https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&feedformat=atom&user=Gmarsden 2026-05-20T22:18:31Z User contributions MediaWiki 1.30.0 https://www.explainxkcd.com/wiki/index.php?title=1365:_Inflation&diff=66870 2014-05-07T16:46:05Z

<p>Gmarsden: /* Explanation */ wmap image was not reversed</p> <hr /> <div>{{comic<br /> | number = 1365<br /> | date = May 7, 2014<br /> | title = Inflation<br /> | image = inflation.png<br /> | titletext = Wait till they notice the faint reflection of Michael Jordan and Bugs Bunny in the E-mode.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|Added a basic explanation. Still needs some work.}}<br /> The comic is inspired by the recent {{w|BICEP2}} discovery of gravitational waves from the early universe, hence providing evidence for the {{w|Inflation_(cosmology)|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 &quot;imprinted&quot; the gravity waves.<br /> <br /> 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 {{w|Wilkinson_Microwave_Anisotropy_Probe|Wilkinson Microwave Anisotropy Probe}}.<br /> <br /> The concept of an expanding universe is often explained by comparing it with a basketball [https://books.google.nl/books?isbn=0691147310], where the leather skin represents our three-dimensional universe and the inflation of the ball represents expansion over time.<br /> <br /> The elliptical {{w|Mollweide_projection|Mollweide projection}} of most {{w|Cosmic_microwave_background|cosmic microwave background}} images of the sky make the maps look a bit like a basketball. [[Randall]] emphasizes this by superimposing the traditional curves that are visible on a basketball and the {{w|Spalding_(sports_equipment)|Spalding}} company logo over the original image [http://map.gsfc.nasa.gov/media/121238/index.html].<br /> <br /> They are both disconcerted by this, and the title text references the 1996 basketball movie ''{{w|Space_Jam|Space Jam}}'' by promising images of main characters Michael Jordan and Bugs Bunny if the polarization of the view is changed to {{w|B-modes|E-mode}}.<br /> <br /> 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.<br /> <br /> ==Transcript==<br /> <br /> [Megan sits at a computer, conversing with Ponytail.]<br /> <br /> Megan: Imprinted on the sky are the gravity waves that were sloshing across the universe when it was ''this'' big.<br /> <br /> Megan: So really, we're using the entire universe as a giant microscope pointed at itself when it was small.<br /> <br /> [Megan turns to face computer.]<br /> <br /> Ponytail: That's neat.<br /> <br /> Megan: Yeah. But...<br /> <br /> Ponytail: But what?<br /> <br /> Megan: Well, look.<br /> <br /> Ponytail: Oh. Hmm.<br /> <br /> Megan: Yeah.<br /> <br /> Ponytail: What...<br /> <br /> Megan: I don't know.<br /> <br /> [Below is an infrared-esque image of the universe, featuring a series of circles and the Spalding logo, as though the universe had been imprinted with the image of a basketball.]<br /> <br /> ==External links==<br /> *[http://map.gsfc.nasa.gov/media/121238/index.html Original cosmic microwave background image published by NASA.]<br /> <br /> {{comic discussion}}</div>

Gmarsden