Dark matter and dark energy are aspects of one force?

[yevaud]

<b>Theoretical Physics: Dark matter and dark energy are different aspects of a single unknown force</b><br /><br /><i>In the last few decades, scientists have discovered that there is a lot more to the universe than meets the eye: The cosmos appears to be filled with not just one, but two invisible constituents-dark matter and dark energy-whose existence has been proposed based solely on their gravitational effects on ordinary matter and energy.<br /><br />Now, theoretical physicist Robert J. Scherrer has come up with a model that could cut the mystery in half by explaining dark matter and dark energy as two aspects of a single unknown force.</i><br /><br /> His model is described in a paper titled "Purely Kinetic k Essence as Unified Dark Matter" published online by Physical Review Letters on June 30 and available online at http://arxiv.org/abs/astro-ph/0402316.<br /><br />"One way to think of this is that the universe is filled with an invisible fluid that exerts pressure on ordinary matter and changes the way that the universe expands," says Scherrer, a professor of physics at Vanderbilt University.<br /><br />According to Scherrer, his model is extremely simple and avoids the major problems that have characterized previous efforts to unify dark matter and dark energy.<br /><br />In the 1970s, astrophysicists postulated the existence of invisible particles called dark matter in order to explain the motion of galaxies. Based on these observations, they estimate that there must be about 10 times as much dark matter in the universe as ordinary matter. One possible explanation for dark matter is that it is made up of a new type of particle (dubbed Weakly Interacting Massive Particles, or WIMPs) that don't emit light and barely interact with ordinary matter. A number of experiments are searching for evidence of these particles.<br /><br />As if that weren't enough, in the 1990s along came dark energy, which produces <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[harmonicaman]

<p>For the longest time I've argued that "Dark Matter" and "Dark Energy" theries were completely seperate entities with absolutely no relationship to each other. With the recent discovery of dark matter and the revelation that it is likely comprised of something exotic, I've had to completely change my thinking...<br /><br />I've been giving the matter some thought and I now beliveve Dark Energy is related, or even the very same thing as Dark Matter.<br /><br />Here's something I posted earlier in another thread in an attempt to get my thoughts together...:<br /><br />**************<br />(Repost)<br /><br />Ever since this recent observation of "Dark Matter", I've been poring over all my old physics textbooks trying to find something cromulent which I can relate to this new and exciting discovery...<br /><br />What's been observed here may not actually be matter at all, but energy existing in another quantum dimension. (Just think of mass as a highly concentrated form of energy and converesly, energy as a highly diluted form of mass.)<br /><br />Stephen Hawking explains in his book, A Brief History Of Time that virtual photons are the force carrying particles of the electromagnetic field.<br /><br />As you increase the frequency of energy, you wind up with photons of more measurable mass:<br /><br />Planck's formula: E=hf where: <br /><br />E is the energy of a single photon, <br />f is the photon's frequency, <br />h is Planck's constant.<br /><br />Einstein's formula: E=mc2 where: <br /><br />E is energy, <br />m is mass, <br />c2 is the speed of light squared, <br /><br />hence; hf=mc2 <br /><br />thus showing that the mass of a photon is directly proportional to the frequency of the photon. <br /><br />(E=hf and E=mc2 so hf=mc2) <br /><br /><br />At the EHF end of the</p>

 

[observer7]

I like it.<br /><br />I have a thread "There is no dark matter" where I propose that the effect attributed to dark matter is really large scale curvature of space. It appears that this K-essense may be a way of describing just that. After all, any field approach describes a geometry on the space-time in a similar way to the metric tensor in GR. <br /><br />I like it.<br /><br />-- <div class="Discussion_UserSignature"> <em><font size="2">"Time exists so that everything doesn't happen at once" </font></em><font size="2">Albert Einstein</font> </div>

 

[search]

Yevaud<br /><br />Although a 2 year old article it is still a compelling view on dark matter. Thank you for bringing it to our attention. Most of the threads have concentrated more in dark matter than in dark energy and with your post you open up a new front for discussion and therefore help us all understand these latest misteries of cosmology. We look to the details like dark matter, dark energy, neutrinos, gravity, light and they are pieces of a puzzle.<br /><br />And like a puzzle: when all the pieces fit together then we will be able to see the picture.<br /><br />The real question is about Universe expansion and "acceleration".<br /><br />Although there is consensus in the expansion part there is still many sceptics over Universe acceleration. ( I am not one of them)<br /><br />Is it accelerating?<br />Why is it doing so?<br />How is it doing so?<br />Was it always like that?<br />Will it continue doing so?<br /><br />These five simple questions are puzzeling the brightest minds in the world and you can imagine what it does to everybody else.<br /><br />The complexity starts at the singularity that we so well know as Big Bang and like the Universe it only gets bigger (this does not denote anyhing against big crunch its just a figure of speech).<br /><br />Was (is) this singularity uniform (homogenous and isotropic)?<br />http://www.astro.ucla.edu/~wright/cosmo_01.htm<br />http://math.ucr.edu/home/baez/physics/Relativity/GR/centre.html<br />(this relates to the aspect of universe, clusters, galaxies, stars, inflation and CMBR)<br />Note: the "is" relates to the fact that some theories consider the Universe still being fed by the singularity it does not denote any opinion.<br /> <br />What is the Omega (what is the space curvature)?<br />(the answer t

 

[alokmohan]

There may be another cause .Universe is decelerating.In 1998,diastant supernova were receding.From there we knew it is huge percent of mass of Universe.http://www.sciencenews.org/articles/20010407/bob14.asp

 

[search]

Alokmohan good to ear from you<br /><br /><br />The article you give is actually pointing out that the universe is accelerating...but it also refers to dark matter and energy so the thread is still not stolen<br /><br />Here it is in an "openable" form:<br />http://www.sciencenews.org/articles/20010407/bob14.asp<br /><br />Here is a small problem on universe acceleration for those who like maths:<br />http://casa.colorado.edu/~ajsh/astr3740_04/prob6.html

 

[search]

I guess nobody likes maths...

 

[yevaud]

Actually, I found it very refreshing. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>