I talked a bit on Twitter last night about the Past Hypothesis and the low entropy of the early universe. Responses reminded me that there are still some significant misconceptions about the universe (and the state of our knowledge thereof) lurking out there. So I’ve decided to quickly list, in Tweet-length form, some true facts about cosmology that might serve as a useful corrective. I’m also putting the list on Twitter itself, and you can see comments there as well.
- The Big Bang model is simply the idea that our universe expanded and cooled from a hot, dense, earlier state. We have overwhelming evidence that it is true.
- The Big Bang event is not a point in space, but a moment in time: a singularity of infinite density and curvature. It is completely hypothetical, and probably not even strictly true. (It’s a classical prediction, ignoring quantum mechanics.)
- People sometimes also use “the Big Bang” as shorthand for “the hot, dense state approximately 14 billion years ago.” I do that all the time. That’s fine, as long as it’s clear what you’re referring to.
- The Big Bang might have been the beginning of the universe. Or it might not have been; there could have been space and time before the Big Bang. We don’t really know.
- Even if the BB was the beginning, the universe didn’t “pop into existence.” You can’t “pop” before time itself exists. It’s better to simply say “the Big Bang was the first moment of time.” (If it was, which we don’t know for sure.)
- The Borde-Guth-Vilenkin theorem says that, under some assumptions, spacetime had a singularity in the past. But it only refers to classical spacetime, so says nothing definitive about the real world.
- The universe did not come into existence “because the quantum vacuum is unstable.” It’s not clear that this particular “Why?” question has any answer, but that’s not it.
- If the universe did have an earliest moment, it doesn’t violate conservation of energy. When you take gravity into account, the total energy of any closed universe is exactly zero.
- The energy of non-gravitational “stuff” (particles, fields, etc.) is not conserved as the universe expands. You can try to balance the books by including gravity, but it’s not straightforward.
- The universe isn’t expanding “into” anything, as far as we know. General relativity describes the intrinsic geometry of spacetime, which can get bigger without anything outside.
- Inflation, the idea that the universe underwent super-accelerated expansion at early times, may or may not be correct; we don’t know. I’d give it a 50% chance, lower than many cosmologists but higher than some.
- The early universe had a low entropy. It looks like a thermal gas, but that’s only high-entropy if we ignore gravity. A truly high-entropy Big Bang would have been extremely lumpy, not smooth.
- Dark matter exists. Anisotropies in the cosmic microwave background establish beyond reasonable doubt the existence of a gravitational pull in a direction other than where ordinary matter is located.
- We haven’t directly detected dark matter yet, but most of our efforts have been focused on Weakly Interacting Massive Particles. There are many other candidates we don’t yet have the technology to look for. Patience.
- Dark energy may not exist; it’s conceivable that the acceleration of the universe is caused by modified gravity instead. But the dark-energy idea is simpler and a more natural fit to the data.
- Dark energy is not a new force; it’s a new substance. The force causing the universe to accelerate is gravity.
- We have a perfectly good, and likely correct, idea of what dark energy might be: vacuum energy, a.k.a. the cosmological constant. An energy inherent in space itself. But we’re not sure.
- We don’t know why the vacuum energy is much smaller than naive estimates would predict. That’s a real puzzle.
- Neither dark matter nor dark energy are anything like the nineteenth-century idea of the aether.
Feel free to leave suggestions for more misconceptions. If they’re ones that I think many people actually have, I might add them to the list.
Robert Thomas,
That is a specifically Western view, with the object orientation, as opposed to the Eastern polarity and contextuality, ie. yin/yang. Nodes versus networks. A big part of it is that we are mobile, tactile, story telling organisms, so a reality composed of “things” is a natural assumption. Along with viewing time narratively, past to future, as opposed to change turning future to past.
The Eastern view of time is even different. Rather than thinking of the future being in front and the past behind, as we see ourselves as distinct entities moving through our environment, their view is the past is in front and the future behind, as the past and what is in front are known, while the future and what is behind are unknown. Being part of the context, we do see events after they happen and the energy goes onto other events. Both are true, in their own ways.
My favorite description of reality is Emersons; “We are but thickened light.”
Anastasia Greenberg
* “We understand death for the first time when he puts his hand upon one whom we love.
Madame de Stael
* “I regard the brain as a computer which will stop working when it’s components fail. There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark.”
Stephen Hawking
* “To mourn for the time when one will be no more is just as absurd as to mourn over the time when as yet one was not.”
Arthur Schopenhauer
*** “My doctor gave me two weeks to live. I hope they’re in August.”
*** “I like life. It’s something to do.”
Ronnie Shakes
Stand up comedian. Shakes died at age 40 of a heart attack while jogging.
Roger makes two relevant points about Sean’s assertions. His first point is on target by being substantively correct. In the context of “existence,” there are basically two states for a topological assessment of physical reality. In terms of association, things and events are either “associated” or “disassociated.” In short, the universe exists in a continuous state of complete association as a “singularity”—a pure continuity. Fully disassociated states are not physically possible; so are effectively consigned to the dysfunctional realm of “oblivion.” However, a self-contained state, like the universe, can and does evolve through self-referential and recursive combinatorial processes that lawfully relate to genetically emergent properties (e.g. dimensions of space, operational time, matter and energy) Which brings us to Roger’s second point about Sean’s fifth assertion about “the Big Bang.” The “Big Bang” marks an inflection point of universal evolution, which has everything to do with the observable events that follow, especially in interactive terms of thermodynamic and gravitational distributions. The full course of this phased evolution related to the “Big Bang” can be structurally explained and demonstrated by properties of “instability” and counterpoints of stability.”
It’s interesting that even with no knowledge of what consciousness is, we know it doesn’t survive death.
While that may seem attractive to scientific types, they might well consider at least the agnostic alternative. Frankly, as much as I love science, I have no desire for information about life’s purpose from a scientist.
Why do you call them “true facts” when on almost every point you say we really don’t know?
Charles M,
That raises an interesting question: Is reality ultimately a singular entity, or a network?
Obviously we have a cosmology that is convinced reality is an entity, but the premise is starting to crack open and now we have the “multiverse,” as a network of such entities.
I would make the observation that a network is also a process that generates entities. Such as life is a process generating individual organisms, which are nodes in the network. One way to think about this is they go opposite directions of time. Think of a factory, where the products go start to finish, while the production process goes the other direction, consuming material and expelling product.
With life, we, as individuals, go from being in the future to being in the past, birth to death. While the species goes onto future generations, shedding old. Similarly our consciousness generates thoughts, which go future to past, while the process goes onto subsequent thoughts.
So, accepting current cosmology, what would be that deeper process generating universes and presumably being seeded and fertilized by them? Does it exist dimensionally, which would seem necessary at some level, as the generating would imply the effect of change and time. As well as the connections of this network, that would imply some dimensionality that is space.
Space does seem to function as the relationship between equilibrium and infinity, so would equilibrium be the central balance around which entities coalesce, while infinity would be the field that makes the network equally fundamental?
Reply to John Merryman: From my perspective, your question and observations begin to tap into the confusions which surround many fallacies of perception and the rough analogies formulated by general patterns, especially in terms of limits on physical processes which must be both discrete and continuous to fit into the context of an operational reality entailing the natural constructs of space and time.
You ask a legitimate question, but it is incompletely premised upon assumptions about the lawful mechanisms of discrete complexity and emergent orders of associative dependence related to discrete coupling and decoupling. Due to demonstrable principles of associative combinatorics (related to dimensional evolution and inflation), natural evolutionary processes cannot create multiples outside a local context (related to quantum events) which enables recursive production as seen in the consequences of the “Big Bang.” Those scalar limitations are self-referential, and the inflationary evolution of spatial dimensions is “close” by those gravitational processes of recursive distribution and displacement related to operational time, matter, and energy. To outline in brief, you can think of universal evolution in terms of causal processes. “Strict” causality phasically entails the dimensional inflation that underpins “the Big Bang,” which marks the inflection point of causality that then “interactively” drives the emergent thermodynamic processes, which eventually enables the evolution of (self-conscious) life as “agents with intent.” In this universal context, reality represents a singular dimensional entity that in manifesting unstable and stable associations lawfully generates a functional spatial network with temporal attributes (simultaneously entailing conjunctive perturbative packets for processes of past-present and present-future states).
Charles,
Thank you for the reply.
As I’ve hopefully made clear in prior posts, I’m not a fan of BBT. Two reasons already covered are that when it was appreciated that redshift is proportional in all directions, creating the impression we are at the center of this expansion, the premise of spacetime was used to argue space itself is expanding, not just an expansion in space, yet that ignores the fact that if the light is redshifted, its speed is not Constant to intergalactic space. So two metrics of space are being derived from the speed and spectrum of the same light.
Also that the premise of falsifiability was ignored when Dark Energy was applied to the gap between prediction and observation, that Perlmutter and company discovered.
The assumption, from the edge of the universe, was the rate would drop off evenly, yet it dropped off precipitately and then flattened out, as if the universe had been shot out of a cannon, then a rocket motor kicked in. Though if it is considered from our point of view, it starts off slowly and eventually goes parabolic. An effect that would be expected, if it is actually an optical effect compounding on itself.
Inflation basically explains why the overall curvature is flat, with expansion and gravity balancing out. More could be said there…
The primary issue goes to the nature of quantization and the assumption light is first and foremost photon units, but here is an interesting experiment, arguing for the loading theory of light;
https://fqxi.org/data/essay-contest-files/Reiter_challenge2.pdf
Combine that with this. A paper observing multi spectrum “packets of light” do redshift due to distance;
https://fqxi.org/data/forum-attachments/2008CChristov_WaveMotion_45_154_EvolutionWavePackets.pdf
So basically what our telescopes observe is a sampling of the wave front, not individual photons traveling billions of lightyears.
While this premise is always open to debate, I find it hard to believe the accepted view, no matter how many people believe it, when it ignores basic logic.
More I could say, but work beckons….
A Misconception not yet Skewered is Heliocentrism.
Newton’s law states that “two bodies attract each other with a force…”, so no preference for Earth or Sun. And while General Relativity attributes gravity to the space-time curvature, it conserves the neutrality. It just happens that one body is much larger than the other but we do not discriminate, do we?
Here are some areas of confusion for me:
1. DE is associated with the vacuum energy of space. Hence, more space, more DE. But where does this energy come from? It seems to me that just as the SS model required the continuous creation of matter, the LCDM model requires the continuous creation of DE.
2. Is the vacuum energy field also the medium through which light travels and which fixes its speed?
3. What exactly is spacetime? Conceptually, it is a mathematical model which describes the relationship between space and time, but in GR it also interacts with physical matter like a physical aether.
4. In the early universe, expansion resulted in matter particles emerging out of an initially pure radiation field. Did light also emerge out of some other kind of earlier energy field? If so, this could explain thermal equilibrium without requiring thermalization (i.e., the radiation was ‘born’ thermalized).
5. If DE drives the late-time expansion, what drove the early expansion? Was it the cosmic fluid pressure (which drops away just as DE comes on stream)?
6. How does gravity balance the total energy of the universe, and how does it reduce entropy in the early universe? In GR, gravity is a geometric property; the gravitational field itself has no energy.
7. What exactly is the “standard cosmological model” (SCM)? To me, this term refers only to the classical LCDM model (including the possibility of curvature) which implies a big-bang beginning, but excludes adjunct theories such as inflation (based on quantum physics), and the CMB interpretation (based on particle physics).
Bruce commented . . . .
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My answer.
1 – It was, it is, it will be forever an infinite /eternal continuum T=0K.
Why ?
There is fundamental fact in Nature that
the critical density in the whole Universe is so small
( 9.9 x 10^-30 g/cm^3) that its masses cannot ”close”
the Universe into sphere and therefore the Universe
as whole is ”open”- flat.
And because the Universe (as whole) is homogeneous and isotropic
therefore its density ( 9.9 x 10^-30 g/cm^3 ) must always remain
constant. It means that the Universe (as whole) is infinite flat and cold:
(after every cosmic flat homogeneous and isotropic horizon there is
other one and so, and so, and so. . . )
#
Today there is opinion that the Universe as whole has
temperature: T= 2,7K . The parameter T=2,7K is not constant.
It is temporal parameter and it goes down and in the future
it will come to T= 0K.
Therefore, sooner or later concept T=0K
would be accepted as fundamental basis in Physics.
2 – Einstein’s SRT postulate: the speed of light in a vacuum is constant
regardless of the motion of the source of the light / Michelson experiment /
3 – SRT has reference frame ” spacetime ” — continuum without masses.
Continuum without masses is called ”vacuum”
(look the Einstein’s SRT postulate )
GRT has masses and therefore it is another story.
4 – They say: ”the early universe, expansion resulted of hot point” . . .
Two electrons (anti-electrons) will not allow such process.
5 – The cosmic pressure is ( 9.9 x 10^-30 g/cm^3)
6 – ” The Law of conservation and transformation of energy / mass”
keeps balance in the Universe as whole.
And this law is not the simple accounting solution of debit and credit.
The sense of this law is dipper and it says more than is usually accepted.
7 – The zero vacuum is still dismissed by the majority of scientists, but
” When the next revolution rocks physics, chances are it will be
about nothing—the vacuum, that endless infinite void.”
http://discovermagazine.com/2008/aug/18-nothingness-of-space-theory-of-everything
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Looking at the classic picture of the measured cosmic microwave background we have the impression that the earth is in the center of a large sphere and the satellite measured the radiation coming from the “border” of that sphere. As most scientists says, this is just an illusion, but what is the best we to interpret the “shape” of the universe? What a “open” or “closed” universe really mean?
Sadovnik,
Keep in mind you are describing two qualities of space. That it is infinite and that it is the equilibrium, absolute zero, frame with the fastest clock and longest distance, vacuum from which this fluctuation arises and around which it circulates.
So space is the absolute and the infinite.
Time, on the other hand, is an effect of the activity emerging from the fluctuation, like temperature, pressure, color, etc. It is change turning future to past. Potential to residual. What we measure is frequency. Duration is the present, as events come and go.
It is quite natural to assume that there might be innumerable parallel universes . All our observations are limited to the capacity of our sensory organs and brain . We are limited by our body machine.
“13. Dark matter exists.”
At this point, every way we have of testing for it physically and astronomically (including Voyager signals as it leaves our solar system) has produced inconclusive or negative results*–with the exception of the CMB, but that is a second-hand result which may be due to other unknown means. It seems premature to me to state #13 as a scientific fact. (But what do I know? Just that some other experts have made arguments against it which make sense to me.*)
* See the Triton Station blog for the lack of predictive power of the dark-matter model on galactic rotation curves. See Back Reaction for how the Bullet Cluster can be explained by modified gravity models just as well as by dark matter.
JimV commented . . .
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My opinion.
13 – Dark matter and Dark energy exist in the Black holes.
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Jim,
Gravity is described as an inward curvature of space. As with the rubber sheet and the ball.
So what is missing is enough mass to indent that sheet sufficient to create the actual curvature of galaxies. Something is pulling them together, far more than the apparent mass.
Yet what if gravity is not so much a property of mass, as mass is an effect of gravity? What if it is the wave collapse that starts as quanta coalescing out of fields, that is the initial state of gravity?
Consider the analogy of the ball on a rubber sheet; Presumably, to keep things equal, when the sheet is curved inward in spots, it curves out in the more open spaces. Think of the sheet being over water, so the dent caused by the ball is transferred to the open spaces, in an equal proportion. Effectively Einstein’s Cosmological Constant. The balance to gravity.
So then consider that galaxies, the primary entities in the universe, are energy radiating out, as structure coalesces in. What if this is a cosmic convection cycle and the reason that it’s balanced out, Omega=1, isn’t coincidence, but they are opposites sides of this process.
Our mental obsession is with what can be measured and the more precisely the better, yet the only thing that lends itself to measurement is the structure and definition, so we think of everything as quanta, rather than the quanta as measurable units of this “energy.” Yet that process of measurement is a process of consolidation and definition. Which begins at the very point energy peaks and starts to form as structure and quanta. Starting with the most elemental quantization, such as photons.
So the “dark matter” is actually just the inward curvature/gravity playing out across the entire spectrum of the collapse/attraction, not just what is substantial enough to qualify as mass.
As I mentioned previously, redshift can be explained by photons being multi spectrum samplings of the wavefront, not just individual photons traveling the entire distance. So the underlaying light is a field of expanding energy, not just quanta.
Math likes form and form is static, but the actual, physical reality is dynamic.
Applying natural processes to the sociological dynamic of the field of theoretical physics, think of how skin and shells harden to protect, but eventually have to break open and be shed, or grow in the joints, in order for the organism to continue to grow. We are witnessing this dynamic occurring in the field. Some will have to be shed, aka funerals, while some will grow with the process. Future generations of physicists are not going to spend their careers chasing after multiverses.
Sadovnik,
Think of black holes as the eye of a storm. What is really happening is what goes on around them, as the mass falling in, converts to energy radiating out.
John Merryman commented . . .
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Book: ”’ Stephan Hawking, A life in science,”
/ by Michael White and John Gribbin./
#
”Together with Brandon Carter and Jim Bardeen, Hawking
wrote a paper, published in Communications in Mathematical
Physics , pointing out . . . . . the team commented,
” In fact the effective temperature of a black hole is
absolute zero . . . . No radiation could be emitted from the hole.”
/ page 156./
But later (!!!) , . . using concept of entropy and Heisenberg uncertainty
principle and quantum fluctuations Hawking changed his mind
and wrote that black hole can emit — Hawking radiation.
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John Merryman
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”curvature of space” near gravity-masses (!) is local phenomena
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Nothing new is open at the large collider. New discoveries are waiting at the level of Planck’s length; now it is impossible, I agree with her, it is better to study space.
Sadovnik,
“In fact the effective temperature of a black hole is absolute zero.”
Yes. It’s inert. The eye of the storm. Whatever falls onto the boundaries radiates out the poles. Most of the energy radiates out before it gets that far. Stars, etc.
https://scitechdaily.com/ocean-eddies-mathematically-equivalent-black-holes/
“”curvature of space” near gravity-masses (!) is local phenomena”
As into galaxies. Yet there is that outward curvature between galaxies. And they balance out.
What do you think of the negative mass theory attempting to unify dark matter and dark energy, which J. S. Farnes recently argued for using simulations?
https://arxiv.org/abs/1712.07962
https://theconversation.com/bizarre-dark-fluid-with-negative-mass-could-dominate-the-universe-what-my-research-suggests-107922
Is there any inconsistency in this theory, do the simulation results count as evidence, what future observations would add credibility or falsify this theory?
Kuyukov V.P. commented . .
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” . . . more and more money for less and less knowledge
about hypothetical specks of matter that go so far beyond the
infinitesimal as to border on sheer nothingness.”
/ Ed Regis. Science writer./
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John Merryman commented . . .
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Ocean Eddies Are Mathematically Equivalent to Black Holes
By ANGELIKA JACOBS,
ETH , ZURICH , SEPTEMBER, 24, 2013
https://scitechdaily.com/ocean-eddies-mathematically-equivalent-black-holes/
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Ha, ha, ha . . . Mr. John Merryman are you joking ?
. . . black-hole-type ocean eddies are equivalent (!) black holes function . . .
. . . .as a transportation vehicle . . . for . . . micro-particles
/ funny comparison: black holes as taxis for negative virtual particles.
Maybe, . . . ocean eddies equations can be similar black holes,
but they cannot be equivalent. /
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