New Map of the Universe's Matter Reveals Something Missing
- Institut Max Planck untuk Astrofisika
These ripples pushed away the matter that hadn't already been drawn into the center of a clump, where it came to rest as a halo around it. At that point, most of the universe's matter was distributed as a series of thin films surrounding countless cosmic voids, like a nest of soap bubbles in a sink.
Once this matter, primarily hydrogen and helium, had sufficiently cooled, it clotted further to birth the first stars, which, in turn, forged heavier and heavier elements through nuclear fusion.
To map how the cosmic web spins, the researchers combined observations taken with the Dark Energy Survey in Chile and the South Pole Telescope, which is located in Antarctica, and studies the microwave emissions that form the cosmic microwave background.
Although they looked at different wavelengths of light, both telescopes used a technique called gravitational lensing to map the clumping of matter.
Gravitational lensing is an excellent tool for tracking normal matter and mysterious dark matter. Although 85 percent of the Universe does not interact with light, except to distort it with gravity.
With this approach, the researchers used data from both telescopes to determine the location of the matter and removed errors from one telescope's data set, comparing it to the other.
The map of cosmic matter that the researchers produced closely matches our understanding of how the universe evolved, except for the difference that it is more evenly distributed and less clumpy than suggested by the standard model of cosmology.
There are two possibilities to explain this discrepancy. The first is that we are not looking at the universe very precisely and the apparent deviation from the model, will disappear as we get better tools to peer into the cosmos.
The second and more significant possibility is that our cosmological model is missing some seriously big physics. Figuring out which is right will require more surveys and cross-mapping, as well as a deeper understanding of the cosmological constraints that bind the universe.
