In a moment of serendipity, Verschuur found that his contour radio maps of cold hydrogen in interstellar space seem to fit the false-color speckled microwave background pattern (shown above). It's like a child putting a puzzle piece into a pre-shaped slot.
Peaks in the foreground radio emission appear to overlay the peaks in the warmest region of the background, or appeared slightly offset.
In 2007 and 2010, Verschuur published a list of over 100 apparent matches between the CMB pattern and his interstellar hydrogen pattern.
Verschuur would have dismissed this as an odd coincidence until he realized that small interstellar clouds of hydrogen collide and jostle electrons to generate high-frequency radio emissions.
Like other foreground sources this would overlay the CMB. Because the WMAP team didn't consider or know about the contribution of such a phenomenon they didn't try and subtract it as they did numerous other electromagnetic "contaminants" in their data reduction, says Verschuur.
If Verschuur's theory is correct, the consequences would send seismic waves through the cosmology community. It implies that at least some of the small-scale structure in the CMB map doesn't exist at all.
But hold on. Detailed analysis of the angular diameter of CMB blobs yield a power spectrum that exactly fits theoretical predictions. The first peak in the spectrum shows a geometrically flat universe. The next peak determines the density of normal matter. The third peak provides information about the density of dark matter. And it all fits together beautifully.
Verschuur shrugs off the interpretation, saying that astronomers can analyzed the data and then stop when, "they find what they are looking for.
Cosmologists have also said that Verschuur's claim needs a detailed statistical analysis. But Verschuur is equally dismissive: "astronomers who study interstellar structure do not use statistics to show associations between different forms of matter ... they go by what the data look like."
Astrophysicists Kate Land and Anze Slosar conducted an analysis of Verschuur's study that was published in the Dec. 10, 2007, edition of The Astrophysical Journal. In an email to Wired, they concluded that Verschuur's correlation of the radio emissions from nearby hydrogen and the WMAP data was nothing more than a coincidence.
"Notoriously, by eye, one can often think they see correlations between patterns," Land told Wired. "But one doesn't really see the anti-correlations. So two maps (of the sky) that just fluctuate randomly can appear correlated."
This wouldn't be the first time that random fluctuations in the CMB have led researchers to claim that they have seen patterns, only for their claims to be refuted and found flawed.
Observations from the European Space Agency's Planck mission that is now measuring the CMB promises to yield a more detailed all-sky map than WMAP. Assuming the datasets between the missions agree at some level, this would rule out Verschuur's claim as simply being an over-interpretation of his radio observations - agreeing with Land's 2007 rebuttal.
However, if Verschuur is right, WMAP cosmologists might not have seen the forest for the trees.
Image credits: NASA, G. Verschuur