A new use for logarithmic mapping.
When talking about the pale blue dot that is our Earth, Carl Sagan once said: “It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.” That image was taken by the Voyager 1 spacecraft on February 14, 1990 from more than 4 billion miles (6 billion kilometers) away. At the time, it seemed an incredible feat to have such an image that made us feel so tiny and trivial.
The image below is far more mind-boggling. It is an image of the entire known universe created by Pablo Carlos Budassi using images from Princeton University and NASA.
Photo credit: Pablo Carlos Budassi
The original map that Budassi modified came from the Princeton team, led by astronomers J Richard Gott and Mario Juric, who used data from the Sloan Digital Sky Survey. Over the past 15 years they have used a 2.5-metre, wide-angle optical telescope at Apache Point Observatory in New Mexico to create the most detailed three-dimensional maps of the Universe ever made.
Most maps that we use are linear. Every distance increment on the map is equivalent to a proportional real distance. What makes this map so special is that it uses a logarithmic scale. This means that distance increments get smaller and smaller — by factors of ten — as you near the edges of the map. It makes it far easier to show incredibly huge distances on the same map as smaller ones.
Budassi had the idea to create the map circular while making hexaflexagons — really neat paper folding that I encourage you to take a look at — for his son’s birthday present: "I started drawing central views of the cosmos and the Solar System. That day the idea of a logarithmic view came, and in the next days I was able to [assemble] it with Photoshop using images from NASA and some textures created [on] my own," he told Tech Insider.
Some of the main things to look for in the image are our solar system in the middle, the Kuiper belt, the Oort cloud, the Alpha Centauri star, our galaxy (the Milky Way), other nearby ones like Andromeda, as well as the cosmic web, cosmic microwave radiation, and invisible plasma produced by the Big Bang.
The diameter of the observable universe is about 93 billion light-years (or about 558 trillion miles or 898 trillion kilometers), so fitting it all in a single picture is absolutely astounding. Calling it the observable universe might be a tad confusing however. Observable isn’t suggesting that that we can actually see it with our current astronomical instruments. Rather, it's the distance that the oldest photons have had a chance to travel. The entire Universe is hypothesized to be about 1023 times larger.
Although we don’t know what lies beyond this boundary, scientists have made many predictions. For all we know, it could be pretty much the same as what is inside the boundary. Maybe some day we’ll have a picture of far more of it. Although, it keeps expanding so we’ll still be missing a lot.