The oldest light in the universe could soon provide the decoration for your bedroom, office, or Christmas tree, thanks to the work of a team of researchers from Imperial College London, who have 3D printed a spherical representation of the cosmic microwave background (CMB). The scientists have also made the files they used to print the model available for free online, so anyone with access to a 3D printer can now make their own copy.
The CMB is radiation left over from the period during which the universe first became transparent, roughly 13.5 billion years ago. This occurred as a result of a process called recombination, whereby protons and electrons combined to form hydrogen atoms for the first time.
Our most detailed maps of the CMB have been created by the Planck satellite, which scans the entire sky at nine different frequencies in order to detect subtle differences in the temperature of the CMB, caused by oscillations in the plasma of the early universe.
Hotter areas tend to be denser, and it was in these regions that the very first stars and galaxies formed.
“Presenting the CMB in a truly 3D form, that can be held in the hand and felt rather than viewed, has many potential benefits for teaching and outreach work, and is especially relevant for those with a visual disability,” explained Dave Clements from the Department of Physics at Imperial.
The fact that the model is spherical also makes it superior to existing maps of the CMB, which are normally viewed flat on a screen and therefore slightly distorted out of shape.
Temperature differences are manifested as changes in the contouring of the sphere, with hotter regions standing out and cooler areas appearing as hollows. “Representing these differences as bumps and dips on a spherical surface allows anyone to appreciate the structure of the early universe. For example, the famous 'CMB cold spot', an unusually low temperature region in the CMB, can be felt as a small but isolated depression,” explained Clements.
Details of how Clements and his colleagues produced the model are published in the European Journal of Physics.