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Dark Matter and Dark Energy… the Same Thing?

by Fraser Cain on February 6, 2008

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Dr. Zhao
I’ve said it many times, but it bears repeating: regular matter only accounts for 4% of the Universe. The other 96% – dark matter and dark energy – is a total mystery. Wouldn’t it be convenient if we could find a single explanation for both? Astronomers from the University of St. Andrews are ready to decrease the mysteries down to one.

Dr. HongSheng Zhao at the University of St. Andrews School of Physics and Astronomy has developed a model that shows how dark energy and dark matter are more closely linked than previously thought.

Dr Zhao points out, “Both dark matter and dark energy could be two faces of the same coin. “As astronomers gain understanding of the subtle effects of dark energy in galaxies in the future, we will solve the mystery of astronomical dark matter at the same time.”

Just a quick explainer. Dark energy was discovered in the late 1990s during a survey of distant supernova. Instead of finding evidence that the mutual gravity of all the objects in the Universe is slowing down its expansion, researchers discovered that its expansion is actually accellerating.

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Dark matter was first theorized back in 1933 by Swiss astronomer Fritz Zwicky. He noted that galaxies shouldn’t be able to hold themselves together with just the regular matter we can see. There must be some additional, invisible matter surrounding the regular matter that provides the additional gravitational force to hold everything together.

And since their discoveries plenty of additional evidence for both dark energy and dark matter have been seen across the Universe.

In Dr. Zhao’s model, dark energy and dark matter the same thing that he calls a “dark fluid”. On the scale of galaxies, this fluid behaves like matter, providing a gravitational force. And in the large scales, the fluid helps drive the expansion of the Universe.

Dr. Zhao’s model is detailed enough to produce the same 3:1 ratio of dark energy to dark matter measured by cosmologists.

Of course, any theory like this only gains ground when it starts making predictions that can be tested through observation. Dr. Zhao expects the work at the Large Hadron Collider to be fruitless. If he’s right, dark matter particles will have such low energy that the collider won’t be able to generate them.

The paper was recently published in the Astrophysical Journal Letters in December 2007, and Physics Review D. 2007.

Original Source: University of St. Andrews News Release

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About

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay.

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  • princeLaharl

    You know, Newton discovered this inverse square Law, based on a simple algebraic equation. He used math to explain his Law, and math is a theory, The Theory of Numbers… Hmmm, this is getting interesting. Maybe there is some Imaginary Universe, like, U i = (U(-1)). Hey, maybe Universe has a trigonometric identity that makes it seem different, but it is actually the same thing. What if the Universe is a Sum of Riemman (or Riemann, wathever) of an infinite amouth of Universes, and so, of matter, wich, by the way, implies that matter could be created or destroyed…. Oh, what da’ I completely lost it, HAHAHA! I’m saying that classic Physics is wrong because its laws are based and explained by a theory. Man I’m not making sense at all…right???
    Sorry to poke your Einstein for a dull moment.

  • princeLaharl

    Sorry for the misspelling. AMOUNT it should say.

  • Pingback: » 20% Time 2/12 Mary’s Blog

  • Rick

    Seems to me that super string theory provides an approachable explanation as it posits the existence of all things, matter, energy, particles, waves and space/ time itself as manifestations of variations in string vibrations. If this line of reasoning is followed, it becomes possible to reconcile what appears to be contradictory into a unified description of “how stuff works” and what stuff is. It still leaves open the ultimate question of the origin of any and all of it. However, it is likely that the end of all inquiry will be but to arrive at the place whence it began.

  • John Tomassoni

    If the Big Bang really was, then before it happened, it must have been the biggest-baddest black hole ever. And if it was indeed a big black hole, then why did it destabilize and explode, or eject all of its contents? Is this ‘ejection’ finished? The contents and distribution of the universe suggests that this ‘ejection’ is ‘still’ going on, depending on the time scale due to light speed. Does this indicate/suggest that black holes (as we currently know them — they suck and do not spit) can explode or eject matter? And if they do explode or eject, is the result of this the start of a galaxy?

  • Cloy

    I asked sorta the same thing a couple weeks ago, John. Apparently we (myself included) say that the universe was started, not in space, but in a certain time.
    This is from what I understand.

    Think of the universe like a balloon. The “air” inside and around this balloon isn’t a place in space, but a place in time (the inside being the past and the outside being the future). When the balloon started swelling, that was the beginning of time. But as you know, balloons are hollow and the elastic isn’t found in the exact center of the balloon. All that’s inside it is air, or in this case, time. If your black hole, or an explosion existed to begin with, is not really likely unless the explosion expanded like a balloon.

    To answer your galaxy question, a supernova is what you’re thinking of. The intense explosion/implosion of a superstar scatters matter all around the universe, but due to the immense energy/gravity of the implosion, it then creates a black hole. Since the matter surrounding the black hole is traveling at an incredible velocity, it somewhat gets caught by the gravity and fights to be freed. Thus you get rotation and the birth of a galaxy. I understand that might not be quite the whole process, but thats the gist of it i guess. Someone correct me if i’m wrong.

  • http://www.universetoday.com Mark Younger

    I believe that the smallest possible space “particles” are actually the bosons of the gravitational field. It would explain many divergent theories. Space “particles” overlapping under massenergy density would explain space-time curvature, it would give a mechanism for gravitational waves and would unify general relativity with quantum mechanics. It’s really neat.

  • Murad Shibli

    Dr. Murad Shibli with the Aamerican University of Sharjah has proposed a new theory on dark energy and has been publihsed at IEEE and entitled as “The Foundation of the Theory of Dark Energy: Einsteinapos;s Cosmological Constant, Universe Mass-Energy Densities, Expansion of the Universe, a New Formulation of Newtonian Keplerapos;s Laws and the Ultimate Fate of the Universe”. For more information please visit the following link.

  • http://www.icrepq.com Murad Shibli

    Dr. Murad Shibli at the American University of Sharjah has proposed a new unified model on dark energy and dark matter. This model will b epresented at INTERNATIONAL CONFERENCE ON RENEWABLE ENERGIES AND POWER (ICREPQ 08 ) in Spain on March 12-14, 2008. The article presents a proposed equation of state of dark energy and dark matter as one unified entity. Such an equation is derived based on the assumption that dark
    energy and dark matter behave as a perfect fluid, the ideal gas equation, Boltzmann constant and the energy-mass
    principle of Einstein. As a result of that, it is found that dark energy and dark matter are not distinct, on the contrary, both dark energy and dark matter represent one
    unified entity. This agrees with the recent observations of NASA that dark energy and dark matter has close density values and in the range of 10^-26 kg/ m^3. The ratio between the energy density (in Joules) and the mass density (in kg/ m^3) are proportional to the Square of the Speed of
    light. Moreover, this ratio is found to be equal to the product of the space temperature and the dark energydark matter parameter (as a perfect fluid). An alternative presentation shows that the ratio between the dark energy
    and dark matter molecular density is proportional to Boltzmann constant. Furthermore, this approach might be
    useful to utilize the free source of energy associated with dark energy and dark matter at high temperatures. Finally, simulation for our milky way shows the validity of these results

  • Gerald Blancett

    If dark matter really existed, the amount of dark matter mass necessary to cause the observed irregularities would logically preclude the rapid expansion of the Universe that we now have. Furthermore, I cannot conceive of such a mass that would not have pulled itself together forming very large bodies. May I suggest that our observed irregularities could be “Space Time Warp Proportional Factor”; depending upon how close a body is to the center of the Galaxy? Gerald Blancett

  • Chuck Lam

    Maybe dark energy is continuely birthing dark matter. The dark matter in turn could be slowly coalescing into visible matter. And just maybe this mysterious dark energy and material could be the actual stuff of the “big bang.” Who said the “big bang” happened in a fraction of a second? Could it be the “big bang” was nothing more than this dark energy chaotically converting into invisible and than into visible matter in our part of a boundless universe and continues today? That might explain blue-shifted galaxies and the mind-bending hodgepodge of all that we see in the universe.

  • fuzzylumpkins

    is it possible that the universe began with a dark matter implosian?

  • idiot

    there is no universe. there is no matter. there is no energy. we are all just living in dreams.

  • Stephen Hobbs

    Electron Mass Me=9.1093818872e-31
    Proton Mass Mp=1.67215813e-27
    Neutron Mass Mn=1.6749271613e-27
    Difference in mass of proton and neutron is 2.7690312999999995e-30 (possibly the mass of an neutrino or quark. )

    1/3 mass of an electron is:
    Mx=3.0397576194394586

    Integerizing this slightly we can see the mass of a proton is very close to the mass of a neutron minus the mass of an electron, the rest can be possibly explained by energy release as some form of EM radiation and the kinetic energy required to keep the electron spinning around the nucleus, which may well be faster than the speed of light as if you read more carefully and correctly the equation E=mc² (wether correct or not is not the debate here) is possible as the speed at which all matter becomes energy is c² (not c as popularly misconstrued.)
    Mn/Mp=1.0016559625853087
    Is this the ratio of elementals in each particular particle.

    IF electron is base unit(1) then should be integer number within proton.
    Mp/me=1835.6439006576552
    IF electron is base unit(1) then should be integer number within neutron.
    Mn/me=1838.6836582770947
    Could actually say fractional part is due to error at this level and for ease of sums say:
    No. of electrons per proton is:1836
    No. of electrons per neutron is:1839
    As measurements increase in accuracy, there is a slight upward trend in the value of mn,mp and me but this is such that
    The trend suggests mn/me tends towards 1836 while mp/me tends towards 1836. As increase in descrepency on mp is greater than that in me This is only a difference of only 3 units which as postulated by Quark theory that an electron is a group of 3 quarks(-+-) grouping is rather suprising, that is to say that by removing the same 3 basic units of an electron from a neutron you’d get a proton.

    Even without rounding the figure is only:
    1835.6439006576552/1838.6836582770947=-3.0397576194395697 or to put it another way accounts for a pretty accurate 99.83467750932817% of the mass of the electron, considering the errors that could creep in on such small scales this is pretty damn fantastic I’d say and so far involves no special case maths and quite possibly simply follows the same rules as the rest of the universe!

    In fact these slight errors could be easily dismissed as errors in magnitudes of 10 from the true number of particles within each subatomic particle.

    For example would the same hold true to the figures if the unit of mass of the absolute small particle was not 1/3 of the mass of an electron… but by moving along the scale of the figure 3.03646062906… recurring, we could equally say this is 303 particles and the 0.646062906666..7 is the error. Would it still hold true for the rest of the workings to the same level of accuracy in that
    The proton+electron = neutron. AND neutron/mass of particle AND proton/mass of particle are whole numbers (near enough) and that these hold true to the numbers above in that
    particles/neutron = particles/proton + particles/election. And also that if particles/electron is odd then particles/neutron=even and particles/proton=odd.
    In a C program this could be written as fullfilling the requirements.
    (ParticlesPerNeutron==ParticlesPerProton+ParticlesPerElectron) &&
    ((ParticlesPerElectron & 1)==(ParticlesPerProton&1)) &&
    ((ParticlesPerElectron & 1)!=(ParticlesPerNeutron&1))

    This I will not go into here as there is no need, for the basic rule should follow of all the groups and subgroups within whatever particles are found until the ultimate singular particle is found (if indeed it ever can or will be and isn’t some singularity as some suggest blinking in and out of existence).

    In theory other conditions could be met too, such as ParticlesPerParticle should be able to fit in a perfect equal sided lattice of perfect spheres in each case, that’s assuming they are to be spherical and all equal in size, as there a lot of gumph on sub-atomic physics and it seems almost anyone can make it up but irrelevant of this I think it is most likely that the very very basic building block, no matter what it is would be spherical in overall effect as particulate form.

    Not spherical objects would defy most common sense of equal distribution due to equal forces throughout the singularity which is at least possibly the one thing most physisists can agree upon when dealing at the level of a single unit with no outside influences at all except its own internal binding, however completely unlikely or indeed impossible such a possibility would exist anywhere in the universe!

    A similar theory was postulated by the man who predicted the existence of quarks!

    The reason the “Dark matter” was invented is in fact that scientists are arrogant enough to think they can estimate the mass of the universe when they do not even know what percentage of it they can yet see, much like answering the conundrum:
    “On the other side of a piece of paper is a length of cotton, through a small hole you can see only 2 inches of the cotton, how long is the cotton in total and what percentage of the cotton can you see?”

    The whole problem with quark theory is how do you arrange only + and – in a clump so that there are no ++ interactions and no–interactions… when there is not another force at this “primary” level in fact it is theoretically and practically impossible.

    Going along this line obviously facilitates the need for a neutral particle in the model so either there is +- and neutral or just a minus and a neutral (or a plus and a neutral for that matter)

    In fact it feels better in the gut to think of a positron as having a “lack” of electrical charge than the opposite of it and so these are the neutral part. After-all it was at once standard scientific practice to measure the well know Volts as “Potential difference”.

    In fact though simple is possibly the best explanation that we have at present.

    An electron is thus a minus-nuetral-neutral combination as this is the only possible combination where there is no — repulsion from itself wherin it would tear itself apart.

    A proton is in effect 1836 of these 3 bit combinations and A neutron is in effect 1839 of these 3 bit combinations in this simple model.

    If we break this down further then the sum totals is 1839 (neutron):1839 (electron+proton).

    The proportion of these particles in the universe is thus most likely to be 1:1 in the universe.

    A “positron” is thus (N-N)
    An “Electron” is thus (-N-)

    A note on the apparent occurence of positrions in a Neutral-negative model. The effect of magnetism in one direction is the result on the interaction on a particle that is
    -N- or where charge outweighs mass. Whereas under reverse conditions when neutral particles outnumbercharged particles then the effect is reversed.

    Conclusion:For the above to happen all substances must have some effect under magnetism, even uncharged. [After looking this fact up]:This is found to be the case and so fits the results.

    From these figures I would conclude that there is a 99.83467750932817% chance that the explosive composition of the big bang was a 1:1 mix of “neutral” and “charge”, though what as the name is just that it could be the neutral is a plus and then negative is a 0 if you catch my drift. Whichever perspective you take on that, the ratio will be 1:1 for one to the other overall.

    Thus if you ask me, there are two points to be made, the big bang (if u believe in it) would of been a uniform explosion from that point of singularity. The quantity of mass in the universe would be about 1:1 charged to non-charged, including all forms (energy too I guess).

    As for the 90% inaccuracy, isn’t it a bit pompous to think we can guess the mass of an unknown volume of mass and energy, maybe it’s the 90% we can’t see or calculate for and even with our best efforts we are still only a tenth of the way to knowing what scale we are really dealing with.

    Time: Was einstein’s theory actually not trying to simply say, if something travels as fast or faster than light, it would APPEAR to do so instantaneously to us as viewers, well not instantly (wrong wording), we would not be visible until we reached our destination (that’s a better way of wording it)

    If I’m sat on a ship at light speed and I travel for one second of my time, that time still passed for me. It still passes for you too, but you can’t see me until I slow down again below the speed of the very light that our primative eyes use to detect our 3D environment. We as a species are limited to light speed or far less at present because we have no direct thrust sytem that can approach the forces required to attain any greater speed for much larger than small particles.

    Now at the quantum level we are told a similar ratio exists between pion and neutral-pions and still the theory holds true.

  • Stephen Hobbs

    On the subject of time. Is it not true that all forms of radiation are emitted from our sun, so what effect would that have on an atomic clock as it passed into the earth’s shadow?

    You would get a time “increase” reading on your clock in direct sunlight and this would be curved due to the simple fact that as your path approached 90 degrees to the stream it would cut through more of them (like rain in a moving car seems heavier effect). and then decrease again as you went into the shadows, peaking at an all time low directly behind the earth, but this effect due to distortion by atmosphere and earth’s mgnetic and gravitational effects would produce a non-circular distortion on our clocks reading if not continuously subtracting only the background influence on an identical counter at almost the exact same spot (or as near as can be).

    This effect would mean that our atomic clocks would show an effect of time increase and decrease effects as if time were distorted by the earth’s shadow.

    That would certainly explain a few “time” issues and the problems associated with the “time-gravity well” theory in that it does not quite fit!

    In fact it’s a bit like re-inventing the sundial but keeping track of it digitally then wondering why it loses time overnight if you can imagine such a scenario.

  • Stephen Hobbs

    LOL on time and how we change it as needed because it is an arbitary unit to measure our existence and events in it … time zones.

    The server says posted 8:47pm whereas my PC clock here in the UK says 4:47am

  • Chuck Lam

    Maybe the pre-universe void occupied by the present visible universe contained the “dark energy” of creation that is mystifying us. And the “dark matter” we detect currently could be a condensation of this primordial void energy into matter. Crazy? Maybe not! The estimated 3:1 ratio of “dark energy to matter” that probably existed at the start of the original “big bang” may explain the residual background heat detected today. Condensing the 3 of energy into the 1 of matter may be the case here and is still in progress, albeit, on a scale we simply can’t detect. The classic “bursting forth of matter from a single point” big bang theory is highly questionable. There appears to be entirely too much chaos in the universe for all matter to have “bursted forth from a single point.” A single point origination suggests there should be more uniformity of motion due to straight-line momentum. The accelerating expansion of the visible universe could be a “thinning our” of galixies resulting in a weaking of gravity producing the expansion effect. A bit like 32 fps/fps, only on a mind bending scale. Could be the universe hasn’t yet reached terminal velocity. I suspect we fail to see the simplicity of all that perplexs us in the visible universe.

  • almost clueless

    I am only in high school and do not know very much about this kind of stuff but I find it very interesting when I find out more things. But what if the big bang, “bursting forth of matter from a single point”, really did happen but was caused by antimatter colliding into matter, because I heard that if that happens there would be a humungous explotion. If this is true that could explain why the universe is expanding. Maybe we only see it as expanding but it is only stretching out. This could be causing the acceleration of the universe because the gravitational pull of everything is thinning out. The “explotion” caused by antimatter and matter colliding could have also created the dark matter and energy. It could be a product of anti- and matter meeting.

  • COWBOY

    A lot of what has been said has been very intriguing, although I have yet to see anyone mention a complete possibility. I offer an insight that has not been refuted to my knowledge.
    Take, c = the past, b = the present and a = the future, then time, as we perceive it goes in the direction of c, b, a. Time as we all know, has been around before us and when we got here our ancestors, up to us, have always perceived time as c, b, a. I submit that the fourth dimension (time), is the catalyst. An example of this would be when you are sitting in your car in the center lane and there are two cars on either side of you. The two cars on either side of your car move slowly and simultaneously backwards, you will perceive it as if you were moving forward, even though you are sitting still. Suppose time’s natural motion is to move through space as a, b, c, (in our perspective, reverse). This could get a little complicated, being that this would mean that we all know what is going to happen after the present, (our past) but we would not know what is going to happen before our present, (our future). Gravity has been shown to be getting weaker and disappearing from our universe in our perspective, but in my concept, gravity would be getting stronger and everything in our universe would be coming together and in about 13 billion years we will have a big collapse (BIG BANG).

  • cecilia

    wow, really sounds like “and Gd hovered over the waters”

    i don’t know guys, sounds like macroscopic electrochemicals to me. I like it.

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