Do We Live in a Fluid Universe?

If we conceive of the universe as a kind of fluid, the physics of the cosmos makes a lot more sense (at least in my limited understanding). This cool article from Quanta Magazine offers a fluid model of the cosmos.

Big Bang Secrets Swirling in a Fluid Universe

By: Natalie Wolchover
February 12, 2014


A new model that treats the matter in the universe as a fluid could enable researchers to retrace the flow of the cosmos back to the Big Bang. In this image, fluidlike wisps are created as ejected gas from a supernova collides with gas and dust in the surrounding interstellar medium. Canada-France-Hawaii Telescope/Coelum
To a sound wave, the cosmos has the consistency of chocolate syrup.

That’s one discovery that scientists investigating the Big Bang have made using a new approach that treats the matter in the universe as a peculiar kind of fluid. They have calculated properties that characterize the universe’s behavior and evolution, including its viscosity, or resistance to deformation by sound waves and other disturbances.

“Twenty pascal-seconds is the viscosity of the universe,” said Leonardo Senatore, an assistant professor of physics at Stanford University — just as it is for the ice cream topping.

Leonardo Senatore, an assistant professor at Stanford University, is leading an effort to develop a new computational approach to cosmology that could reveal details about how the universe began.

The viscosity calculation could help cosmologists sleuth out the details of the Big Bang, and possibly someday identify its trigger, by enabling them to track the fluidlike flow of the cosmos back 13.8 billion years to its initial state.

As other techniques for probing the Big Bang reach their limits of sensitivity, cosmologists are co-opting the fluid approach, called “effective field theory,” from particle physics and condensed matter physics, fields in which it has been used for decades. By modeling the matter swirling throughout space as a viscous fluid, the cosmologists say they can precisely calculate how the fluid has evolved under the force of gravity — and then rewind this cosmic evolution back to the beginning. “With this approach, you can really zoom in on the initial conditions of the universe and start asking more and more precise questions,” said Enrico Pajer, a postdoctoral research fellow at Princeton University with a recent paper on the technique that has been accepted by the Journal of Cosmology and Astroparticle Physics.

The more information that astronomers gather about the distribution of galaxies throughout space — known as the “large-scale structure” of the universe — the more accurate the fluid model becomes. And the data are pouring in. The sketchy scatter plot of several thousand nearby galaxies that existed in the 1980s has given way to a far richer map of millions of galaxies, and planned telescopes will soon push the count into the billions. Proponents believe that tuned with these data points, the fluid model may grow precise enough within 10 or 15 years to prove or refute a promising Big Bang theory called “slow-roll inflation” that says the universe ballooned into existence when an entity called an inflation field slowly slid from one state to another. “There has been a big community trying to do this type of calculation for a long time,” said Matias Zaldarriaga, a professor of cosmology at the Institute for Advanced Study in Princeton, N.J. Further in the future, the researchers say, applying effective field theory to even bigger datasets could reveal properties of the inflation field, which would help physicists build a theory to explain it.

M. Blanton and Sloan Digital Sky Survey. Cosmologists hope to extract information about the Big Bang from the the next generation of large-scale structure surveys like this one from the Sloan Digital Sky Survey, which shows the distribution of galaxies from the Earth at the center to a distance of two billion light-years at the outer circle.

“It’s obviously the right tool to be using,” said John Joseph Carrasco, a theoretical physicist at Stanford. “And it’s the right time.”

Senatore, Carrasco and their Stanford collaborator Mark Hertzberg first proposed the fluid approach to modeling the universe’s large-scale structure in a 2012 paper in the Journal of High Energy Physics, motivated by the Big Bang details it could help them glean from the increasingly enormous data sets. Other researchers have since jumped on board, helping to hone the method in a slew of papers, talks and an upcoming workshop. “We’re a small, plucky band of people who are convinced this is the way forward,” said Sean Carroll, a theoretical cosmologist at the California Institute of Technology.

A Fluid Cosmos

In water, chocolate syrup and other fluids, matter is smoothly distributed on large scales and partitioned into chunks, such as atoms or molecules, on small scales. To calculate the behavior of water on the human scale, where it is a fluid, it isn’t necessary to take into account every collision between H₂O molecules on the atomic scale. In fact, having to do so would render the calculation impossible. Instead, the collective effects of all the molecular interactions at the atomic scale can be averaged and represented in the fluid equations as “bulk” properties. (Viscosity, for example, is a measure of the friction between particles and depends on their size and shape as well as the forces between them.)

Enrico Pajer, a postdoctoral fellow at Princeton University, says the matter in the universe behaves “in a very similar way as water or air.”

A similar trick works for modeling the evolution of the universe’s large-scale structure.

Just like water, the universe is smooth on large scales: The same amount of matter exists in one billion-light-year-wide region as the next. Slight variations in the matter distribution, such as more- and less-dense patches of galaxies, appear when you zoom in. At short distances, the variation becomes extreme: Individual galaxies are surrounded by voids, and within the galaxies, stars pinprick empty space. The matter distribution is constantly changing at every scale as gravity causes stars, galaxies and galaxy clusters alike to clump together and dark energy stretches the space between them. By modeling these changes, cosmologists can use the output — galaxy distribution data — to deduce the input — the initial conditions of the universe.

To a first approximation, the matter distribution at each distance scale (from large to small) can be treated as if it evolves independently. However, just as small ripples in the surface of water can affect the evolution of bigger waves, smaller clumps of matter in the universe (such as galaxy clusters) gravitationally influence the larger clumps that encompass them (such as superclusters). Accounting for this interplay in models of cosmic evolution is problematic because the gravitational effects at the shortest distance scales — at which the universe is not smooth like a fluid but rather condensed into isolated, particlelike objects — sabotage the calculation.

Effective field theory fixes the problem by accounting for the interplay between scales only down to a few times the distance between galaxies. “Everything smaller than that length scale, we treat as complicated and hard to understand, and whatever goes on at those small scales can be bundled up into one big effect,” Carroll explained. The average gravitational effect of matter on small scales is represented as a fluid’s viscosity; hence, the connection between the cosmos and chocolate syrup.

Although the former is sparse and cold while the latter is thick and usually served warm, their viscosities are calculated from data and simulations to be almost exactly equal. The number means both fluids immediately damp out an incident sound wave. “It just goes ‘dum,’ and then it disappears,” Pajer said.

The Ultimate Probe

“It’s still early days for the effective field theory of large-scale structure,” said Marc Kamionkowski, a professor of physics and astronomy at Johns Hopkins University who is not involved in developing the approach. While “it certainly does present some advantages,” he said, much work is needed before the tool can be used to extract new discoveries from astronomical data.

For example, so far, cosmologists have only developed an effective field theory model of the evolution of dark matter, an invisible substance that makes up roughly six-sevenths of the matter in the universe. Visible matter is slightly more complicated, and researchers say its behavior on short distance scales might be more difficult to represent as bulk properties of a fluid. “That is the next challenge,” said Zaldarriaga, who co-authored a November 2013 paper on the effective field theory approach. “We are doing one thing at a time.”

The researchers’ ultimate goal is to measure so-called “non-Gaussianities” in the initial conditions of the universe. If inflation theory is correct and an inflation field briefly transitioned to an unstable state, causing space to balloon 1078 times in volume, random ripples of energy called quantum fluctuations would have surfaced in the field and later grown into the large-scale structure that exists today. These ripples would be expected to follow a “Gaussian” distribution, in which energy is evenly distributed on both sides of a bell curve. Cosmologists look for non-Gaussianities, or subtle biases in the energy distribution, as signs of other, more meaningful events during inflation, such as interactions between multiple inflation fields. The recently released Planck satellite image of the cosmic microwave background indicated that energy fluctuations in the primordial universe followed a Gaussian curve to at least one part in 100,000, compatible with the slow-roll model in which the universe arose from a single inflation field. But alternative models that would have produced even smaller amounts of non-Gaussianity have not yet been ruled out.

By tuning the effective field theory model with galaxy distribution data from imminent sky surveys such as the Large Synoptic Survey Telescope project and Euclid mission, cosmologists estimate that it may be possible to improve detection of non-Gaussianities by a factor of 10 or 20. If none is detected at that sensitivity level, “we can be sure it is standard slow-roll inflation,” Senatore said. “This is extremely exciting.”

If it can be proved that the Big Bang began with slow-roll inflation, the next task would be to probe the properties of the “inflaton” — the particle associated with the inflation field, and a component of an all-encompassing theory of nature. During inflation, the inflaton must at least have interacted with itself and gravity, and both interactions would nudge the inflation field’s energy distribution ever so slightly to one side or another. Planned sky surveys will not be sensitive enough to detect such subtle non-Gaussianities, but researchers expect them to be imprinted on a signal emitted by hydrogen gas in the early universe. “This is the ultimate probe,” Pajer said.

Telescopes should detect this hydrogen signal, called the 21-centimeter line, in approximately 30 or 40 years, and effective field theory will be used to try to tease out the non-Gaussianities. “While we’re old,” said Senatore, who is 35, “we will for sure detect something.”

This article was reprinted on ScientificAmerican.com.

Michael White - Are We Still Evolving?

Short answer is yes.

For the last 50,000 years or so, we've adapted to the local environments where have settled to build villages, towns, and cities. Going forward, we will adapt to the social (meat-space and online) and physical (including further urbanization and climate change) environment we are creating for our grandchildren.

We are less likely to exhibit considerable physical changes than we are to develop greater intellectual and interpersonal (brain changes) stages in our evolution.

Are We Still Evolving?

Yep, but there's a catch: Our identities might be too fluid for any advantageous mutations to take hold.

October 30, 2013 • By Michael White

(PHOTO: LONELY/SHUTTERSTOCK)

Our evolutionary trajectory over the last three million years took us from small-brained walking apes who lived in East African grasslands to modern humans who have colonized just about every type of environment of every major land mass on the planet. So what's next? Are we still evolving? If so, have our culture and our technology changed our evolutionary trajectory? Using new genetic inventories of world populations, researchers are now tracing our recent evolutionary path in remarkable detail. They are discovering that our culture and our general restlessness as a species have had a big impact on our genetic makeup.

A human living in Africa 50,000 years ago wouldn't look out of place groomed and dressed up in a business suit, sipping coffee at a Starbucks in Manhattan. Yet while fully modern humans evolved in Southern Africa, a glance around a Manhattan Starbucks is enough to show you that human evolution has continued since we migrated out of Africa and settled the rest of the world: our stature, skin color, hair, eye color, and other facial features clearly show where in the world at least some of our ancestors lived. Modern humans began branching out into the Near East, Asia, Europe, and Australia by about 40,000 years ago, finally arriving in South America by 12,000 years ago. As our species colonized new environments around the world, we confronted new foods, new pathogens, and other new challenges posed by differences in sunlight, temperature, and altitude. Different populations around the world evolved in response to their unique environmental challenges; as a result, we differ from each other not only in our outward appearance, but also in the inner workings of our bodies. The effects of different evolved adaptations among humans in different parts of world can be seen today in the strong influence our ancestry can have on our health.

To get a better understanding of the changes in our recent evolutionary past, scientists have been looking under the hood at the genetic workings of those evolutionary changes. They're using large genetic inventories of different world populations, such as the Human Genome Diversity Project, to look for mutations that show signs of being actively promoted by evolution. Among the findings are mutations that cause lighter skin color in northern human populations. Lighter colored skin may have evolved in response to the need to maintain sunlight-activated vitamin D synthesis as humans migrated northward. Scientists have discovered different mutations in Europeans and East Asians that are responsible for the lighter skin color in these populations. Other studies have uncovered mutations responsible for straight hair in Asians and blue eyes in Europeans; the evolutionary basis for the short stature of “Pygmy” populations that live in the tropical forests of Africa, Asia, and South America; and the different genetic adaptations of Andean, Tibetan, and Ethiopian high-altitude societies to low oxygen levels that would make the rest of us sick. These changes may seem subtle when you consider what can happen over millions of years, but there is no question that humans have continued to evolve.

There is also no question that we've managed to influence the course of our own evolution. One of the biggest cultural changes we've undergone as a species has been to settle down into villages and cities, and support ourselves by raising crops and livestock. In the process, we've altered the evolution of our immune system and our metabolism. The clearest example of a diet-induced evolutionary change is adult lactose tolerance in dairy-consuming Europeans and African Maasai, a useful trait to have before the availability of Lactaid.

Our species' wanderlust has also had a profound impact on how we've experienced evolutionary change. Much of our genetic makeup is due to what geneticists call founder effects, meaning that our genes reflect the chance membership of the small band of colonists that we've descended from, rather than evolutionary pressure to adapt. The fact that Scots commonly have red hair, while Norwegians have blond hair is likely due to founder effects and not because red hair is better suited to the Scottish climate. Our long tradition of pulling up stakes and seeking our fortunes elsewhere has also had the effect of putting the brakes on natural selection in many cases. One research team studied the fate of seemingly favorable mutations worldwide and concluded that human "populations may be too mobile, or their identities too fluid" for advantageous mutations to spread completely through a population. By moving around so much, we stir up the human gene pool and alter how evolutionary pressures act on our genes.

The recent evolutionary changes studied by scientists all occurred well before a few game-changing developments that include antibiotics, vaccines, mass-produced food, fertility drugs, and online dating services. We've raised the odds that, in most areas of the world, children will live to adulthood and go on to have their own children. Does this mean that we've transcended the messy process of evolution and made ourselves largely immune to natural selection? Not quite—just because our children aren't eaten by predators or don’t succumb to childhood diseases does not mean that evolution has lost its power over our species. For the past 40,000 years, we've been adapting to the local environments that we've colonized; in the future, we will adapt to the social and physical environment we are making for ourselves. We'll face the uncertain new challenges of climate change, but we also continue to confront the questions of how to successfully choose a mate and whether and when to have children. More people are choosing to have children later in life or not at all, a choice that generally wasn't an option for most women not too long ago. The well-being of our children today depends less on the chance occurrence of a famine or epidemic, and more on the choices we make as parents. These kinds of decisions clearly influence whose DNA ends up in the next generation. Our future evolutionary trajectory depends on how billions of people resolve these choices over the next 40,000 years.

Robert Kernodle - FLUID is God

Hmmmm . . . I'm not a believer in ANY form of supreme being, but if I were, this might be the closest thing to how I would conceive of it. Or not.

Interesting art to go with his philosophical perspective. Sounds a little like panentheism to me.

FLUID is God

By Robert Kernodle

The Supreme Being is like a liquid.

ASPECT 396 - PhotoFluidism by Robert Kernodle

Beyond Religion

I do not claim to be a Christian. Neither do I claim to be a member of any other religion that treats the Supreme Being as an entity with human-like intelligence. I do not condemn anyone’s religious beliefs, nor do I preach to people to believe as I believe. I write here to share a unique point of view on a very popular topic – God.

Supreme Being

I DO believe in a Supreme Being, but this being is a verb as much as a noun. In my way of thinking, the Supreme Being is not a conscious spirit, but simply the action of existence that all things share. Anything that exists is part of all being, and all being is the Supreme Being. The Supreme Being, thus, is the sum total of all that exits.

All that exists has the common connection of existing. All that exists has the common action of being. Being is the united action of all things. The Supreme Being is both matter and energy, both substance and its relationships, both stuff and its motions. Being cannot be without a substance, and substance cannot be without motions to relate it. The Supreme Being, thus, cannot be an entity without substance, because having no substance means having no being. Consequently, the Supreme Being is always someTHING in motion.

ASPECT 283 - PhotoFluidism by Robert Kernodle

Sublime Fluidity

What is reality? To what thing and to what motion can all things relate? I believe that all things relate to a fluid. All being is a fluid being, forever morphing and creating recurring self-similar forms. Human beings are results of this great fluid being that came before it.

Life, consciousness, intelligence, feeling, and the sensation of existing all arise from the supreme fluid being. This fluidity is the marvel of being – humans are part of it, we are it, we are a consequence of it. Human intelligence comes from the substance and motion of the Supreme Being, which does not think as humans think.

Proto-Intelligence

What we call “chaos”, “chance” or “accident” is what exists prior to minds that can name it. We humans arise from this condition of matter and motion that we call “chaos”. Life is truly amazing, because something that seems so opposite to it actually gives birth to it. The very nature of being is to create life like us.

The great fluid being of reality is capable of swirling humans into existence, because the way of fluid is to seek self-consciousness to reflect back on itself. Consciousness, therefore, is a reflection in the greatest of all liquid pools.

If someone wants to call this idea of Supreme Being “God”, then I can agree to this label. This God, however, is not person-like, not father-like, and not king-like. This God is not power wielding. This God is simply what is.

God is like a stream that knows how to flow, because it flows along the only path it can – the path that enables it to flow. God is like water with infinite and eternal morphing ability, fitting what contains it without conforming permanently to any one container. God is like a bubble that forms in the only sequence of events that exists to accommodate it. God, thus, is beyond absolute containment by the human mind, because mind is finite, and God is infinite fluidity.

Humans can only feel God – we can never know God. The effort of trying to contain what is far beyond containing is how we feel God. God is the overwhelming sensation of trying to grasp something far greater and far more complex than consciousness can grasp.

God is like the huge scale of a fractal that dwarfs all of its budding beautiful designs on smaller scales. God has no mind, yet God is all minds. Human minds, in this way, are only very remotely similar to the fluid processes that created them. God cannot know each mind personally. Each mind is simply a fragment of God’s whole existence in the unison of existence that God is.

Minds arise from something that precedes mindfulness. This something that precedes mindfulness is God. In this way, humans are perfected God. Sand is perfected God. Trees are perfected God. The ocean is perfected God. Any one thing that we can name is perfected God, just as everything named together is God being realized.

ASPECT 602 - PhotoFluidism by Robert Kernodle

Human Responsibility

In my concept of God, humans must assume total responsibility for their existences. We cannot reason with all existence the way we reason among ourselves. We learn from our own existences and from our own thoughts, because these are processes of God, and this is how God moves through us. Each part of God manifests its own particular perfection or imperfection, so these things are in human hands to the degree that the greater flow allows it. Humans, thus, are in a sensitive position of being creators who must learn when they are able to shape specific forms and when they must participate with forms greater than they can control.

Humans rule God to some degree, as God rules humans. We are all in existence together, in unison, and in similar roles. God, in this sense, gave us a small dose of God-like power to control part of our being. Human being, after all, is a miniature of Supreme Being.

Tags: Religion, Philosophy, fluidity, Robert Kernodle, FLUID is God, reality, divinity, art, Supreme Being, God, PhotoFluidism, panentheism