New model of cosmic stickiness favors ‘Big Rip’ demise of universe
The universe can be a very sticky place, but just how sticky is a matter of debate.
That is because for decades cosmologists have had trouble reconciling the classic notion of viscosity based on the laws of thermodynamics with Einstein’s general theory of relativity. However, a team from Vanderbilt University has come up with a fundamentally new mathematical formulation of the problem that appears to bridge this long-standing gap.
The new math has some significant implications for the ultimate fate of the universe. It tends to favor one of the more radical scenarios that cosmologists have come up with known as the “Big Rip.” It may also shed new light on the basic nature of dark energy.
The new approach was developed by Assistant Professor of Mathematics Marcelo Disconzi in collaboration with physics professors Thomas Kephart and Robert Scherrer and is described in a paper published earlier this year in the journal Physical Review D.
“Marcelo has come up with a simpler and more elegant formulation that is mathematically sound and obeys all the applicable physical laws,” said Scherrer.
The type of viscosity that has cosmological relevance is different from the familiar “ketchup” form of viscosity, which is called shear viscosity and is a measure of a fluid’s resistance to flowing through small openings like the neck of a ketchup bottle. Instead, cosmological viscosity is a form of bulk viscosity, which is the measure of a fluid’s resistance to expansion or contraction. The reason we don’t often deal with bulk viscosity in everyday life is because most liquids we encounter cannot be compressed or expanded very much.
Disconzi began by tackling the problem of relativistic fluids. Astronomical objects that produce this phenomenon include supernovae (exploding stars) and neutron stars (stars that have been crushed down to the size of planets).
Scientists have had considerable success modeling what happens when ideal fluids – those with no viscosity – are boosted to near-light speeds. But almost all fluids are viscous in nature and, despite decades of effort, no one has managed to come up with a generally accepted way to handle viscous fluids traveling at relativistic velocities. In the past, the models formulated to predict what happens when these more realistic fluids are accelerated to a fraction of the speed of light have been plagued with inconsistencies: the most glaring of which has been predicting certain conditions where these fluids could travel faster than the speed of light.
“This is disastrously wrong,” said Disconzi, “since it is well-proven experimentally that nothing can travel faster than the speed of light.”
These problems inspired the mathematician to re-formulate the equations of relativistic fluid dynamics in a way that does not exhibit the flaw of allowing faster-than-light speeds. He based his approach on one that was advanced in the 1950s by French mathematician André Lichnerowicz.
Next, Disconzi teamed up with Kephart and Scherrer to apply his equations to broader cosmological theory. This produced a number of interesting results, including some potential new insights into the mysterious nature of dark energy.
In the 1990s, the physics community was shocked when astronomical measurements showed that the universe is expanding at an ever-accelerating rate. To explain this unpredicted acceleration, they were forced to hypothesize the existence of an unknown form of repulsive energy that is spread throughout the universe. Because they knew so little about it, they labeled it “dark energy.”
Most dark energy theories to date have not taken cosmic viscosity into account, despite the fact that it has a repulsive effect strikingly similar to that of dark energy. “It is possible, but not very likely, that viscosity could account for all the acceleration that has been attributed to dark energy,” said Disconzi. “It is more likely that a significant fraction of the acceleration could be due to this more prosaic cause. As a result, viscosity may act as an important constraint on the properties of dark energy.”
Another interesting result involves the ultimate fate of the universe. Since the discovery of the universe’s run-away expansion, cosmologists have come up with a number of dramatic scenarios of what it could mean for the future.
One scenario, dubbed the “Big Freeze,” predicts that after 100 trillion years or so the universe will have grown so vast that the supplies of gas will become too thin for stars to form. As a result, existing stars will gradually burn out, leaving only black holes which, in turn, slowly evaporate away as space itself gets colder and colder.
An even more radical scenario is the “Big Rip.” It is predicated on a type of “phantom” dark energy that gets stronger over time. In this case, the expansion rate of the universe becomes so great that in 22 billion years or so material objects begin to fall apart and individual atoms disassemble themselves into unbound elementary particles and radiation.
The key value involved in this scenario is the ratio between dark energy’s pressure and density, what is called its equation of state parameter. If this value drops below -1 then the universe will eventually be pulled apart. Cosmologists have called this the “phantom barrier.” In previous models with viscosity the universe could not evolve beyond this limit.
In the Desconzi-Kephart-Scherrer formulation, however, this barrier does not exist. Instead, it provides a natural way for the equation of state parameter to fall below -1.
“In previous models with viscosity the Big Rip was not possible,” said Scherrer. “In this new model, viscosity actually drives the universe toward this extreme end state.”
According to the scientists, the results of their pen-and-paper analyses of this new formulation for relativistic viscosity are quite promising but a much deeper analysis must be carried out to determine its viability. The only way to do this is to use powerful computers to analyze the complex equations numerically. In this fashion the scientists can make predictions that can be compared with experiment and observation.
###
The research was supported by National Science Foundation grant 1305705 and Department of Energy grant DE-SC0011981.
Ah…,the Ivory Towers…!
Younger women ! Faster computers ! More money ! Older whisky !
Rinse , repeat ….(8>))
With all that stuff, who needs to drink?
Durn! I thought I was the “big rip”…outclassed by the universe. Again.
rip
It must be dark CO2 whats hiding the missing heat. It is also the cause of expanding grants, which will end the economy of our universe in the Big Ripoff.
Requiescat In Pace
The Big Bang never happened! How in physics do you create something from nothing? Did it start from an infinitely small particle? We do not understand what infinity is! All we have is formulas and more formulas and renormalization where infinity exists in their equations. When we do not know, we call it inflation, dark matter or dark energy to fit our hypotheses. When we find that the red shift may mean age instead of speed, thereby disagreeing with the Big Bang, the dogma quiets the investigations. The mainstream cosmology is not much different then the problems we have with global warming. If you do not believe, you will not be funded in your research.
It likely did. It is a delightful exercise to contemplate “NOTHING”. Not a vacuum, or space with nothing in it, No Space, No time, No Nothing! It is quite a task to image Nothing.
From that very difficult abstraction, we don’t simply get “something” as you put it Earl. We get Everything.
We get, all of physics, we get the concept of Math, we get ideation, we get space, we get time. we also get the paradoxes.
Until something better comes along, the discipline of science requires respect of the big bang theory.
Here is Leonard Susskind stating his 4 possibilities to the explain the basis for the big bang and our fine-tuned (knife edge) anthropic universe: He is deeply and surprisingly honest.
Time stamps:
3:25
6:05 ( God, accident, Who knows, we’ll never know exactly within infinite possibilities)
Early universe acoustics and quantum theory imply an infinite universe in which the big bang never occurred or was a ” local ” event. http://m.livescience.com/49958-theory-no-big-bang.html
I heard about this theory. It has the disadvantage of not having any evidence and is speculative of “before” big bang(s). IMO, it is an attempt to circumvent the obvious implication of a first cause.
Read the post. Laws of physics break down before the singularity of the big bang occurs. The theory is an attempt to unify quantum physics with relativity. This is subsequent to the acoustic and other observations which imply a universe infinite in size. http://www.extremetech.com/extreme/174427-astrophysicists-create-the-first-accurate-map-of-the-universe-its-very-flat-and-probably-infinite
JimG1 OK Man. I will read it but I am busy for a few days. I will get back to it.
astrophysicists-create-the-first-accurate-map-of-the-universe-its-very-flat-and-probably-infinite
=========================
now there is a contradiction.
One day Nothing added nothing to nothing and nothing plus nothing equals everything…..or something like that. Right?
I have a table booked to watch it happen.
There will be a big band as well,
to play it all out.
Oh! the very thought of it.
I have my towel too.
I always get the table nearest the window.
“The only way to do this is to use powerful computers to analyze the complex equations numerically. In this fashion the scientists can make predictions that can be compared with experiment and observation.”
Let’s hope they make those comparisons and disgard those models when they don’t jive. Doesn’t happen in all disciplines.
so all the CO2 molecules will be ripped apart?
This is another HOW TO.
The inescapable reality, whether it is big Bang to accelerated Fizzle, or otherwise, the end result is completely consistent with the Borde Vilenkin, Guth theorem.
Not sure how the “viscosity” in this article interacts with the overall geodesics.
Here is Alex Vilenkin presenting the theory. Only 8 minutes.
Isn’t that a quaint concept. So I would imagine that when the computer prediction fails to match observation then one of two things can happen.
1. If their grant and/or job depends on the model correctness, then the observations are wrong and they need adjustments, cherrypickings, and dubious statistcal treatments.
2. They can be honest scientists and say, “Our model was apparently wrong. We’re not sure why at the present. There is something(s) fundamental to the problem we don’t understand.”
Now when literally Trillions of future Euros, Pound sterling, and Dollars in new taxes to be controlled and spent depend on #1, is there really any doubt about the lengths and depths of depravity that science will be subordinated a Big Lie?
Coming soon to a University near you!:
Who knew that the universe had a reservoir tip?
I feel a big rip coming on…..wait for it! Oh….crap.
It’s hopeless, but not serious.
“The only way to do this is to use powerful computers to analyze the complex equations numerically. In this fashion the scientists can make predictions that can be compared with experiment and observation”
Um.. what ‘experiment and observation’ do they have in mind?
Grant App version 2 “We want a million dollars per year, inflation proofed, for 8.5 billion years, to show that our computer models are correct …”
The viscuous universe might have to rip, just as long as the BBT doesn’t RIP. (;
The method:
“The only way to do this is to use powerful computers to analyze the complex equations numerically. In this fashion the scientists can make predictions that can be compared with experiment and observation.”
Processing and teasing noise from space or particle collisions until the proper curve is found, and handing out PhDs for all of the computer work is the new science.
Here is a basic question. Does the speed of light vary with the density of the universe?
Disconzi, “since it is well-proven experimentally that nothing can travel faster than the speed of light.”
Photonic phase travels faster than the speed of light.
“… disastrously wrong” in this context stated by the scientist is a bit too colorful, no? In that this has little to do with much presently.
I’m sure that the EPA will try to blame CO2 somehow.
A few decades ago it was the BIG Crunch as gravitational forces overcame the expansion and the Universe contracted to a Singularity. Then another Bounce into a new Universe.
Now its the Big Rip due to Dark energy and Dark Matter that we recently discovered.
And it another few decades it will be the BIG THINGAMAJIG.
I’ve put it on my calendar in the year 2,000,000 AD to check up on those predictions. Then I’ll feel I should start worrying.
According to the diagram, after Earth explodes, galaxies are destroyed, and atoms are ripped apart, time’s arrow flies on for another c8-9 billion years, which should give them time to refine their work, or at least draw a more accurate diagram.
But at least you are here lines up with now, so they may be on to something.
I thought methane was the cause of a big rip.
Oh noes…. another tipping point.
Maybe Dark are just the stretchmarks of the universe. A little vitamin E on them and we’ll be good for another few billion years.
OK, I’m done. 😉
Hippy Revelator Zeus Moses Guy fades in from white, to the sound of choral singing, to answer some questions about the Big Bang.
https://youtu.be/nVsHjnY-o9s?t=2m33s
The answer is: Your question is meaningless. 😀 😉
Probably the Jesuit Priest Georges Lemaître got the Cosmic Egg from Ovid.
The Cosmic Egg broke.
So in that case, it all ends with Ovid’s Section IV Book XII–Book XV (end, line 879):
Rome and the Deified Ruler
Stay tuned for that.
>>Probably the Jesuit Priest Georges Lemaître got
>>the Cosmic Egg from Ovid.
Actually, he probably got it from the Egyptians. The Cosmic Egg was the egg of the Phoenix, which was cognate with the Primaeval Mound. And the Primaeval egg-mound broke open at the birth of the universe to reveal the Sun. And the Phoenix will return every 2,140 years, to engender the birth of the new revitalised Sun.
http://riverbankoftruth.com/wp-content/uploads/2013/04/735238_253269324803451_264192963_n.jpg
What emerged from the Cosmic Egg in the case of the Big Bang Theory, though, is:
Gravity – let’s name it Nephalim, for the Hebrew word “to fall”
Time – go with Chronos
Darkness – how about Apollyon or Abaddon
Chance – O Fortuna, perhaps Eris
And together they created everything.
Nice cyclic Egyptian touch too, I really like the Cosmic Egg with the Bird.
>>Nice cyclic Egyptian touch too,
>>I really like the Cosmic Egg with the Bird.
The story of the rejuvenation of the Phoenix was actually an account of the precession of the equinox. As the Earth precesses on its axis, it causes the zodiac constellations to move through the vernal point, with a new constellation appearing every 2,140 years or so. This was the rejuvenation event of the cosmic Phoenix, when a new Great Month began.
The Phoenix’s last change in the zodiac was in AD 00. So the year now is not 2015 Anno Domini, it is actually 2015 of the Great Month of Pisces – and we stand at the ‘Dawn of the Age of Aquarius’.
5th Dimension, Age of Aquarius. – love the ’60s fashions.
Ralph
Ralfellis says, “Dawning of the Age of Aquarius”
No, no noo no, not sixties racket! Not hippy chicks!
Anything but that! I give up! You win! (:
Anyways, ralfellis, the ancient Egyptian constellations from the Dendera figure here:
http://mainfacts.com/_files/_zodiac/calendar.jpg
I try to collect ancient constellations, but tradition has preserved mainly the Greek Ptolemy’s, for the most part.
Just for fun, the Etruscan Liver of Piacenza divides the sky into 16 sections.
http://hilobrow.com/wp-content/uploads/2014/11/piacenza_liver_commons.jpg
>>the ancient Egyptian constellations from the Dendera figure here.
Indeed. Pisces top right. Aquarius the very top. Followed by Capricorn.
The change I like, is that the northern Europeans did not know what a hippo was, so they called it a bear – Ursa Major.
.
Egads! Look at all that Greek graffiti.
Thanks ralfellis, you just converted me to the late date for the construction of that temple and bas relief. 50 BC under the Ptolemies, plainly. (:
Those quantum physicists are such a riot. I haven’t stopped laughing about the big bang, and now the big rip! I will just break out laughing in public whenever I think of it.
>>It may also shed new light on the basic nature of dark energy/matter.
I prefer the idea that gravity varies with distance. Elegant solutions are normally the best.
R
Well I hope they are not using the words “new light” in relation to anything in the physical universe.
“Light” is defined in “The Science of Color” published by the Committee on Colorimetry of the Optical Society of America; which was one of the original founding bodies of the American Institute of Physics.
And it is defined as “The psycho-physical response of the human eye and brain to the stimulation by electro-magnetic radiation in a narrow one octave bandwidth from about 400 to 800 nm wavelength.”
So “light” is all in your head and can’t be shed on anything.
Same goes for all of the human senses. They may be stimulated by physical processes; but they are not identical to those physical processes.
Which is why a tree can fall in the forest and not make a sound. You need somebody with functioning ears to turn the acoustic compression longitudinal waves in the forest into a functioning ear and brain’s response as a sound.
People without functioning ears, hear NO sound when a tree falls in the forest, even when they are there. So clearly it is the ear which makes the sound, and not the tree.
“And it is defined as “The psycho-physical response of the human eye and brain to the stimulation by electro-magnetic radiation in a narrow one octave bandwidth from about 400 to 800 nm wavelength.”” ~george e smith
Any receptor that is finely tuned enough to pick up this spectrum of wavelengths is a genuine antenna. That is not “all in your head,” but is extraordinary biological signal reception.
An antenna must be precisely one half or one wave length to be excited by an em wave.
Half Wave Dipole Antenna
One of the most commonly used antennas is half a wavelength long.
http://reviseomatic.org/help/2-antenna/Antenna-wave-diagram.gif
The insects that find each other, even when up wind, are likely doing so by receiving the em emissions from pheromone molecules, rather than by the sense of smell.
Well Zeke,
“””””…..“Light” is defined in “The Science of Color” published by the Committee on Colorimetry of the Optical Society of America; which was one of the original founding bodies of the American Institute of Physics. …..”””””
Why don’t you go and take that up with them. I simply reported what they say.
Would you like me to go and open that Text book and see if I can scan their exact words, without destroying the binding of the book ??
So what structures in the retina of the human eye are half wave antennas; which I guess you would argue must be from 200 to 400 nm long ?
“””””……An antenna must be precisely one half or one wave length to be excited by an EM wave.
Half Wave Dipole Antenna
One of the most commonly used antennas is half a wavelength long…….”””””
So which of these two conflicting assertions do you wish to keep ??
An antenna MUST be PRECISELY one half or one wavelength ……
or One of the most common used antennas is half a wavelength long ……
Where would I be able to purchase a half wave antenna for the Loran C signals.
The carrier frequency is 100.000 kHz, so I guess a half wave antenna would be about 1500 metres long.
My Loran C antenna is only eight feet long, and it seems to work ok.
And I do have a B Sc. degree in Radio-Physics so I’m at least a little familiar with antenna theory; but thanks for the instruction.
And my FM radio half wave dipole antenna just sits on my wall, and it neither lights up nor makes a sound, even though I know for sure it is detecting FM radio broadcast signals.
I wonder why EM waves of all types are measured in ordinary physical units of energy or power or the densities of those; but for some strange reason, the very same people quantify “light” in units of Photometry, which are completely separate from those used for EM waves.
Here just for reference is the exact wording from the text book.
” Light is the aspect of radiant energy of which a human observer is aware through the visual sensations which arise from the stimulation of the retina of the eye. ”
They then (immediately) go on to add:
” Light as thus defined is a psychophysical concept.
Light is not identified with either radiant energy or visual sensation. ”
Well I won’t retype the entire text book. You can buy your own copy from Amazon if you want to learn more about light or color.
Note the above definition even restricts the observation of “light” to just humans.
We don’t know just what lobsters “see” , and there’s more critters that look like them than look like us.
Forgot to mention that my Radio-Physics Professor; Dr. Karl Kreielscheimer (long since late) was an acknowledged expert on Antenna Theory.
Didn’t know anything about transistors though.
g
“””””…..
I don’t know. Help me out george. Is it a series-tuned circuit? ……”””””
No Zeke, it isn’t a tuned circuit, at all.
An EM wave travelling in free space can be characterized for “signal strength” by the RMS volt per meter strength of the electric field vector (assuming here the simple case of say an on / off Morse code signal). Well it will usually be at levels of microvolts per meter.
The system can be represented as an RF signal generator at some specific frequency and some specific uV / m with the source impedance of that generator being resistive (voltage and current in phase) with a resistance value of about 377 ohms.
That is the characteristic impedance of free space, calculated from:
R = sqrt (mu-nought / epsilon-nought) Where mu nought is the permeability of free space with a value 4pi E-7 Vs / Am (volt seconds per amp meter)
And epsilon nought is the permittivity of free space with a value 8.85418781762 E-12 As / Vm (amp seconds per volt meter).
M\mu nought and epsilon nought have exact values; the error is zero. They are two of the only three physical constants that have exact defined values.
If you multiply mu-nought by epsilon nought and take the square root, then invert it you get the value 2.99792458 E +8 m/s which just happens to be (c) the velocity of EM waves. That is the third physical constant with an exact value.
So we now have space as an EM wave generator with a source resistance of 377 ohms putting out so many microvolts per meter for the electric field vector RMS value.
Now any “tuned” antenna, also has a purely resistive “radiation resistance” that determines what level of EM electric field it will generate from a given RMS AC current in the antenna or verse vicea for a receiving antenna.
A “short” antenna which is any antenna shorter than the resonant half wave for that antenna, now exhibits a capacitive antenna impedance, and that is particularly true for a very short antenna like a Loran C antenna. An 8 ft Loran whip antenna is simply a few (10-30) pF capacitance in series with the free space generator and the 377 ohms space resistance.
And you can calculate the induced current in the short antenna from i = C dV/dt so the only thing a Loran antenna needs besides being as high as you can put it (on your boat) is a whole lot capacitance and hence lots of metal.
Many years ago, I outfitted a well known prominent Tarpon fisherman with a Loran C nav system, so he could record where the tarpon were actually running on the flats down in the keys and other locations. Now you can’t fly cast with any 8ft stick poking up in the sky on your boat.
But this chap had his flats boat built with a “boxing ring” in the middle of it.
An elevated platform maybe five feet square standing on top of a single aluminum metal tube, and all made out of welded aluminum tubing with ropes so he could stand on an elevated platform in the middle of his boat , protected by safety ropes all around, and literally cast in any direction with no impediment, and a good elevated view of the fish in the water. He wanted no part of any 8ft whip antenna.
So his welded aluminum bull pen was mounted on fiberglass reinforcement in the bottom of his boat so it was electrically insulated from the boat and the water.
So it was a perfect mass of metal with a lot of capacitance to free space. So we tucked his Loran antenna coupler, under the elevated deck, where his fly line couldn’t tangle on it, and then electrically connected it to all that fancy tubing.
It made a perfect Loran antenna with no sky blocking at all.
The first week we tried that thing out, my fishing guide was on the radio now and then asking the guide running “Billy’s” boat; “Say how is that fancy phased array working out for Y’alls ??”
Well the “phased array” was nothing but a bunch of aluminum tubing with lots of capacitance to free space. The chap is now at the big fishing hole in the sky, so I can tell the secret of how he kept track of those tarpon runs.
But bottom line Zeke, is that I don’t really care if you want to say that “light ” is an EM wave. Doesn’t bother me a bit.
I don’t even care if people want to wander out onto the railroad track playing with their finger toys, while the train is running them down. To each his own.
We invented language to communicate with each other. Then we all invented our own languages so we couldn’t communicate with each other.
Some people think ebonics is a communication system. Well it depends on who you don’t care to communicate with.
I find it easier to communicate if I use words that have generally agreed on meanings,tht are well thought out.
g
And I don’t care if you think light is defined as a psychophysical concept either.
“Where would I be able to purchase a half wave antenna for the Loran C signals. The carrier frequency is 100.000 kHz, so I guess a half wave antenna would be about 1500 metres long.
My Loran C antenna is only eight feet long, and it seems to work ok.”
I don’t know. Help me out george. Is it a series-tuned circuit? Electrical shortening and lengthening of the antenna or waveguide so that it matches the length of the incoming wave is accomplished by placing a coil and an adjustable condenser in series with the antenna. That way the same antenna can tune electrically to fit waves from 4″ to 33′ long.
But most antennas are cut to half or quarter wavelengths – whole, half or quarter. Then you have electrical resonance and the antenna receives.
Light is an em wave.
http://1.bp.blogspot.com/-s5V9o45d4kA/VIB8Ip-IX4I/AAAAAAAAE1M/vEU-_KbEO3Q/s1600/ems_length_final.gif
Now we can look at space, yay.
http://imagine.gsfc.nasa.gov/Images/science/observatories_across_spectrum_labeled_full.jpg
My intent was to point out how exquisitely tuned biological systems must be to be able to utilize em waves. Now that the technology is understood, it is possible to see that nature already uses antenna technology.
Phil Callahan:
http://gaiaqi.net/Antenna_Theory/AntennaTheoryImages/CallahanNatureAntennaFig11.jpg
You know george, Dr. S was talking about using the underground pipe systems of cities as receivers for VLF or ELF, I think.