The afterglow of the oldest light in the universe — the light from when it was just a 380,000-years-old infant — can be seen in the form of an imprint called cosmic microwave background, or CMB. We can view and map CMB with instruments like the Planck satellite, but those maps remain hard to really dig into after we make them. Now, physicists have devised a brilliant solution to allow us to better view those maps — 3D printing them to create a tiny model of the early universe.
The new study, published today in the European Journal of Physics, means you’ll be able to literally hold the universe (a model of course, but you get the idea) in the palm of your hand. Dr. Dave Clements, from the Department of Physics at Imperial College London, said it will make an invaluable teaching tool that will help people visualize the universe in its entirety, and without being flattened and distorted. You can feel and see the variations in temperature, density, and type of matter.
In the earliest days of the universe, just after the Big Bang, things weren’t transparent the way they are now. Instead, the universe was a hot, cloudy mess from all the plasma and radiation. Light couldn’t escape through this density, and became trapped. CMB is thermal radiation that originated during recombination — protons and electrons combining for the first time to form hydrogen atoms — when the nascent universe began to thin out into the transparent form we’re familiar with today.
Because of this, it’s essentially a freeze-frame image of what the universe was like in those early stages — meaning we can study it to see the origins of what would later become stars, galaxies, and all other matters of astrophysical and celestial phenomena to develop in the coming billions of years.
As you’ve no doubt heard, the universe is still expanding. When we measure CMB, we can look at the composition of the universe in its entirety, and distinguish dark energy from dark matter, dark matter from regular matter (like planets and stars), and so forth. Mapping the trajectory of our universe, from infinitely dense to less dense, might give us an idea of what the future universe will look like.
You can download the files to make this yourself, assuming you have access to a 3D printer.
“We’re looking at photons,” said Clements, “that have been free-streaming towards us ever since the universe became transparent. I wouldn’t put it past somebody trying to whittle one out of wood. That’s also possible, but that’s going to be more of a craftsman job than what I can manage.”