≡ Menu

New CMB Measurements Support Standard Model

The measure of polarized light from the early Universe allowed researchers to better plot the location of matter - the left image - which later became the stars and galaxies we have today. Image Credit: Sarah Church/Walter Gear

New measurements of the cosmic microwave background (CMB) – the leftover light from the Big Bang – lend further support the Standard Cosmological Model and the existence of dark matter and dark energy, limiting the possibility of alternative models of the Universe. Researchers from Stanford University and Cardiff University produced a detailed map of the composition and structure of matter as it would have looked shortly after the Big Bang, which shows that the Universe would not look as it does today if it were made up solely of ‘normal matter’.

By measuring the way the light of the CMB is polarized, a team led by Sarah Church of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University and by Walter Gear, head of the School of Physics and Astronomy at Cardiff University in the United Kingdom were able construct a map of the way the Universe would have looked shortly after matter came into existence after the Big Bang. Their findings lend evidence to the predictions of the Standard Model in which the Universe is composed of 95% dark matter and energy, and only 5% of ordinary matter.

Polarization is a feature of light rays in which the oscillation of the light wave lies in right angles to the direction in which the light is traveling. Though most light is unpolarized, light that has interacted with matter can become polarized. The leftover light from the Big Bang – the CMB – has now cooled to a few degrees above 0 Kelvin, but it still retains the same polarization it had in the early Universe, once it had cooled enough to become transparent to light. By measuring this polarization, the researchers were able to extrapolate the location, structure, and velocity of matter in the early Universe with unprecedented precision. The gravitational collapse of large clumps of matter in the early universe creates certain resonances in the polarization that allowed the researchers to create a map of the matter composition.

Dr. Gear said, “The pattern of oscillations in the power spectra allow us to discriminate, as “real” and “dark” matter affect the position and amplitudes of the peaks in different ways. The results are also consistent with many other pieces of evidence for dark matter, such as the rotation rate of galaxies, and the distribution of galaxies in clusters.”

The measurements made by the QUaD experiment further constrain those made by previous experiments to measure properties of the CMB, such as WMAP and ACBAR. In comparison to these previous experiments, the The QUaD experiment, located at the South Pole, allowed researchers to measure the polarization of the CMB with very high precision. Image Credit: Sarah Churchmeasurements come closer to fitting what is predicted by the Standard Cosmologicl Model by more than an order of magnitude, said Dr. Gear. This is a very important step on the path to verifying whether our model of the Universe is correct.

The researchers used the QUaD experiment at the South Pole to make their observations. The QUaD telescope is a bolometer, essentially a thermometer that measures how certain types of radiation increase the temperature of the metals in the detector. The detector itself has to be near 1 degree Kelvin to eliminate noise radiation from the surrounding environment, which is why it is located at the frigid South Pole, and placed inside of a cryostat.

Paper co-author Walter Gear said in an email interview:

“The polarization is imprinted at the time the Universe becomes transparent to light, about 400,000 years after the big bang, rather than right after the big bang before matter existed. There are major efforts now to try to find what is called the “B-mode” signal”  which is a more complicated polarization pattern that IS imprinted right after the big-bang. QuaD places the best current upper limit on this but is still more than an order of magnitude away in sensitivity from even optimistic predictions of what that signal might be. That is the next generation of experiments’s goal.”

The results, published in a paper titled Improved Measurements of the Temperature and Polarization of the Cosmic Microwave Background from QUaD in the November 1st Astrophysical Journal, fit the predictions of the Standard Model remarkably well, providing further evidence for the existence of dark matter and energy, and constraining alternative models of the Universe.

Source: SLAC, email interview with Dr. Walter Gear

Comments on this entry are closed.

  • Anaconda November 5, 2009, 5:30 PM

    DrFlimmer wrote: “Ah, so sometimes NASA is right and sometimes NASA is just wrong….. that is convenient…..”

    Do you have any specific objections to NASA’s explanation of electromagnetism in space?

    See, that’s the difference, you won’t even challenge NASA because…well…you know they are right regarding electromagnetism in the solar system.

    On the other hand, I’ve been specific about my disagreements with “dark matter”, “dark energy”, the “big bang” and “black holes” and all the rest, over the course of these ongoing comments on this website.

    DrFlimmer, do you think a person or an organization can be right about specific issues and wrong about other issues?

    Or are they either right about everything or wrong about everything?

    If so, I suggest that is a simplistic world-view.

    Obviously, NASA has access to copious in situ satellite probe observations & meaurements regarding the solar system.

    Again, DrFlimmer, do you have specific objections to NASA’s interpretations & analysis of the in situ observations & measurements?

    NASA is like everybody else when it comes to remote observation & measurement outside the solar system.

  • Anaconda November 5, 2009, 5:33 PM

    @ Crowell:

    Again, thanks.

  • Anaconda November 5, 2009, 5:38 PM

    From the NASA link:

    “…the entire Universe was contained in a single point in space.”

    How much volume does “a single point in space” have?

    I’m still waiting for an answer…

    crickets chirping…

  • DrFlimmer November 5, 2009, 5:47 PM

    I have no objections, as you might have noticed.

    The thing is, that it really seems like Nereid is right. And that is the problem.
    As you might have noticed, as well, I was trying to be ironic with my statement…..

    How much volume does “a single point in space” have?

    Depends on the space it is in, I guess. In a zero-dimensional space its volume should be infinite……

  • DrFlimmer November 5, 2009, 5:48 PM

    Btw: I know exactly what will happen next….

  • Lawrence B. Crowell November 5, 2009, 6:16 PM

    DrFlimmer,

    In a sense that is right. A projective space is thought of as the blow up of a point. So any point has associated with it a projective geometry, which is infinte.

    When it comes to Anaconda, you still have not answered the question about the impedance of free space. Jeez, at this point you could probably look this up somewhere.

    This thread is about to sunset off page one here. I have abandoned the filament thread on page 2. This is chewing up too much time. I will look tomorrow to see if my question is anwered.

    LC

  • Anaconda November 6, 2009, 2:32 AM

    Crowell asks: “When it comes to Anaconda, you still have not answered the question about the impedance of free space.”

    Off hand, I don’t know.

  • IVAN3MAN November 6, 2009, 3:20 AM

    @ Anaconda,

    For someone who claims to know a lot about plasma cosmology, you display little knowledge of the basics of general physics.

    You would be well advised to enroll yourself into a real university, like DrFlimmer has, instead of parroting that EU/PC rubbish, which you obviously learned by rote from that Thunder[bollocks].info group! Just a suggestion.

  • Lawrence B. Crowell November 6, 2009, 6:03 AM

    Anaconda,

    This is further telling. On the impedance of free space we start with the two Maxwell equations

    curlE = -&B/&t

    curlH = J + &D/&t

    curl V, for V a vector is the determinant of partial derivatives, & = partial. J is a current and E and B are the electric and magnetic fields, D is the electric displacement field:

    D = eps*E eps= dielectrtic constant

    and H is the magnetization field:

    H = B/mu, mu = magnetic permittivity.

    Ok take the curl on both sides of curlE = -&B/&t,

    curl curl E = -&(curl B)/&t

    Now use some vector identities and substitute in curlB = mu*curlH and use the second of these equations. Now assume a plane wave solution E, B ~ exp(ikx – iwt) with a dispersion that frequency w = kc, for c the speed of light, which above I set to unity (it is common to set c = 1 until later) and you find an equation of the form

    E = eps*c*J

    This is a form of Ohm’s law and the resistance is R = eps*c = sqrt(eps/mu). You can fill in the details.

    It is clear that to understand these things you really need to take the appropriate course work and maybe get a degree, at least an undergraduate degree. Then you might actually understand something rather than just parroting a lot of jargon.

    LC

  • Popisfizzy November 8, 2009, 3:48 PM

    I just want to point out that if Anaconda thinks he’s going to proselytize the masses who know not of his hypotheses, he’s going to have trouble considering it’s at least one guy (if not more) with a Ph.D. and [b]the very website he’s preaching[/b] along with a handful of other people against one guy who seems to be frothing at the mouth about the idea of anyone believe things he doesn’t like.

    So, yeah, he’s probably not going to succeed. Hurrah for exercices in futility!

  • Popisfizzy November 8, 2009, 3:49 PM

    Gah, “the very website he’s preaching on” is what I meant. I wasn’t sure what method of mark-up this used.

hide