We go to the appropriate explanation:
1365: Inflation
The comic is inspired by the recent BICEP2 discovery of gravitational waves from the early universe, hence providing evidence for the cosmic inflation hypothesis. Megan is excited about this and tells Ponytail all about it. She is impressed by the fact that these waves were created when the universe was extremely small and the expanding universe has "imprinted" the gravity waves.
She compares this to the nature of a microscope - which optically expands a small image, just like the universe has done to itself. Ponytail is impressed by it until Megan looks at the image captured by the Wilkinson Microwave Anisotropy Probe (WMAP).
The concept of an expanding universe is sometimes explained by the "balloon model", where the two-dimensional skin represents our three-dimensional universe and the inflation of the balloon represents expansion over time. But instead of showing a balloon Randall uses a basketball which can not inflate that much like a balloon.
The elliptical Mollweide projection of this cosmic microwave background (CMB) image of the sky makes the map look a bit like a basketball. Randall emphasizes this by superimposing the traditional curves that are visible on a basketball and the Spalding company logo over the original image available at the bottom here.
Megan and Ponytail are both disconcerted by this, and the title text references the 1996 basketball movie Space Jam by promising images of main characters Michael Jordan and Bugs Bunny if the polarization of the view is changed to E-mode.et voila!
The image was updated between 7 AM and 8:30 AM EST on May 7. Originally the Spalding logo was shown from left-to-right; however, in the updated image, the Spalding logo is shown in reverse. The WMAP image has the correct orientation in both versions. This was likely due to a mistake on Randall's part, as the comic suggests the universe is contained inside a Spalding basketball. Seen from the inside, the Spalding logo would be shown in reverse, as seen in the updated image. The first image can be found here: inflation_first_verion.png.
Explain xkcd
HT: Techdirt
