its quantum nature, they needed to bring in the Quantum.

A cosmological map of Interfering Quantum strings:

To the usual simulation of cold dark matter were added two extra equations in order to simulate galaxy formation in a fuzzy dark matter universe. The first, Schrödinger’s equation, describes how a quantum wave evolves in the presence of (potential) energy, while the second, Poisson’s equation, describes how that (self-interfering) quantum wave generates a density field, or distribution of Dark Matter, and how that distribution leads to (uneven) gravity — the force that eventually pulls in matter to form galaxies. They then coupled this simulation to a model that describes the behavior of gas in the universe, and the way it condenses into galaxies in response to gravitational effects.

In all three scenarios, galaxies formed wherever there were over-densities, or large concentrations of gravitationally collapsed Dark Matter. The pattern of this Dark Matter, however, was different, depending on whether it was cold, warm, or fuzzy.

In a scenario of cold dark matter, galaxies formed in spherical halos, as well as smaller subhalos. Warm Dark Matter produced  first galaxies in tail-like filaments, and no subhalos. This may be due to warm dark matter’s lighter, faster nature, making particles less likely to stick around in smaller, subhalo clumps.

Similar to warm dark matter, fuzzy dark matter formed stars along filaments. But then quantum wave effects took over in shaping the galaxies, which formed more striated filaments, like strings on an invisible harp. This striated pattern is due to constructive interference, an effect that occurs when two waves overlap, similarly to the famous Double Slit experiment. When constructive interference occurs, for instance in waves of light, the points where the crests and troughs of each wave align form darker spots, creating an alternating pattern of bright and dark regions.

In the case of fuzzy dark matter, instead of bright and dark points, it generates an alternating pattern of over-dense and under-dense concentrations of dark matter.

“You would get a lot of gravitational pull at these over-densities, and the gas would follow, and at some point would form galaxies along those over-densities, and not the under-densities. This picture would be replicated throughout the early universe.”Vogelsberger explains.

The team is developing more detailed predictions of what early galaxies may have looked like in a universe dominated by fuzzy dark matter. Their goal is to provide a map for upcoming telescopes, such as the James Webb Space Telescope, that may be able to look far enough back in time to spot the earliest galaxies. If they see filamentary galaxies such as those simulated by Mocz, Fialkov, Vogelsberger, and their colleagues, it could be the first signs that Dark Matter’s nature is fuzzy.

“It’s this observational test we can provide for the nature of dark matter, based on observations of the early universe, which will become feasible in the next couple of years,” Vogelsberger says.

SQPR predicts less “fuzzy” Dark Matter in the earlier universe. However, a lot of the effects described by the MIT team would nevertheless happen, and for the same exact reasons. So the apparition of striated structures would not be surprising… even if LCDM was completely wrong.

Patrice Ayme

***

***

[1] There is a famous theorem that Newton needed for his celestial mechanics and tried to prove (and may have succeeded to prove; it’s controversial whether he did or not) according to which a ball of mass M acts gravitationally as a point of mass M.

***

[2] Vogelsberger is a co-author of a paper appearing (October 2019) in Physical Review Letters, along with the paper’s lead author, Philip Mocz of Princeton University, and Anastasia Fialkov of Cambridge University and previously the University of Sussex.

Galaxy Without Dark Matter Found: Another Proof of New Physics?

March 31, 2018

ASTRONOMERS OGLE GALAXY DEVOID OF DARK MATTER!

The newfound object NGC 1052-DF2, a vast, diffuse galaxy, defies conventional explanations. It is to be feared (just kidding!) that various breakthroughs are in the offing, including in fundamental physics (if I believe that what could be true, SQPR, a proposed new foundation for physics, is really true).

The “ultra-diffuse” galaxy NGC1052-DF2, seen here in an image from the Hubble Space Telescope, is the same size as our Milky Way but contains just 1 percent as many stars. It also appears to be empty of Dark Matter. And therein a big problem for Conventional Wisdom:

Yes, that’s a galaxy… Looks dark, but without DM… Nothing the LCDM model saw coming… Is resistance to the New Physics Futile?
NGC1052-DF2 doesn’t look like a typical spiral or elliptical galaxy, but rather a loosely connected glob of star-pocked gas and dust. If it contained an amount of Dark Matter typical for a galaxy of its size, the Dark Matter’s gravity would hasten the motions of several star clusters that orbit it. Instead, van Dokkum’s team found those star clusters moving languidly around NGC 1052-DF2… That suggests Dark Matter can decouple not only from regular, visible matter, but from entire galaxies—a phenomenon LCDM cosmologists claimed couldn’t happen.

Large galaxies, radiant agglomeration of stars, are tied up together by the gravitational pull of Dark Matter, a hidden material that is revealed and observed by its gravitational pull upon the shiny stars it seems to outmass by a factor of ten (we know this from the virial theorem, which basically say: v^2 ~ M/R, where M is the global gravitational mass, v the (“dispersion”) speed, and R the radius where the speed is measured; so the higher the speed of the orbiting stars, clusters, galaxies, at the greater distance, the higher the global mass M).

Dark Matter is considered to be as a defining feature of galaxies as stars and gas… and is thought in the reigning LCDM model, to provide the gravitational seeds from which galaxies assemble and grow (a top cosmologist Sean Carroll insisted on this point in correspondence with me). I strongly disagree with the latter point (in my model, Dark Matter is EMERGENT, a fruit of the Quantum Interaction).

A galaxy without Dark Matter—or without some bizarre, twisted deformation of gravity (such as MOND) that would mimic Dark Matter behavior, in some, only some, cases, and not in cases such as the Bullet Cluster —would contradict the religion of LCDM (Lambda Cold Dark Matter) and the sect of MOND, in other words, such a heretical galaxy would shred official thinking and its main alternative. Yet that is exactly what Yale University astronomer Pieter van Dokkum and his colleagues have found, they report in a study published Wednesday in Nature.

From the horse’s mouth:

(Pieter van Dokkum and Al.)

Studies of galaxy surveys in the context of the cold dark matter paradigm have shown that the mass of the dark matter halo and the total stellar mass are coupled through a function that varies smoothly with mass. Their average ratio Mhalo/Mstars has a minimum of about 30 for galaxies with stellar masses near that of the Milky Way (approximately 5 × 10^10 solar masses) and increases both towards lower masses and towards higher masses… Here we report the radial velocities of ten luminous globular-cluster-like objects in the ultra-diffuse galaxy NGC1052–DF2, which has a stellar mass of approximately 2 × 10^8 solar masses. We infer that its velocity dispersion is less than 10.5 kilometres per second with 90 per cent confidence, and we determine from this that its total mass within a radius of 7.6 kiloparsecs is less than 3.4 × 10^8 solar masses. This implies that the ratio Mhalo/Mstars is of order unity (and consistent with zero), a factor of at least 400 lower than expected. NGC1052–DF2 demonstrates that dark matter is not always coupled with baryonic matter on galactic scales.

The twelve (!) authors from Yale, Harvard, Heidelberg, Santa Cruz, who used the giant Keck observatory in Hawai’i, don’t shrink from the exciting consequences:

Regardless of the formation history of NGC1052–DF2, its existence has implications for the dark matter paradigm. Our results demonstrate that dark matter is separable from galaxies, which is (under certain circumstances) expected if it is bound to baryons through nothing but gravity. The ‘bullet cluster’ demonstrates that dark matter does not always trace the bulk of the baryonic mass, which in clusters is in the form of gas. NGC1052–DF2 enables us to make the complementary point that dark matter does not always coincide with galaxies either: it is a distinct ‘substance’ that may or may not be present in a galaxy. Furthermore, and paradoxically, the existence of NGC1052–DF2 may falsify alternatives to dark matter. In theories such as modified Newtonian dynamics (MOND) and the recently proposed  emergent gravity paradigm, a ‘dark matter’ signature should always be detected, as it is an unavoidable consequence of the presence of ordinary  matter. In fact, it had been argued previously that the apparent absence of  galaxies such as NGC1052–DF2 constituted a falsification of the standard cosmological model and offered evidence for modified  gravity. For a MOND acceleration scale of a0 = 3.7 × 103 km2 s−2 kpc−1, the expected28 velocity dispersion of NGC1052–DF2 is σM ≈  (0.05GMstarsa0)1/4 ≈ 20 km s−1, where G is the gravitational constant—a factor of two higher than the 90% upper limit on the observed dispersion.

So exit MOND, Modified Newtonian Dynamics, once again! How many times do we need to kill that vampire? MOND is philosophically ugly, as it is an ad hoc theory; strictly engineered to explain a peculiar feature that is observed… Whereas my own theory, SQPR, was invented for reasons which have strictly to do with the foundations of Quantum Theory, and Dark Matter, and, moreover, Dark Matter as it turns out to be, is just a particular consequence.

***

SQPR, Sub Quantum Patrice Reality Shines, Once Again:

In SQPR, Dark Matter is created by the Quantum Interaction, at particular cosmic distances from ordinary matter, and only then. The density of matter at cosmic distances needs to be just so, otherwise Dark Matter, Patrice’s way, will NOT decouple from normal matter. Instead the galaxy will not develop Dark Matter, just DELOCALIZED Matter.

So how did we get to the present situation, as found in NGC1052–DF2? Suppose the existence of an ultra diffuse gas, on a larger scale than the Milky Way, way back in time. Under its own gravity, the ultra diffuse gas, will gather, and form stars. What is the difference with LCDM? In LCDM, Dark Matter is present to start with, seeds and accelerates galaxy formation.

Whereas in my model, the universe, being much older, perhaps 100 billion years old, there is no need for Dark Matter to seed galaxies: in complete contrast with LCDM, there is plenty of time for ultra diffuse gas to gather into ultra diffuse galaxies…. So this is not just about Dark Matter: the way I see it, it’s the entire vision of cosmology and the Quantum, which is in question.

Patrice Aymé

***

Contextual Notes: 1) Only discovered in 2015, ultra-diffuse galaxies are thought cosmic laboratories for Dark Matter. Surely, astronomers thought, Dark Matter must provide severely needed mass to form these objects so devoid of normal stars. That thinking led van Dokkum and his colleagues to build the Dragonfly Telephoto Array, a telescope in New Mexico created for the express purpose of scrutinizing ultra-diffuse galaxies. The researchers initially used Dragonfly to study a different galaxy, which possesses an almost inconceivably gargantuan amount of dark matter, a “weird” result in and of itself. When van Dokkum and his team found NGC 1052-DF2, they expected to see something similar.

“Instead we saw the opposite, leading to this remarkable conclusion that there’s actually no room for dark matter at all in this thing,” van Dokkum says. “It’s not something we were looking for or expecting. At all. But you go in the directions the data takes you, even if it’s in contradiction to what you’ve found before.”

In Dragonfly images, NGC 1052-DF2 looked like a standard ultra-diffuse galaxy. But when the team compared them to a better image from the Sloan Digital Sky Survey, they found a surprising mismatch. What had seemed to be dim basic galactic structures in Dragonfly’s view appeared as point-like sources in the Sloan image. To resolve the discrepancy, the team scrutinized the galaxy with the Hubble Space Telescope, the W.M. Keck Observatory and the Gemini Observatory, the latter two on giant volcano Mauna Kea in Hawaii.

The point sources proved to be 10 globular clusters—compact and spherical groupings of stars orbiting the galaxy’s core. The researchers then set about measuring the movements of the clusters as a way to estimate the galaxy’s total mass. Simply put, the velocity at which clusters orbit a galaxy is related to the amount of matter—normal or dark—that a galaxy contains. Using information from the Keck telescopes, the team found the globular clusters were moving much more slowly than expected. And therefrom the tale above…

2) Without modifying vastly the age of the universe, as I boldly suggest, there are a few theories to explain how galaxies like NGC 1052-DF2 could come together without being seeded by Dark Matter (as LCDM necessarily has it). That would be a downer (for me!) but, in the interest of scientific fairness, let’s mention them.

It could be that NGC 1052-DF2 was once a glob of gas perturbed by another unseen (?) galaxy nearby, sparking DF2 star formation. Or, van Dokkum speculates, perhaps this ultra-diffuse, dark-matter-free galaxy arose from two streams of gas that collided and compressed to form a scattering of stars. Another idea, first proposed more than two decades ago by Yale astronomer Priyamvada Natarajan, suggests galaxies like NGC 1052-DF2 form from galaxy-sized globs of gas clumping together in jets ejected by supermassive black holes in large galaxies’ hearts. NGC1052-DF2 does reside in a region where such things could occur, as it lies near a giant elliptical galaxy, those are the largest galaxies, with a supermassive black hole at its heart.

Notice that, in any case, it looks bad for MOND… MOND has several variants, but, basically, says that, at the scale of 50,000 light years (say) gravity, as described by the French astronomer Ismael Bullaldius (Ismaël Boulliau), a notion picked up by Hookes, Newton, etc. and amply confirmed since on the scale of the Solar System, is actually false. Thus the virial theorem (see above), at the scale of R = 50,000 light years, should be false. But above, everybody (not just me, but also the honorable professional astronomers) assumed it was true! Not just that, but the pull of gravity was observed to be just as needed. MOND assumes it’s stronger! So MOND, in case there is indeed NO apparent Dark Matter in NGC 1052-DF2, predicts the existence of NEGATIVE mass (reference the movies Avatar? I presume?) Laughter, please!

In any case, time will tell… Paradigm shift, or overlooked subtleties? Big telescopes are coming soon to a desert near you…

DARK MATTER-ENERGY, Or How Inquiry Proceeds

September 7, 2016

How to find really new knowledge? How do you find really new science? Not by knowing the result: this is what we don’t have yet. Any really new science will not be deduced from pre-existing science. Any really new knowledge will come out of the blue. Poetical, and, or, emotional logic will help before linear logic does.

A top lawyer, admitted to the US Supreme Court, and several countries. told me that the best judges know, emotionally, where they want to go, and then build a logical case for it.

The case of Dark Matter is telling: this increasingly irritating elephant in the bathroom has been in evidence for 80 years, lumbering about, smashing the most basic concepts of physics. As the encumbering beast did not fit existing science, it was long religiously ignored by the faithful of the church of standard physics, as a subject not worthy of deep inquiry by very serious physicists. Now Dark Matter, five times more massive than Standard Model matter, is clearly sitting heavily outside of the Standard Model, threatening to crush it into irrelevance. Dark matter obscures the lofty pretense of known physics to explain everything (remember the grandly named TOE, the so-called “Theory Of Everything“? That TOE was a fraud, snake oil, because mainstream physics celebrities crowed about TOE, while knowing perfectly well that Dark Matter dwarfed standard matter, and while being completely outside of the Standard Model).

Physicists are presently looking for Dark Matter, knowing what they know, namely that nature has offered them a vast zoo of particles, many of them without rhyme or reason. or symmetries to “explain” (indeed, some have rhyme, a symmetry, a mathematical group such as SU3 acting upon them; symmetries have revealed new particles, sometimes).

Bullet Cluster, 100 Million Years Old. Two Galaxies Colliding. The Dark Matter, In Blue, Is Physically Separated From the Hot, Standard Matter Gas, in Red.

This sort of picture above is most of what we presently have to guess what Dark Matter could be; the physical separation of DM and SM is most telling to me: it seems to indicate that SM and DM do not respond to the same forces, something that my Quantum theory predicts; it’s known that Dark Matter causes gravitational lensing, as one would expect, as it was first found by its gravitational effects, in the 1930s…

However, remember: a truly completely new (piece of) science cannot be deduced from pre-existing paradigm. Thus, if Dark Matter was really about finding a new particle type, it would be interesting, but not as interesting as it would be, if it were not, after all, a new particle type, but instead, a consequence from a completely new law in physics.

This is the quandary about finding truly completely new science. It can never be deduced from ruling paradigms, and may actually overthrow them. What should then be the method to use? Can Descartes and Sherlock Holmes help? The paradigm presented by Quantum Physics helps. The Quantum looks everywhere in space to find solutions: this is where its (“weird”) nonlocality comes in. Nonlocality is crucial for interference patterns and for finding lowest energy solutions, as in the chlorophyll molecule. This suggests that our minds should go nonlocal too, and we should look outside of a more extensive particle zoo to find what Dark Matter is.

In general, searching for new science should be by looking everywhere, not hesitating to possibly contradict what is more traditional than well established.

An obvious possibility to explain Dark Matter is, precisely, that Quantum Physics is itself incomplete, and generating Dark Matter, and Dark Energy, in places where said incompleteness (of the present Quantum theory) would be most blatant: large cosmic distances.

More precisely, Quantum processes, stretched over cosmic distances, instead of being perfectly efficient and nonlocal over gigantically cosmic locales, could leave a Quantum mass-energy residue, precisely in the places where extravagant cosmic stretching of Quanta occurs (before “collapse”, aka “decoherence”). (I call this theory of mine SQPR, Sub Quantum Patrice Reality.)

This would happen if what one should call the “Quantum Interaction” proceeds at a finite speed (much faster than c, by a factor of at least 10^23…). It’s enough.

The more one does find a conventional explanation (namely a new type of particle) for Dark Matter, the more likely my style of explanation is likely. How could one demonstrate it? Not by looking for new particles, but by conducting new and more refined experiments in the foundations of Quantum Physics.

If this guess is correct, whatever is found askew in the axioms of present Quantum Physics could actually help future Quantum Computer technology (because the latter works with Quantum foundations directly, whereas conventional high energy physics tend to eschew the wave aspects, due to the high frequencies involved).

Going on a tangent is what happens when the central, attractive force, is let go. A direct effect of freedom. Free thinking is tangential. We have to learn to produce tangential thinking.

René Descartes tried to doubt the truth of all his beliefs to determine which beliefs he could be certain were true. However, at the end of “The Meditations” he hastily conclude that we can distinguish between dream and reality. It is not that simple. The logic found in dreams is all too similar to the logic used by full-grown individuals in society.

Proof? Back to Quantum Physics. On the face of it, the axioms of Quantum Physics have a dream like quality (there is no “here”, nor “there”, “now” is everywhere, and, mysteriously, the experiment is Quantum, whereas the “apparatus” is “classical”). Still, most physicists, after insinuating they have figured out the universe, eschew the subject carefully.  The specialists of Foundations are thoroughly confused: see Sean Carroll, http://www.preposterousuniverse.com/blog/2013/01/17/the-most-embarrassing-graph-in-modern-physics/

However unbelievable Quantum Physics, however dream-like it is, physicists believe in it, and don’t question it anymore than cardinals would Jesus. Actually, it’s this dream-like nature which, shared by all, defines the community of physicists. Cartesian doubt, pushed further than Descartes did, will question not just the facts, the allegations, but the logic itself. And even the mood behind it.

Certainly, in the case of Dark Matter, some of the questions civilization has to ask should be:

1. How sure are we of the Foundations of Quantum Physics? Answer: very sure, all too sure!
2. Could not it be that Dark Matter is a cosmic size experiment in the Foundations of Quantum Physics?

Physics, properly done, does not just question the nature of nature. Physics, properly done, questions the nature of how we find out the nature of anything. Physics, properly done, even questions the nature of why we feel the way we do. And the way we did. About anything, even poetry. In the end, indeed, even the toughest logic is a form of poetry, hanging out there, justified by its own beauty, and nothing else. Don’t underestimate moods: they call what beauty is.

Patrice Ayme’