ASK NOT WHAT YOUR UNIVERSE CAN DO FOR YOU, ASK HOW BIG IT IS.
Abstract: A spotted recapitulation of gravitation and basic cosmology is offered, as an historical progression, using the occasion to show that the history of ideas meanders, and why. Dark Energy is presented.
In combination with the non locality of Quantum Physics, Dark Energy leads us to believe that the universe we know could be animated (so to speak) by a universe we cannot see. (Whereas most of the essay is standard fare, its last few paragraphs constitute some new physics.)
LET THERE BE DARK:
Dark Energy is a paradigm shattering discovery in physics. It’s blowing the universe apart, and that has various consequences.
What is the basic story? Dark Energy is a mysterious force, a form of anti-gravity, which pervades the universe. One has to go back a bit to understand the novelty of the situation. The ancients believed the universe was more or less fixed. Then, following Giordano Bruno, it was realized that the universe was full of distant stars.
The theocrats tortured and burned Bruno alive for this insight, because they wanted everybody to cling to the metaprinciple that all old beliefs and ways are correct… the safest way to insure that the masses would not suspect that Christianity was just a myth. Clinging to old beliefs, and old ways, as if they were always correct, always serves the oligarchies in power. (A picturesque manifestation of clinging to the past, hence of an oligarchic mental clamp down, is that the USA, is clinging to antique measuring units, that nobody else uses anymore, an indication that the USA is losing its grip on the cliff of reason.)
The French astronomer Ismaël Boulliau suggested that Kepler was wrong about the gravitational force. Kepler had declared that the gravitational force holding the planets in place decreased inversely to distance. Boulliau held instead that the force decreased as an inverse square law. He deduced this in analogy to light. This is interesting in two ways: Isaac Newton acknowledged Boulliau’s discovery of the inverse square law, using it as an argument that his adversary Hooke was lying, about having had the idea first. Thus Isaac was less chauvinistic than many to be born in centuries since, who have insisted Newton invented everything, including the principle of inertia (due to Buridan, circa 1320 CE), and the inverse square law.
I do not make such snide remarks out of base feelings. It is just the opposite. It is important to understand how ideas appear, grow, and morph. Or how they get suppressed. The body of knowledge gathered by Buridan was a victim of the an eruption of fascist theocracy, a full century after his death (which soon caused two centuries of religious wars and terror).
It is important to understand that intellectual fascism is frequent, a master driver of history, and thus a clear and present danger. When there are masters, and they decide that some knowledge is dangerous, they can, not only suppress it, but suppress loudly all and any knowledge beyond the task at hand their slaves are ordered to do.
This suppression of spontaneous intellectual activity, and general curiosity, often replaced by an obnubilation with team sports (as Juvenal smirked 19 centuries ago) makes “We The People” closer in intellectual temperament to sheep. It’s primordial to teach them to bleat and enjoy nothing more than herd mentality and being fleeced now and then. Thus, the insistence on the exceptionalism of the USA: “We Are The United States Of America”, a form of bleating. Right now some in the USA want to resurrect the espionage Act of 1917, which basically punished free speech (although, of course, the Supreme Court of the USA found that it did not.)
Another important point in exposing an accurate history of ideas is that really new ideas are hard to come by. Because of a weird seduction of the fascist instinct, the tendency to elevate heroes one can adulate, those who write history have the misleading habit to make it into mythology, a bit like Homer. They pile up most of the creation of ideas on a few characters, the super heroes. It is handy for hero worship, and it facilitates memory, but it does not reflect the real creative process, which is more diffuse and democratic.
To realize how new ideas truly arise, not from The One, but out of a more democratic process, has implications for the growth and maintenance of civilization: looking for a small elite of patented geniuses is not the way to do it. But then, of course, when power becomes fascist, it enjoys, and needs, to show to the masses, that superlative thinking is highly elitist, in a way fully compatible with the grandeur of the fascist leaders. Newton having invented it all was a perfect reason to trust the other geniuses leading the Anglo-Saxon empires.
Notice also that Boulliau made an analogy to light: that analogy is one of the main ingredients in Einstein’s gravitation. It is also one of the key ingredient of “Quantum Gravity”. This highly speculative theory argues that because light is made of particles, the photons, and they carry the electromagnetic force, so should gravity be carried by its own particles, the gravitons. Science does not exclude simplicity, in first approach.
The question of why the universe was not collapsing upon itself ought to have been already blatant in conventional astronomy, but nobody paid any attention to it. Instead stability of the universe was viewed as God-given, to the point that Einstein, the sacred genius, contrived an anti-gravity term in his gravitational equation, just so that the universe would stay suspended, like the rock islands of the planet Pandora in the movie “Avatar”. It was about as pretty, and as justified.
Unfortunately for Einstein, the American astronomer Edwin Hubble in Los Angeles discovered in the 1920′s, using what was then the world’s most powerful telescope, that galaxies receded from us the faster, the further they were (another astronomer had already discovered the Doppler shifts, in Arizona).
So the far universe was far from static. It was as if there had been a big explosion, and the debris were galaxies flying away from each other. When one looks at galaxies further and further away from us they move away faster and faster, closer and closer to the speed of light. From the Doppler effect, galaxies appear redder and redder (it’s called the cosmological redshift), until they fade away because they move too fast (the distance at which they disappear from sight is called the event horizon). Parts of the universe far enough from us could move away at more than the speed of light (at least if the expansion is everywhere true and we can’t see the whole universe). That the speed of light is constant in Relativity ought to be taken with a grain of salt, as Einstein himself pointed out. (Or he uttered words to that effect, more exactly.) More precisely, constancy of light speed is a local phenomenon in space, which puts no limit on the speed of space, a global phenomenon.
Einstein whined that he would have predicted the expansion of the universe, if not for that anti-gravity that he added on because he had believed, with all very serious people, in the universe’s stability (the anti gravity term that Einstein had added in his gravitational equation is known by honorable people as the “Cosmological Constant“).
Einstein called this failure of his guesswork his “greatest blunder”. Whatever. The instability of the universe ought to have been already clear, well before that. Any philosopher could have suggested it, let alone an astronomer. And maybe some thought about it. However, nobody had dared to suggest it before Hubble, and he came up with the proof. The hard work was done by Hubble.
As it is turning out, anti-gravity seems to exist, indeed, and it is Dark Energy.
Science is about indomitable facts, not just the flights of fancy that allows us to guess more facts than we already have. Einstein introduced, and then removed, his cosmological constant. Now it has been re-introduced, to describe what is seen. But it’s all about tweaking an equation so that it is not blatantly contradicted by the observed facts.
The initial discovery of anti-gravity, so called Dark Energy, came when it was observed that supernovae (and the local pieces of universe they were attached to) were accelerating away from each other faster than standard cosmology held to be true.
This has an interesting physical and philosophical consequence: in the fullness of time far away galaxies will recede away from our local group of galaxies (which are in tight orbits around each other). Hence, after dozens of billions of years, they will get out of sight. Of course, by then the sun will have exhausted its thermonuclear fuel, collapsed, blown apart as a red giant, and collapsed again, crushing itself into a white dwarf. But let’s suppose, for the sake of the argument, that a race of astronomers appear, 50 billion years in the future. They will observe that the universe reduces to the local galactic group. They will have no idea of its true size.
At least the little scenario above is conventional wisdom, as faithfully depicted by Brian Greene in the New York Times. Notwithstanding, watch it, because here I come… I am a specialist of hidden conspiracies, and how to detect them nevertheless. If the Nazis and their plutocratic collaborators in the USA did not escape, nor will the universe.
So I am going to focus on a conspiracy in physics, non-locality. Conventional physics assumed that the physical universe was made of points, and finite bits (atoms). The idea came from the Greco-Romans. Perhaps the main subtlety of Quantum Physics is that it is not so. Philosophically, it’s not too surprising: how to define points if physical objects are made of bits? If points are the ultimate bit of reality, what are they made of? Intimately related to this is the nature of space.
Quantum Physics changed the conceptual game completely, by acknowledging that these concepts are related. It remains to be seen whether they transmogrify into each other, as I believe.
After a quantum interaction (or, as Feynman put it, a “fundamental process“), the products of the interaction are ENTANGLED. (To be precise the probability waves representing the products have merged into a single probability wave; I prefer “Quantum Interaction”, because some fundamental processes, such as planets crashing into each other, have nothing Quantum about them, so Feynman’s semantics is imprecise.)
Where does this come from? OK, to simplify the discourse, to bring it to a higher level of abstraction, I will identify particles and the probability waves describing them to each other. That’s what abstraction does: identifying differences, from a common essence.
When propagating, particles are waves. When they crash somewhere, though, the whatever-was-propagating crash as a point, not as a wave. This is the mystery of so called “wave-particle duality“. There is no contradiction: propagation = waves, and end of propagation = particles. But there is a mystery: how does the wave becomes a particle, and conversely? This used to be called the “collapse of the wave packet“, and caused most geniuses of physics serious headaches. So now the expression has been replaced by the more nebulous wording of “decoherence“. However, this metamorphosis [wave <-> particle] is the central practical notion, and difficulty, in constructing a quantum computer, and also the deepest problem in physics.
So let’s suppose an interaction is such that it will give two particles, A & B, in the end (the most basic type of interaction, if we ignore the possibility of self interaction). After the interaction, when the products are in flight (so to speak), they are represented by one wave. Just one single wave. That wave has NO notion of physical distance. So this math, or, rather, this absence of math, tells us immediately that we are inside a physical point. (Warning: in my own theory, this is not exactly what happens; but this is what the standard formalism of Quantum Physics says, although most physicists are too afraid for their neurons, to contemplate the notion; another way to phrase the absence of distance is by saying that time is only a one parameter group of transformation.)
One says (loosely) that the “particles A and B” are entangled. Then if one interacts with A (say), one destroys that single wave which entangled A and B. Thus one destroys it for B too. Even if B is twenty galaxies away. That effect, known as the EPR (Einstein Podolski Rosen), frustrated Einstein deeply. He called it a “spooky interaction at a distance“. Einstein, following Newton, hated interactions at a distance. Faraday’s field theory, with a help from Maxwell, had removed that difficulty for electromagnetism, and Einstein’s gravitation theory tried to mimic it.
Entangled particles are common in classical physics, and they are no problem: two billiard balls which have hit each other are the arch typical example. In classical physics, if one knew the position and speed of the two balls before collision, and of one of them after the collision, one can tell what the position and speed of the other are, and that all along.
In Quantum physics, the situation is seriously different. This is related to the fact that one cannot know the position and moment of a (small enough) particle simultaneously. In that case, if one measures either, it affects the other. And it’s like that all over Quantum Physics. To make it worse, as Niels Bohr correctly insisted, in Quantum Physics, the experimental device changes what it measures. .
Now imagine again that interaction creating two entangled particles. If one measures A, one has to use experimental device X. For example we force A through a polarizer X. Results will differ according to which direction X is pointing.
Initially we had just one wave, Wave (A,B). Then we interact with A, using X. So what we have now is no more Wave (A,B), but [Wave (A,B) + Wave (A, X)]. The wave has changed! It has changed for B! And B maybe two million parsecs away! (That’s further than our sister giant galaxy, Andromeda.)
So let’s recapitulate. Entanglement is the greatest mystery of physics. After interacting, two particles, A and B, will often share properties as just one probability wave. Thus measuring one of these properties on A will immediately have an EPR effect on B (by the way, biology uses this EPR to transport energy cleverly and effortlessly! So although I talk galaxies here, to make some aspects of the situation more obvious, non-locality in Quantum physics is central to life itself… and obviously central to consciousness many of the apparent features of which it shares.)
Now let’s suppose A and B interacted, and billions of years passed by. Suppose they end up in different places in cosmological space which separated from each other according to Hubble, and even more so, according to Dark Energy. Then suppose finally, after all these eons, that a little green monkey interacts with A. It will have an effect on B, in a part of the universe, that little green monkey does not even know exist.
Physics progresses a lot by thought experiments. Aristarchus’ (320 BCE) and Buridan’s (1320 CE) speculations about the heliocentric theory are famous. More generally most of theoretical physics is a set of mathematically assisted thought experiments. Maxwell is famous (among other things) for “Maxwell Demon”, a tiny creature selecting fast particles, and thus creating a hot container (heat is speed). It’s a cute picture, and Maxwell wanted to use it to violate the Second Law of Thermodynamics That law says that entropy, that is disorder, always augments.
However, one had to be careful to consider the entire system… and to include the demon, though, who heats up, and generally blows up, so Maxwell’s idea was incorrect, although it has led, ever since, to a lot of refinement in thinking on the whole subject.
I have my own demon, and it’s not tiny, but cosmic, as the true devil of course is. So suppose a lot of Dark Energy operated for a long time, blowing the universe apart, and our galactic group is isolated in an apparently empty universe: nothing else can be seen. So we started from our present universe (call it U15, for 15 billion, a concession for Big Bang naivety). And now we are contemplating U100, the universe 100 billion years later, restricted, in appearance, to our local group.
Now suppose super intelligent little blue crabs starting from Neo Earth, have colonized the entire local galactic group. Could they tell their apparently isolated U100 universe is a small part of a much larger universe, for example U15, most of which is completely out of sight?
Enters Tyranosopher’s demon. That demon measures all the particles of the local group (how to do that? Ask Maxwell!). In the Quantum sense (so there are still indeterminacies). At that point the evolution of the local group is fully predictable (up to Quantum indeterminacies).
Meanwhile, let the little green monkey, who is out of sight, somewhere in the rest of U15, act on A. Then B, in turn, acts up. There is no limit on how much that could be scaled up: zillions of A and B pairs could be involved. So the green monkey could make zillions of Bs act up.
Would that be detectable? Yes. Once the Tyranosopher demon has catalogued the entire local group, if the action of green monkey is large enough, Tyranosopher demon will find more indeterminacy than normal physics would predict.
Bring that logic to bear on our present universe. Suppose that, however hard we tried, however meticulous our own demon was, cataloguing all the interactions leading to decoherence, we could not fully account for all the decoherence we observe. What would that tell us? That the part of the universe we cannot see is interacting with us. (Notice in passing that the situation is analogous with Black Holes, which are pretty much defined, conceptually speaking, by their event horizon.)
Can one apply the idea to Dark Energy? Yes. According to the (loose) philosophy of Quantum Field Theory, interaction are associated to particles. In the case of Dark energy we have an interaction out of nowhere, just space. Exactly what we would expect if EPR interactions were creating particles at a distance, from somewhere else in the universe.
Technical note: Simplicio: “OK, so the demon catalogues everything, and then a particle shows up, call it C. How do you know that it comes from the action of the forever invisible Green Monkey, and is not simply due to a local entanglement, which, as such, would not have showed up in the prior classification by the demon?” Tyranosopher: “Because then the demon, during the classification which discovered C, would find a particle D, which was not there before (D is entangled with C). Simplicio: “What if D has been taken away by Dark Energy too?” Tyranosopher:”Impossible if the demon cataloguing is frequent enough, as the particle D could not have escaped (it’s roughly limited by the speed of light, c). Simplicio: “And what of single particle diffracting?” Tyranosopher:”Well, this is a thought experiment. By waiting long enough for light to cross the local group, one should be able to exclude those.”
P/S: Out Of The Window with Causality, Light Speed, etc: It should be pretty obvious that the preceding has bearing on the various superstitions, and first order mistakes, surrounding relativity, in particular pertaining speed of light and causality (both independently, or as they relate with each other).